植物盐超敏感基因(SOS1)的演化分析与选择压力检测

Phylogenetic Analysis and Detection of Selective Pressure on Plant Salt Overly Sensitive Genes

以植物盐超敏感基因(Salt Overly Sensitive 1,SOS1)为研究对象,通过探讨SOS1基因在演化过程中所受到的选择压力,为植物逆境生长适应性的研究提供依据。通过生物信息学分析方法,从NCBI等网站获取完整的植物SOS1基因编码区核酸序列和蛋白质氨基酸序列,并利用MEGA和Mrbayes软件构建演化关系树;用PAML等软件剖析了61条SOS1基因序列受到生物选择压力,并计算了相关系数。系统进化树揭示了植物SOS1基因能被划分为3个分支,分别为SOS1单子叶植物分支,SOS1双子叶植物类群分支,SOS1苔藓植物分支。利用PAML软件对植物SOS1基因序列位点进行正选择位点分析,发现:(1)M8模型检测出39个正选择位点,22个位点达到显著水平,其中17个达到极显著水平;(2)净化选择对SOS1基因起主导作用。

This paper aimed to uncover the evolutionary patterns of the Plant Salt-Sensitive(SOS1) genes, and to provide some clues and basis for investigation of plant growth adaptability under adverse situations. The plant SOS1 nucleic acid and protein sequences were completely obtained from the NCBI website. Utilizing MEGA and Mrbayes softwares, the phylogenetic trees were constructed. Evolutionary relationships, selective pressure and correlation coefficient of the 61 SOS1 genes were analyzed using PAML. The phylogenetic trees revealed that plant SOS1 genes could be divided into 3 groups: the monocotyledon groups, the dicotyledonous、monocotyledon groups and the moss groups. Selective analysis with PAML showed that:(1) M8 detected 39 positive selection sites, among which 22 sites reached significant level and 17 sites reached extremely significant level;(2) purifying selection played a dominant role during SOS1 genes evolution.