无芒隐子草CsPEAMT基因克隆及表达特性分析

以无芒隐子草(Cleistogenes songorica)干旱胁迫下的cDNA文库中磷酸乙醇胺N-甲基转移酶(phosphoethanolamine N-methyltransferase,PEAMT)基因的EST序列为基础,采用RACE方法克隆该基因编码区序列,该序列全长为2 104bp,开放读码框1 506bp,编码501个氨基酸。无芒隐子草PEAMT蛋白编码的氨基酸序列与多种植物的PEAMT氨基酸序列有较高相似性,其中与高粱SbPEAMT、玉米ZmPEAMT的蛋白序列相似性最高(93%),说明PEAMT基因在植物进化中非常保守。采用实时定量RT-PCR分析无芒隐子草幼苗在干旱过程中CsPEAMT基因的表达结果显示,干旱胁迫诱导CsPEAMT基因在根和叶中大量表达,且在干旱第8天时CsPEAMT基因在叶和根中表达量分别是未干旱对照的43.35倍和13.25倍,复水后CsPEAMT基因的表达量开始下调。研究表明CsPEAMT基因可能是无芒隐子草抗旱性相关的基因。

Clone and Expression Characterization of CsPEAMT Gene in Cleistogenes songorica

Based on the highly homologous EST sequence of phosphoethanolamine N-methyltransferase(PEAMT) gene obtained from drought-induced cDNA library of Cleistogenes songorica,a full-length cDNA of PEAMT gene was isolated from C.songorica.Full length of CsPEAMT was 2 104 bp,containing a 1 506 bp ORF and encoding 501 amino acids.Comparative analyses revealed that the amino acid sequence encoded by CsPEAMT gene was highly homologous to PEAMTs from other plant species,and CsPEAMT had the highest similarity with that of Sorghum bicolor and Zea mays(93%).The expression patterns of CsPEAMT during drought stress were investigated by real-time quantitative RT-PCR analysis.The results showed that drought stress induced a large number of the gene expression in root and leaf.And the CsPEAMT expression level in leaf and root are 43.35 times and 13.25 times higher than that of control,respectively,then the expression level began to decrease afer rewatering.This study indicated that CsPEAMT may be a drought-related gene.