title: Comparative effect of Al, Se, and Mo toxicity on NO3(-) assimilation in sunflower (Helianthus annuus L.) plants.
abstract: Here, we study the effect caused by three trace elements--Al, Se, and Mo--applied at the same concentration (100 microM) and in their oxyanionic forms--NaAl(OH)(4), Na(2)SeO(4), and Na(2)MoO(4)--on NO(3)(-) assimilation (NO(3)(-), nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) activities, and concentrations of amino acids and proteins) in sunflower (Helianthus annuus L. var. Kasol) plants. The most harmful element for sunflower plants proved to be selenate, followed by aluminate. On the contrary, the application of molybdate had no negative effect on the growth of this plant, suggesting the possibility of using sunflower for the phytoremediation of this metal, mainly in agricultural zones used for grazing where the excess of this element can provoke problems of molybdenosis in ruminants (particularly in cattle). In addition, we found that the alteration of NO(3)(-) assimilation by SeO(4)(2-) and Al(OH)(4)(-) directly influences the growth and development of plants, foliar inhibition of NR activity by SeO(4)(2-) being more harmful than the decrease in foliar availability of NO(3)(-) provoked by Al(OH)(4)(-).
authors.affiliation: Department of Plant Physiology, Faculty of Science, University of Granada, 18071 Granada, Spain. jmrs@ugr.es
authors.forename: Juan M
authors.initials: JM
authors.lastname: Ruiz
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Rivero
authors.forename: Luis
authors.initials: L
authors.lastname: Romero
mesh_terms: D000535:Aluminum / Q000633:toxicity*; D000596:Amino Acids / Q000378:metabolism; D005970:Glutamate Synthase / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D006368:Helianthus / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008982:Molybdenum / Q000633:toxicity*; D050901:Nitrate Reductase / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D009572:Nitrite Reductases / Q000378:metabolism; D010936:Plant Extracts / Q000032:analysis / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D012643:Selenium / Q000633:toxicity*
chemical_list: D000596:Amino Acids; D009566:Nitrates; D010936:Plant Extracts; D011506:Proteins; D008982:Molybdenum; D000535:Aluminum; D005970:Glutamate Synthase; D009572:Nitrite Reductases; D050901:Nitrate Reductase; D005974:Glutamate-Ammonia Ligase; D012643:Selenium