Zhao Zhao, Shi Huijuan, Duan Dongzhu, Li Hongmei, Lei Tingwen, Wang Maolin, Zhao Hai, Zhao Yun
School of Basic Medical Sciences, Guiyang Medical University, 550000 Guiyang, Guizhou, China; Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, 610064 Chengdu, Sichuan, China; Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, China.
School of Basic Medical Sciences, Guiyang Medical University, 550000 Guiyang, Guizhou, China.
Aquat Toxicol. 2015 Jul;164:92-8. doi: 10.1016/j.aquatox.2015.04.019. Epub 2015 Apr 17.
In excess, copper is toxic to plants. In the plants, Landoltia punctata and Lemna minor grown in mixed and monoculture, the effects of exposure to varying concentrations of copper (0.01, 0.1, 0.5 and 1mgL(-1) Cu) for seven days were assessed by measuring changes in the chlorophyll, protein and malondialdehyde (MDA) content, catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity. According to results, Cu levels in plants increased with increasing Cu concentration. The level of photosynthetic pigments and crude proteins decreased only upon exposure to high Cu concentrations. However, the starch and malondialdehyde (MDA) content increased. These results suggested a stress alleviation that was possibly the result of antioxidants such as CAT and SOD, the activities of which increased with increasing Cu levels. APX activity increased in L. punctata, but decreased in L. minor, under monoculture or mixed culture conditions. In addition, the duckweed in mixed culture exhibited increased antioxidant enzyme activities which provide increased resistance to copper in moderate copper concentrations. As the copper concentration increased, the duckweed in the mixed culture limited the uptake of copper to avoid toxicity.
过量的铜对植物有毒。在混合培养和单培养条件下生长的细绿萍和浮萍中，通过测量叶绿素、蛋白质和丙二醛（MDA）含量以及过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（APX）活性的变化，评估了暴露于不同浓度铜（0.01、0.1、0.5和1mgL(-1) Cu）七天的影响。结果显示，植物中的铜含量随铜浓度的增加而增加。仅在暴露于高铜浓度时，光合色素和粗蛋白水平才会下降。然而，淀粉和丙二醛（MDA）含量增加。这些结果表明存在一种应激缓解现象，这可能是由CAT和SOD等抗氧化剂导致的，其活性随铜含量的增加而增加。在单培养或混合培养条件下，APX活性在细绿萍中增加，但在浮萍中降低。此外，混合培养中的浮萍表现出抗氧化酶活性增加，这使其在中等铜浓度下对铜的抗性增强。随着铜浓度的增加，混合培养中的浮萍限制铜的吸收以避免毒性。
