Molybdenum in the Biosphere

Molybdenum in plants

 

Metals Content in HERBAL SUPPLEMENTS

Obesity has become an international epidemic. To evaluate the level of metals in extracts of plants prescribed as weight loss supplements, different brands containing Camellia sinensis (L.) Kuntze, Citrus aurantium L., Cordia ecalyculata Vell, Ilex paraguariensis A. St.-Hil, Cissus quadrangularis L., Senna alexandrina Mill were purchased in local market, hot acid digested, and analyzed while metal content by inductively coupled plasma optical emission spectrometry, ICP-OES. Quality assurance and quality control tests were carried out in order to monitor and control the reliability of the analytical method. For each metal evaluated, a calibration curve was prepared with certified reference material. The recovery test was performed for each batch of samples. Analyses were performed in triplicate. Quantification of aluminum, barium, cadmium, cobalt, chromium, copper, iron, lithium, manganese, molybdenum, nickel, lead, vanadium, and zinc were determined. The metals most frequently detected were manganese (15.3-329,60 mg kg-1) aluminum (11.76-342.4 mg kg-1), and iron (11.14-73.01 mg kg-1) with higher levels in products containing C. sinensis China origin, I. paraguariensis Brazilian origin, C. quadrangularis, and C. aurantium China origin, respectively. To ensure safety consumption, an adequacy of the certification of Brazilian suppliers for herbal weight loss products is indispensable.

Barrella, M. V., Heringer, O. A., Cardoso, P. M., Pimentel, E. F., Scherer, R., Lenz, D., and Endringer, D. C.,Metals Content in Herbal Supplements, Biological trace element research, 2017, 175, 488-494.

Molybdenum and iron mutually impact their homeostasis in CUCUMBER (Cucumis sativus) plants

Molybdenum (Mo) and iron (Fe) are essential micronutrients required for crucial enzyme activities in plant metabolism. Here we investigated the existence of a mutual control of Mo and Fe homeostasis in cucumber (Cucumis sativus). Plants were grown under single or combined Mo and Fe starvation. Physiological parameters were measured, the ionomes of tissues and the ionomes and proteomes of root mitochondria were profiled, and the activities of molybdo-enzymes and the synthesis of molybdenum cofactor (Moco) were evaluated. Fe and Mo were found to affect each other's total uptake and distribution within tissues and at the mitochondrial level, with Fe nutritional status dominating over Mo homeostasis and affecting Mo availability for molybdo-enzymes in the form of Moco. Fe starvation triggered Moco biosynthesis and affected the molybdo-enzymes, with its main impact on nitrate reductase and xanthine dehydrogenase, both being involved in nitrogen assimilation and mobilization, and on the mitochondrial amidoxime reducing component. These results, together with the identification of > 100 proteins differentially expressed in root mitochondria, highlight the central role of mitochondria in the coordination of Fe and Mo homeostasis and allow us to propose the first model of the molecular interactions connecting Mo and Fe homeostasis.

Vigani, G., Di Silvestre, D., Agresta, A. M., Donnini, S., Mauri, P., Gehl, C., Bittner, F., and Murgia, I.,Molybdenum and iron mutually impact their homeostasis in cucumber (Cucumis sativus) plants, The New phytologist, 2017, 213, 1222-1241.

Molybdate in Rhizobial Seed-Coat Formulations Improves the Production and Nodulation of ALFALFA

Rhizobia-legume symbiosis is the most well researched biological nitrogen fixation system. Coating legume seeds with rhizobia is now a recognized practical measure for improving the production of legume corp. However, the efficacy of some commercial rhizobia inoculants cannot be guaranteed in China due to the low rate of live rhizobia in these products. A greenhouse experiment was conducted to assess the effects of different rhizobial inoculant formulations on alfalfa productivity and nitrogen fixation. Two rhizobia strains, (ACCC17631 and ACCC17676), that are effective partners with alfalfa variety Zhongmu No. 1 were assessed with different concentrations of ammonium molybdate in seed-coat formulations with two different coating adhesives. Our study showed that the growth, nodulation, and nitrogen fixation ability of the plants inoculated with the ACCC17631 rhizobial strain were greatest when the ammonium molybdate application was0.2% of the formulation. An ammonium molybdate concentration of 0.1% was most beneficial to the growth of the plants inoculated with the ACCC17676 rhizobial strain. The sodium carboxymethyl cellulose and sodium alginate, used as coating adhesives, did not have a significant effect on alfalfa biomass and nitrogen fixation. However, the addition of skimmed milk to the adhesive improved nitrogenase activity. These results demonstrate that a new rhizobial seed-coat formulation benefitted alfalfa nodulation and yield.

Zhou, J., Deng, B., Zhang, Y., Cobb, A. B., and Zhang, Z.,Molybdate in Rhizobial Seed-Coat Formulations Improves the Production and Nodulation of Alfalfa, PLoS One, 2017, 12, e0170179.

 

PLANTS            

Nutrient deficiencies in Brassica napus modify the ionomic composition of plant tissues: a focus on cross-talk between molybdenum and other nutrients

The composition of the ionome is closely linked to a plant's nutritional status. Under certain deficiencies, cross-talk induces unavoidable accumulation of some nutrients, which upsets the balance and modifies the ionomic composition of plant tissues. Rapeseed plants (Brassica napus L.) grown under controlled conditions were subject to individual nutrient deficiencies (N, K, P, Ca, S, Mg, Fe, Cu, Zn, Mn, Mo, or B) and analyzed by inductively high-resolution coupled plasma mass spectrometry to determine the impact of deprivation on the plant ionome. Eighteen situations of increased uptake under mineral nutrient deficiency were identified, some of which have already been described (K and Na, S and Mo, Fe, Zn and Cu). Additionally, as Mo uptake was strongly increased under S, Fe, Cu, Zn, Mn, or B deprivation, the mechanisms underlying the accumulation of Mo in these deficient plants were investigated. The results suggest that it could be the consequence of multiple metabolic disturbances, namely: (i) a direct disturbance of Mo metabolism leading to an up-regulation of Mo transporters such as MOT1, as found under Zn or Cu deficiency, which are nutrients required for synthesis of the Mo cofactor; and (ii) a disturbance of S metabolism leading to an up-regulation of root SO4 2- transporters, causing an indirect increase in the uptake of Mo in S, Fe, Mn, and B deficient plants.

Maillard, A., Etienne, P., Diquelou, S., Trouverie, J., Billard, V., Yvin, J. C., and Ourry, A.,Nutrient deficiencies in Brassica napus modify the ionomic composition of plant tissues: a focus on cross-talk between molybdenum and other nutrients, Journal of experimental botany, 2016.

 

Molybdenum FERTILIZATION effect on nodulation, yield and quality of green gram grown in the soils of southern agro-climatic zone of Tamil Nadu, India

A pot experiment was conducted under natural condition with green gram (cultivar CO 6) using twenty bulk soil samples collected from major soil series of Southern agro climatic zone of Tamil Nadu.

Application of graded levels of molybdenum (Mo) at 0, 0.025, 0.050, 0.075 and 0.1 mg kg-1 positively influenced the yield, nodulation characteristics and nutritional quality of green gram crop. The highest number of nodules, dry weight nodules per plant, nodule N concentration and chlorophyll content of leaves were registered at 0.075 mg kg-1 level.

Similarly, the seed and stover yield, uptake of N, P, K and Mo by green gram were also increased with molybdenum application up to 0.075 mg kg-1 level beyond which they declined.

However, the amount of protein in seed significantly increased with increasing levels of Mo up to 0.1 mg kg-1 level in different soils.

Hence, Mo application not only increased the yield but also enhanced the nutritional quality of green gram through effective nodulation.

Velmurugan, R., and Mahendran, P. P.,Molybdenum fertilization effect on nodulation, yield and quality of green gram grown in the soils of southern agro-climatic zone of Tamil Nadu, India, Legume Research, 2015, 38, 798-803.

[Green gram, also known as the mung bean, is a small round bean similar in shape to the field pea. People in the U.S. primarily eat green gram as a sprout, and as a bean it cooks up fast and has a sweet flavor. With its high fiber and nutrient content, it offers a number of health benefits. www.livestrong.com.]

Molybdate effect of molybdenum on nodulation, plant yield and nitrogen uptake in hairy vetch (Vicia villosa Roth)

Hairy vetch (Vicia villosa Roth) is a leguminous cover crop that is generally used as a green manure to sustain soil health in arable land. Molybdenum (Mo) acts as a cofactor for the nitrogenase (NA) and nitrate reductase (NR) enzymes, which are important for nitrogen (N) fixation, nitrate reduction and N transport in plants. In this study, we applied various doses of Mo to soil to evaluate their efficacy on nodulation, nodule characteristics and biomass production of hairy vetch. Mo application increased the number and size of nodules and NA and NR enzyme activity in hairy vetch. This increase in enzyme activity increased N assimilation and led to higher biomass yield. Plants grown in soil that received 0.5mg Mo kg-1 showed optimal physical and biochemical properties in nodules, and these properties may explain the increased N fixation in hairy vetch. Higher Mo doses (1.0 mg kg-1) led to the deterioration of nodule structure and, hence, reduced enzymatic activity in plants. The 16S rRNA gene sequencing and cluster analysis showed that the bacterial isolates found in the nodules of hairy vetch roots belonged to the Rhizobiaceae family and shared high sequence similarity with Rhizobium leguminosarum and Agrobacterium tumefaciens. Application of 0.63mg Mo kg-1 to soil was the optimum dose to maximize the biomass yield of hairy vetch.

Alam, F., Kim, T. Y., Kim, S. Y., Alam, S. S., Pramanik, P., Kim, P. J., and Lee, Y. B.,Effect of molybdenum on nodulation, plant yield and nitrogen uptake in hairy vetch (Vicia villosa Roth), Soil Science and Plant Nutrition, 2015, 61, 664-675.

MOLYBDATE PLANTS SOYBEAN SEED COATING
In Japan, soybeans are generally cultivated in paddy fields which often have poor drainage. West of the Kanto region, the seeds are sown in the rainy season. Therefore, the seedling establishment is prone to damage by the rain after sowing. The generation of sulfide ions in flooded and reduced soil is thought to be one factor causing this flooding damage. Since molybdate ions suppress the generation of sulfide ions, the effect of coating soybean seeds with molybdenum compounds, on the seedling establishment under a flooded condition was examined. Soybean seeds were coated with several kinds of poorly-soluble molybdenum compounds at different concentrations. The coated seeds were sown in soil and then flooded for 3 d at 25 - 30 degrees C. Seedlings were not established from seeds not coated with molybdenum compounds. Seedling establishment was appreciably improved by coating the seeds with a molybdenum compound at the rate of 0.5 - 1 mol-Mo kg(-1) seed. Seedling establishment was especially improved by coating with molybdenum trioxide. Accordingly, coating the soybean seed with molybdenum compounds could mitigate the flooding damage occurring after sowing.

Hara, Y.,Improvement of Soybean Seedling Establishment under a Flooded Condition by Seed Coating with Molybdenum Compounds, Plant Production Science, 2015, 18, 161.

MOLYBDATE (?) PLANTS DRY BEAN MOLYBDENUM REQUIREMENTS NO LIMING
Molybdenum (Mo) is an essential micronutrient for crop plants, and its deficiency has been reported in many parts of the world. Two greenhouse experiments were conducted with the objective to determine Mo requirements of dry bean (Phaseolus vulgaris L.) grown on a Brazilian Oxisol with and without liming. The Mo treatments were 0, 5, 10, 15, and 20mgkg(-1). In one experiment dolomitic lime was added at the rate of 2.5g per kg of soil before the application of Mo treatments and incubated 5weeks before sowing. In other experiments, Mo treatments were same as the lime-added experiment but no lime was added. Most of the growth, yield, and yield components were significantly increased with the addition of Mo in both the experiment. Growth, yield, and yield components were increased in a quadratic fashion when Mo was applied in the range of 0 to 20mgkg(-1). Maximum shoot dry weight was obtained with the addition of 17mgMokg(-1) in the experiment with Mo rates without lime and 9.69mgMokg(-1) in the experiment of Mo rates with lime application. Maximum seed yield was obtained with the application of 10.48mgMokg(-1) in the experiment that did not receive lime along with Mo treatments and 10.28mgMokg(-1) in the experiment that received lime along with Mo treatments. Similarly, the maximum number of pods per plant was obtained with the addition of 9.33mgMokg(-1) in the experiment that did not receive lime and 8.83mgMokg(-1) in the experiment that did receive lime. Maximum root length was obtained with the addition of 12.38Mokg(-1) in the experiment that did not receive lime and 9.75mgMokg(-1) in the experiment that received lime. Maximum root dry weight was obtained with the addition of 11.67mgMokg(-1) in the experiment that did not receive lime and 9.28mgMo in the experiment that received lime. Soil properties determined after harvest of dry bean plants were not influenced significantly with the addition of Mo in the Oxisol under investigation.

Fageria, N. K., Stone, L. F., and Santos, A. B.,Molybdenum Requirements of Dry Bean with and without Liming, Communications in Soil Science and Plant Analysis, 2015, 46, 965.

MOLYBDATE (?) PLANTS RED BASIL
Red basil (Ocimum basilicum L.) cv. Red Rubin was cultivated in model pot experiment in the soil amended by arsenic, cadmium and lead solutions in stepwise concentrations representing the soil concentration levels of former mining area in the vicinity of Pribram, Czech Republic. The element levels added to the soil reached up to 40 mg Cd, 100 mg As, and 2000 mg Pb per kg of soil. Moreover, essential macro-and microelements as well as cyanidine contents were investigated to assess their potential interactions with the risk elements. The extractable element portions in soils determined at the end of vegetation period differed according to the individual elements. Whereas the plant-available (extractable with 0.11M CH3COOH) content of Cd represented 70-100% of the added Cd, the mobile portion of Pb did not exceed 1%. The risk element content in plants reflected the increasing element contents in soil. The dominant element portions remained in plant roots indicating the limited translocation ability of risk elements to the aboveground biomass of this plant species. Although the risk element contents in amended plants significantly increased, no visible symptoms of phytotoxicity occurred. However, the effect of enhanced risk element contents on the essential element uptake was assessed. Considering inter-element relationships, elevated sulphur levels were seen in amended plants, indicating its possible role of phytochelatin synthesis in the plants. Moreover, the molybdenum contents in plant biomass dropped down with increasing risk element uptake by plants confirming As-Mo and Cd-Mo antagonism. The increasing content of cyanidine in the plant biomass confirmed possible role of anthocyanins in detoxification mechanism of risk element contaminated plants and suggested the importance of anthocyanin pigments for risk element tolerance of plants growing in contaminated areas.

Ruzickova, P., Szakova, J., Havlik, J., and Tlustos, P.,The effect of soil risk element contamination level on the element contents in Ocimum basilicum L, Archives of Environmental Protection, 2015, 41, 47.


Molybdate in plants deficiency

Molybdenum is a trace element included in the molybdenum enzymes. It is known that acid soils (pH < 6.5) cause formation of molybdenum complexes. As a result molybdenum becomes unavailable to plants and molybdenum deficiency has been reported. Shortage of Mo causes severe reduction of aldehyde oxidase (AO-EC 1.2.3.1) and xanthine dehydrogenase (XDH-EC 1.1.1.204) enzyme activities, but XDH and AO protein content is less influenced. We now demonstrate slight decrease of MPT/form A amount in winter wheat plants, caused by molybdenum insufficiency, while XDH transcripts are unchanged. We speculate that the final post-translational modification step, which is accomplished by Moco sulfurase, is influenced by the concentration of molybdenum. We also show considerable amount of inactive XDH enzyme molecules in winter wheat leaf tissue. In plant cells, the content of active XDH and AO enzymes can rapidly be increased by changing the ratio of inactive and active molecules


Stroumin, P. and Vunkova-Radeva, R., Posttranslational Modification Regulates the Activity of Xanthine Dehydrogenase and Aldehyde Oxidase Enzymes in Wheat Plants, Comptes Rendus de l Academie Bulgare des Sciences, 2015, 68, 209-216.

