小麦非生物胁迫相关基因TaAIM的表达分析

Expression Analysis of Abiotic Stress Related Gene TaAIM in Wheat

MYB转录因子是一个在植物的应激反应中起着核心作用的蛋白质家族。为了进一步研究小麦非生物胁迫诱导转录因子的表达特性,利用同源克隆的方法从小麦中获得了1个R2R3-MYB转录因子基因TaAIM,采用生物信息学方法对TaAIM的序列进行分析,采用半定量RT-PCR方法研究TaAIM在不同组织以及不同非生物逆境胁迫条件下的表达。序列分析表明,TaAIM的全长cDNA序列为1 509 bp,开放阅读框为960 bp,编码319个氨基酸,蛋白质预测分子量约为35.207 kD,等电点为4.8,预测其蛋白质二级结构包含12个α-螺旋。系统进化树分析表明,TaAIM与二穗短柄草中的1个R2R3-MYB转录因子有较高的相似性。序列多重比对表明,TaAIM与其同源蛋白序列的MYB结构域均高度保守。半定量RT-PCR分析表明,TaAIM在小麦各个组织中均表达,在根和叶中的表达量较为明显;在盐、PEG、ABA和低温处理后均能够诱导TaAIM表达。这些结果表明,TaAIM基因参与了小麦对非生物胁迫的响应,可为进一步研究TaAIM的生物学功能提供理论基础。

MYB transcription factors are a family of proteins that plays central roles in the stress response in plants.In order to explore the expression characteristics of transcription factors induced by abiotic stress in wheat, TaAIM gene of R2R3-MYB transcription factor was obtained from wheat by homologous cloning, bioinformatics methods were used to analyze the TaAIM sequence. The expression of TaAIM genes in different tissues and in different abiotic stress conditions of wheat was analyzed by semi-quantitative RT-PCR. Sequence analysis indicated that TaAIM is 1 509 bp in full length with a 960 bp ORF, encoding 319 amino acids with a predicted molecular mass of 35.207 kD and a basic isoelectric point of 4.8. The protein secondary structure was predicted to contain 12 alpha-helices. Phylogenetic analysis showed that TaAIM had a high similarity to a R2R3-MYB transcription factor in Brachypodium distachyon. Multiple sequences alignment showed that the MYB domain of TaAIM and its homologous protein sequences were highly conserved. Semi-quantitative RT-PCR analysis indicated that TaAIM was expressed in all tissues of wheat. Moreover, it was expressed obviously in roots and leaves. TaAIM expression can be induced after salt, PEG, ABA, and low temperature treatment. These results indicate that the TaAIM gene was involved in response to the abiotic stress, which laid a foundation for further study of the biological function of TaAIM.