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.
出处
《草业学报》
CSCD
北大核心
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