Molybdate in plants phytotoxicity

Heavy metal ions such as cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), and zinc (Zn) are considered essential/beneficial for optimal plant growth, development, and productivity. However, these ions readily impact functions of many enzymes and proteins, halt metabolism, and exhibit phytotoxicity at supra-optimum supply. Nevertheless, the concentrations of these heavy metal ions are increasing in agricultural soils worldwide via both natural and anthropogenic sources that need immediate attention.
Considering recent breakthroughs on Co, Cu, Fe, Mn, Mo, Ni, and Zn in soil-plant system, the present paper: (a) overviews the status in soils and their uptake, transport, and significance in plants; (b) critically discusses their elevated level-mediated toxicity to both plant growth/development and cell/genome; (c) briefly cross talks on the significance of potential interactions between previous plant-beneficial heavy metal ions in plants; and (d) highlights so far unexplored aspects in the current context

Anjum, N. A., Singh, H. P., Khan, M. I. R., Masood, A., Per, T. S., Negi, A., Batish, D. R., Khan, N. A., Duarte, A. C., Pereira, E., and Ahmad, I., Too much is bad-an appraisal of phytotoxicity of elevated plant-beneficial heavy metal ions, Environmental Science and Pollution Research, 2015, 22, 3361-3382.[Phytotoxicity is a toxic effect by a compound on plant growth.]

 Wheatgrass salinity stress -  molybdenum prevented oxidative damage to plant tissues

Crested wheatgrass (Agropyron cristatum) is a novel halophyte crop for sustainable agriculture in Northern Kazakhstan. This study investigated the effect of molybdenum (Mo) as molybdate (Na2MoO4.2H2O) and its chemical antagonist tungsten (W) as tungstate (Na2WO4.2H2O) on plant response to salinity treatment. The results showed that the treatment of A. cristatum with Mo significantly improved plant health, as opposed to the W application, which negatively correlated with root and shoot development. Indeed, Mo prevented oxidative damage to plant tissues subjected to salinity stress through increased activities of the three Mo-containing enzymes, nitrate reductase, aldehyde oxidase and xanthine dehydrogenase. Contrarily, treatment with tungsten negatively affected these enzymes' activities, resulting in increased sensitivity to salt stress. Hence, our results suggested that the Mo-treatment might play an important role in the process of halophyte plant A. cristatum adaptation to salt stress

Babenko, O. N., Brychkova, G., Sagi, M., and Alikulov, Z. A., Molybdenum application enhances adaptation of crested wheatgrass to salinity stress, Acta Physiologiae Plantarum, 2015, 37,

Molybdenum in plants – Chinese cabbage - organic

A comparative study was made of the yield, morphological characteristics, biochemical variations and antioxidant activity of Chinese cabbage, grown conventionally, naturally and organically.
A significant increase in most amino acids, calcium (63.1 mg/100 g), magnesium (82.4 mg/100 g) and molybdenum (0.12 mg/100 g) was observed with organic cultivation.
Conventionally grown Chinese cabbage had higher sugars and organic acid levels than organically grown cabbage, but sucrose level was higher (4.27 g/100 g) in those grown naturally. Though the moisture content of organic and conventional was comparable, the level of crude lipids, ash and carbohydrate content was higher in natural and control grown plants. Under different cultivation methods the total phenolic content was higher with the natural (302 mu g/g) followed by organic (283 mu g/g) cultivation. Similarly the 1,1-dipheny1-2-picrylhydrazyl and nitrite scavenging potential was highest in natural (70.12, 43.87%) followed by organic (67.28, 42.14%) cultivation. Crop yields were highest with conventional cultivation and slightly increased compared to organic cultivation. Amino acid and phenolic contents were highest with organic cultivation, suggesting that organic cultivation may provide health benefits. (C) 2014 Elsevier Inc. All rights reserved

Kim, J. J., John, K. M. M., Hae-Kyung, M., Jin, K., Enkhtaivan, G., and Kim, D. H., Morphological and biochemical variation of Chinese cabbage (Brassica rapa spp. Pekinensis) cultivated using different agricultural practices, Journal of Food Composition and Analysis, 2014, 36, 12-23.

Molybdenum in plants - molybdenum copper interaction

Molybdenum in plants - molybdenum copper interaction
During the last 40 years, crop breeding has strongly increased yields but has had adverse effects on the content of micronutrients, such as Fe, Mg, Zn and Cu, in edible products despite their sufficient supply in most soils. This suggests that micronutrient remobilization to edible tissues has been negatively selected. As a consequence, the aim of this work was to quantify the remobilization of Cu in leaves of Brassica napus L. during Cu deficiency and to identify the main metabolic processes that were affected so that improvements can be achieved in the future.
While Cu deficiency reduced oilseed rape growth by less than 19% compared to control plants, Cu content in old leaves decreased by 61.4%, thus demonstrating a remobilization process between leaves. Cu deficiency also triggered an increase in Cu transporter expression in roots (COPT2) and leaves (HMA1), and more surprisingly, the induction of the MOT1 gene encoding a molybdenum transporter associated with a strong increase in molybdenum (Mo) uptake.
Proteomic analysis of leaves revealed 33 proteins differentially regulated by Cu deficiency, among which more than half were located in chloroplasts. Eleven differentially expressed proteins are known to require Cu for their synthesis and/or activity. Enzymes that were located directly upstream or downstream of Cu-dependent enzymes were also differentially expressed.
The overall results are then discussed in relation to remobilization of Cu, the interaction between Mo and Cu that occurs through the synthesis pathway of Mo cofactor, and finally their putative regulation within the Calvin cycle and the chloroplastic electron transport chain

Billard, V., Ourry, A., Maillard, A., Garnica, M., Coquet, L., Jouenne, T., Cruz, F., Garcia-Mina, J. M., Yvin, J. C., and Etienne, P., Copper-Deficiency in Brassica napus Induces Copper Remobilization, Molybdenum Accumulation and Modification of the Expression of Chloroplastic Proteins, Plos One, 2014, 9,

Enhancement of Saline Water for Irrigation of the bean Phaseolus vulgaris L. Species in Presence of Molybdenum

Salinity constitutes a major obstacle in the production and plant growth especially in the Mediterranean region where water quality plays a major role. In the Maghreb more than 30% of water for irrigation is loaded with salt, and it induces the reduction of growth and yield of sensitive varieties. So, research for plants adapted to high levels of salinity becomes an imperative for agricultural production.

The bean (Phaseolus vulgaris L.) is an important source of dietary protein in many developing countries but is considered as sensitive species to salinity compared to other vegetables. Molybdenum (Mo) is a trace element in soil, it is involved in the biosynthesis of several enzymes necessary for growth of most biological organisms, plants and animals.

We tried in our work to elucidate the effect of different concentrations of molybdenum (M0: 0, M1: 0.1ppm, M2: 0.2ppm and M3: 0.4ppm) by the addition of ammonium molybdate ((NH4)6Mo7O24.4H2O) on seedlings of Phaseolus vulgaris Var. Djedida subjected to salt stress by providing five NaCl treatments (T0: 0, T1: 3g/l, T2: 6g/l, T3: 9g/l and T4: 12g/l) in water of irrigation. To highlight the response of these seedlings we conducted an assay of total chlorophyll (Chl (a+b)) by spectrophotometer, and determination of the morphological parameters such as length and biomass of shoots and roots. The bean plants are able to maintain an optimum level of total chlorophyll and their morphological parameters under the condition of mild salt stress (3g/l) but in the presence of molybdenum, it could alleviate the negative effect of NaCl.

We concluded that the presence of molybdenum in concentrations of 0.1 and 0.2ppm in the culture medium of Phaseolus vulgaris irrigated with saline water increased the chlorophyll content and the plant biomass yield. (C) 2012 Published by Elsevier Ltd. Selection and peer-review under responsibility of ISWEE'11

Bouzid, S. and Rahmoune, C., Enhancement of Saline Water for Irrigation of Phaseolus vulgaris L. Species in Presence of Molybdenum, Iswee'11, 2012, 33, 168-173.

Mechanism of resistance to molybdenum stress in wheat, barley and canola grown in north-west of Karaj, Iran

As the level of molybdenum pollution in the environment is increasing, it is essential to understand the functional roles and toxic effects of molybdenum in plants.

Plants have different resistance mechanisms against heavy metal toxicity. Increase of antioxidant enzyme activity is one of the most important mechanisms in higher plants. In order to identify resistance mechanisms in wheat, barley and canola, some samples were collected from contaminated and uncontaminated regions to study biochemical changes due to molybdenum stress.

The results showed that the highest molybdenum concentration was observed in canola, wheat and barley leaves, respectively. Moreover, leaves, stems and roots had the highest molybdenum accumulation, respectively. So, the molybdenum concentration in leaves of canola was four times more than stem and thirty times more than roots. The highest and the lowest superoxide dismutase activity was related to canola leaves collected from contaminated region and barley root collected from uncontaminated regions, respectively

Ghooshchi, F., Moghadam, H. R. T., and Lack, S., Mechanism of resistance to molybdenum stress in wheat, barley and canola grown in north-west of Karaj, Iran, Research on Crops, 2012, 13, 834-839.

Chickpea (Cicer arietinum L.) response to zinc, boron and molybdenum application under field conditions

In Spain-Europe's leading chickpea producing country-chickpea (Cicer arietinum) is mainly cultivated on non-irrigated soils with low native fertility. This study was carried out from 2006 to 2008 in the province of Leon, Spain, under acid soil field conditions, with the aim of determining whether the application of zinc (Zn), boron (B) and molybdenum (Mo) improved chickpea growth and yield on acid soils.

A split-split-plot design with three replications was used. Chickpea responded only to the Zn and Mo applications. At maturity, plants fertilized with Zn and with Mo had a greater total dry matter production and seed yield, mainly due to an increment in pod dry matter. For Zn, the highest yield was obtained with 2 mg Zn per plant (6.80 g plant-1), whereas for Mo the highest yield was obtained with 1 mg Mo per plant (6.73 g plant-1).

Interaction was observed between B and Mo, interpreted as indicating that Mo can counteract the effect of B application

Valenciano, J. B., Boto, J. A., and Marcelo, V., Chickpea (Cicer arietinum L.) response to zinc, boron and molybdenum application under field conditions, New Zealand Journal of Crop and Horticultural Science, 2011, 39, 217-229.

Molybdenum is an essential micronutrient for plant growth and for microsymbionts. Even when the total Mo content of the soil is sufficient, since Mo is often sequestered by Fe- or Al-oxohydroxides, especially in acidic soils, the concentration of the water-soluble molybdate anion available for uptake by plants may be limiting for the plant. No specific molybdenum uptake system is known for plants, but since molybdate and sulfate behave similarly and have similar structure, uptake of molybdate could be mediated unspecifically by one of the sulfate pathways.

Zimmer, W, Mendel, R, Molybdenum metabolism in plants, Plant Biology, 999,1, 160-168.

Plants: Root uptake and phytotoxicity of nanosized molybdenum octahedral clusters

Here are examined the root uptake and phytotoxicity of octahedral hexamolybdenum clusters on rapeseed plants using the solid state compound Cs2Mo6Br14 as cluster precursor.

[Mo6Br14]2 cluster units are nanosized entities offering a strong and stable emission in the near-infrared region with numerous applications in biotechnology.

To investigate cluster toxicity on rapeseed plants, two different culture systems have been set up, using either a water-sorbing suspension of cluster aggregates or an ethanol-sorbing solution of dispersed nanosized clusters.

Size, shape, surface area and state of clusters in both medium were analyzed by FE-SEM, BET and XPS.

The potential contribution of cluster dissolution to phytotoxicity was evaluated by ICP-OES and toxicity analysis of Mo, Br and Cs.

We showed that the clusters did not affect seed germination but greatly inhibited plant growth. This inhibition was much more important when plants were treated with nanosized entities than with microsized cluster aggregates.

In addition, nanosized clusters affected the root morphology in a different manner than microsized cluster aggregates, as shown by FE-SEM observations.

The root penetration of the clusters was followed by secondary ion mass spectroscopy with high spatial resolution (NanoSIMS) and was also found to be much more important for treatments with nanosized clusters

Aubert, Tangi, Burel, Agnes, Esnault, Marie Andree, Cordier, Stephane, Grasset, Fabien, and Cabello-Hurtado, Francisco, Root uptake and phytotoxicity of nanosized molybdenum octahedral clusters, Journal of hazardous materials, 2012, 219-220, 111-118.

Molybdenum concentrations in various plants

 

Molybdenum Concentrations in Plants [1]

Source

Concentration /ppm dry weight

Land Plants

0.9

Plankton

1.0

Brown Algae

0.45

Bryophytes

0.7

Ferns

0.8

Gymnosperms

0.13

Angiosperms

0.9

Fungi

1.5

hay [2]

0.78

citrus leaves [2]

0.14

[1] Bowen, H. J. M., Trace Elements in Biochemistry, 1966, Academic Press, N. Y.
[2] Alonso, J.I.G., Camblor, M.G., Bayon, M.M., Marchante Gayon, J.M., Sanz Medel, A., Different quantification approaches for the analysis of biological and environmental samples using inductively coupled plasma mass spectrometry, Journal Of Mass Spectrometry, 1997, 32, 556-564.

Tobacco 0.3 – 1.76 microg Mo/g

Voss, R.C., Nicol, H., Metallic trace elements in tobacco, Lancet, 1960, 2, 435 – 436.

Concentrations of barium (Ba), calcium (Ca), Cu, iron (Fe), K, magnesium (Mg), manganese (Mn), molybdenum (Mo), sodium (Na), rubidium (Rb), strontium (Sr), and zinc (Zn) in leaf and stem tissues were correlated with treatment and tissue. Generally, increasing Cu resulted in elevated Ba, Fe, Mo, and Sr as well as Cu levels.
The presence of peat resulted in reduced levels, generally in both leaf and stem, of Ba, Mg, Mn, Rb, and Zn and increased levels of Fe, K, and Mo.

Elemental concentrations were higher in leaf tissue rather than stem, with the exceptions of Na and Zn.
Elemental concentration ranges, over all tissues and conditions of added Cu and peat were (mg kg-1) Ba 9-49, Ca 6380-16340, Cu 2-11, Fe 10-57, K 4070-16950, Mg 900-4260, Mn 22-197, Mo 0.02-0.19, Na 28-124, Rb 0.7-12, Sr 41-58, Zn 18-48

Ihnat, M., Neilsen, G. H., and Hogue, E. J., Elemental content relationships in greenhouse grown apple seedlings supplemented with copper and peat, Communications in Soil Science and Plant Analysis, 2000, 31, 803-825.

Tropical grasses

Mo 0.02-1.23 mg kg-l dry matter

Youssef, F.G., McDowell, L.R., Brathwaite, R.A.I., The status of certain trace minerals and sulphur of some tropical grasses in Trinidad, Tropical Agriculture, 1999, 76, 57-62.

Molybdenum in plants uptake and accumulation

Molybdenum is utilized by selected enzymes to carry out redox reactions. Enzymes that require molybdenum for activity include nitrate reductase, xanthine dehydrogenase, aldehyde oxidase and sulfite oxidase. Loss of Mo-dependent enzyme activity (directly or indirectly through low internal molybdenum levels) impacts upon plant development, in particular, those processes involving nitrogen metabolism and the synthesis of the phytohormones abscisic acid and indole-3 butyric acid. It is unclear how plants access molybdate from the soil solution or later redistribute it once in the plant. Plants have similar physiological molybdenum transport phenotypes to those found in prokaryotic systems. Analysis of prokaryotic molybdate transport mechanisms and anion transport mechanisms in plants will help our understanding of how molybenum is accumulated.

Kaiser, B.N., Gridley, K. L., Brady, J. N., Phillips, T., and Tyerman, S. D., The role of molybdenum in agricultural plant production, Annals of Botany, 2005, 96, 745-754.

Molybdenum concentration varies with location and species: for example, in pastures in different areas molybdenum concentrations varying from 0.1 to 200 ppm dry weight have been reported

[Underwood, 1962; Kolomiitseva et al., 1970].
Underwood, E. J., Trace Elements in Human and Animal Nutrition, 2nd Ed. 1962, 100. Academic Press, London.
Kolomiitseva, M. G., Polonskaya, M. N. and Osipov, G. K.,Mikroelem. Sel. Khoz. Med., 1968, 4, 183;
Warren, H . V., Delavault, R. E., Fletcher, K. W., Geology Environ. Contr. Bull., 1971, 6, 34.
U.S Department of the Interior, 1967, 1968, 1970
Sequi, P., Agrochimica, 1972 (Publ. 1973), 17, 119
Webb, J. S., Geol. Soc. Amer., Mem., 1971, 123, 31.
Ivanova, N. N., Agrochimica, 1972 (Publ. 1973), 17, 96.

