title: Urea-induced oxidative damage in Elodea densa leaves.
abstract: Urea being a fertilizer is expected to be less toxic to plants. However, it was found that urea at 100 mg L(-1) caused the oxidative stress in Elodea leaves due to the formation of reactive oxygen species (ROS) and lipid peroxidation that are known to stimulate antioxidant pathway. Urea at a concentration of 500 and 1000 mg L(-1) decreased low-molecular-weight antioxidants. In this case, the antioxidant status of plants was supported by the activity of antioxidant enzymes such as superoxide dismutase and guaiacol peroxidase. A significant increase in the soluble proteins and -SH groups was observed with high concentrations of urea (30-60 % of control). Thus, the increased activity of antioxidant enzymes, low-molecular-weight antioxidants, and induced soluble protein thiols are implicated in plant resistance to oxidative stress imposed by urea. We found that guaiacol peroxidase plays an important role in the removal of the peroxide in Elodea leaves exposed to 1000 mg L(-1)of urea.
authors.affiliation: Department of Plant Physiology and Biochemistry, Faculty of Biology, Institute of Natural Sciences, Ural Federal University named after the first President of Russia B.N. Yeltsin, Lenin av., 51, Ekaterinburg, 620000, Russia, maria.maleva@mail.ru.
authors.forename: Maria
authors.initials: M
authors.lastname: Maleva
authors.forename: Galina
authors.initials: G
authors.lastname: Borisova
authors.forename: Nadezda
authors.initials: N
authors.lastname: Chukina
authors.forename: M N V
authors.initials: MN
authors.lastname: Prasad
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005308:Fertilizers / Q000633:toxicity*; D031321:Hydrocharitaceae / Q000187:drug effects* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D009195:Peroxidase / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014508:Urea / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D005308:Fertilizers; D017382:Reactive Oxygen Species; D014508:Urea; C121048:guaiacol peroxidase; D009195:Peroxidase; D013482:Superoxide Dismutase