title: Lead-induced oxidative damage in steriled seedlings of Nymphoides peltatum.
abstract: The effects of increasing concentrations of lead (Pb) on Pb accumulation and its influence on nutrient elements, malondialdehyde (MDA) content, generation of superoxide anion (O2(-·)), hydrogen peroxide (H2O2) content, antioxidant enzymes activities, soluble protein, and photosynthetic pigment, as well as chloroplast ultrastructure in steriled seedlings of Nymphoides peltata (S. G. Gmel.) Kuntze were investigated in order to understand Pb-induced toxicity. The accumulation of Pb was found to increase in a concentration-dependent manner. Nutrient elements (Ca, K, Fe, Mn, and Mo) were also affected. MDA content and O2(-·) generation rate increased progressively, while H2O2 content first boosted up at a low Pb concentration of 12.5 μM but then declined. Guaiacol peroxidase and catalase activities increased alternately, while superoxide dismutase activity gradually fell. Negative correlations were found between Pb and soluble protein and photosynthetic pigment. Moreover, Pb exposure resulted in a significant damage of chloroplasts. Taken together, these findings supported the hypothesis that Nymphoides peltatum underwent oxidative stress induced by Pb. In addition, both the disorder of nutrient elements and the damage to the ultrastructure of chloroplasts were indicative of general disarray in the cellular functions exerted by Pb.
authors: Jiangsu Key Lab of Biodiversity and Biotechnology, College of Life Science, Nanjing Normal University, No. 1 Wenyuan Road, Nanjing 210046 Jiangsu, People's Republic of China.
authors: Xuqiang
authors: X
authors: Qiao
authors: Guoxin
authors: G
authors: Shi
authors: Lin
authors: L
authors: Chen
authors: Xiuli
authors: X
authors: Tian
authors: Xiaoying
authors: X
authors: Xu
mesh_terms: D002736:Chloroplasts / Q000187:drug effects / Q000648:ultrastructure; D029624:Ferns / Q000737:chemistry / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007854:Lead / Q000633:toxicity*; D008315:Malondialdehyde / Q000032:analysis; D018384:Oxidative Stress / Q000187:drug effects*; D009195:Peroxidase / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D036226:Seedlings / Q000187:drug effects*; D013481:Superoxides / Q000378:metabolism
chemical_list: D013481:Superoxides; D007854:Lead; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; C121048:guaiacol peroxidase; D009195:Peroxidase