杨树14-3-3基因家族的分子进化及表达模式研究

14-3-3蛋白在植物细胞信号传导中发挥重要的作用,探索木本植物14-3-3蛋白家族的进化模式对深入理解该基因家族的功能有重要的指导意义。本文采用生物信息学的方法,在基因组水平上搜索和鉴定了12个杨树14-3-3蛋白基因,其中ε类有7个,非ε类有5个。通过对杨树14-3-3基因家族的系统进化、序列相似性、基因结构和染色体位置分析,发现杨树14-3-3基因的扩张主要是通过最近的一次全基因组加倍事件产生的。在全基因组加倍事件中共产生5对重复基因对,Ka/Ks分析显示这5对重复基因对处于较强的净化选择压力。RT-PCR分析显示在杨树12个14-3-3基因中有8个在不同组织中均表达,另外4个基因的表达部位发生了变异。因此,杨树14-3-3基因家族的分子进化及表达模式的研究结果预示着基因重复后其功能发生了分化。

Molecular evolution and expression pattern of the Populus 14-3-3 gene family

The 14-3-3 protein plays an important role in the cellular signal transduction and primary metabolism of plants. To explore the evolutional pattern of the 14-3-3 gene family will facilitate the understanding of its function in woody plants. In this study, twelve 14-3-3 genes were identified from the Populus trichocarpa genome based on bioinformatics. A phylogenetic study showed that Populus 14-3-3 proteins contain both ε and non-ε forms. A recent whole genome duplication event contributed to the expansion of Populus 14-3-3 gene family, among which a total of five paralogous gene pairs were formed. The analysis of Ka/Ks showed that the purifying selection is the predominant evolutionary force acting on the five paralogous gene pairs. RT-PCR revealed expression divergence in twelve Populus 14-3-3 genes. In conclusion, the results indicate that there are functional divergences in the Populus 14-3-3 gene family after gene duplication.