水杨酸对黄瓜幼苗光氧化胁迫的缓解效应

Mitigative effect of salicylic acid on photooxidative stress in cucumber seedling

在黄瓜幼苗四叶期分别喷施浓度为0,50,100和200μmol/L的水杨酸溶液,1d后,各处理同时涂抹500μmol/L的甲基紫精溶液,4h后测定黄瓜幼苗叶片的生理生化指标,以探讨水杨酸对黄瓜幼苗光氧化胁迫伤害的缓解效应。结果表明,不同浓度的水杨酸溶液对黄瓜幼苗叶片在光氧化胁迫下遭受的伤害有不同程度的缓解作用,可使相对电导率降低19.11%～38.03%,SOD活性增加8.06%～19.32%,丙二醛含量下降11.22%～26.07%,且以100μmol/L的水杨酸溶液效果最佳。

Cucumber seedling with four leaves were sprayed with 0,50,100 and 200 μmol/L Salicylic acid (SA) solutions,they were smeared by 500 μmol/L methyl viologen (MV) solution after 1 d,the physiological and biochemical targets of leaves in the cucumber seedlings were determined after 4 h.The results showed that:SA solutions of different concentrations could to different extent mitigate the injury cucumber seedlings suffered under photooxidative stress,reduce the relative electrical conductivity from 19.11% to 38.03% and the content of malondialdehyde (MDA) from 11.22% to 26.07%,increase SOD activity from 8.06% to 19.32%;and the SA solution with the best mitigative effect was the SA solution of 100 μmol/L.