外源水杨酸对水曲柳幼苗遭受冷害后抗光氧化能力的影响 I.对抗氧化酶活性的影响

Effects of Exogenous Salicylic Acid on the Ability to Resist Photooxidative Stress in Fraxinus manshurica Seedlings after Chilling Treatment I.Effects of salicylic acid on Activities of Antioxidant Enzymes

在植物遭受冷害后 ,较强的光照能在植物体内引起光氧化胁迫。外源水杨酸(SA)能改变植物叶片内抗氧化酶的活性而影响其抗氧化能力。在冷处理后的光氧化胁迫中 ,外源SA抑制了超氧化物歧化酶活性而增加了超氧阴离子的含量。SA处理提高了过氧化氢酶活性而抑制抗坏血酸过氧化物酶活性 ,从而使H2 O2 含量降低。在整个光氧化过程中 ,SA处理使过氧化物酶和多酚氧化酶活性提高 。

Plants often suffer from photooxidative stress when plants are under strong light in days after they suffer from chilling in night.Exogenous salicylic acid(SA) can alter plants' ability to resist photooxidative stress through its effects on activities of antioxidant enzymes in plants. During photooxidative stress, exogenous SA inhibited superoxide dismutase activity and increased the levels of superoxide anion radicals; SA treatment increased catalase activity and inhibited activity of ascorbic acid peroxidase, and decreased H 2 O 2 levels. In addition, exogenous SA increased peroxidase activity and polyphenol oxidase activity, helpful to scavenge reactive oxygen species.