水杨酸对铅胁迫下黄瓜幼苗叶片膜脂过氧化的影响

以黄瓜幼苗为材料,研究了外源水杨酸对铅胁迫下黄瓜幼苗叶片膜脂过氧化的影响。结果表明:水杨酸使铅胁迫的黄瓜幼苗叶片的丙二醛(MDA)含量下降,可溶性蛋白质含量升高,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性降低;在0~1 mmol.L-1范围内的外源SA对铅胁迫的黄瓜幼苗叶片的丙二醛含量下降量和超氧化物歧化酶活性增加量与水杨酸处理浓度呈正相关,与外源水杨酸处理浓度呈正相关,而过氧化物酶活性增加量与外源水杨酸浓度呈负相关。外源水杨酸的作用可能是通过提高黄瓜叶片对膜脂过氧化的抗性来提高黄瓜幼苗对铅毒害的耐受力。

Effects of exogenous salicylic acid on peroxidation of leaf membrane-lipid in cucumber seedlings under lead stress

Using cucumber seedlings as the material,effects of salicylic acid on peroxidation of leaf membrane-lipid under lead stress were studied.The results showed as follow: Content of malonadehyde in leaves under lead stress was decreased and content of soluble proteins was increased,activities of superoxide dismutase and peroxidase decreased by salicylic acid treatment;Within the SA concentration range of 0~1 mmol.L-1,the decrease of malonadehyde and the increase of superoxide dismutase activity in seed-ling leaves were positively correlated with exogenous salicylic acid concentration,but the increase of peroxidase activity were nega-tively correlated with exogenous salicylic acid concentrations under lead stress.Tolerance to lead was increased through improving resistance to the peroxidation of membrane-lipid of seedling leaves by exogenous salicylic acid.