低温胁迫对巨尾桉幼苗膜脂过氧化及保护酶的影响

Effects of low temperature stress on membrane lipid peroxidation and cell defense enzyme activity in leaves of E.grandis×E.urophylla seedlings

以木本植物巨尾桉幼苗为材料 ,研究低温胁迫对巨尾桉膜脂过氧化及保护酶的影响 ,测定了幼苗叶片的O 2(超氧阴离子 )产生速率、H2 O2 、(过氧化氢 )、MDA(丙二醛 )含量、相对电导率和SOD(超氧化物歧化酶 )、POD(过氧化物酶 )、CAT(过氧化氢酶 )、APX(抗坏血酸过氧化物酶 )活性。结果表明 :低温胁迫使叶片O 2 产生速率、H2 O2 、MDA含量和相对电导率增加 ,但抗寒锻炼植株的增幅远小于对照 ;抗寒锻炼植株的SOD、POD、CAT和APX活性均低于对照。

E.grandis×E.urophylla seedlings were used as materials,and effects of low temperature stress on membrane lipid peroxidation and cell defense enzyme in leaves were studied. O~~_2 production rate,contents of H_2O_2 and amlondialdehyde (MDA),relative conductance ratio,and activity of superoxide dismutase(SOD),peroxidase (POD),catalase (CAT) and ascrobate peroxidase (APX) were determined. The results showed that the rate of O~~_2 production,the contents of H_2O_2,and amlondialdehyde (MDA) and the relative conductivity rate were increased under low temperature stress,but the extent of raise on cold pretreated seedlings were lower than that of unpretreated. Activity of SOD,POD,CAT and APX on cold pretreated seedlings were lower than that of unpretreated.