Ministry of Education, Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, College of Environment, Hohai University, Nanjing 210098, China.
Ecotoxicol Environ Saf. 2012 Apr;78:28-34. doi: 10.1016/j.ecoenv.2011.11.008. Epub 2011 Dec 3.
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.
采用生物化学和组织化学方法研究了 0-100μMPb(2+)处理 0-6d 后的水蕴草叶片中 Pb 对光合色素、氧化应激和抗氧化响应的影响。Pb 含量随暴露时间的增加而增加，在 6d 时达到最高 Pb 吸收值（约 9.4mg Pbg(-1)干重）。Pb 诱导了 H(2)O(2)和 O(2)(-)的积累。在 Pb 胁迫下，水蕴草中丙二醛含量增加，总叶绿素和类胡萝卜素含量减少。在暴露于 75μMPb(2+)的植物中，NAD(P)H 氧化酶、愈创木酚过氧化物酶、谷胱甘肽还原酶和抗坏血酸过氧化物酶的活性在 2-6 天内增加，而过氧化物歧化酶和过氧化氢酶的活性以及抗坏血酸的含量在暴露于 75μMPb(2+)的两天内增加，随后下降。讨论了 Pb 的吸收和积累机制。
