镉胁迫对小麦不同生育期活性氧代谢的影响

Effects of cadmium stress on reactive oxygen aetabolism in wheat at different developemental stages

以不同Cd2+浓度对土培小麦进行处理,分别在拔节、抽穗、灌浆初期以及灌浆中期,分析不同浓度Cd2+胁迫下活性氧及酶促和非酶促抗氧化系统的变化.结果表明,随着小麦生育进程的变化,Cd2+胁迫使O2.-、H2O2和MDA含量增加,且生育前期的增长量明显大于后期;各生育时期的抗氧化酶和抗氧化物也出现不均衡变化:抽穗—拔节期间,SOD活性升高,CAT保持稳定,酶促抗氧化系统对活性氧的清除作用显著;灌浆期后,SOD、CAT活性均比对照有所下降,而抗坏血酸-谷胱甘肽氧化还原途径中的APX、GR活性以及AsA、GSH含量经前期速降后,逐渐稳定.

When wheat was treated with Cd^2＋ of different concentrations, the changes in enzymatic and nonenzymatic antioxidative system at jointing, heading, early filling and middle filling stage was studied. The result showed that the level of O2.^ - ,H2O2,MIDA progressively increased and the increase rate at early developemental stages were significantly higher. The change in aetioxidative enzymes and antioxidant were also unbalanced：from jointing stage to heading stage, Enzymatic antioxidative system played an important role on ROS scavenging because of the increase in SOD activity and stability in CAT activity; at filling stage, the activity of SOD and CAT evidently decreased respect to the controls, but the activity of APX and GR, content of AsA and GSH were stabe after significant decrease.