高温对玉米幼苗膜脂过氧化作用的影响

EFFECT OF HIGH TEMPERATURE ON MEMBRANE LIPID PEROXIDATION IN LEAVES OF MAIZE SEEDLING

以玉米为研究对象,人为模拟高温,以质膜相对透性、丙二醛(MDA)含量、可溶性蛋白质含量、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性和过氧化物酶(POD)活性为主要测定指标,研究了高温对玉米幼苗保护酶活性及膜脂过氧化作用的影响.结果表明,玉米幼苗经过38℃高温处理24h后,POD活性增强,SOD、CAT活性先升后降.O-2的产生速率增加.同时,高温处理后的玉米幼苗叶片MDA含量、膜透性增加,幼苗的膜系统受到明显的伤害.由此认为,高温协迫后,活性氧积累以及由此引发的膜脂过氧化作用是玉米幼苗高温伤害的原因之一.

The effect of high temperature on the maize seedlings was studied in the laboratory. The results showed that the activities of SOD and CAT decreased and POD increased under 38 ℃ high temperature stress after 24 h; generation of activated oxygen O-_2 increased. And in the meantime the MDA contents and relative plasmalemma permeability increased under high temperature stress in maize leaves. It indicated that the membrane systems had been damaged. According to these results, it is thought that the accumulation of active oxygen by initiation of membrane lipid peroxidation may be a cause to the injury of high temperature stress to maize seedlings.