Mo in plants grown on a landfill site

The mean concentrations (microg/g dry weight) of Se and Mo in the shoots of plants grown on a landfill site did not exceed, respectively,
0.12 (Se) and 18.7 (Mo) in bird's-foot trefoil (Lotus corniculatus L.),
0.06 and 12.1 in red clover (Trifolium pratense L.),
0.07 and 5.3 in timothy (Phleum pratense L.),
0.09 and 2.2 in a mixture of grasses.

These concentrations were greater than those in the same species harvested concurrently from a non-landfill site.

Molybdenum uptake in plants

The uptake of Mo is induced by NO3- and inhibited by sulfate.

W. Reid, R.J., Mechanisms of micronutrient uptake in plants, Australian Journal of Plant Physiology, 2001, 28, 659-666.

When supplied with molybdate Indian mustard (Brassica juncea) seedlings accumulated water-soluble blue crystals in their peripheral cell lavers. A mutant without anthocyanin did not show accumulation of a blue molybdenum compound. Mo appears to be sequestered in vacuoles of the peripheral cell layers of Brassica spp. as a blue compound, probably a Mo-anthocyanin complex.

Hale, K.L., McGrath, S. P., Lombi, E., Stack, S. M., Terry, N., Pickering, I. J., George, G. N., and Pilon-Smits, E. A. H., Molybdenum sequestration in Brassica species. A role for anthocyanins?, Plant Physiology, 2001, 126, 1391-1402.

Molybdate cellular transport

For molybdoenzymes synthesis, e.g. nitrogenase, molybdenum as molybdate must be transported inside the cell. In Bradyrhizobium japonicum, the modABC genes code for a high-affinity ABC-type molybdate transporter.

The effect of inoculation of soybean plants with strains affected in the molybdate transport was investigated with the modA and modB mutants, unable to grow in culture media under molybdate-deficient conditions.

When soybean plants were inoculated with one of these strains and grown in a molybdate-deficient mineral solution the nodulation was not affected, but the nitrogen-fixing ability of the mod mutants was impaired.

Addition of molybdate to the nutrient mineral solution used for plant growth restored the wild-type phenotype.

The amount of molybdate required for supression of the mutant phenotype was dependent on sulfate concentration. The molybdate concentration required for the functioning of the mutant strains was greater when the medium was supplemented with high amounts of sulfate.

There exists in B. japonicum, at least, three independent molybdate transport systems: a high-affinity transporter encoded by the modABC genes, a low affinity system corresponding to a sulfate transporter, and a third transporter that would be functional in the presence of high sulfate concentrations.

Tresierra-Ayala, A., Delgado, M. J., Guzman, R. A., Rengifo, A. L., and Bedmar, E. J., Molybdate Transport in the Bradyrhizobium Japonicum - Glycine Max L. Symbiosis, Journal of Soil Science and Plant Nutrition, 2011, 11, 8-17.

Foliar applications of molybdate improved wheat yield

The objective of this work was to evaluate the effect of foliar application of molybdenum on agronomic characteristics and yield of wheat in a no-till system. The experiment was carried out in a clayey Rhodic Hapludox, in Maripa, State of Parana, Brazil. The experimental design was randomized blocks with five replications. Treatments consisted of four doses of molybdenum (0, 13.8, 27.6 and 55.2 g ha(-1) Mo), divided into two foliar applications, the first at tillering (18 days after plant emergence) and the second at the boot stage (65 days after emergence). The foliar application of molybdenum up to a dose of 35 g ha-1 increased the number of spikes per square meter and yield of wheat; however, it had no effect on the agronomic characteristics of the crop in a no-till system

Zoz, Tiago, Steiner, Fabio, Paulo Testa, Joao Vitor, Seidel, Edleusa Pereira, Fey, Rubens, Castagnara, Deise Dalazen, and Zoz, Andre, Foliar fertilization with molybdenum in wheat, Semina-Ciencias Agrarias, 2012, 33, 633-638.

Molybdenum uptake and transport in plants

The molybdenum concentration in the sap was approximately 11 times greater in the absence of sulfate in the nutrient medium. Restoring sulfate to the nutrient medium without sulfur depressed the Mo concentration of the sap at the next harvest to a value similar to that in plants receiving sulfate from the onset of the growth period and, similarly, raised the S concentration as well. Sulfate and molybdate compete for the same carrier and transport sites in uptake, and sulfate deficiency leads to excess Mo uptake.

Alhendawi, R.A., Kirkby, E. A., and Pilbeam, D. J., Evidence that sulfur deficiency enhances molybdenum transport in xylem sap of tomato plants, Journal of Plant Nutrition, 2005, 28, 1347-1353.

Molybdate transport in plants

A molybdate transporter, ‘MOT1’, has been identified from the plant Arabidopsis thaliana. The following is a summary of the paper. The reader is recommended to consult the original paper and key references for methods and justifications.

MOT1 is expressed in both roots and shoots. The MOT1 protein is localized, in part, to plasma membranes and to vesicles. MOT1 enhances molybdate uptake from soil into root cells for utilization and also for translocation to shoots. MOT1 is required for efficient uptake and translocation of molybdate and for normal growth under conditions of limited molybdate supply. MOT1 is a high-affinity Mo transporter. The high molybdate affinity of MOT1 enables plants to obtain scarce molybdate from soil.

MOT1 is also specific for molybdate (as opposed to sulfate).

The affinity of MOT1 for molybdate was determined from kinetic studies in yeast of uptake of molybdate (applied as ammonium heptamolybdate) vs time. For time-course analysis of molybdate uptake, cells were transferred to the medium supplemented with 24 nM ammonium heptamolybdate, and shaken at 30°C for 0, 5, 10, 15, 20, 30, 45, or 60 min. For kinetic analysis of molybdate uptake cells were transferred to the medium supplemented with 7, 8, 10, 12, 16, 24, 97 or 194 nM ammonium heptamolybdate, and shaken at 30 °C for 15 min.

The stationary level of molybdenum concentration in cells expressing MOT1 was roughly 30 microM; more than 100-fold higher than that in the medium used for the uptake study. Thus MOT1 is a molybdate transporter capable of transporting molybdate against a concentration gradient.

Analysis of the kinetics of molybdate uptake (Lineweaver–Burk plot) by yeast expressing MOT1 gave Km 21 ± 4 nM and Vmax 0.5 ±0.1 microg_g-1DW min-1 where Km, the Michaelis constant, is the dissociation constant of a MOT1-molybdate complex and Vmax is the maximal uptake velocity. The authors comment that 20 nM is the lowest reported Km value of the mineral–nutrient transporters in plants.

So MOT1 is well described as a high-affinity molybdate transporter.

The genetic mechanism that controls Mo concentration in Arabidopsis thaliana shoots, was studied in detail. The trait is mostly regulated by a single locus on chromosome 2 in a region containing a gene (At2g25680) annotated as Sultr5;2 (representing a member of the sulfate transporter group). At2g25680 was identified as a molybdate transporter by studying the molybdate uptake of Arabidopsis thaliana mutant lines (mot1-1 and mot1-2 having modified At2g25680) grown in the presence of 170 nM molybdate for five weeks, after which the molybdenum concentrations in shoots and roots were determined. The molybdenum concentrations in shoots of the mot1-1 and mot1-2 mutant plants were reduced to 10% and 20% of that in the wild type, and, in roots, the molybdenum concentrations were reduced to 20% and 25% of that in the wild type. Thus At2g25680 (named MOT1) is the determinant of the Mo concentration in both roots and shoots.

Tomatsu, H., Takano, J., Takahashi, H., Watanabe-Takahashi, A., Shibagaki, N., and Fujiwara, T., An Arabidopsis thaliana high-affinity molybdate transporter required for efficient uptake of molybdate from soil, Proceedings of the National Academy of Sciences of the United States of America, 2007, 104, 18807-18812.

Uptake of elements including molybdenum by Lotus Japonicus

Lotus japonicus was used to study the distribution and interconnections of 15 elements in plant tissues, including essential and non-essential elements: boron (B), sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), strontium (Sr), molybdenum (Mo), cadmium (Cd) and cesium (Cs). Large amounts of B and Ca accumulated in plant leaves, while Fe, Na, Ni, As and Cd tended to mainly occur in the roots, and Mo was the only element to accumulate in the stems. The elemental compositions within plants were severely disturbed by treatment with toxic elements. Competition between element pairs in the same group (e.g. K and Cs; Ca and Sr) was not found. Iron, Cu and Zn accumulation were induced by Cd and Ni addition. When natural variants grew in a nutrition solution with subtoxic levels of As, Cd, Cs, Ni, Mo and Sr, intriguing relationships between the elements (such as Fe, As and K; Mg and Ni; Mn and Ca) were revealed using principal-component analysis. This study on the plant ionome offers detailed information of element interactions and indicates that chemically different elements might be closely linked in uptake or translocation systems

Chen, Z., Watanabe, T., Shinano, T., Ezawa, T., Wasaki, J., Kimura, K., Osaki, M., and Zhu, Y. G., Element interconnections in Lotus japonicus: A systematic study of the effects of element additions on different natural variants, Soil Science and Plant Nutrition, 2009, 55, 91-101.

Molybdate and selenate alter sulfate transport and assimilation in Brassica

The interaction of selenate and molybdate with the transport and assimilation of sulfate, and the effect of sulfur on selenium and molybdenum accumulation were investigated in Brassica juncea. Plants were supplied with different combinations of sulfur and selenium, or sulfur and molybdenum for 24 h, and selenate and molybdate were given to plants at concentrations (200 microM) equal to that of sulfate in the sulfur -sufficient condition.

Selenium and molybdenum significantly reduced the plant growth. In sulfur -sufficient plants, selenium and molybdenum decreased sulfate uptake rate (at 24 h), and selenium repressed the expression of the sulfate transporter BjSultr2.1. This effect was different from the one observed for sulfate, which rapidly inhibited the sulfate uptake rates in + sulfur plants.

In sulfur -starved plants, selenium. molybdenum and sulfur repressed sulfate uptake immediately (after 10 min), and the concomitant down-regulation of BjSultr2.1 occurred only in roots of plants treated with sulfur. In plants exposed to selenium or molybdenum the root expression of BjSultr2.1 was repressed later, after 6 h.

Sulfur-starved plants accumulated significantly more selenium and molybdenum than sulfur -sufficient plants, likely due to the lack of competition of molybdate or selenate with sulfate for the transport through the same carriers. The up-regulation of the molybdenum transporter (MOT1) gene expression could explain the higher amount of molybdenum than selenium measured in the plant tissues.

Selenium and molybdenum reduced the levels of cysteine (Cys) and glutathione (GSH) in + sulfur plants, but increased the amount of these non-protein thiols in - sulfur plants. The increase of GSH content in - sulfur + selenium plants was likely responsible for the down-regulation of the selenium binding protein (SBP1) gene, while the induction of SBP1 observed in + sulfur plants was mainly due to selenium toxicity. The up-regulation of SBP1 was also evidenced in plants exposed to molybdenum, regardless of sulfur availability and GSH content.

The results give better insight into plant uptake mechanisms for selenium and molybdenum, and also have implications for phytoremediation. The interactions between sulfate and selenate or molybdate must be carefully considered when plants are employed for the remediation of selenium - or molybdenum -contaminated sites, as the accumulation of the two contaminants in plants might be altered by the sulfate concentration in the growing medium.

Schiavon, M., Pittarello, M., Pilon-Smits, E. A. H., Wirtz, M., Hell, R., Malagoli, M.Selenate and molybdate alter sulfate transport and assimilation in Brassica juncea L. Czern.: Implications for phytoremediationEnvironmental and Experimental Botany, 2011,75, 41-51.

Requirement of Micronutrients by Lowland Rice

Lowland or flooded rice is mainly responsible for about 76% of total rice production at global level, yet information on micronutrient requirements for this crop is limited.

Six greenhouse experiments were conducted at the National Rice and Bean Research Center of EMBRAPA, Santo Antonio de Goias, Brazil, to determine requirements of zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), manganese (Mn), and iron (Fe) for lowland rice grown on a Brazilian Inceptisol. The levels of micronutrients used were Zn (0, 10 20, 40, and 80 mg kg(-1)), Cu (0, 5, 10, 20, and 40 mg kg(-1)), B (0, 5, 10, 20, and 40 mg kg(-1)), Mo (0, 2, 4, 8, and 16 mg kg(-1)), Mn (0, 50, 100, 300, and 600 mg kg(-1)), and Fe (0, 250, 500, 1000, and 2000 mg kg(-1)).

Grain yield was significantly increased in a quadratic fashion with the addition of Zn, Cu, B, Mo, Mn, and Fe.
The adequate rates of micronutrients for maximum grain yield were Zn 33 mg kg(-1), Cu 25 mg kg(-1), B 26 mg kg(-1), Mo 10 mg kg(-1), Mn 250 mg kg(-1), and Fe 1269 mg kg(-1).

In addition to grain yield, plant height, straw yield, panicle density, and root growth of lowland rice were also improved with the addition of most of these micronutrients.

Improvement in root growth has special significance in improving nutrient-use efficiency under nutrient-stress conditions. Micronutrient-use efficiency (grain yield per unit nutrient applied) was in the order of Cu > Zn > Mn > Fe > Mo > B

Fageria, N. K. and Santos, A. B., Requirement of Micronutrients by Lowland Rice, Communications in Soil Science and Plant Analysis, 2014, 45, 844-863.

Micronutrient Contents and Nutritional Values of Commercial Wheat Flours and Flours of Field-grown Wheat Varieties - A Survey in Hungary

Wheat-based food has great importance in human nutrition: in European countries they provide 20-30% of the daily calorie intake, and additionally, the wholemeal and healthy food becomes even more popular.

Mineral content in grains is dependent on genetic and environmental factors (varieties, soil type, geographical location of the growing area, etc.), therefore, it is complicated to estimate how many percentage of the daily micronutrient requirements can be covered by wheat-based products.

In this study, copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se) and zinc (Zn) contents of 13 commercial wheat flour products, and the white flour and wholemeal of 24 winter type bread wheat varieties were studied to estimate the nutritional value of these products. All investigated samples were produced in Hungary.

Significant variation was revealed in the case of all mineral elements in the different brands of wheat flours. Generally, the white flour enriched with germ showed higher mineral contents than the average values of normal white flours. Furthermore, the wholemeal has higher Cu, Fe, Mn and Zn, but not higher Se contents than the white flours.

Mo content was also higher in some brands of white flour than in wholemeal.

The investigated winter wheat varieties showed significant differences in the case of Fe, Mn, Se and Zn contents, but none of the varieties showed outstandingly high micronutrient content.

The milling process - as it was expected - reduces the concentrations of four elements (Fe 33%; Mn 88%; Zn 71%; Cu 44%); however, the Se and Mo concentrations were not affected significantly.

Using the average micronutrient content in the wholemeal of varieties, the daily Mn and Fe requirement can be covered by the consumption of about 250 g wholemeal.

Additionally, the daily Mo requirement could be met by the daily consumption of 140-190 g of commercial white or wholemeal flour

Szira, F., Monostori, I., Galiba, G., Rakszegi, M., and Balint, A. F., Micronutrient Contents and Nutritional Values of Commercial Wheat Flours and Flours of Field-grown Wheat Varieties - A Survey in Hungary, Cereal Research Communications, 2014, 42, 293-302.

Micronutrient concentrations in relation to phenological development of red clover (Trifolium pratense L.), perennial ryegrass (Lolium perenne L.) and timothy (Phleum pratense L.)

The main aim of this study was to examine how concentrations of the micronutrients cobalt, copper, iron, manganese, molybdenum, nickel and zinc change with phenological development in red clover, perennial ryegrass and timothy.

An additional aim was to investigate micronutrient concentrations and the dry matter (DM) proportions of the leaves, stems and flowers at the flowering stage.

The plants were harvested at five phenological stages, ranging from stem elongation to flowering, in a greenhouse pot experiment.

