海滨雀稗PvSAMS1基因及外源SAM调控耐盐的生理机制  

Physiological mechanism of PvSAMS1 and exogenous SAM regulating salt tolerance in seashore paspalum

作　　者：李炎朋 刘宇 郑钰莹 刘君 杨志民 李志华 张明 陈煜 LI Yanpeng;LIU Yu;ZHENG Yuying;LIU Jun;YANG Zhimin;LI Zhihua;ZHANG Ming;CHEN Yu(College of Agro-grassland Science,Nanjing Agricultural University,Nanjing 210095,China;Meipu Lawn Planting Professional Cooperative,Zhouji Town of Shuyang County,Shuyang 223600,China)

机构地区：[1]南京农业大学草业学院,江苏南京210095 [2]沭阳县周集乡美濮草坪种植专业合作社,江苏沭阳223600

出　　处：《南京农业大学学报》2022年第2期304-314,共11页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(31872953,31672193);江苏省科技厅苏北科技专项(SZ-SQ202068)。

摘　　要：[目的]本文旨在探究海滨雀稗S-腺苷甲硫氨酸(SAM)合成途径与耐盐性的关系,为解析海滨雀稗的耐盐机制奠定基础,同时为基于SAM途径的植物耐盐育种提供优异基因资源。[方法]克隆了海滨雀稗PvSAMS1(Paspalum vaginatum S-adenosylmethionine synthetase 1)基因并异源转化野生型拟南芥,分析其耐盐表型及生理指标;通过外源SAM处理野生型海滨雀稗,检测NaCl胁迫下的表型差异和离子含量。[结果]NaCl胁迫下,PvSAMS1基因过表达拟南芥株系表现出更好的生长和较低的电解质渗漏率,其相对含水量、SAM含量、K^(+)含量、抗氧化酶活性均显著高于野生型拟南芥,而Na^(+)含量显著低于野生型拟南芥;外源添加0.5 mmol·L^(-1)SAM能显著缓解海滨雀稗在NaCl胁迫下的伤害,表现出更高的叶片含水量和较低的电解质渗漏率,同时能抑制Na^(+)积累和促进K^(+)吸收,其中在500 mmol·L^(-1)NaCl处理下,Na^(+)在叶片和根部的抑制率分别达到11.6%和22.5%,K^(+)在叶片和根部的增加率分别达到39%和14.5%。[结论]PvSAMS1能显著促进SAM合成,调控NaCl胁迫下的离子平衡和增强抗氧化酶活性,进而提高植物耐盐性。[Objectives]This study was aimed to explore the relationship between the synthetic pathway of seashore paspalum S-adenosylmethionine(SAM)and salt tolerance,to lay a foundation for the analysis of the salt tolerance mechanism in seashore paspalum and to provide excellent genetic resources for plant salt tolerance breeding on basis of SAM pathway.[Methods]Seashore paspalum PvSAMS1(Paspalum vaginatum S-adenosylmethionine synthetase 1)gene was seperated and heterologously transformed into Arabidopsis.The salt-tolerant phenotypes were observed and physiological indicators were detected.Then,seashore paspalum was treated with exogenous SAM and the phenotypic differences and ion content under NaCl stress were measured.[Results]Under NaCl stress,PvSAMS1 overexpressing Arabidopsis lines showed better growth and lower electrolyte leakage rate,with their relative water content,SAM content,K^(+) content,and antioxidant enzymes activity significantly higher than those of wild-type Arabidopsis,while their Na^(+) content significantly lower than the wild-type Arabidopsis.The addition of 0.5 mmol·L^(-1) SAM could significantly alleviate the damage of seashore paspalum under NaCl stress,showing higher leaf water content and lower electrolyte leakage rate,inhibiting Na^(+) accumulation and promoting K^(+) absorption.Under the treatment of 500 mmol·L^(-1) NaCl concentration,the inhibition rates of Na^(+) in leaves and roots were 11.6%and 22.5%respectively,and the increase rates of K^(+) in leaves and roots were 39%and 14.5%respectively.[Conclusions]PvSAMS1 could improve plant salt tolerance by significantly promoting SAM synthesis,regulating ion balance and enhancing antioxidant enzyme activity under NaCl stress.

关 键 词：S-腺苷甲硫氨酸合成酶 拟南芥 海滨雀稗 耐盐性 

分 类 号：S688.4[农业科学—观赏园艺]