干旱胁迫对构树幼苗抗氧化酶活性变化的影响

以盆栽当年生构树幼苗为实验材料,研究不同程度土壤干旱胁迫下及复水之后构树叶片细胞质膜的伤害程度(相对电导率)、丙二醛(MDA)含量和其酶促抗氧化保护系统(超氧化物歧化酶SOD、过氧化氢酶CAT和过氧化物酶POD)的活性.结果表明:构树幼苗能够适应低度的干旱胁迫,长期的中度和重度干旱胁迫会对构树造成一定的伤害,但复水之后伤害会明显恢复.SOD和POD是构树幼苗抗干旱的重要抗氧化酶,它能够通过自身诱导抗氧化酶系统以提高适应能力而忍受逆境,但构树幼苗的CAT酶在抗干旱胁迫上的作用不明显.

Effects of Drought Stress on Activities of Antioxidant Enzymes in Broussonetia papyrifera L.

Seedlings of one-year-old Broussonetia papyrifera L.were subjected to the drought stress of soil under different moisture conditions.The injury degree of cell plasma membrane and the correlative enzyme activity of plasma-membre protection system in the leaves of the seedlings were studied.Their relative conductivity,MDA content and activities of superoxide dismutase,catalase and peroxidase were measured.The results showed that seedlings of Broussonetia papyrifera L.were well adapted to low drought stress.Medium and heavy drought for a long period did some harm to them,but after rewatering they could recover obviously.SOD and POD were important antioxidant enzymes for resisting drought in seedlings of Broussonetia papyrifera L.,which can effectively avoid the iniury of oxidative stress for the trees through inducing the plasma-membre protection system.But the function of CAT to resist drought was not obvious.