The results show that micronutrient concentrations generally decreased with phenological development of the grasses, but that the reduction was larger in timothy than in perennial ryegrass.

Concentrations of cobalt, iron, manganese and nickel were more constant in red clover than in the other species. Flowers and leaves had higher concentrations than stems.

The generally low concentrations found in timothy were largely due to the high DM proportion of micronutrient-poor stems.

Our results suggest that harvest at an early phenological stage is not only preferred due to high digestibility but also with regard to micronutrient concentrations. They also highlight the importance of considering phenological development and DM harvested when comparing forage species with regard to micronutrient concentrations.

Lindstrom, B. E. M., Frankow-Lindberg, B. E., Dahlin, A. S., Wivstad, M., and Watson, C. A., Micronutrient concentrations in relation to phenological development of red clover (Trifolium pratense L.), perennial ryegrass (Lolium perenne L.) and timothy (Phleum pratense L.), Grass and Forage Science, 2014, 69, 276-284.

Food

Molybdenum in food

A useful review of the molybdenum content of foods in Germany. The molybdenum content of food (microg kg-1 dry matter) in Germany varied between 10 and 6000: 10-400 for cereal products, sugar-and starch-rich food, luxury food, bread, rolls, cake, spices and most kinds of fruits; 4000 for cucumber, herbs and vegetables and pulses are generally rich in molybdenum; animal products, are poor in molybdenum with exception of liver and kidney. Vegetable foodstuffs as part of mixed diets in Germany deliver 70% of the human intake, animal foodstuffs about 20% and beverages less than 10%

Seifert, M., Dorn, W., Muller, R., Holzinger, S., and Anke, M., The Biological and Toxicological Importance of Molybdenum in the Environment and in the Nutrition of Plants, Animals and Man Part III. Molybdenum Content of the Food, Acta Alimentaria, 2009, 38, 471-481.

Molybdenum in foodstuffs: meat

The levels of cadmium, lead, iron, zinc, selenium, manganese, copper and molybdenum in different cuts of beef, pork, lamb, chicken and foal collected from supermarkets and butcheries in Switzerland were determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Molybdenum concentrations were in the range 0.9 and 3.2 mu g/100 g and were higher in chicken meat than in mammalian meats,

Gerber, N., Brogioli, R., Hattendorf, B., Scheeder, M. R. L., Wenk, C., and Gunther, D., Variability of selected trace elements of different meat cuts determined by ICP-MS and DRC-ICPMS, Animal, 2009, 3, 166-172.

Trace Elements in Fruit Juices

Fruit juices are widely consumed in tropical countries as part of habitual diet. The concentrations of several minerals in these beverages were evaluated. Four commercially available brands of juices were analyzed for cadmium, lead, copper, zinc, aluminum, iron, chromium, manganese, and molybdenum. The levels ranged from 0.02 to 0.08 mg/L for copper, from 0.05 to 0.23 mg/L for zinc, from 0.1 to 0.4 mg/L for aluminum, from 0.02 to 0.45 mg/L for iron, and from 0.01 to 0.22 mg/L for manganese and molybdenum. The levels of cadmium, lead, and chromium in all samples were very low or undetectable.

The metal contents of fruit juices depend on a number of factors, including the soil composition, the external conditions during fruit growing and fruit harvesting, as well as on details of the fruit juice manufacturing processes employed.

The concentrations of none of the metals in juice samples analyzed exceeded the limits imposed by local legislation

Braganca, V. L. C., Melnikov, P., and Zanoni, L. Z., Trace Elements in Fruit Juices, Biological Trace Element Research, 2012, 146, 256-261.

Bioaccessibility of essential elements from food

Bioaccessibility of five essential micronutrients (iron, zinc, copper, manganese and molybdenum) from the Lebanese food basket including bread, different varieties of white cheese, fruit and vegetables was evaluated using the in vitro gastrointestinal digestion model.

Bioaccessibility (%)of essential elements in foods
 MnFeCuZnMo
apple >50 <10 >50 56 >50
bread 25 10 >50 10 >50
cheese 30 >50 >50 50 >50
cucumber >50 10 >50 10 >50
squash >50 10 >50 10 >50

Khouzam, Rola Bou; Pohl, Pawel; Lobinski, Ryszard, Bioaccessibility of essential elements from white cheese, bread, fruit and vegetables TALANTA, 2011,86, 425-428

Composition infant foods

The study reported herein was conducted in order to establish the concentration of 20 essential and non-essential elements in a representative range of commercial infant foods in the UK targeted for infants aged between 6-12months. The primary objective of this study was to examine the nutritive values and safety of such complementary infant foods on the UK market in relation to dietary and safety guidelines. Quantitative analyses were conducted on eight different products representing four popular brands (poultry and fish based) of ready to-feed infant foods currently on sale in the UK. Six essential elements, namely: calcium, iron, magnesium, potassium, sodium and zinc were determined by ICP-OES. The concentrations of six essential trace elements (selenium, molybdenum, cobalt, copper, chromium, manganese) and eight non-essential, potentially toxic, elements (arsenic, barium, nickel, cadmium, antimony, lead, mercury, aluminium) were determined by ICP-MS due to the higher sensitivity required. The total daily intakes of essential and trace elements from the consumption of such products were then estimated, based on the results of this study, and were referenced to the Recommended Nutrient Intake (RNI) values and safety guidelines for 6-9months old children. Based on these comparisons the concentration of essential, except for potassium, and trace elements were found to be inadequate in meeting the RNI. In terms of the risk of exposure to toxicity, the concentration of toxic elements in ready to feed products analysed in this study, were not considered to be of concern. These results suggest that commercial complementary infant foods on the UK market may not contain minimum levels of minerals required for labelling declaration of micronutrient content (Commission Directive 2006/125/EC). This provides opportunities and scope for product optimisation to improve their nutritive value

Zand, Nazanin, Chowdhry, Babur Z., Wray, David S., Pullen, Frank S., and Snowden, Martin J., Elemental content of commercial 'ready to-feed' poultry and fish based infant foods in the UK, Food chemistry, 2012, 135, 2796-2801.

Molybdenum in agriculture

Application of molybdenum to leaves of winter beans

The objective was to evaluate the performance of irrigated winter beans, in a no-tillage system, with increasing levels of side dressing nitrogen application (zero, 30, 60, 90 and 120 kg ha-1) and its interaction with leaf application of molybdenum (zero and 80 g ha-1). The common bean can fix nitrogen in symbiosis with Rhizobium, but the fixed nitrogen is not enough to meet the nitrogen requirement of the plant. Molybdenum application aims to improve symbiosis in the Rhizobium-common bean plant, given its importance in the metabolism nitrogen, thus being able to reduce the application of nitrogen fertilizer. The research was carried out on soil previously cultivated with corn culture. The levels of nitrogen proved consistent regarding the effects on some production components, and on dry mass of plants, providing better development of irrigated beans cultivated under no-tillage. The application of molybdenum in leaves did not influence the majority of evaluated parameters.

Barbosa, G. F., Arf, O., do Nascimento, M. S., Buzetti, S., and Freddi, O. D., Side dressing nitrogen and leaf molybdenum in the winter common bean plant, Acta Scientiarum-Agronomy, 2010, 32, 117-123.

Application of molybdenum and lime to beans

For successful bean production in acidic soils attention is needed to supply important nutrients in the study area.The effects of Rhizobium inoculation, lime and molybdenum on photosynthesis and chlorophyll content of Phaseolus vulgaris L. were investigated in a split-split plot design in a greenhouse and field experiment. R. inoculation, molybdenum and lime had effects on the leaf chlorophyll content (Chl), the photosynthesis (A), the intercellular CO2 concentration (Ci) and the transpiration rate (E) of Phaseolus vulgaris L. Application of Mo and lime at the highest rates (12 g of Mo per kg seed and 3 t lime ha-1 respectively) was superior to the control and the 6 g of Mo per kg seed and 2 t lime ha-1. The combination of these supplies at different levels resulted in significant interactions between some parameters.

Bambara, S. and Ndakidemi, P. A., Effects of Rhizobium inoculation, lime and molybdenum on photosynthesis and chlorophyll content of Phaseolus vulgaris L, African Journal of Microbiology Research, 2009, 3, 791-798.

Li, Cr, Mn, Co, Ni, Cu, Zn, Se and Mo levels in foodstuffs from the Second French TDS [Total Diet Study]

In 2006, the French Food Safety Agency (AFSSA) conducted the Second French Total Diet Study (TDS) to estimate dietary exposures to the main minerals and trace elements from 1319 samples of foods typically consumed by the French population. The foodstuffs were analysed by inductively coupled plasma-mass spectrometry (ICP-MS) after microwave-assisted digestion. Occurrence data for lithium, chromium, manganese, cobalt, nickel, copper, zinc, selenium and molybdenum were reported and compared with results from the previous French TDS. The results indicate that the food groups presenting the highest levels of these essential trace elements were "tofu" (for Li, Mn, Ni, Cu, Zn and Mo),"fish and fish products" particularly "shellfish" (for Li, Co, Cu, Zn, Se and Mo), "sweeteners, honey and confectionery" particularly dark chocolate (for Cr, Mn, Co, Ni and Cu), "cereals and cereal products" (for Mn, Ni and Mo) and "ice cream" (for Cr, Co and Ni). (C) 2011 Elsevier Ltd. All rights reserved

Noel, L., Chekri, R., Millour, S., Vastel, C., Kadar, A., Sirot, V., Leblanc, J. C., and Guerin, T., Li, Cr, Mn, Co, Ni, Cu, Zn, Se and Mo levels in foodstuffs from the Second French TDS, Food Chemistry, 2012, 132, 1502-1513.

Molybdenum and trace element concentrations in red and white cabbage

Cabbage (Brassica oleracea) is a vegetable food that is found in red and white varieties, and consumed worldwide raw or cooked. The mineral composition of cabbage collected in 24 Brazilian cities was determined and the results were evaluated using multivariate analysis. The samples (31 white, 24 red) were digested with nitric acid and hydrogen peroxide and analyzed with inductively coupled plasma optical emission spectrometry. The accuracy of the method was confirmed by analysis of a certified reference material of spinach leaves, from the National Institute of Standard and Technology. Element concentrations (mg element/kg sample) were: potassium, 1602.9 to 4068.3; phosphorus, 217.5 to 766.2; calcium, 221.9 to 744.7; magnesium, 67.2 to 286.0; manganese, 0.81 to 4.40; iron, 1.91 to 8.60; molybdenum, 0.01 to 0.24; zinc, 1.17 to 5.10; sodium, 27.2 to 591.0; strontium, 0.35 to 5.79. The mineral composition of the red species was not different from the white species.

Anunciacao, D. S., Leao, D. J., de Jesus, R. M., and Ferreira, S. L. C., Use of Multivariate Analysis Techniques for Evaluation of Analytical Data-Determination of the Mineral Composition of Cabbage (Brassica oleracea), Food Analytical Methods, 2011, 4, 286-292.

Molybdenum improves antioxidant and osmotic-adjustment ability against salt stress in Chinese cabbage (Brassica campestris L. ssp. Pekinensis)

A pot experiment was conducted to determine the effects of molybdenum on antioxidative defense and osmotic-adjustment systems of Chinese cabbage under salt stress. Molybdenum fertilizer was applied at three levels (0, 0.15, 0.3 mg kg-1). Ten days after sowing, 500 ml 136.8 mM of NaCl solution was added to half of the plants for each treatment every 10th day for three consecutive times. The results revealed that with the application of molybdenum in Chinese cabbage under salt stress the fresh weight significantly increased; activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were dramatically improved; the contents of non-enzymatic antioxidants such as glutathione (GSH), carotenoid (CAR) and ascorbic acid (ASA) were significantly increased. There was also an significant increase in low molecular osmotic-adjustment products such as soluble sugar, soluble protein and proline. Moreover, molybdenum significantly increased potassium ion (K+) content and reduced sodium ion (Na+) contents, which eventually improved the K+/Na+ ratios. The present study suggests that the application of molybdenum enhances the salt stress tolerance in Chinese cabbage by increasing the capacity to eliminate active oxygen and the ability of osmotic-adjustment

Zhang, Mu, Hu, Chengxiao, Zhao, Xiaohu, Tan, Qiling, Sun, Xuecheng, Cao, Anyong, Cui, Min, and Zhang, Ying, Molybdenum improves antioxidant and osmotic-adjustment ability against salt stress in Chinese cabbage (Brassica campestris L. ssp. Pekinensis), Plant and Soil, 2012, 355, 375-383.

Mo absorption by cress

Mo is readily absorbed both into cress (Lepidium sativum) and into french beans (Phaseolus vulg. var. nanus) [Giussani et al., 1998]. For cress grown from seeds in Petri dishes on blotter paper moistened with tap water solutions of molybdate of different concentrations, the Mo content increased linearly with time before harvesting and with the molybdate concentration.

Giussani, A., Heinrichs, U., Roth, P., Werner, E., Schramel, P., Wendler, A., Biokinetic studies in humans with stable isotopes as tracers. Part 1: A methodology for incorporation of trace metals into vegetables, Isotopes In Environmental And Health Studies, 1998, 34,291-296.

Mo in sugarcane leaves

In crops of the sugarcane, the concentrations of molybdenum (Mo) in the leaves are generally lower than 0.3 mg Mo kg-1 . These low concentrations have resulted in limitations in the methods and instruments that can be used for these analyses. The objective of this study was to evaluate three different techniques to determine the concentration of Mo in sugarcane leaves sampled in the principal sugarcane-producing areas in Brazil. Two spectrometric techniques were evaluated by using ICP-EAS (Inductively Coupled Plasma-Emission Automated System) and DCP-MEAS (Direct Coupled Plasma-Multiple Emission Automated System) and a colorimetric technique of the reaction between potassium iodide and hydrogen peroxide (KI-H2O2). The techniques ICP-EAS and KI-H2O2 produced results of satisfactory accuracy and precision, whereas the DCP-MEAS consistently overestimated the Mo concentrations in cane leaves. The KI-H2O2 technique showed sensitivity 5 times greater than the ICP-EAS, with minimum detection limits of 0.1 and 0.5 mg Mo kg-1 , respectively

Polidoro, J. C., Medeiros, A. F. A., Xavier, R. P., Medeiros, J. A., Boddey, R. M., Alves, B. J. R., and Urquiaga, S., Evaluation of techniques for determination of molybdenum in sugarcane leaves, Communications in Soil Science and Plant Analysis, 2006, 37, 77-91

Lettuce – yield increased by fertilisation with molybdenum and nitrogen

The aim was to evaluate the influence of nitrogen and molybdenum doses on the yield and contents of macronutrients in crisphead lettuce (Lactuca sativa L.). The experiment was carried out in the town of Tres Pontas, State of Minas Gerais, Brazil, from October to December, 2002.

The treatments combined nitrogen doses in the top dressing additional to the 60 kg/ha N dose applied by the agriculturist (0.0, 60.0, 120.0, and 180.0 kg/ha) and five foliar molybdenum doses (0.0, 35.1, 70.2, 105.3, and 140.4 g/ha).

The largest commercial fresh mass was obtained with the dose of 89.1 kg/ha nitrogen in the top dressing and 94.2 g/ha molybdenum.

With increasing doses of nitrogen and molybdenum

  • the levels of N and P increased
  • the levels of potassium decreased
  • the levels of Ca, Mg and S increased in the plant tops.

de Resende, G. M., Alvarenga, M. A. R., Yuri, J. E., de Souza, R. J., Mota, J. H., de Carvalho, J. G., and Rodrigues, J. C., Yield and content of macronutrients in crisphead lettuce (Lactuca sativa L.) in the summer planting as a function of nitrogen and molybdenum doses, Ciencia e Agrotecnologia, 2009, 33, 153-163.

Plants lettuce accumulation of molybdenum in plants and soils following amendments of Mo compost

A limit for molybdenum loading of soil developed from compost additions is proposed as 55 mg Mo/ kg soil, a value which is presently greater than the Canadian Council for Ministers of the Environment (CCME) Guidelines for the use of type B compost in Canada

The growth of lettuce (Lactuca sativa L.) and barley (Hordeum vulgar) and accumulation of molybdenum in plants and soils were evaluated in a pot experiment following amendments of molybdenum compost (1.0 g/ kg) to a Truro sandy loam.

