Effects of Exogenous ABA on Physiological Characteristics of Tomato Seedlings under Salt Stress

[Objective] The objective of this study was to investigate the effects of exogenous ABA on physiological characteristics of tomato seedlings under salt stress.[Method] 100 mmol/L NaCl was used to produce the salt pressure.The effects on oxidative damage to leaves and protective enzyme activities of tomato seedlings under different concentration of ABA were investigated.[Result]The damage to tomato seedlings caused by the salt stress of 100 mmol/L NaCl was significantly reduced in the presence of 0.05 mmol/L ABA.Specifically,MDA content in leaves and the level of cell membrane permeability were decreased by 34.01% and 42.42 %,respectively.The enzyme activities of SOD,POD and CAT in leaves were increased by 30.99 %,45.69 % and 30.29 %,respectively.When treated with lower concentration(0.01 mmol/L)and higher concentration(0.10,0.15 mmol/L)of ABA,the alleviating effects were reduced obviously entirety.[Conclusion] Under salt stress,0.05 mmol/L ABA significantly alleviated the oxidative damage to leaves and enhanced the protective enzyme activities of tomato seedlings.Thereby,the salt-resistance capacity of seedlings was enhanced.There was a concentration effect of ABA.