title: Effects of Pb on the oxidative stress and antioxidant response in a Pb bioaccumulator plant Vallisneria natans.
abstract: The effects of Pb on photosynthetic pigments, oxidative stress and antioxidant response were assayed using biochemical and histochemical methods in leaves of Vallisneria natans (Lour.) Hara treated with 0-100 μM Pb(2+) for 0-6d. The Pb content increased with the increase of exposure duration and a highest Pb uptake value (about 9.4 mg Pbg(-1) dry weight) was obtained at 6d. Pb induced the accumulation of H(2)O(2) and O(2)(-). The increase of malondialdehyde content and the decrease of total chlorophyll and carotenoids were detected in V. natans under Pb stress. Activities of NAD(P)H oxidase, guaiacol peroxidase, glutathione reductase and ascorbate peroxidase increased at 75 μM Pb(2+) for 2-6 days, while activities of superoxide dismutase and catalase and the content of ascorbic acid increased within two days in plants exposed to 75 μM Pb(2+) and decreased thereafter. The Pb uptake and accumulation mechanism were discussed.
authors.affiliation: Ministry of Education, Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing 210098, China.
authors.forename: Peifang
authors.initials: P
authors.lastname: Wang
authors.forename: Songhe
authors.initials: S
authors.lastname: Zhang
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Lu
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D031321:Hydrocharitaceae / Q000187:drug effects* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007854:Lead / Q000633:toxicity*; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D009195:Peroxidase / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D012989:Soil Pollutants / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D012989:Soil Pollutants; D002734:Chlorophyll; D007854:Lead; D002338:Carotenoids; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; C121048:guaiacol peroxidase; D060387:Ascorbate Peroxidases; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D001205:Ascorbic Acid