Cloning and Phylogenetic Analysis of Ubiquitinconjugating Enzyme Gene TaUBC4 in Different Wheat Cultivars

不同品种小麦泛素结合酶TaUBC4基因的克隆及进化分析(英文)

[Objective] This study aimed to clone ubiquitin-conjugating enzyme gene TaUBC4 from different wheat cultivars and thus analyze their phylogenetic relationship.[Method] The UBC4 coding sequences were cloned through reverse transcription PCR （RT-PCR） from 21 wheat varieties.After sequencing,the UBC4 sequence in wheat cultivar Zhongguochun （GenBank accession No：M28059） was selected as the reference gene,to analyze the mutation frequency and evolutionary distance in the CDSs and corresponding amino acid sequences of the different wheat cultivars.Moreover,the phylogenetic tree based on the amino acid sequences of these TaUBC4 genes were constructed,involving the homologous sequences of TaUBC4 in eight other monocots.[Result] TaUBC4 sequence was highly conserved because the similarity in DNA sequences of the wheat varieties was over 94％,while that in amino acid sequence was over 96％.And the amino acid sequence difference only can be seen at two sites among some varieties.Phylogenetic tree constructed revealed the evolutionary relationships among these wheat varieties.[Conclusion] This study reveals the polymorphism and evolutionary characteristics in the nucleotide and amino acid sequences in different wheat varieties,which lays foundation for investigating the evolution and biological function of TaUBC4 gene.In addition,the phylogenetic tree constructed provides theoretical references for the classification of the wheat varieties with complicated background.

[目的]分析不同品种小麦泛素结合酶TaUBC4基因序列及进化特点。[方法]通过反转录PCR(Reverse transcription PCR,RTPCR)方法克隆了21个小麦品种的TaUBC4编码序列(Coding Sequence,CDS),测序后以中国春的UBC4(GenBank登录号:M28059)序列为参照,对各品种小麦基因的CDS及其编码的氨基酸序列进行了不同位点的突变频率及品种间的进化距离的分析;同时参考其他8种单子叶植物中与小麦UBC4同源的氨基酸序列构建了系统进化发育树。[结果]TaUBC4序列高度保守(DNA序列的相似度>94%,氨基酸序列相似度>96%),部分品种仅存在两个氨基酸的差异。系统发育树的构建揭示了各小麦品种间的进化关系。[结论]该研究揭示了不同品种间小麦TaUBC4基因序列及其氨基酸位点的多态性和进化特点,为深入研究小麦TaUBC4基因的进化及生物学功能奠定良好的基础,同时系统进化发育树的构建为复杂来源小麦品种的分类提供依据。