Dry-matter yield: up to 25% molybdenum compost, no effect; at the 50% compost treatment dry-matter yield decreased.

pH: 50% compost treatments, soil pH increased an average of 0.5 units.

Extractable molybdenum:
50% compost treatments:

in the growth medium increased the nitric acid extractable molybdenum to 150 mg/ kg and diethylenetriaminepentaacetic acid extractable molybdenum to 100 mg/ kg; tissue Mo concentration to 569 and 478 mg/ kg in the lettuce and barley.

25% compost treatment:

in the growth medium produced about 55 mg/ kg of total molybdenum; tissue Mo concentration of 348 mg/ kg in lettuce and 274 mg/ kg in barley without any phytotoxicity.

Kashem, M. A. and Warman, P. R., Effect of High-Molybdenum Compost on Soils and the Growth of Lettuce and Barley, Communications in Soil Science and Plant Analysis, 2009, 40, 2225-2233.

Barley: effect of Salinity and Molybdenum Application on Photosynthesis, Nitrogenase Activity and Yield of Barley Inoculated with Azosprillium brasilense

In order to evaluate the effect of Azosprillium inoculation and molybdenum application on common barley grown in saline condition, a greenhouse experiment was conducted at Azad university, branch of Eghlid, Iran.

The experimental design was factorial based on complete randomized design with four replications.

The first factor comprised of four salinity treatments (1 as control, 5, 10 and 15 ds m-1),
second factor comprised the levels of Mo application (1: treated and 2: untreated =3D control) and
the third factor included two levels of Azosprillum inoculation (inoculated and uninoculated =3D control).

The measured parameters were chlorophyll fluorescence, photosynthesis (Ps) rates, carbohydrates, nitrate, ammonium and protein content, nitrogenase activity, grain yield (GY) and yield components.

The results showed that salinity decreased GY in all levels. GY reduction in inoculated treatment was lower (12.9%) than uninoculated treatment (29.7%). GY reduction was highly related to the reduction of grain number (GN) rather than reduction in ear mX(2).

Inoculation and application of Mo reduced harmful effects of salinity especially on mean kernel weight and grain number. Soluble saccharides and protein contents increased with increasing salinity. Inoculation and Mo application significantly increased the content of fructan and sucrose respectively. The mean values of Fv/Fm and photosynthesis rate reduced in the salinity treatments compared to the control. Inoculation and Mo application significantly increased photosynthesis rates at all salinity levels. The highest plant N content was obtained from inoculated, control salinity treatment by applying Mo.

In inoculated barley roots with application of Mo, nitrogenase activity (NA) was not severely inhibited by salinity.

Data also showed that Mo application positively affected nitrogenase activity. Inoculation, caused plant to cope on the stress, effectively by increasing fructan content and NO3/NH4 ratio and lower decrease in whole plant N content and Fv/Fm ratio.

Generally, Azosprillium inoculation helped plants perform better under salinity treatments and Mo application ameliorated plant nitrogen status

Bagheri, A. R. and Jafari, A. R., Effect of Salinity and Molybdenum Application on Photosynthesis, Nitrogenase Activity and Yield of Barley Inoculated with Azosprillium brasilense, Cereal Research Communications, 2012, 40, 235-245.

Strawberies: Characterization of Toxicity Symptoms of Molybden and Determination of Tissue Threshold Levels for Diagnostic Criteria in Korean Bred Strawberries

This study was carried out to investigate the influence of molybdenum (Mo) concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries.

Tissue analysis based on the dry weight was also conducted to determine the threshold levels in plants when Mo toxicity developed in strawberries.

The leaf chlorophyll contents decreased lineally as Mo concentrations in the fertilizer solution were elevated. The differences among treatments in chlorophyll contents were statistically significant.

The fresh and dry weights decreased significantly when the Mo concentrations in fertilizer solution were higher than 3.0 mM in 'Keumhyang' and 'Maehyang' strawberries and 1.0 mM in 'Seolhyang' strawberry.

The elevation of Mo concentrations in fertilizer solution resulted in severe toxicity and crops developed the unique symptoms. The margin of older leaves became yellow and desiccated. Then, the margin of leaf blade rapidly became bronze colored and died as the symptoms spread up the plants. The interveinal area of the young leaves became yellowing.

The elevation of Mo concentrations in fertilizer solution did not influence the tissue P, K, and Mg contents based on the dry weight.

The tissue Ca contents were higher in 1.0 mM treatment than other treatments of 'Keumhyang' and 'Seolhyang' strawberries.

The tissue Mo contents based on the dry weight of 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries were 76.5, 104.0, and 187.3 mg.kg-1, respectively, in the 0.25 mM treatments and 4,155, 5,367, and 2,190 mg.kg-1, respectively, in the 4.0 mM treatments. The contents increased lineally as Mo concentrations in fertilizer solution were elevated.

When the concentration of Mo at which growth of crops were retarded by 10% is regarded as threshold level, the Mo contents based on dry weight of above ground plant tissue should be lower than 653.4, 686.2, and 589.7 mg.kg-1, in 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries, respectively

Choi, Jong Myung, Min, Ho Nam, Lee, Chiwon W., and Chun, Jong Pil, Characterization of Toxicity Symptoms of Molybden and Determination of Tissue Threshold Levels for Diagnostic Criteria in Korean Bred Strawberries, Korean Journal of Horticultural Science & Technology, 2012, 30, 392-399.

Molybdenum-enriched soybean seeds enhance N accumulation, seed yield, and seed protein content in Brazil

High soybean yields require large amounts of nitrogen from symbiotic N2 fixation. The efficiency of nitrogen fixation can be limited by molybdenum deficiency. In Brazil, soybean responds positively to fertilization with molybdenum in soils of low fertility and in fertile soils depleted of molybdenum due to long-term cropping.

Molybdenum can be supplied by seed treatment, however toxicity of molybdenum to Bradyrhizobium strains applied to seed as inoculant has been observed, resulting in bacterial death and reductions in nodulation, N2 fixation and grain yield. Therefore, use of seeds enriched in molybdenum is a viable alternative to exterior seed treatment, allowing elite inoculant strains of Bradyrhizobium to sustain high rates of biological N-2 fixation.

Molybdenum-rich seeds of several soybean cultivars were obtained from plants treated by two foliar sprays of 400 g molybdenum ha (1) each, between the R3 and R5 stages, with a minimum interval of 10 days between sprays. Considerable increases in seed-molybdenum content were obtained, of as much as 3000%, in comparison to seeds obtained from plants which received no molybdenum.

In field experiments performed in soils with low nitrogen content and without any nitrogen-fertilizer supply, inoculation of molybdenum-rich seeds produced plants with increased nitrogen and molybdenum contents in the grain and higher yields of total nitrogen and of grain. Molybdenum-rich soybean seeds did not require any further application of molybdenum-fertilizer.

Campo, R. J., Araujo, R. S., and Hungria, M., Molybdenum-enriched soybean seeds enhance N accumulation, seed yield, and seed protein content in Brazil, Field Crops Research, 2009, 110, 219-224.

Plants agriculture seed treatment

Molybdenum was applied as a concentrated suspension of molybdenum trioxide in water to soybean seeds resulting in in higher soybean yields than in a control.

Lana, R. M. Q., de Faria, M. V., Bonotto, I., and Lana, A. M. Q., Cobalt and Molybdenum Concentrated Suspension for Soybean Seed Treatment, Revista Brasileira de Ciencia do Solo, 2009, 33, 1715-1720.

Molybdenum in pastures and herbage

Increased yield of direct seeded rice (Oryza sativa L.) by foliar fertilization through multi-component fertilizers

Foliar application of fertilizers can guarantee the availability of nutrients to rice for obtaining higher yield. Rice responds favorably to macro-and micronutrients and the tolerance to salinity hazards improves by decreasing the N/S ratio. In this study, results showed that nutrient concentrations (g L-1) for rice are: nitrogen (N) 108.0, phosphorus (P2O5) 6, potassium (K2O) 81.0, calcium (CaO) 15.0, and magnesium (MgO) 6 g L-1; and for iron (Fe), manganese (Mn), zinc (Zn), cupper (Cu), boron (B), molybdenum (Mo) and silicon (Si) the recommended concentrations are 0.6, 0.45, 0.21, 0.06, 0.09, 0.0002 and 0.004 g L-1, respectively. A significant increase was recorded in number of panicles m-2, 1000 grain weight, biological yield and grain yield with foliar application of nutrients. Five foliar applications of nutrients resulted in maximum number of panicles m-2, grains panicle-1, 1000 grain weight and biological yield. It is concluded that five foliar applications of balanced amounts of fertilizers at the seedling stage (two sprays), tillering (single spray) and at panicle initiation and panicle differentiation (two sprays) helped in enhancing yield and yield components of rice. In this research, five foliar applications produced the smallest damaging effects of blast (Pyricularia oryzae) in rice

Shaygany, Jamshid, Peivandy, Noura, and Ghasemi, Seyedhadi, Increased yield of direct seeded rice (Oryza sativa L.) by foliar fertilization through multi-component fertilizers, Archives of Agronomy and Soil Science, 2012, 58, 1091-1098.

Each tiller has a head, or panicle, that actually produces the grains of rice. It is a prolific seed producer with open panicle seed production in mid summer.

Influence of Salinity on the Nitrogen Metabolism of Cordyline fruticosa

The aim was to study the influence of irrigation water salinity on the nitrogen metabolism of Cordyline fruticosa var. 'Red Edge'.

Irrigated agriculture depends on adequate and quality water supplies. As the level of salt increases in an irrigation source, the quality of that water for plant growth decreases. Crop plants are usually nonhalophytes that tolerate only moderate salt concentrations. Under salinity, they accumulate salt in their aboveground organs and, to a smaller extent, in roots. High salinity reduces plant growth and leaf area, which prejudices quality, especially in ornamental crops. The study of the behavior of ornamental plants that are tolerant to saline waters can be an advantage in areas with poor quality waters.

Four nutrient solutions with different electrical conductivity levels were applied by adding sodium chloride to the irrigation water. As salinity increases, nitrogen concentration increases in the roots but not the leaves. In leaves, nitrate reductase in vivo activity declines when salinity increases; when a substrate, nitrate, or a cofactor, molybdenum, is added, nitrate reductase activity increases. Potential nitrate reductase activity shows no differences between treatments; nitrate reductase synthesis is not affected by salinity. So, the diminution of the nitrate reductase in vivo activity suggests a nitrate and molybdenum level metabolic imbalance. In roots, molybdenum is more restrictive of the nitrate reductase activity than the nitrate substrate level. There are more amino acids in T1 than in T4, but it seems that there are no significant differences in T2 and T3. No significant differences are observed in the protein content; this indicates that amino acid diminution is due to the maintenance of the protein content. In conclusion, it can be said that the increased activity of nitrate reductase in roots may constitute part of an adaptation strategy of the plant to an increasing salinity in the growing medium

Plaza, B. M., Jimenez, S., Segura, M. L., Contreras, J. I., and Lao, M. T., Influence of Salinity on the Nitrogen Metabolism of Cordyline fruticosa, Communications in Soil Science and Plant Analysis, 2009, 40, 462-472.

Molybdenum and phosphorus interaction photosynthesis and grain yield of Brassica napus

A pot experiment with acid yellow-brown soil was conducted to investigate the interactive effects of molybdenum and phosphorus fertilizers on the photosynthetic characteristics of seedlings and grain yield of Brassica napus which is sensitive to soil P and Mo deficiency.

Both Mo and P fertilizers were applied at three levels (mg kg-1 soil):

Mo: 0, 0.15, 0.30
P: 0, 80, 160

P fertilizer application in the absence or presence of Mo fertilizer increased grain yield, soluble sugar concentrations of seedling leaves, DM and P accumulation of seedling shoots of Brassica napus.

Mo fertilizer increased these parameters only in the presence of P fertilizer.

Mo accumulation in shoots, chlorophyll concentrations and net photosynthesis rate (P (n)) of seedling leaves were increased by both Mo and P fertilizers, particularly with the combination of the two fertilizers.

the Mo and P fertilizers increased photosynthetic rate through two different mechanisms, with Mo increasing photosynthetic activity of mesophyll cells, and P increasing stomatal conductance.

There was a synergetic effect on photosynthesis and grain yield between Mo and P fertilizers and it is beneficial for Brassica napus growth to co-apply both the Mo and P fertilizers

Liu, H. G., Hu, C. X., Sun, X. C., Tan, Q. L., Nie, Z. J., and Hu, X. M., Interactive effects of molybdenum and phosphorus fertilizers on photosynthetic characteristics of seedlings and grain yield of Brassica napus, Plant and Soil, 2010, 326, 345-353.

White clover molybdenum and phosphorus

Role of Molybdenum on Yield, Quality, and Photosynthetic Efficiency of White Clover as a Result of the Interaction with Liming and Different Phosphorus Rates in Andisols

A greenhouse study was conducted to determine the effects of liming, molybdenum (Mo), and phosphorus (P) rates on yield, mineral and nutritional quality, and photosynthetic efficiency of Trifolium repens L. in two Andisols. The experiment used a factorial design with four, three, and two rates for Mo, P, and lime. Molybdenum and P application increased both shoot dry weight and Mo shoot concentration (10-30%). A strong competition for sorption sites between phosphate and molybdate resulted in an increase of available Mo in soil solution and therefore an increase of Mo uptake (20-40%). Significant increases (P <= 0.05) were observed in plants' mineral and nutritive quality and photochemical efficiency. This effect was greater in limed soils. Our results suggest a SPAD 50 value can be used as indicator of an adequate N shoot concentration in T. repens, and Mo fertilization is required to improve pasture yield and quality for livestock production

Vistoso, Erika M., Alfaro, Marta, and Mora, M. L., Role of Molybdenum on Yield, Quality, and Photosynthetic Efficiency of White Clover as a Result of the Interaction with Liming and Different Phosphorus Rates in Andisols, Communications in Soil Science and Plant Analysis, 2012, 43, 2342-2357.

Rye flour and rye

Trace Elements Species including molybdenum fractionation in Rye Flour and Rye

The fractionation of Cd, Cu, Mo, Ni, and Zn species in extracts of rye (cv. Fernando) seedlings and rye flour was performed by SEC/ICP-MS method. The majority of Cu, Zn, and Ni in all samples were bound in the 1-2 kDa fraction. Molybdenum occurred in all samples in the fraction of 3 kDa.

Polak, J., Mestek, O., Koplik, R., Santrucek, J., Kominkova, J., and Kodicek, M., Trace Elements Species Fractionation in Rye Flour and Rye (Secale cereale L.) Seedlings, Czech Journal of Food Sciences, 2009, 27, 39-48.

Plants alfalfa

Alfalfa crops were grown in the field at the University of Ankara over two seasons between 2001 and 2003 with sulfur supplied as gypsum at rates of 0 (control), 160 (S1), and 240 (S2) kg /ha. Sulfur fertilization increased sulfur concentrations and improved alfalfa hay yield for both years. Molybdenum concentration of the alfalfa was significantly reduced by S1 treatment in year 1. Applied S had no effect on copper.

Gunes, A., Inal, A., Pilbeam, D. J., and Kadioglu, Y. K., Effect of Sulfur on the Yield and Essential and Nonessential Element Composition of Alfalfa Determined by Polarized Energy Dispersive X-ray Fluorescence, Communications in Soil Science and Plant Analysis, 2009, 40, 2264-2284.

Plants rice beneficial effect of molybdenum and nickel interaction on plant growth

This is the first evidence for a beneficial effect of molybdenum and nickel interaction on plant growth. Upland rice plants, cultivar 'IAC 202,' were grown in nutrient solution until full tillering. Treatments consisted of ammonium nitrate or urea as nitrogen source plus molybdenum and/or nickel.

Moraes, M. F., Reis, A. R., Moraes, L. A. C., Lavres, J., Vivian, R., Cabral, C. P., and Malavolta, E., Effects of Molybdenum, Nickel, and Nitrogen Sources on the Mineral Nutrition and Growth of Rice Plants

Pasture

Concentrations in normal herbage may range from 0.1 to 0.3 ppm on a dry matter basis. The molybdenum is present as soluble ammonium molybdate, insoluble molybdenum trioxide, calcium molybdate and molybdenum disulfide. In areas of high industrial activity herbage values of up to 231 ppm have resulted. The differential in the molybdenum concentration of soils due to pH could result in differing levels due to the consumption of herbage grown in soils of regional type.

