低温对不同抗冷性玉米幼苗H_2O_2及其清除酶类的影响

在低温时,抗冷性不同的两个玉米品种的 H_2O_2含量升高,过氧化氢酶,过氧化物酶活性下降,同工酶数增加,且前三个指标的变化都是不抗冷品种大于抗冷品种,这说明,这三个指标可以作为玉米幼苗抗冷性的指标。从试验结果可知,低温处理到第四天 H_2O_2含量、过氧化氢酶活性又恢复到对照水平;并在低温胁迫时,如上指标的变化幅度苗期要大于芽期。这说明,玉米幼苗对低温胁迫具有适应力,其冷害敏感性苗期大于芽期。低温胁迫时,两品种过氧化物同工酶数都有增加,且只发生在特定的区带,这个结果支持这样的观点即植物抗冷性只与同工酶的一定类型有关。

THE EFFECT OF LOW TEMPERATURE ON H_2O_2 AND ITS CLEARANEC ENZYMES IN MAIZE SEEKLINGS WITH DEFFERENT CHILLING RESISTANCE

In chilling,the content of H_2O_2 increased,the activity of CAT.POD decreased,the unmber of POD isoenzymes increased in two maize varieties.The changes of three index in low resistance variety was greater than those in high resistantce variety.This indicated that the three index could be used for index of chilling—resistance in maize seedling.In fourth day after treatment,the content of H_2O_2 activity of CAT reversed to check level and changed amount of three index inseedling stage was greater than that in bud stage When chiniling.This indicate that maize seedling has adaptdbility to chilling.The chilling sensitive of maize seedling was greater than its bud stage.The number of POD isoenzymes in two varieties increased and this changeha—ppened in special zone.This rdsult suport this view that chilling—resistance of plant only correlated with special type of isoenzymes.