木薯MePIL1基因克隆与表达分析

Clone and Expression Analysis of MePIL1 in Cassava

旨在克隆木薯Me PIL1基因,揭示其在木薯遮荫等非生物逆境胁迫中的作用。用RT-PCR的方法从木薯栽培种Ku50叶片中克隆Me PIL1基因,对其进行序列比对和系统进化树分析,研究其在木薯野生种和栽培种之间的结构变异,并应用荧光定量PCR技术分析其表达特性。结果显示,克隆获得木薯Me PIL1基因,该基因具有一个1 578 bp的开放阅读框,编码525个氨基酸,含有一个HLH保守结构域。系统进化树分析表明,Me PIL1与其在杨树和杞柳中的同源基因聚在一起,亲缘关系较近。基因结构变异分析显示,Me PIL1在HLH结构域非常保守,其结构变异主要来自于栽培种与野生种之间的差异,且整体上分布比较均匀。表达分析结果显示,Me PIL1在叶片中高表达,而且其表达量受到遮荫和渗透胁迫的诱导。结果表明,成功克隆了木薯Me PIL1基因,并且Me PIL1在转录水平参与木薯对遮荫和渗透胁迫的应答。

This work aims to clone Me PIL1 gene from cassava and to reveal its functional roles in abiotic stresses（e.g.,shade）,whichwill provide theoretical bases for optimizing the planting density of cassava. Me PIL1 gene was cloned from leaf of cassava cultivar ‘Ku50＇by RT-PCR method,and the sequences of Me PIL1 and its homology genes with other species were aligned and their phylogenetic tree wasconstructed. Subsequently,structural variations of Me PIL1 were revealed between wild and cultivated cassava,and their expression patternswere investigated by quantitative RT-PCR. Results showed that Me PIL1,which had a 1 578 bp open reading frame and encoded 525 aminoacids and contained a HLH conserved domain,was cloned from cassava. Phylogenetic analysis showed that Me PIL1 and homologous genes fromPopulus trichocarpa and Salix purpurea were clustered together,indicating that they had close genetic relationships. Analysis of gene structuralvariation revealed that the region of HLH domain was highly conserved,while most variations were derived from the differences between thewild and cultivated cassava species,and the distribution overall was relatively even. Expression pattern analysis showed that Me PIL1 was highlyexpressed in leaf,and its expression was induced by osmotic stress and shade treatments. In conclusion,Me PIL1 of cassava was successfullycloned and it was involved in the responses to shade and osmotic stresses at the transcriptional level in cassava.