Gardner, A. W. and Hall-Patch, P. K., J. Nutr. , 1962, 84, 31.

Some soils may require supplemental molybdenum. These include soils low in organic matter, severely eroded or heavily weathered soils, soils low in total molybdenum, sandy soils, soils high in iron, and acid soils (pH <6.3). Molybdenum is not readily absorbed by plants from acid soils and liming or addition of molybdenum is required to increase the molybdenum concentration in pasture. Some plants exhibit visual symptoms of molybdenum deficiency, e.g., the classic whiptail in cauliflower and yellow spot in citrus, but often visual symptoms of molybdenum deficiency are not present or appear as symptoms of nitrogen deficiency. A typical supplemental molybdenum addition for legumes is approximately 0.25 kg molybdenum per acre. Molybdenum can be applied in fertilisers, by seed treatment or foliar sprays.

Some pastures have exceptionally high concentrations of molybdenum (generally associated with alkaline soils), and may give rise to symptoms of molybdenum toxicity in sheep and cattle. Guideline values of up to 50 mg/kg dry weight have been fixed for molybdenum concentrations in agricultural soils [Hornick et al., 1977]. A higher incidence of uratic diathesis was reported from a locality in Armenia where the soil was found to contain 77 mg/kg of molybdenum and 39 mg/kg of copper. The total daily intake of molybdenum and copper in the adults of this area were estimated to be 10 times that of an adult in a control area [Kovalskij et al., 1961; ILO Geneva, 1980].

Hornick, S. B., Baker, D. E. and Guss, S. B., Molybdenum in the Environment, 1977, 2, Marcel Dekker, New York.
Kovalskij, V. V., Jarovaja, G. A. and Smavonjan, D. M., Z. Obsc. Biol., 1961, XII, 179.
ILO Geneva, 1980.

Forests

Nitrate reductase activity in two temperate forests - effects of elevated carbon dioxide and nitrogen fertilization

The effects of elevated CO2 and nitrogen availability on the activity of nitrate reductase, the enzyme catalyzing the reduction of nitrate to nitrite, are reported in two temperate forests-a closed canopy sweetgum (Liquidambar styraciflua) plantation in Tennessee (Oak Ridge National Laboratory) and a loblolly pine (Pinus taeda) stand in North Carolina (Duke). Both CO2 and nitrogen enrichment had species specific impacts on nitrate reductase activity. Elevated CO2 and nitrogen fertilization decreased foliar nitrate reductase activity in P. taeda, but there were no treatment effects on L. styraciflua nitrate reductase activity at Oak Ridge National Laboratory or Duke. Nitrate reductase activity in 1-year P. taeda needles was greater than in 0-year old needles across treatments. P. taeda nitrate reductase activity was negatively correlated with bio-available molybdenum concentrations in soils; CO2 and nitrogen-mediated changes in soil nutrient status may be altering soil-plant nitrogen-dynamics. The variation in response among species may reflect different strategies for acquiring nitrogen; elevated CO2 may alter plant nitrogen dynamics through changes in nitrate reductase activity.

Nitrogen availability limits plant production in many terrestrial ecosystems and is a key regulator of plant response to elevated CO2. Plant nitrogen status is a function of both soil nitrogen availability and plant nitrogen uptake and assimilation capacity. As a rate-limiting step in nitrate assimilation, the reduction of nitrate is an important component of plant physiological response to elevated CO2 and terrestrial carbon sequestration.

Natali, S., Sanudo-Wilhelmy, S. A., and Lerdau, M., Effects of elevated carbon dioxide and nitrogen fertilization on nitrate reductase activity in sweetgum and loblolly pine trees in two temperate forests, Plant and Soil, 2009, 314, 197-210.

Nitrogen fixation in tropical forests - increased by molybdenum addition to soil

Nitrogen fixation, the biological conversion of dinitrogen to plant-available ammonium, requires the enzyme nitrogenise of which molybdenum is a co-factor. Nitrogen fixation is the primary natural input of nitrogen to ecosystems(1), and influences plant growth and carbon exchange at local to global scales(2-6). The role of nitrogen fixation in tropical forests is of particular concern, as tropical forest ecosystems harbour abundant nitrogen-fixing organisms(1,4) and represent one third of terrestrial primary production(4,7,8).

Molybdenum is shown to limit nitrogen fixation by free-living heterotrophic bacteria in soils of lowland Panamanian forests. The nitrogen fixation response to long-term nutrient manipulations in intact forests, and to short-term manipulations in soil microcosms was measured. Nitrogen fixation increased sharply in treatments of molybdenum alone, in micronutrient treatments that included molybdenum by design and in treatments with commercial phosphorus fertilizer, in which molybdenum was a contaminant. Nitrogen fixation did not respond to additions of phosphorus that were not contaminated by molybdenum.

Molybdenum alone can limit asymbiotic nitrogen fixation in tropical forests. Molybdenum limitation may be common in highly weathered acidic soils, and may constrain the ability of some forests to acquire new nitrogen in response to CO2 fertilization(9)

1.Galloway, J. N. et al. Nitrogen cycles: Past, present, and future. Biogeochemistry70, 153–226 (2004).
2.Mahaffey, C., Michaels, A. F. & Capone, D. G. The conundrum of marine N2 fixation. Am. J. Sci. 305, 546–595 (2005).
3.Vitousek, P. M. et al. Towards an ecological understanding of biological nitrogen fixation. Biogeochemistry 57, 1–45 (2002).
4.Cleveland, C. C. et al. Global patterns of terrestrial biological nitrogen (N2) fixation in natural ecosystems. Glob. Biogeochem. Cycles 13, 623–645 (1999).
5.Reich, P. B., Hungate, B. A. & Luo, Y. Q. Carbon-nitrogen interactions in terrestrial ecosystems in response to rising atmospheric carbon dioxide. Annu. Rev. Ecol. Evol. Syst. 37, 611–636 (2006).
6.Gutschick, V. P. Evolved strategies in nitrogen acquisition by plants. Am. Nat. 118, 607–637 (1981).
7.Field, C. B., Behrenfeld, M. J., Randerson, J. T. & Falkowski, P. Primary production of the biosphere: Integrating terrestrial and oceanic components. Science 281, 237–240 (1998).
8.Clark, D. A. Detecting tropical forests' responses to global climatic and atmospheric change: Current challenges and a way forward. Biotropica 39, 4–19 (2007).
9.Hungate, B. A. et al. CO2 elicits long-term decline in nitrogen fixation. Science 304, 1291–1291 (2004).
Barron, A. R., Wurzburger, N., Bellenger, J. P., Wright, S. J., Kraepiel, A. M. L., and Hedin, L. O., Molybdenum limitation of asymbiotic nitrogen fixation in tropical forest soils, Nature Geoscience, 2009, 2, 42-45.

Nitrogenase Molybdenum and Phosphorus Interact

Molybdenum and Phosphorus Interact to Constrain Asymbiotic Nitrogen Fixation in Tropical Forests

Biological di-nitrogen fixation (N2) is the dominant natural source of new nitrogen to land ecosystems. Phosphorus (P) is thought to limit N2 fixation in many tropical soils, yet both molybdenum (Mo) and P are crucial for the nitrogenase reaction (which catalyzes N2 conversion to ammonia) and cell growth. We have limited understanding of how and when fixation is constrained by these nutrients in nature.

Here we show in tropical forests of lowland Panama that the limiting element on asymbiotic N2 fixation shifts along a broad landscape gradient in soil P, where Mo limits fixation in P-rich soils while Mo and P co-limit in P-poor soils. In no circumstance did P alone limit fixation. We provide and experimentally test a mechanism that explains how Mo and P can interact to constrain asymbiotic N2 fixation.

Fixation is uniformly favored in surface organic soil horizons - a niche characterized by exceedingly low levels of available Mo relative to P. We show that soil organic matter acts to reduce molybdate over phosphate bioavailability, which, in turn, promotes Mo limitation in sites where P is sufficient.

Our findings show that asymbiotic N2 fixation is constrained by the relative availability and dynamics of Mo and P in soils. This conceptual framework can explain shifts in limitation status across broad landscape gradients in soil fertility and implies that fixation depends on Mo and P in ways that are more complex than previously thought

Wurzburger, Nina, Bellenger, Jean Philippe, Kraepiel, Anne M. L., and Hedin, Lars O., Molybdenum and Phosphorus Interact to Constrain Asymbiotic Nitrogen Fixation in Tropical Forests, Plos One, 2012, 7,

Molybdenum in animals

Bioaccumulation of selected metals in the gill, liver and muscle tissue of rednose labeo Labeo rosae from two impoundments on the Olifants River, Limpopo river system, South Africa

Metal concentrations in the gill, muscle and liver tissues of Labeo rosae from two impoundments, Loskop and Flag Boshielo dams on the Olifants River, were evaluated in 2011 to detect patterns in metal associations between tissues and impoundments. Elevated concentrations of Ba, Zn, B, Al, Si and Fe, relative to a pristine site in the catchment, were found in the muscle, liver and gill tissues at both impoundments. Molybdenum concentrations were exceptionally high in all tissues at Loskop Dam and in liver at Flag Boshielo Dam. No definite pattern in the ratio metal concentrations within, or between, fish tissues was identified. The expected trend, liver > gills > muscle, was found at both impoundments, but was less prominent at Loskop Dam. Metal concentrations in muscle of Loskop Dam fish were significantly higher than in those at Flag Boshielo Dam. The inverse was true for liver. The long-term impact of elevated metal concentrations on fish health at both impoundments raises concern.

Marr, S. M., Lebepe, J., Steyl, J. C. A., Smit, W. J., and Luus-Powell, W. J.,Bioaccumulation of selected metals in the gill, liver and muscle tissue of rednose labeo Labeo rosae from two impoundments on the Olifants River, Limpopo river system, South Africa, African Journal of Aquatic Science, 2017, 42, 123-130.

The toxicity of molybdate to freshwater and marine organisms. III. Generating additional chronic toxicity data for the refinement of safe environmental exposure concentrations in the US and Europe

The freshwater and marine long-term ecotoxicity datasets used in the European REACH registration dossiers for molybdenum and molybdenum compounds resulted in the derivation of a HC5,50%,freshwater (38.2 mg Mo/L) and HC5,50%,marine (5.70 mg Mo/L) by means of the statistical extrapolation method. Both datasets, however, did not meet the US-EPA information requirements for deriving Final Chronic Values (FCV) that were based on chronic data. US-EPA compliance was achieved by generating chronic no-effect data for the freshwater benthic amphipod Hyalella azteca and the marine inland silverside fish Menidia beryllina, using sodiummolybdate dihydrate as test substance. A 42d-EC10 of 44.6 mgMo/L for reproduction was determined in a water-only exposure with H. azteca. For M. beryllina, a 37d-NOEC of 139 mg mMo/L for standard length and blotted wet weight was found. Other end-points (e.g., survival, hatching success) proved to be less sensitive. Data were added to the existing chronic toxicity datasets, together with new long-term no-effect values that were identified in open literature for brown trout Salmo trutta, the marine alga Isochrysis galbana, the marine snail Nassarius dorsatus and the marine barnacle Amphibalanus amphitrite. The updated data sets resulted in a freshwater and marine HC5,50% of 35.7 and 6.85 mg Mo/L, respectively. The same data sets were also used for the determination of US-EPA FCVs, where the FVCfreshwater was 36.1 mg/L, and the FCVmarine was 3.85 mg Mo/L. As the Final Plant Values for both aquatic environments were higher than their respective FCVs, the Criterion Continuous Concentration (CCC) for molybdenum is equal to the FCV. (C) 2017 The Authors. Published by Elsevier B.V.

Heijerick, D. G., and Carey, S.,The toxicity of molybdate to freshwater and marine organisms. III. Generating additional chronic toxicity data for the refinement of safe environmental exposure concentrations in the US and Europe, Science of the Total Environment, 2017, 609, 420-428.

Molybdate. Changes of Antioxidant Function and the mRNA Expression Levels of Apoptosis Genes in Duck Ovaries Caused by Molybdenum or/and Cadmium

To investigate the effects of molybdenum (Mo) combined with cadmium (Cd) on the antioxidant function and the mRNA expression levels of apoptosis-related genes in duck ovaries, 60 healthy 11-old-day female ducks were treated with hexaammonium molybdate ([(NH4)6Mo7O24.4H2O]) or/and cadmium sulfate (3CdSO4.8H2O) at different doses on a daily basis for 120 days. On the 120th day, ten female birds in each group were euthanized, and the ovaries and blood were collected to determine the antioxidant indexes and the mRNA expression levels of Bak-1, Bcl-2, and caspase-3 in ovaries. In addition, ovary tissues were subjected to histopathological analysis with optical microscope. The total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity decreased significantly (P < 0.01) in treated groups comparing with control while the nitric oxide synthase (NOS) activity increased (P < 0.01) both in ovary tissue and serum. The Bak-1 and caspase-3 expressions were upregulated while the Bcl-2 was downgraded by Mo or/and Cd. Biomolecules were affected in all metal-treated groups, whereas combined-treated animals showed greater effects. What is more, pathological damage in Mo and Cd combination treated groups was more severe. The results from the present study indicated that Mo or/and Cd caused oxidative stress and apoptosis in duck ovaries. Combination of Mo and Cd showed additive or synergistic effect leading to apoptosis and oxidative stress, and the pathway might be the mitochondrial pathway.

Cao, H., Xia, B., Zhang, M., Liao, Y., Yang, Z., Hu, G., and Zhang, C.,Changes of Antioxidant Function and the mRNA Expression Levels of Apoptosis Genes in Duck Ovaries Caused by Molybdenum or/and Cadmium, Biol Trace Elem Res, 2015.

[mRNA: messenger RNA. Apoptosis: programmed cell death. Bak-1: Protein Coding gene. BCL2: protein, localizes to mitochondria, and functions to induce apoptosis. CASP3:  protein, a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. From Wikipedia.]

MOLYBDATE GOATS MOLYBDENUM-INDUCED APOPTOSIS IN KIDNEY CELLS
Molybdenum (Mo) is an essential microelement for the health of animals and human beings, and high dietary intake of Mo can lead to pathological conditions. However, the cytotoxic effects of high levels of Mo on the renal cells in ruminants have not been reported.
Therefore, this in vivo study in goats was designed to investigate the impact of Mo on kidney-related apoptosis genes, and histopathological and ultrastructural changes in renal cells using real-time quantitative polymerase chain reaction (RT-qPCR), light microscopy, and transmission electron microscopy.
A total of 48 goats were randomly distributed in equal number into four groups and assigned with one of three oral treatments of ammonium molybdate (15, 30, and 45 mg Mo kg(-1) BW), while control group received no Mo.
Kidney tissues were taken from individual goat at days 0, 25, and 50 for determining expression of apoptosis genes including Bax, Bcl-2, Cyt c, caspase-3, and Smac.
The results revealed that the expression of Bax, Smac, Cyt c, and caspase-3 was significantly (P < 0.05 or P < 0.01) upregulated in renal cells, whereas Bcl-2 was downregulated (P < 0.01).
Histopathological lesions showed degeneration of renal tubule, glomerular atrophy, and dilation of Bowman's capsule.
In addition, ultrastructural injury that predicted varying degrees of vacuolization, irregularity, fission of the nucleus, and swelling of mitochondria was observed in the cytoplasma of cells in groups treated with 30 and 45 mg Mo kg(-1).
This concluded that high levels of molybdenum, which induces apoptosis of caprine renal cells, might be involved in the mitochondrial intrinsic pathway.

Gu, X., Ali, T., Chen, R., Hu, G., Zhuang, Y., Luo, J., Cao, H., and Han, B.,In vivo studies of molybdenum-induced apoptosis in kidney cells of caprine, Biol Trace Elem Res, 2015, 165, 51.


