外源5-氨基乙酰丙酸对盐胁迫下决明幼苗生理特性的影响

Effects of ALA on physiological characteristics of Cassia obtusifolia seedlings under salt stress

为寻找提升决明幼苗耐盐性的方法,测量了不同处理下决明幼苗叶片的光合色素、超氧阴离子、丙二醛的含量,以及保护酶系统中SOD、POD、CAT的活性。结果表明,经150mmol·L-1NaCl处理,决明幼苗叶片的光合色素含量显著降低,而超氧阴离子、丙二醛的含量以及保护酶SOD、POD、CAT的活性显著升高。不同浓度的外源5-氨基乙酰丙酸在不同程度上增加了决明幼苗叶片的叶绿素、类胡萝卜素含量,进一步增强了保护酶SOD、POD、CAT的活性,降低了超氧阴离子、丙二醛的含量。在外源5-氨基乙酰丙酸浓度为50mg·L-1时,恢复效果最为明显(80.0、196.4和114.1U·g-1),有效地缓解了盐胁迫对决明幼苗的伤害。

In order to get the method to improve the salt resistance of seedlings for Cassia obtusifolia under salt stress,physiological characteristics of C. obtusifolia seedlings were studied. Several physiological indexes of C. ob- tusifolia seedlings under salt stress like photosynthetic pigment, superoxide anion（O2 ）, malondialdehyde（MDA）, superoxide（SOD）, peroxidase（POD） and catalase（CAT ） were measured. The rate of decrease was re- lieved and the content of O2 ,MDA decreased. The activities of three enzymes including SOD, POD and CAT were increased by the treatment of ALA,and reached the maximin（80.0 U·g^-1 ,196.4 U·g^-1and 114.1 U·g^-1 respectively）with the concentration of 50 mg·g^-1. ALA with concentration of 50 mg·L^-1 could significantly alleviate the damages to the seedlings of C. obtusifolia under salt stress, and promote the salt resistance of the seedlings.