水杨酸和脱落酸对强光所致小麦叶片氧化损伤的防护效应

Protective Effects of Exogenous Salicylic Acid and Abscisic Acid Against Oxidative Damage to Wheat Leaves Caused by High Irradiance

为了给人工调控植物的光合作用提供试验依据,研究了外源SA(水杨酸)和ABA(脱落酸)对小麦叶片强光所致氧化损伤的防护效应及对光合作用的影响。结果表明,以适宜浓度的SA和ABA预先处理小麦叶片,可有效防护强光所致的氧化损伤,维持较高的SOD和APX活性,减少H2O2的积累,抑制脂质过氧化作用,使叶片在光抑制条件下,维持较高的Fm/Fo、Fv/Fm、ΦPS、qP、Pn和较低的qN。其中以较低浓度的SA(50mg·kg-1)和中等浓度的ABA(100mg·kg-1)效果较好。

In order to look for the measures to protect photosynthetic apparatus against damage to wheat leaves resulted from high irradiance, the influence of exogenous salicylic acid (SA) and abscisic acid (ABA) on active oxygen metabolism and photosynthesis in wheat leaves were studied. The results indicated that pretreatment with salicylic acid and abscisic acid in proper concentration could effectively protect wheat leaves from oxidative damage caused by high irradiance. Therefore, higher activity of SOD and APX and lower content of H_2O_2 and MDA in wheat leaves were maintained under the condition of photoinhibition. As a result, the increases in Fm/Fo, Fv/Fm, Φ_ PSⅡ, qP, Pn and the decrease in qN were observed under high irradiance stress. Comparatively, lower concentration of SA (50 mg·kg -1) and middle concentration of ABA(100 mg·kg -1) were most efficient.