MOLYBDATE DIET RAT TUNGSTEN-INDUCED MOLYBDENUM DEFICIENCY
Organ molybdenum (Mo) concentration and the activity of hepatic sulfite oxidase and xanthine oxidase were compared in tungsten-administered rats as well as rats fed with a low Mo diet to evaluate the use of tungsten-administered rats as a model of Mo deficiency. Twenty-four male 6-week-old Wistar rats were divided into four groups according to diet (AIN93G diet (control diet) or the control diet minus ammonium molybdate (low Mo diet)) and drinking water (deionized water or deionized water containing 200 mug/mL tungsten in the form of sodium tungstate). Mo content in the control and low Mo diets were 196 and 42 ng/g, respectively. Intake of the low Mo diet significantly reduced the Mo content of several organs and serum. Decrease in hepatic sulfite oxidase activity was also induced by the low Mo diet. The administration of tungsten induced marked decreases in organ Mo content and the activity of hepatic sulfite oxidase and xanthine oxidase. These decreases induced by tungsten administration were more pronounced than those induced by just a low Mo diet. Serum uric acid was also reduced by tungsten administration irrespective of Mo intake. Although a comparatively high accumulation of tungsten (3 to 9 mug/g) was observed in the kidneys and liver, adverse effects of tungsten accumulation on liver and kidney function were not observed in serum biochemical tests. These results indicate that tungsten-administered animals may be used as a model of Mo deficiency.

Yoshida, M., Nakagawa, M., Hosomi, R., Nishiyama, T., and Fukunaga, K.,Low molybdenum state induced by tungsten as a model of molybdenum deficiency in rats, Biol Trace Elem Res, 2015, 165, 75.

TUNGSTATE RAT TOXICITY
The subchronic toxicity of sodium tungstate dihydrate aqueous solution in male and female Sprague-Dawley rats was evaluated by daily oral gavage of 0, 10, 75, 125, or 200 mg/kg/d for 90 days. Measured parameters included food consumption, body weight measurements, hematology, clinical chemistry, and histopathological changes. There was a significant decrease in food consumption and body weight gain in males at 200 mg/kg/d from days 77 to 90; however, there was no effect in food consumption and body weights in females. There were no changes in the hematological and clinical parameters studied. Histopathological changes were seen in kidney of male and female and epididymis of male rats. Histopathological changes were observed in the kidneys of male and female rats dosed at 125 or 200 mg/k/d consisting of mild to severe cortical tubule basophilia in 2 high-dose groups. Histological changes in epididymides included intraluminal hypospermia with cell debris in the 200 mg/kg/d dosed male rats. Histopathological changes were observed in the glandular stomach including inflammation and metaplasia in the high-dose groups (125 or 200 mg/kg/d) of both sexes of rats. Based on histopathology effects seen in the kidneys, the lowest observable adverse effect level was 125 mg/kg/d and the no observable adverse effect level was 75 mg/kg/d in both sexes of rats for oral subchronic toxicity.

McCain, W. C., Crouse, L. C., Bazar, M. A., Roszell, L. E., Leach, G. J., Middleton, J. R., and Reddy, G.,Subchronic Oral Toxicity of Sodium Tungstate in Sprague-Dawley Rats, Int J Toxicol, 2015.


MOLYBDATE TESTICULAR DEGENERATION DUCKS

To investigate the chronic toxicity of molybdenum (Mo) and cadmium (Cd) on the trace elements and the mRNA expression levels of ceruloplasmin (CP) and metallothionein (MT) in duck testicles, 120 healthy 11-day-old male ducks were randomly divided into six groups with 20 ducks in each group. Ducks were treated with the diet containing different dosages of Mo or Cd. The source of Mo and Cd was hexaammonium molybdate ([(NH4)6Mo7O24.4H2O]) and cadmium sulfate (3CdSO4.8H2O), respectively, in this study.
After being treated for 60 and 120 days, ten male birds in each group were randomly selected and euthanized and then testicles were aseptically collected for determining the mRNA expression levels of MT and CP, antioxidant indexes, and contents of trace elements in the testicle. In addition, testicle tissues at 120 days were subjected to histopathological analysis with the optical microscope.
The results showed that co-exposure to Mo and Cd resulted in an increase in malondialdehyde (MDA)level while decrease in xanthine oxidase (XOD) and catalase (CAT) activities. The mRNA expression level of MT gene was upregulated while CP was decreased in combination groups. Contents of Mo, copper (Cu), iron (Fe), and zinc (Zn) decreased in combined groups while Cd increased in Cd and combined groups at 120 days. Furthermore, severe congestion, low sperm count, and malformation were observed in low dietary of Mo combined with Cd group and high dietary of Mo combined with Cd group. Our results suggested that Mo and Cd might aggravate testicular degeneration synergistically through altering the mRNA expression levels of MT and CP, increasing lipid peroxidation through inhibiting related enzyme activities and disturbing homeostasis of trace elements in testicles. Interaction of Mo and Cd may have a synergistic effect on the testicular toxicity.

Xia, B., Chen, H., Hu, G., Wang, L., Cao, H., and Zhang, C.,The Co-Induced Effects of Molybdenum and Cadmium on the Trace Elements and the mRNA Expression Levels of CP and MT in Duck Testicles, Biol Trace Elem Res, 2015.

Molybdate in goats renal apotosis

Molybdenum (Mo) is an essential microelement for the health of animals and human beings, and high dietary intake of Mo can lead to pathological conditions. However, the cytotoxic effects of high levels of Mo on the renal cells in ruminants have not been reported. Therefore, this in vivo study in goats was designed to investigate the impact of Mo on kidney-related apoptosis genes, and histopathological and ultrastructural changes in renal cells using real-time quantitative polymerase chain reaction (RT-qPCR), light microscopy, and transmission electron microscopy.
A total of 48 goats were randomly distributed in equal number into four groups and assigned with one of three oral treatments of ammonium molybdate (15, 30, and 45 mg Mo kg(-1) BW), while control group received no Mo.
Kidney tissues were taken from individual goat at days 0, 25, and 50 for determining expression of apoptosis genes including Bax, Bcl-2, Cyt c, caspase-3, and Smac.
The results revealed that the expression of Bax, Smac, Cyt c, and caspase-3 was significantly (P < 0.05 or P < 0.01) upregulated in renal cells, whereas Bcl-2 was downregulated (P < 0.01).
Histopathological lesions showed degeneration of renal tubule, glomerular atrophy, and dilation of Bowman's capsule. In addition, ultrastructural injury that predicted varying degrees of vacuolization, irregularity, fission of the nucleus, and swelling of mitochondria was observed in the cytoplasma of cells in groups treated with 30 and 45 mg Mo kg(-1).
This concluded that high levels of molybdenum, which induces apoptosis of caprine renal cells, might be involved in the mitochondrial intrinsic pathway.


Gu, X., Ali, T., Chen, R., Hu, G., Zhuang, Y., Luo, J., Cao, H., and Han, B., In Vivo Studies of Molybdenum-Induced Apoptosis in Kidney Cells of Caprine, Biological Trace Element Research, 2015, 165, 51-58.
[Apoptosis. In multicellular organisms, cells that are no longer needed or are a threat to the organism are destroyed by a tightly regulated cell suicide process known as programmed cell death, or apoptosis.
Caprine, of or relating to goats
Cytotoxicity is the quality of being toxic to cells.]

Molybdate in sheep and goat livers

Energy-dispersive X-Ray fluorescence spectrometry was used to determine the concentrations of copper (Cu), zinc, iron and molybdenum in the liver of 76 sheep and goats from the regions of Macedonia-Thrace, northern Greece. In general, metal concentrations were in the adequate range, with one main exception of Cu-deficiency observed in all of the examined goat liver samples and Cu-toxicity found in 4 % of the sheep liver samples. One-way analysis of variance was carried out to determine significant differences among means depending on animal species, sex and age. Pearson correlation analysis was used to explore correlations between metal concentrations. The results obtained in the present study are discussed in the framework of diagnostic ranges, suggested for classifying the metal status of sheep and goats, and are compared with liver metal concentrations reported world-wide.


Papachristodoulou, C., Stamoulis, K., Tsakos, P., Vougidou, C., Vozikis, V., Papadopoulou, C., and Ioannides, K., Liver Concentrations of Copper, Zinc, Iron and Molybdenum in Sheep and Goats from Northern Greece, Determined by Energy-Dispersive X-Ray Fluorescence Spectrometry, Bulletin of Environmental Contamination and Toxicology, 2015, 94, 460-467.

Molybdate in rat tungstate-induced molybdenum deficiency

Organ molybdenum (Mo) concentration and the activity of hepatic sulfite oxidase and xanthine oxidase were compared in tungsten-administered rats as well as rats fed with a low Mo diet to evaluate the use of tungsten-administered rats as a model of Mo deficiency.
Twenty-four male 6-week-old Wistar rats were divided into four groups according to diet (AIN93G diet (control diet) or the control diet minus ammonium molybdate (low Mo diet)) and drinking water (deionized water or deionized water containing 200 mu g/mL tungsten in the form of sodium tungstate). Mo content in the control and low Mo diets were 196 and 42 ng/g, respectively.
Intake of the low Mo diet significantly reduced the Mo content of several organs and serum.
Decrease in hepatic sulfite oxidase activity was also induced by the low Mo diet.
The administration of tungsten induced marked decreases in organ Mo content and the activity of hepatic sulfite oxidase and xanthine oxidase. These decreases induced by tungsten administration were more pronounced than those induced by just a low Mo diet.
Serum uric acid was also reduced by tungsten administration irrespective of Mo intake.
Although a comparatively high accumulation of tungsten (3 to 9 mu g/g) was observed in the kidneys and liver, adverse effects of tungsten accumulation on liver and kidney function were not observed in serum biochemical tests.
These results indicate that tungsten-administered animals may be used as a model of Mo deficiency.


Yoshida, M., Nakagawa, M., Hosomi, R., Nishiyama, T., and Fukunaga, K., Low Molybdenum State Induced by Tungsten as a Model of Molybdenum Deficiency in Rats, Biological Trace Element Research, 2015, 165, 75-80.

Liver concentration in sheep and goats

Energy-dispersive X-Ray fluorescence spectrometry was used to determine the
concentrations of copper (Cu), zinc, iron and molybdenum in the liver of 76 sheep
and goats from the regions of Macedonia-Thrace, northern Greece. In general,
metal concentrations were in the adequate range, with one main exception of
Cu-deficiency observed in all of the examined goat liver samples and Cu-toxicity
found in 4 % of the sheep liver samples. One-way analysis of variance was carried
out to determine significant differences among means depending on animal species,
sex and age. Pearson correlation analysis was used to explore correlations
between metal concentrations. The results obtained in the present study are
discussed in the framework of diagnostic ranges, suggested for classifying the
metal status of sheep and goats, and are compared with liver metal concentrations
reported world-wide.

Papachristodoulou C(1), Stamoulis K, Tsakos P, Vougidou C, Vozikis V,Papadopoulou C, Ioannides K. Liver Concentrations of Copper, Zinc, Iron and Molybdenum in Sheep and Goats from Northern Greece, Determined by Energy-Dispersive X-Ray Fluorescence Spectrometry. Bull Environ Contam Toxicol. 2015 Feb 19. [Epub ahead of print]

Molybdenum concentrations in animals

Molybdenum Concentrations in Animals
SourceConcentration / ppm dry weight
Marine Animals 0.6 - 2.5
Coelenterates 0.7
Molluscs 2.0
Echinoderms 2.5
Crustacea 0.6
Insects 0.6
Fish 1.0
Mammals <1.0
Bone <2.6

Bowen, H. J. M., Trace Elements in Biochemistry, 1966, Academic Press, N. Y.

Molybdenum Concentrations in Animal Organs [2,3]
AnimalBrainKidneyLiverLungMuscleSpleen
Adult rat 0.24 1.0 1.8 0.37 0.06 0.52
Chicken - 4.4 3.6 - 0.14 -
Seaducks Southeast Alaska [4]   <10 <10      
bovine [5]     3.62      
horse [5]   2.20        

Concentrations in ppm Mo on dry weight basis.

[2](a) Underwood, E. J.,Trace Elements in Human and Animal Nutrition, 1962, 2nd Ed. Academic Press, London, 100; (b) Kolomiitseva, M. G., Polonskaya, M. N. and Osipov, G. K., Mikroelem. Sel. Khoz. Med., 1968, 4, 183; (c) Schroeder, H. A., Balassa, J. J. and Tipton, I. H., J. Chronic Diseases, 1970, 23, 481.
[3] Tipton I. H. and Cook, M.J., Health Phys., 1963, 9, 103.
[4] Franson, J.C., Koehl, P.S., Derksen, D.V., Rothe, T.C., Bunck, C.M., Moore, J.F., Heavy-Metals In Seaducks And Mussels From Misty-Fjords-National-Monument In Southeast Alaska, Environmental Monitoring And Assessment, 1995, 36,149-167.
[5] Alonso, J.I.G., Camblor, M.G., Bayon, M.M., Marchante Gayon, J.M., Sanz Medel, A., Different quantification approaches for the analysis of biological and environmental samples using inductively coupled plasma mass spectrometry, Journal Of Mass Spectrometry, 1997, 32, 556-564.

Serum and liver concentrations of copper, iron, zinc and molybdenum in goats and sheep

Serum and liver concentrations were measured of copper, iron, zinc and molybdenum in sheep and goats slaughtered in the semiarid region of the state of Pernambuco, northeastern Brazil, during the rainy and dry seasons to establish if copper deficiency which occurs in the region is primary, or secondary to high levels of molybdenum and/or iron.

Low copper concentrations are not related with high molybdenum ingestion.

Serum and liver samples from 141 goats and 141 sheep were digested in nitric-perchloric acid and analyzed by coupled plasma atomic absorption spectrophotometry (ICPOES).

Based on copper serum and liver concentrations and on the sporadic occurrence of enzootic ataxia [swayback: progressive incoordination of the hind limbs, disruption of neuron and myelin development in the central nervous system; due to a deficiency of metabolizable copper], copper supplementation is recommended for grazing sheep and goats during the dry and the rainy seasons.

Considering that serum and hepatic concentrations of iron and molybdenum are within normal ranges or are marginal, it is suggested that the low copper concentrations are not related with high iron or molybdenum ingestion.

Marques, A. V. D., Soares, P. C., Riet-Correa, F., da Mota, I. O., Silva, T. L. D., Neto, A. V. B., Soares, F. A. P., and de Alencar, S. P., Serum and liver concentrations of copper, iron, zinc and molybdenum in sheep and goats in the state of Pernambuco, Pesquisa Veterinaria Brasileira, 2011, 31, 398-406.

Mean concentrations and the liver/serum concentration ratios are given in the Tables. The liver concentrations increase with the serum concentrations (not linearly, tending to level off at higher concentrations, as expected). Also, molybdenum is more concentrated in the liver.

Serum/liver concentrations
ElementGoatsSheep
SerumLiverSerumLiver
Concentration
/μmolL-1
Concentration
/mgkg-1
Concentration
/μmolL-1
Concentration
/mgkg-1
Copper 11.37 +/- 2.57 152.46 +/- 79.58 9.85 +/- 2.71 158.45 +/- 83.05
Iron 25.06. +/- 8.10 210.53 +/- 121.99 35.58 +/- 14.89 156.10 +/- 55.99
Molybdenum 0.28 +/- 0.11 6.53 +/- 4.13 0.31 +/- 0.16 8.10. +/- 4.01
Zinc 11.79 +/- 7.42 132.91 +/- 55.28 11.9 +/- 6.07 126.43 +/- 51.50
Ratio liver/serum
 goatssheep
Copper 13.4 16.1
Iron 8.4 4.4
Molybdenum 23.3 26.1
Zinc 11.3 10.6

Concentrations in ppm Mo on dry weight basis.

[2] (a) Underwood, E. J.,Trace Elements in Human and Animal Nutrition, 1962, 2nd Ed. Academic Press, London, 100; (b) Kolomiitseva, M. G., Polonskaya, M. N. and Osipov, G. K., Mikroelem. Sel. Khoz. Med., 1968, 4, 183; (c) Schroeder, H. A., Balassa, J. J. and Tipton, I. H., J. Chronic Diseases, 1970, 23, 481.
[3] Tipton I. H. and Cook, M.J., Health Phys., 1963, 9, 103.
[4] Franson, J.C., Koehl, P.S., Derksen, D.V., Rothe, T.C., Bunck, C.M., Moore, J.F., Heavy-Metals In Seaducks And Mussels From Misty-Fjords-National-Monument In Southeast Alaska, Environmental Monitoring And Assessment, 1995, 36,149-167.
[5] Alonso, J.I.G., Camblor, M.G., Bayon, M.M., Marchante Gayon, J.M., Sanz Medel, A., Different quantification approaches for the analysis of biological and environmental samples using inductively coupled plasma mass spectrometry, Journal Of Mass Spectrometry, 1997, 32, 556-564.

