Cd^(2+)、Hg^(2+)复合污染下金鱼藻的细胞膜脂过氧化和抗氧化酶活性的变化

Changes of Cell Membrance Lipid Peroxidation and Activities of Antioxidant Enzyme Systems of Ceratophyllum demersum L. in Combinative Pollution of Cd^(2+) and Hg^(2+)

研究了不同浓度Cd2 + 、Hg2 + 以及二者共同胁迫对金鱼藻O 、MDA含量和抗氧化酶系统的影响 .实验结果表明 :Cd2 + 、Hg2 + 共同作用所产生的毒性效应大于单一Cd2 + 、Hg2 + ,表现为协同作用 .随着Cd2 + 、Hg2 + 浓度的增加 ,O 2 、MDA含量先升后降 ,MDA峰值较O 2 滞后 ;SOD、POD活性先升后降 ,表现为植物的一种抗性机制 ;CAT活性持续下降 ,在清除活性氧自由基过程中作用不明显 .

The paper deals with the effects of Cd 2+ ?Hg 2+ and their interaction on O  2?MDA and antioxidant enzyme systems of Ceratophyllum demersum L. .The results showed the synergic function of combination of Cd 2+ ?Hg 2+ , as the toxicity of combined pollution is heavier than those of single pollution.With the increasing of the concentration of Cd 2+ ?Hg 2+ ,accumulation of O  2?MDA were stimulated in lower level but decreased afterwards.The crest value of O  2 appeared earlier than MDA.The activities of SOD,POD also raised first and droped then,which may be regarded as a protecting function of plants.The activities of CAT reduced all along and had little effect in antioxidation.