脱落酸预处理对低温胁迫下萝卜幼苗的缓解效应

以‘阳春早秀’萝卜幼苗为试材,通过叶面喷施不同质量浓度的脱落酸(ABA)(0,5,10,15,20 mg.L-1),在找出适宜质量浓度的基础上,进一步探讨了外源ABA对低温胁迫下萝卜幼苗的缓解效应.结果表明,ABA预处理能不同程度地提高萝卜幼苗叶片可溶性糖和脯氨酸(Pro)含量,降低其电解质渗漏率,以15 mg.L-1效果最明显.同一质量浓度ABA(15 mg.L-1)预处理幼苗后,随低温时间延长,可溶性糖和脯氨酸含量逐渐升高,抗氧化酶活性也显著高于同期对照,而丙二醛(MDA)含量显著低于同期对照.以上结果表明,适当质量浓度的外源ABA可通过增加渗透调节物质含量和提高抗氧化酶活性来提高萝卜幼苗对低温胁迫的抗性.

Alleviating effect of abscisic acid on radish seedlings under low temperature stress

Alleviating effect of exogenous ABA on low temperature stress was further elucidated on the basis of finding suitable ABA mass concentration in radish seedlings,by foliar-spraying with different mass concentration ABA(0,5,10,15 and 20 mg·L-1),taking the seedlings of radish ’Yang Chun Zao Xiu’ as test materials.The results showed that the pretreatment with 5,10,15 and 20 mg·L-1 could enhance the contents of soluble sugar and proline,and reduce the electrolyte leakage.And the ABA mass concentration with the best effect was 15 mg·L-1.After pretreatment with the same mass concentration ABA(15 mg·L-1) the contents of soluble sugar and proline were up-regulated as the time extended and the activities of the antioxidant enzyme were also significantly higher than those in the control at the same time.However,the content of MDA was significantly lower than those in those control at the same time.These results indicate that the injuries caused by low temperature stress are mitigated by exogenous appropriate mass concentration ABA in radish seedlings.