外源水杨酸对盐胁迫下苦菜抗氧化系统的影响

以苦菜为试验材料，研究了5 mmol/L水杨酸（SA）预处理后，苦菜幼苗分别在0.6%、0.8%、1.0%NaCl溶液胁迫下5、10、15、20、25 d时抗氧化系统的变化。研究结果表明，5 mmol/L SA处理提高了盐胁迫下苦菜幼苗细胞SOD、POD的活性，抑制了CAT的活性；在盐胁迫处理后10、15 d，苦菜细胞内脯氨酸和H2O2含量分别达到峰值，并显著高于清水对照，说明SA通过诱导H2O2含量增加，提高抗氧化酶活力，缓解盐胁迫伤害，提高苦菜耐盐性。

Effects of Exogenous Salicylic Acid on Antioxidant System of Sonchus oleraceus L. under Salt Stress Condition

Taking Sonchus oleracers L. as experimental material, we studied the variation of antioxidant system in S. oleracers L. seedlings after 5, 10, 15, 20, 25 days under 0.6%, 0.8%, 1.0% NaCl stress, which were pretreated with 5 mmol/L salicylic acid (SA). The results showed that, 5 mmol/L SA could improve SOD, POD activities and inhibit CAT activity in the cells of S. oleracers L. seedings. After 10, 15 days under salt stress, the contents of proline and H2O2 were the highest in the cells of S. oleracers L. seedlings, and were significantly higher than those of the water control treatment. Because of the increase of H2O2 content induced by SA, the activity of antioxidant enzymes was enhanced and the damage under salt stress was alleviated. Eventually, salt tolerance of S. oleracers L. was improved.