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.
Environ Sci Pollut Res Int. 2013 Jul;20(7):5047-55. doi: 10.1007/s11356-013-1475-6. Epub 2013 Jan 20.
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.
为了研究铅（Pb）诱导的毒性，我们研究了不同浓度 Pb 对荇菜无菌幼苗 Pb 积累及其对营养元素、丙二醛（MDA）含量、超氧阴离子（O2(-·)）生成、过氧化氢（H2O2）含量、抗氧化酶活性、可溶性蛋白和光合色素的影响，以及叶绿体超微结构。结果表明，Pb 的积累呈浓度依赖性增加。营养元素（Ca、K、Fe、Mn 和 Mo）也受到影响。MDA 含量和 O2(-·)生成率逐渐增加，而 H2O2 含量在低浓度 12.5 μM 的 Pb 下先增加，然后下降。愈创木酚过氧化物酶和过氧化氢酶活性交替增加，而过氧化物歧化酶活性逐渐下降。Pb 与可溶性蛋白和光合色素呈负相关。此外，Pb 暴露导致叶绿体明显受损。总之，这些发现支持了荇菜受到 Pb 诱导的氧化应激的假设。此外，营养元素的紊乱和叶绿体超微结构的损伤表明 Pb 对细胞功能造成了普遍的混乱。
