title: Effect of molybdenum treatment on molybdenum concentration and nitrate reduction in maize seedlings.
abstract: Since 1940 molybdenum has been known as an essential trace element in plant nutrition and physiology. It has a central role in nitrogen metabolism, and its deficiency leads to nitrate accumulation in plants. In this study, we cultivated maize seedlings (Zea mays L. cv. Norma SC) in nutrient solution and soil (rhizoboxes) to investigate the effect of molybdenum treatment on the absorption of molybdenum, sulfur and iron. These elements have been previously shown to play important roles in nitrate reduction, because they are necessary for the function of the nitrate reductase enzyme. We also investigated the relationship between molybdenum treatments and different nitrogen forms in maize. Molybdenum treatments were 0, 0.96, 9.6 and 96 μg kg(-1) in the nutrition solution experiments, and 0, 30, 90, 270 mg kg(-1) in the rhizobox experiments. On the basis of our results, the increased Mo level produced higher plant available Mo concentration in nutrient solution and in soil, which resulted increased concentration of Mo in shoots and roots of maize seedlings. In addition it was observed that maize seedlings accumulated more molybdenum in their roots than in their shoots at all treatments. In contrast, molybdenum treatments did not affect significantly either iron or sulfur concentrations in the plant, even if these elements (Mo, S and Fe) play alike important roles in nitrogen metabolism. Furthermore, the physiological molybdenum level (1× Mo = 0.01 μM) reduced NO3-N and enhanced the NH4-N concentrations in seedlings, suggesting that nitrate reduction was more intense under a well-balanced molybdenum supply.
authors.affiliation: Institute of Food Science, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, H-4032 Debrecen, Böszörményi Str. 138, Hungary. Electronic address: kovacsb@agr.unideb.hu.
authors.forename: Béla
authors.initials: B
authors.lastname: Kovács
authors.affiliation: Institute of Food Science, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, H-4032 Debrecen, Böszörményi Str. 138, Hungary.
authors.forename: Anita
authors.initials: A
authors.lastname: Puskás-Preszner
authors.affiliation: Institute of Economic Analysis and Statistics, Faculty of Applied Economics and Rural Development, University of Debrecen, H-4032 Debrecen, Böszörményi Str. 138, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Huzsvai
authors.affiliation: Institute of Crop Sciences, Division of Agricultural Botany, Crop Physiology and Biotechnology, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, H-4032 Debrecen, Böszörményi Str. 138, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Lévai
authors.affiliation: Institute of Food Science, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, H-4032 Debrecen, Böszörményi Str. 138, Hungary.
authors.forename: Éva
authors.initials: É
authors.lastname: Bódi
mesh_terms: D008982:Molybdenum / Q000008:administration & dosage* / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism*
chemical_list: D009566:Nitrates; D008982:Molybdenum
keywords: Molybdenum; Nitrate accumulation; Nitrate reduction; Nitrogen metabolism