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% Na Cl stress, which were pretreated with5 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.