The influence of duckweed species diversity on ecophysiological tolerance to copper exposure.
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.
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. Electronic address: zhaozhao2005001@163.com.
Zhao
Z
Zhao
School of Basic Medical Sciences, Guiyang Medical University, 550000 Guiyang, Guizhou, China. Electronic address: shihuijuan0305@163.com.
Huijuan
H
Shi
School of Basic Medical Sciences, Guiyang Medical University, 550000 Guiyang, Guizhou, China. Electronic address: duandongzhu@126.com.
Dongzhu
D
Duan
School of Basic Medical Sciences, Guiyang Medical University, 550000 Guiyang, Guizhou, China. Electronic address: 1147278066@qq.com.
Hongmei
H
Li
School of Basic Medical Sciences, Guiyang Medical University, 550000 Guiyang, Guizhou, China. Electronic address: 451567372@qq.com.
Tingwen
T
Lei
Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, 610064 Chengdu, Sichuan, China. Electronic address: wangmaolin135@163.com.
Maolin
M
Wang
Chengdu Institute of Biology, Chinese Academy of Sciences, 610041 Chengdu, China. Electronic address: zhaohai@cib.ac.cn.
Hai
H
Zhao
Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, 610064 Chengdu, Sichuan, China. Electronic address: zhaoyun@scu.edu.cn.
Yun
Y
Zhao
D029064:Araceae / Q000187:drug effects*; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003300:Copper / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity
D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D008315:Malondialdehyde; D003300:Copper; D002374:Catalase; D013482:Superoxide Dismutase
Antioxidant enzymes; Copper; Duckweeds; Lipid peroxidation; Mixed culture