干旱-低温交叉逆境下小麦活性氧清除系统的变化与交叉适应的关系

采用人工气候箱砂培的方法研究了干旱、低温交叉逆境下2个小麦品种活性氧清除系统的变化与交叉适应的关系.结果表明,经单一逆境(干旱或低温)处理后超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和还原型谷胱甘肽(GSH)含量降低,过氧化物酶(POD)活性和抗坏血酸(AsA)含量有所升高,但总体表现出活性氧清除系统功能降低,质膜相对透性增大(膜系统受损).经2种逆境交叉处理后,保护酶活性及抗氧化剂含量均明显增高,质膜相对透性降低至接近正常水平.表明小麦幼苗对干旱和低温逆境存在着明显的交叉适应现象,经一种逆境处理后可提高对另一逆境的抗性.外施脱落酸(ABA)处理同样也能明显提高逆境下小麦活性氧清除系统的功能,增强对干旱和低温逆境的抗性.这些现象表明植物对不同逆境的适应存在着某些共同的生理基础,而这些生理基础与ABA有关.

Relationships between changes of active oxygen scavenging system of wheat under drought and chilling cross-stress and cross-adaptation

Relationships between changes of the active oxygen scavenging system of wheat seedlings under drought and chilling cross-stress and cross-adaptation was studied with sand culture in artificial illumination incubator.The result showed that the activity of SOD,CAT and content of GSH reduced and the POD activity and AsA content increased under one stress(drought or chilling),but in general,the function of active oxygen scavenging system decreased and the relative permeability of plasma membrane increased(membrane system was injured).Under drought and chilling cross-stress(drought chilling or chilling drought), the activity of SOD,CAT,POD and content of GSH and AsA increased obviously, and the relative permeability of plasma membrane reduced and approached normal level(control experiment level).It showed that the 2 wheat were possessed of cross adaptation for drought and chilling,and pretreatment of one stress can increase resistance to another stress.Exogenous abscisic acid(ABA) pretreatment gave rise to increasing the function of active oxygen scavenging system in the wheat under drought and chilling stress and enhancing resistance.The results showed that there was some common physiological metabolism under different stresses,while the physiological metabolism had a direct interrelationship with ABA.