Effects of ABA on Soda Saline-alkali Osmotic Regulation and Oxidative Damage of Alfalfa Seedlings

Purpose To explore the effects of different concentrations of ABA on the physiological effects of alfalfa seedlings under soda saline-alkali stress.

Method The seedlings cultured with WL343HQ alfalfa seeds were treated with 150 mmol/L soda saline-alkali stress and ABA alleviation at different concentrations. The physiological and biochemical changes of leaves of seedlings alleviated by ABA were determined. The alleviation effect of ABA was comprehensively analyzed by membership function method.

Result After spraying ABA on alfalfa seedlings under saline-alkali stress, the contents of soluble sugar, betaine, proline, soluble protein and the activities of POD, PAL, CAT and AXP in alfalfa leaves increased firstly and then decreased with the increase of ABA concentration. The four osmotic regulating substances and four antioxidant enzymes activities reached their maximum at ABA concentration of 50 or 100 μmol/L.

Conclusion According to the comprehensive analysis of membership function value, it could alleviate the soda saline-alkali stress when the concentration of ABA was 25-100 μmol/L. But when ABA concentration was 50-75 μmol/L it has the best mitigation effect on soda salt damage.