无芒隐子草SAMS1基因的克隆及干旱胁迫下的表达分析  

Cloning of a S-adenosyl methionine synthetase gene from Cleistogenes songorica and its expression under drought stress

作　　者：孔令芳[1] 张吉宇[1] 刘志鹏[1] 王彦荣[1] 

机构地区：[1]兰州大学草地农业科技学院草地农业生态系统国家重点实验室农业部草地农业生态系统学重点开放实验室,甘肃兰州730020

出　　处：《草业学报》2013年第1期268-275,共8页Acta Prataculturae Sinica

基　　金：国家"973"(2007CB108904);科技部国际科技合作重点项目(2004DFA02000);国家科技支撑计划项目(2008BADB3B03);甘肃省基金(1010RJZA105);国家自然科学基金(31072072;30800593和31101759)资助

摘　　要：以无芒隐子草干旱诱导的cDNA文库中获得的一个与S-腺苷甲硫氨酸合成酶(SAMS)基因同源性较高的EST序列为基础,采用RT-PCR技术克隆该基因全长序列(命名为CsSAMS1),该序列全长1 399bp,编码397个氨基酸,具有SAMS基因的典型结构特征。无芒隐子草SAMS1蛋白为亲水性蛋白,无跨膜结构域,其空间结构主要由α-螺旋和无规则卷曲结构构成。与近缘植物SAMS的氨基酸序列多重比较分析表明,不同植物的SAMS的氨基酸相似程度非常高(92%～100%),其中无芒隐子草与水稻的相似性最高(99%),说明SAMS基因在植物进化中非常保守。CsSAMS1基因在无芒隐子草幼苗干旱过程中的半定量和实时定量RT-PCR表达模式分析均表明,干旱胁迫诱导该基因在根中大量表达,叶中表达量变化不明显。CsSAMS1基因受干旱胁迫的诱导表达,为进一步探讨其应用于草类作物抗旱性的遗传改良奠定了基础。To identify more genes for the improvement of drought-tolerance in plants,Cleistogenes songorica was used to investigate differential gene expression under drought stress.A full-length cDNA of the S-adenosyl methionine synthetase（SAMS） gene was isolated from C.songorica.It was named CsSAMS1 and was 1 399 bp in length and encoded 397 amino acids with the three typical domains of SAMS.The CsSAMS1 protein was a hydrophilic protein with no transmembrane domain but with an α-helix spatial structure constituting a random coil.Multiple alignment analysis based on amino acids of SAMS genes from kindred plants indicated that SAMS was very conserved between different species with 92%-99% similarity in amino acid level.CsSAMS1 had the highest similarity with that of Oryza sativa（99%）.The expression patterns of CsSAMS1 under drought were investigated by semi-quantitative and real-time quantitative RT-PCR analysis.The results showed that drought stress induced a large amount of gene expression in roots,but there was no significant change in leaves.The CsSAMS1 gene was induced by drought stress,and it is a basis for further study on genetic improvement of grass drought resistance.

关 键 词：无芒隐子草 SAMS 基因克隆 定量分析 生物信息学 

分 类 号：S688.4[农业科学—观赏园艺] S543.9[农业科学—园艺学]