烟草叶片膜保护酶系统对土壤Hg,Cd,Pb胁迫的响应

采用盆栽实验，就烟草膜保护酶系统对土壤Hg,Cd,Pb胁迫的响应进行研究。结果表明：随着Hg,Cd,Pb浓度的增加，POD活性逐渐增加，CAT活性逐渐减少，SOD活性在三种元素共同作用时逐渐下降，在元素单一或两两作用时，SOD活性呈单峰曲线，但总体水平仍较低。土壤Hg,Cd,Pb的这种影响表现出三元素共同作用＞两两元素作用＞单一元素作用。影响的结果造成活性氧产生与清除之间的不平衡，致使相关生理生化过程紊乱。三种重金属对烟草活性氧清除系统的影响表现出明显地协同作用。

Responses of membrane protection enzyme system of tobacco leaves on Hg, Cd and Pb stresses in soil.

Pot experiment was used to study the responses of membrane protection enzyme system of tobacco leaves on Hg, Cd and Pb stresses in soil. The results showed that POD activity gradually increased with increasing concetrations of Hg, Cd and Pb. CAT and SOD activity gradually decreased under three heavy metals common existing and SOD variation curve showed unimodal curve under single or two elements existing with increase of concentration of Hg, Cd and Pb. The effects of Hg, Cd and Pb in soil: three elemets together > two elements together > single element only. The effects resulted in an imbalance--activated oxygen produce and scavenge and physiological biochemical process disorder. There was a synergistic action for the effect of Hg, Cd and Pb in soil on membrane protection enzyme system in tobacco leaves.