桐花树幼苗根系对镉胁迫的抗氧化生理响应  

Antioxidant physiological responses of Aegiceras corniculatum seedling root system to cadmium stress

作　　者：李裕红[1] 王荣富[2] 应朝阳[3] 

机构地区：[1]厦门大学环境科学研究中心,福建厦门361005 [2]泉州师范学院生物系,福建泉州362000 [3]福建省农业科学院农业生态研究所,福建福州350013

出　　处：《福建农业学报》2007年第2期193-196,共4页Fujian Journal of Agricultural Sciences

基　　金：福建省青年科技人才创新项目(2004J053);福建教育厅资助项目(JA02251);泉州市科技局项目(2003Z11)

摘　　要：研究Cd^2＋胁迫对水培桐花树（Aegiceras corniculatum）幼苗根系丙二醛（MDA）、超氧负离子（O￣2）、过氧化物酶（POD）、过氧化氢酶（CAT）和根系活力的影响。结果显示用0．25-10mg·L^-1的Cd^2＋处理桐花树幼苗，幼苗根系的活力随胁迫浓度升高而下降，而其MDA、O￣2含量及POD、CAT活性均呈诱导性升高，并随Cd^2＋质量浓度的加大而逐渐上升，细胞内O￣2含量增大带来的膜脂过氧化增强是Cd^2＋污染伤害桐花树的主要原因。而根系抗氧化保护酶对0．25-10mg·L^-1的Cd^2＋胁迫均能起到保护性的防御作用，保护酶CAT、POD活性的增强是桐花树抗Cd^2＋污染过氧化伤害的主要机理之一，根系膜保护酶POD和CAT活性可以作为对环境Cd^2＋污染响应的生物学指标。The antioxidant physiological responses to cadmium stress, including the contents of malondialaehyde （MDA）, superoxide anion （O￣2）, peroxide enzyme （POD）, catalase （CAT）, and the root system activity of Ae-giceras corniculaturn seedlings were investigated in water-culture condition. The results showed that, under the ap- plications of Cd^2＋ in the range of 0.25-10 mg· L^-1, the activity of root system decreased with increased Cd^2＋ con-centration, while the content of O￣2, MDA, and the activities of POD and CAT increased. It revealed that the membrane-lipid peroxidation brought about by the superoxide anions was the main cause of the Cd^2＋ damage to Ae-giceras corniculaturn seedling. On the other hand, the protective enzymes exerted Cd^2＋ stress resistance at the Cd^2＋ concentrations from 0.25-10 mg·L^-1. It indicated that increasing POD and CAT activities of the seedlings should be considered an important part of peroxidation resistance mechanism of the plant to cadmium pollution. And, the enzymatic activities might be a useful biological indicator of Cd^2＋ contamination.

关 键 词：桐花树 CD^2+ 胁迫 根系活力 MDA O￣2 抗氧化酶 

分 类 号：Q945.7[生物学—植物学]