摘要
在植物的抗光氧化过程中除了抗氧化酶起作用外,抗氧化剂也起着重要作用。在植物所有抗氧化剂中,抗坏血酸(AsA)和谷胱甘肽(GSH)最重要。外源水杨酸(SA)处理水曲柳(Fraxinusmanshurica)幼苗叶片,同时增加了AsA和脱氢抗坏血酸(DHA)的含量,使叶片中总抗坏血酸含量增加,这有利于水曲柳叶片抵抗光氧化胁迫。外源SA处理却使GSH含量降低,从而GSH在总谷胱甘肽中的比例降低。由于外源SA处理增加了过氧化氢酶(CAT)活性,从而使叶片中H2O2含量降低。众多因素的影响使叶片中丙二醛(MDA)含量降低,表明了外源SA处理使膜脂过氧化降低,保护了叶片不受光氧化胁迫的伤害。
Besides antioxidant enzymes, antioxidants play very important roles when plants resist photooxidative stress. Of all antioxidants in plants, ascorbic acid(AsA )and reduced glutathione(GSH) are more important. AsA and DHA levels in leaves of Fraxinus manshurica seedlings which had been treated with exogenous salicylic acid(SA ) increased during photooxidative stress, thus total ascorbate levels also increased.This showed that the increases were helpful to leaves under photooxidative stress. GSH levels in leaves which had been treated with exogenous SA decreased, and induced decreases of the GSH∶GSSG ratios.H2O2 levels in leaves treated with exogenous SA decreased because of increases of catalase activities. The decreases of malonaldehyde levels in leaves treated with exogenous SA showed the decreases of peroxidation of membrane lipids, suggesting exogenous SA protest leaves of Fraxinus manshurica seedlings from damage induced by photooxidation stress.
出处
《湖北农学院学报》
2003年第1期8-13,共6页
Journal of Hubei Agricultural College
基金
国家九五科技攻关资助项目(96-011-02-07)
