Erciyes University, Faculty of Science, Department of Biology, Kayseri, Turkey.
Int J Phytoremediation. 2011 Sep;13(8):805-17. doi: 10.1080/15226514.2010.525563.
In this study, an experiment was carried out to study the process of stress adaptation in Lemna gibba grown under nickel stress (0-20 mg Ni L(-1)). The results showed that Ni concentrations in plants increased with increasing Ni supply levels and reached a maximum of 142.82 mg.kg1 DW at 0.5 mg x L(-1) Ni treatments. The level of photosynthetic pigments (Chl a, Chi b, and total Chl) and soluble proteins increased upon exposure to high Ni concentrations. At the same time, the level of malondialdehyde (MDA) increased with increasing Ni concentration. These results suggested an alleviation of stress that was presumably the results of antioxidants such as superoxide dismutase (SOD), catalase (CAT) which generally increased linearly with increasing Ni levels. In addition, the proline content in L. gibba increased with increasing nickel levels. Our present work concluded that Lemna gibba has a high level of nickel tolerance and accumulation. We also found that moderate nickel treatment (0.05-5 mg x L(-1)) alleviated oxidative stress in plants, while the addition of higher amounts of nickel (10-20 mg x L(-1)) could cause an increasing generation of ROS, which was effectively scavenged by the antioxidative system. Therefore, L. gibba may be used as a phytoremediator in moderately polluted aquatic ecosystems.
在这项研究中，进行了一项实验，以研究在镍胁迫（0-20mgNiL(-1)）下生长的浮萍（Lemna gibba）的应激适应过程。结果表明，植物体内的镍浓度随镍供应水平的增加而增加，在 0.5mgxL(-1)镍处理时达到最大值 142.82mgkg1DW。在高镍浓度下，光合色素（Chla、Chi b 和总 Chl）和可溶性蛋白的水平增加。同时，随着镍浓度的增加，丙二醛（MDA）的水平增加。这些结果表明，抗氧化剂（如超氧化物歧化酶（SOD）、过氧化氢酶（CAT））的缓解应激作用可能是抗氧化剂的结果，它们通常随镍水平的增加而线性增加。此外，浮萍中的脯氨酸含量随镍水平的增加而增加。我们目前的工作得出结论，浮萍具有高水平的镍耐受和积累能力。我们还发现，适量的镍处理（0.05-5mgxL(-1)）可减轻植物的氧化应激，而添加更高量的镍（10-20mgxL(-1)）可能会导致 ROS 的生成增加，而抗氧化系统可以有效地清除这些 ROS。因此，浮萍可能被用作中污染水生生态系统中的植物修复剂。
