不同倍性菘蓝对干旱胁迫的耐受能力及保护性酶的响应机制

Tolerant Capacity of Drought Stress and Response Mechanism of Protective Enzyme of Different Ploidy Isatis indigotica

为了比较不同倍性菘蓝对干旱胁迫的耐受能力及其体内保护性酶的响应机制,在MS培养基中加入不同浓度的甘露醇模拟干旱胁迫处理,观测不同倍性菘蓝种子的萌发和幼苗生长状况,测定幼苗中丙二醛及脯氨酸含量,同时对其地上部分保护性酶SOD、POD和CAT进行测定。种子萌发、幼苗生长以及丙二醛和脯氨酸含量的测定结果均表明,四倍体菘蓝较二倍体菘蓝对干旱胁迫的耐受能力强。对其体内保护性酶的研究结果表明,随着甘露醇浓度的增加二倍体和四倍体菘蓝中SOD、POD和CAT三种保护性酶均呈现先增加后降低的趋势,各甘露醇浓度下四倍体中的SOD、POD和CAT三种保护性酶活性均高于二倍体,说明在干旱胁迫下四倍体菘蓝对活性氧的清除能力高于二倍体菘蓝,部分解释了四倍体菘蓝较二倍体菘蓝对干旱胁迫的耐受能力强。

To compare tolerant capacity to drought stress of Isatis indigotica with different ploidy and response mechanism of protective enzyme in vivo,different concentration mannitol was added into MS medium to imitate salt stress.For diploid and tetraploid of Isatis indigotica,germination of seed and seeding growth condition were investigated,and malondialdehyde,proline contents in seedling and protective enzyme in overground part including SOD,POD and CAT were measured.The results showed that tolerant stress of tetraploid of Isatis indigotica was better than that of diploid by germination,seedling growth and malondialdehyde and proline contents.The results showed that SOD,POD and CAT activities of tetraploid and diploid appeared the trend of increase-decrease with increase of concentration of mannitol by protective enzyme.SOD,POD and CAT activities of tetraploid were higher than those of diploid under different concentrations of mannitol.The results mentioned above showed that the ability of removing active oxygen for tetraploid was higher than that of diploid under salt stress,which can partly explain that toleranct ability to salt stress of tetraploid was higher that of diploid.