湖北海棠5A基因进化与表达分析

Evolution and Expression Analysis of Malus hupehensis eIF-5A Gene

以水杨酸(SA)诱导的湖北海棠双链cDNA为模板,克隆湖北海棠5A基因并对其序列进行比对分析,用邻位法构建进化树;以根、茎、叶等器官的单链cDNA为模板、以半定量及NCBI数据库相关EST分析研究其5A基因的表达特性,以探讨湖北海棠真核生物蛋白翻译起始因子5A基因序列、表达及进化的相关信息。结果表明:(1)湖北海棠5A基因编码框长度为477个核苷酸,编码159个氨基酸,其序列与部分已报道的双子叶植物一致性达91%,与单子叶植物、细菌、古细菌、藻类一致性分别为96%、55%、70%、63%。(2)蛋白的三级结构显示湖北海棠5A蛋白与拟南芥5A蛋白也十分相似;基因进化分析显示湖北海棠5A基因沿着细菌、古细菌、藻类的进化路径,最后与月季聚在同一分枝中。(3)基因表达分析表明,湖北海棠5A基因不仅在根、茎、叶、花、果实、种子等器官中表达,而且在不同的发育时期和各种胁迫条件下表达,具有组成性表达的特点。

eIF-5A （eukaryotic translation initiation factor 5A） was a small protein that had been found in many organism and it related to many aspects progress in living organism. In order to understanding infor- mation about sequence,evolution and expression of eIF-5A gene of Malus hupehensis ,the dscDNA （double strand cDNA） induced by SA （salicylic acid） was used as template for gene PCR cloning. Then gene se- quence was analyzed and its deduced protein was constructed evolutionary tree by NJ （neighbour joining） method. The single strand eDNA of roots, stems, leaves and others tissues were used as template in semi- quantity PCR and the ESTs from NCBI of Malus genus plants for gene expression analysis. The results shown that. （1）the ORF of M. hupehensis eIF-SA was 477 nucleotides and coded 159 amino acids. The i- dentities between M. hupehensis eIF-SA protein and others reported dicots plants was 91%, and it was 96%,55%,70%,63% in monocots,bacteria,archaea and algae,respectively. （2）The tertiary structure of M. hupehensis eIF-SA protein（A） and A. thaliana elF-SA protein also very similar what ensured the gene cloning result. Gene evolution revealed that M. hupehensis elF-SA derived from bacteria,archaea, algae to asmall grope which included R. chinensis eIF-5A. （3）Gene expression indicated that M. hupehensis elF-5A might be a constitutive expression character that not only expressed in different tissue including roots, stems, leaves, inflorescence, fruits, seeds and so on, but also expressed in different development stages and under different stress.