Molybdenum in Pig liver and mussels

Molybdenum concentrations were:

pig liver 3.8 – 4.0 microg/g
mussel 0.60 – 0.63 microg/g

Jiang, C.Q., Wang, J. Z., and He, F., Spectrofluorimetric determination of trace amounts of molybdenum in pig liver and mussels, Analytica Chimica Acta, 2001, 439, 307-313.

Molybdenum tolerance of sheep, cows, horses and pigs

Sheep and cows, develop adverse reactions to feed containing 2-30 ppm molybdenum; horses and pigs tolerate feed with concentrations > 1000 ppm molybdenum.

Smyth, H.E., Hygienic standard for daily inhalation. Ind Hyg Q, 1956, 17,129-185.

Molybdenum deficiency and elevated xanthine and sulfite

Molybdenum deficiency may lead to amino acid intolerance, irritability, elevated urinary xanthine and sulfite, and reduced uric acid and sulfate. Condition cured by 160 microg Mo/d administered.

Aburnrad NN, Schneider AJ, Steel D, Rogers LS. Amino acid intolerance during prolonged total parenteral nutrition reversed by molybdate therapy. Am J Clin Nutr 198 ; 34:2551-2559.

Molybdenum and insulin in rats

Insulin resistance, hyperinsulinemia, hypertriglyceridemia and hypertension occur in rats fed with high fructose diet. Sodium molybdate has insulin-like effects in animal models of type I and type II diabetes. The effects of Mo on fructose- hypertensive male Wistar rats was investigated. Molybdate treatment prevented fructose- induced hyperinsulinemia and hypertension in rats

Guner, S., Tay, A., Altan, V. M., and Ozcelikay, A. T., Effect of sodium molybdate on fructose-induced hyperinsulinemia and hypertension in rats, Trace Elements and Electrolytes, 2001, 18, 39-46.

Clams and oysters

Molybdenum concentrations in clams and oysters
SourceMo/mg/kg wet
clams hardshell 0.16+/- 0.33
clams softshell 0.31+/-0.38
oysters Eastern 0.08+/-0.24
oysters Pacific below detection

Baseline values for elements in clams and oysters harvested from US coastal waters 1985/1986.

Capar, S.G., Yess, N.J., US Food-And-Drug-Administration Survey Of Cadmium, Lead And Other Elements In Clams And Oysters, Food Additives And Contaminants, 1996,13,553-560.

Scallop

Specific pathways for the incorporation of dissolved barium and molybdenum into the bivalve shell: An isotopic tracer approach in the juvenile Great Scallop (Pecten maximus)

Dissolved barium and molybdenum incorporation in the calcite shell was investigated in the Great Scallop Pecten maximus. Sixty six individuals were exposed for 16 days to two successive dissolved Ba and Mo concentrations accurately differentiated by two different isotopic enrichments (Mo-97, Mo-95; Ba-135, Ba-137). Soft tissue and shell isotopic composition were determined respectively by quantitative ICP-MS (Inductively Coupled Plasma Mass Spectrometer) and laser ablation - ICP-MS. Results from Ba enrichment indicate the direct incorporation of dissolved Ba into the shell in proportion to the levels in the water in which they grew with a 6-8 day delay. The low spike contributions and the low partition coefficient (D-Mo = 0.0049 +/- 0.0013), show that neither the soft tissue nor the shell were significantly sensitive to Mo enrichment. These results eliminate direct Mo shell enrichment by the dissolved phase, and favour a trophic uptake that will be investigated using the successive isotopic enrichment approach developed in this study. (C) 2012 Elsevier Ltd. All rights reserved

Tabouret, Helene, Pomerleau, Sebastien, Jolivet, Aurelie, Pecheyran, Christophe, Riso, Ricardo, Thebault, Julien, Chauvaud, Laurent, and Amouroux, David, Specific pathways for the incorporation of dissolved barium and molybdenum into the bivalve shell: An isotopic tracer approach in the juvenile Great Scallop (Pecten maximus), Marine Environmental Research, 2012, 78, 15-25.

Effect of Cu on Molybdenum concentration in animal livers

Effect of Cu on Molybdenum concentration in animal livers
Source of liverCu/mg/kg wetMo/mg/kg wet
Aborted horse fetus 3.74 1.61
Dead horse 4.35 1.69
Slaughtered cow 1.10 1.38
Control cow 17.7 1.37

 Fly ash used in road construction blew over and contaminated pasture and water. The fly ash pH was ca 10 giving high bioavailabilityof Mo. Mo in forage 6 months after fly ash contamination 1.2mg Mo/kg dry weight (cf ‘normal’ in grasses in Denmark 0.1 - 0.3), Cu 5.0 mg Cu/kg.

Biological half life of Mo in cattle 24 h. Mo in fly ash 7 - 160 mg/kg . Absorption of Mo from gastrointestinal tract of ruminants 80 %, from humans and horses (?) 5 - 72%.

Ladefoged, O., Sturup, S., Copper Deficiency In Cattle, Sheep And Horses Caused By Excess Molybdenum From Fly-Ash - A Case-Report, Veterinary And Human Toxicology, 1995, 37, 63-65.

Trace elements including molybdenum in poultry eggs

Despite substantial interest in the trace element content of eggs by poultry breeders, nutritionists, and environmental scientists, available data about trace elements levels in eggs are scarce. Trace element contents in yolk and albumen of chicken, turkey, duck, goose, and pigeon eggs were analyzed to establish a baseline dataset and assess differences among trace element content in avian species. The selenium (Se), zinc (Zn), manganese (Mn), cobalt (Co), copper (Cu), molybdenum (Mo), vanadium (V), chromium (Cr), nickel (Ni), arsenic (As), cadmium (Cd), and thallium (Tl) contents in both yolk and albumen were measured by inductively coupled plasma mass spectrometry. One hundred twenty eggs deriving from 24 birds of each species, reared in the same poultry farm in northern Greece, were used; bird feed was common and based on cereals and legumes and contained no added vitamins or microminerals. Trace element contents in yolks were far higher than those in albumen, except for V and Ni. In yolks, the highest content for Se, Mo, and Tl were in pigeon eggs, for Zn, Mn, Cu, and Cr in turkey eggs, and for Co and Ni in goose eggs. In albumen, Se was highest in duck eggs, while Zn, Mn, and Co in pigeon ones. It is concluded that there is a substantial, up to threefold, variation for trace element contents in eggs among different domestic avian species offered the same feed.

Nisianakis, P., Giannenas, I., Gavriil, A., Kontopidis, G., and Kyriazakis, I., Variation in Trace Element Contents Among Chicken, Turkey, Duck, Goose, and Pigeon Eggs Analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Biological Trace Element Research, 2009, 128, 62-71.

Fish

Effect of waterborne boron and molybdenum on survival, growth and feed intake of Indian major carp, Cirrhinus mrigala (Hamilton) [Fish]

The effect of either boron (B) or molybdenum (Mo) on survival, growth and feed intake of Indian major carp, Cirrhinus mrigala (Hamilton), advanced fry was studied in two separate experiments.

Survival rates of C. mrigala fry (2.78 +/- 0.14 g) following 50 days' exposure to B at 0.01 (control), 0.5, 1.0, 2.0, 4.0 and 8.0 mg . L-1 were 100% at all concentrations except 8.0 mg . L-1 where the survival rate was 87.5 +/- 7.5%.

We observed 100% survival of mrigala fry at all concentrations of Mo, 0.02 (control), 0.5, 1.0, 2.0, 4.0 and 8.0 mg . L-1.

Both B and Mo at 0.5 mg . L-1 showed significantly (p < 0.05) higher growth of the fish compared with control and other concentrations.

B exposure at 1.0, 2.0 and 4.0 mg . L-1 had no significant effect on growth rate, whereas at 8.0 mg B . L-1 growth of the fish almost ceased.

Mo exposure at 1.0, 2.0, 4.0 and 8.0 mg . L-1 caused no significant effect on growth rate of the fish compared to control.

Both B and Mo at all concentrations had no significant effect on feed intake of the fish compared with control, except at the highest concentration of boron (8.0 mg . L-1)

Adhikari, S. and Mohanty, M., Effect of waterborne boron and molybdenum on survival, growth and feed intake of Indian major carp, Cirrhinus mrigala (Hamilton), Chemistry and Ecology, 2012, 28, 113-121.

Evaluating micronutrient concentrations in liver samples from abortions, stillbirths, and neonatal and postnatal losses in beef calves

The primary objective of the current study was to describe micronutrient concentrations in livers collected during postmortem examination from 501 beef calves and fetuses in western Canada.

The most frequently identified deficiencies based on reported ranges for aborted fetuses were magnesium, copper, and vitamin E.

For stillborn, neonatal, and postnatal calves, the most common deficiencies were magnesium, vitamin A, and vitamin E.

However, for calves that died after 3 days of age, selenium deficiency was also very likely.

Concentrations of all micronutrients examined in the study except zinc (P = 0.85) were different among fetuses, stillbirths, and neonatal and postnatal losses. This included liver selenium, copper, manganese, molybdenum, iron, magnesium, vitamin A, and vitamin E (P < 0.01).

The percentiles of micronutrient concentrations for each age group, empirical prediction intervals for individual calves, and model predicted confidence intervals to compare with average concentrations from groups of calves were summarized for each age group.

Information on cow, calf, and herd management attributes were available for 221 samples from 106 herds collected as part of study 1.

Cow age, supplementation history, water quality, and herd location were associated with the concentration of iron, zinc, and molybdenum.

The current study is unique in the number of samples included from young calves that were submitted as part of routine surveillance and not based on suspicion of either deficiency or toxicity. Most previous studies have been focused on older animals or fetuses and have contained a mix of beef and dairy animals with little or no information on their supplementation history

Waldner, C. L. and Blakley, B., Evaluating micronutrient concentrations in liver samples from abortions, stillbirths, and neonatal and postnatal losses in beef calves, Journal of Veterinary Diagnostic Investigation, 2014, 26, 376-389.

Performance of the antioxidant protection in blood of highly prolific sows before and after farrowing

Increased metabolic burdens put on highly prolific sows during late gestation and lactation cause their exposition to elevated systemic oxidative stress, i.e. uncontrolled imbalance between production and neutralization of reactive oxygen species (ROS). Formation of active free radicals and thus lipid per oxidation (LPO) processes in the body are regulated by the functioning of antioxidant protection (AOP) system.

The aim of presented study was to examine performance of oxidative stress in the blood of highly prolific sows before after farrowing.

The experiment was conducted on Large White sows (n = 20) of the second farrowing with live weight ranging from 180 to 220 kg. The study started on the 100th day of the farrowing period (pregnancy) and continued until the 25th day after farrow.

The material for the study was sows blood obtained from the ocular vein 14 days before (-14d) and on the 10th and 25th days after farrowing (+ 10d and + 25d).

All the biochemical researches were conducted spectrophotometrically.

The intensity of oxidative stress in the blood plasma was estimated by the content of lipid hydroperoxides (LHP) using ammonium thiocyanate; thiobarbituric acid reactive substances (TBARS) and carbonylproteins (CP) with using Lushchak et al. method (2004).

The state of AOP in the erythrocytes was determined by the level of enzymes activity, such as: superoxide dismutase (SOD) with using of nitroblue tetrazolium in the system of NADH-phenazine methosulfate; catalase (CAT) according to the ability of H2O2 to make a complex with ammonium molybdate (VI) tetrahydrate; glutathione peroxidase (GP) by the speed of glutathione oxidation in the presence of tertbutylhydroperoxide; glutathione reductase (GR) by the content reduction of NADPH.

The amount of reduced glutathione (GSH) was found by the reaction with 5,5-dithiobis-(2-nitrobenzoic) acid.
In research, sharp dynamics of oxidative stress indices in the blood of sows was established.

Before farrows, the level of LHP was 1.5-times lower while concentrations of TBARS and CP were about 40% higher in comparison to the +25d (P <= 0.05).

Simultaneously, in relation to the -14d activity in the erythrocytes of SOD and CAT increased about 10% (P <= 0.05), while GP and GR and also concentration of GSH decreased about 1.5- times (P <= 0.05) on the + 10d. In conclusion, changes detected in the blood of sows in critical periods of ontogenesis show development of stress condition in their body and the increase of disease appearance risk due to the weakening of adaptation mechanisms

Demchuk, M., Buchko, O., Lis, M. W., and Niedziolka, J. W., Performance of the antioxidant protection in blood of highly prolific sows before and after farrowing, Large Animal Review, 2014, 20, 135-139.

Molybdenum in Bacteria

Comparative analysis of the molybdate transport proteins in various bacteria and archaea is reviewed. Molybdate is transported by an ABC-type transporter comprising three proteins, ModA (periplasmic binding protein), ModB (membrane protein) and ModC, the ATPase. In the absence of the high-affinity molybdate transporter, molybdate is also transported by another ABC transporter which transports sulfate/thiosulfate as well as by a nonspecific anion transporter.

Self, W.T., Grunden, A. M., Hasona, A., and Shanmugam, K. T., Molybdate transport, Research in Microbiology, 2001, 152, 311-321.

Antimicrobial properties of ketimine molybdenum(VI) complexes

Dioxomolybdenum(VI) and oxovanadium(V) complexes of heterocyclic ketimines, 5-nitro-3-(indolin-2-one)hydrazinecarbothioamide, 5-nitro-3-(indolin-2- one) hydrazinecarboxamide , 6-nitro-3-(indolin-2-one) hydrazinecarbo- thioamide and 6-nitro3-(indolin-2-one) hydrazinecarboxamide were applied to pathogenic bacteria and fungi to assess their growth inhibition potency.

Garg, R., Fahmi, N., and Singh, R. V., Synthetic, spectral, and antimicrobial aspects of biologically relevant coordination compounds of dioxomolybdenum(VI) and oxovanadium(V), Russian Journal of Coordination Chemistry, 2008, 34, 198-203.


Co-CrMo alloy orthopaedic implant staphylococcal biofilm
Biofilms forming on the surface of biomaterials can cause intractable implant-related infections. Bacterial adherence and early biofilm formation are influenced by the type of biomaterial used and the physical characteristics of implant surface.
In this in vitro research, we evaluated the ability of Staphylococcus epidermidis, the main pathogen in implant-related infections, to form biofilms on the surface of the solid orthopaedic biomaterials, oxidized zirconium-niobium alloy, cobalt-chromium- molybdenum alloy (Co-Cr-Mo), titanium alloy (Ti-6Al-4V), commercially pure titanium (cp-Ti) and stainless steel.
A bacterial suspension of Staphylococcus epidermidis strain RP62A (ATCC35984) was added to the surface of specimens and incubated. The stained biofilms were imaged with a digital optical microscope and the biofilm coverage rate (BCR) was calculated. The total amount of biofilm was determined with the crystal violet assay and the number of viable cells in the biofilm was counted using the plate count method.
The BCR of all the biomaterials rose in proportion to culture duration. After culturing for 2-4 hours, the BCR was similar for all materials. However, after culturing for 6 hours, the BCR for Co-CrMo alloy was significantly lower than for Ti-6Al-4V, cp-Ti and stainless steel (P < 0.05). The absorbance value determined in the crystal violet assay and the number of viable cells on Co-Cr-Mo were not significantly lower than for the other materials (P > 0.05).
These results suggest that surface properties, such as hydrophobicity or the low surface free energy of Co-Cr-Mo, may have some influence in inhibiting or delaying the two-dimensional expansion of biofilm on surfaces with a similar degree of smoothness
Koseki, H., Yonekura, A., Shida, T., Yoda, I., Horiuchi, H., Morinaga, Y., Yanagihara, K., Sakoda, H., Osaki, M., and Tomita, M., Early Staphylococcal Biofilm Formation on Solid Orthopaedic Implant Materials: In Vitro Study, Plos One, 2014, 9,