Pb、Cd复合胁迫下4种植物抗氧化防御差异性研究  

Antioxidative defense system differences among four plants under combined Pb and Cd stress

作　　者：高扬[1,2] 毛亮[2,3] 周培[2,4] 张春华[2,4] 施婉君[2,4] 曹杰君[2,3] 靳治国[2,3] 时唯伟[2] 

机构地区：[1]上海交通大学环境科学与工程学院,上海200240 [2]农业部都市农业(南方)重点实验室,上海200240 [3]西南大学资源与环境学院,重庆400716 [4]上海交通大学农业与生物学院,上海200240

出　　处：《中国生态农业学报》2010年第4期836-842,共7页Chinese Journal of Eco-Agriculture

基　　金：国家高技术研究发展计划(863计划)项目(2007AA10Z441);上海市自然基金项目(07DZ12055,07JC14025,08d21900404)资助

摘　　要：为了解植物在Pb、Cd复合胁迫下抗氧化系统的响应,研究了重金属超富集植物龙葵、印度芥菜和非重金属超富集植物玉米和萝卜在Pb、Cd复合胁迫下抗氧化系统的变化。研究结果显示:Pb、Cd复合胁迫下超富集植物印度芥菜和龙葵的叶生物量显著减少,根和茎生物量在低浓度处理下减少不明显;非超富集植物萝卜和玉米的生物量随重金属浓度升高显著降低。超富集植物的SOD活性随重金属浓度升高逐渐升高;4种植物POD活性随重金属浓度变化规律各不相同,非超富集植物玉米和萝卜POD活性总体上随重金属浓度增加而提高;超富集植物叶片MDA含量随重金属浓度升高逐渐升高;印度芥菜和萝卜的总GSH含量显著高于其他两种植物。超富集植物的SOD、MDA、TAST、总GSH和PC与土壤重金属毒性系数呈显著相关;非超富集植物玉米的POD和总GSH与重金属毒性系数呈显著相关,而萝卜的TAST和PC与重金属毒性系数呈显著相关性。不同植物的解毒机制并不相同,因而进一步了解超富集植物的相关酶基因调控对阐明解毒机制尤为重要。The hyperaccumulative plants of Solanum nigrum and Brassica juncea, and non-hyperaccumulative plants of maize （Zea mays） and radish （Raphanus sativus） were used to analyze the antioxidative system response to combined Pb and Cd pollution. The results show that leaf biomass for the hyperaccumulators, S. nigrum and B. junce, significantly decrease under the pollution, against a slight change in root and stem biomass under low Pb and Cd concentration. The biomass of nonhyperaccumulators, maize and radish, significantly decreases with increasing concentration of heavy metals. Hyperaccumulators’ superoxide dismutase （SOD） activity increases with increasing concentration of heavy metals in the soil. While peroxidase （POD） activities for the four plants are different, response of non-hyperaccumulators’ POD activities to heavy metal stress is the same and increases with increasing heavy metal concentration. Hyperaccumulators’s malondialdehyde （MDA） content also increases with increasing heavy metal concentration. B. juncea and radish have higher GSH content than the other two plants. For the hyperaccmulators, SOD, MDA, TSTA, GSH and PC are significantly correlated with heavy metal toxicity coefficient. POD and total GSH in maize significantly correlate with heavy metal toxicity coefficient, while TAST and PC in radish significantly correlate with heavy metal toxicity coefficient. The results indicate the detoxification mechanisms are different for plants. Therefore, it is important to further research on hyperaccumulator gene control and enzyme expression for a greater insight into detoxification mechanism.

关 键 词：超富集植物 非超富集植物 酶 抗氧化系统 重金属毒性系数 解毒机制 

分 类 号：X144[环境科学与工程—环境科学]