title: Cadmium induces two waves of reactive oxygen species in Glycine max (L.) roots.
abstract: Cadmium (Cd) is a non-essential heavy metal that may be toxic or even lethal to plants as it can be easily taken up by the roots and loaded into the xylem to the leaves. Using soybean roots (Glycine max L.) DM 4800, we have analysed various parameters related to reactive oxygen metabolism and nitric oxide (NO) during a 6 day Cd exposure. A rise in H(2)O(2) and NO, and to a lesser extent O(2)(·-) content was observed after 6 h exposure with a concomitant increase in lipid peroxidation and carbonyl group content. Both oxidative markers were significantly reduced after 24 h. A second, higher wave of O(2)(·-) production was also observed after 72 h of exposure followed by a reduction until the end of the treatment. NOX and glicolate oxidase activity might be involved in the initial Cd-induced reactive oxygen species (ROS) production and it appears that other sources may also participate. The analysis of antioxidative enzymes showed an increase in glutathione-S-transferase activity and in transcript levels and activity of enzymes involved in the ascorbate-glutathione cycle and the NADPH-generating enzymes. These results suggest that soybean is able to respond rapidly to oxidative stress imposed by Cd by improving the availability of NADPH necessary for the ascorbate-glutathione cycle.
authors.affiliation: Laboratorio de Química Biológica. Departamento de Bioquímica y Ciencias Biológicas, FQByF. Universidad Nacional de San Luis, Ejercito de los Andes 950, San Luis, 5700, Argentina.
authors.forename: María Verónica
authors.initials: MV
authors.lastname: Pérez-Chaca
authors.forename: María
authors.initials: M
authors.lastname: Rodríguez-Serrano
authors.forename: Alicia S
authors.initials: AS
authors.lastname: Molina
authors.forename: Hilda E
authors.initials: HE
authors.lastname: Pedranzani
authors.forename: Fanny
authors.initials: F
authors.lastname: Zirulnik
authors.forename: Luisa M
authors.initials: LM
authors.lastname: Sandalio
authors.forename: María C
authors.initials: MC
authors.lastname: Romero-Puertas
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism; D008055:Lipids / Q000032:analysis; D009249:NADP / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013025:Glycine max / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D008055:Lipids; D010936:Plant Extracts; D010940:Plant Proteins; D017382:Reactive Oxygen Species; C402172:homoglutathione; D002104:Cadmium; D009569:Nitric Oxide; D009249:NADP; D005978:Glutathione; D001205:Ascorbic Acid
keywords: NADPH; antioxidant enzymes; cadmium; dehydrogenases; oxidative stress