大豆基因组中OSCA基因家族的进化和表达分析

Evolution and expression analysis of OSCA gene family in soybean

OSCA是钙通透性阳离子通道蛋白,在高渗胁迫感应中发挥重要的作用。本研究利用生物信息,筛选并鉴定出21个大豆OSCA家族成员。通过染色体定位及同源性分析表明,OSCA家族成员分布在15条染色体上,且存在大量的复制现象;通过Ka/Ks分析表明大豆OSCA家族基因的进化经受纯化选择压力。通过构建系统进化树,将大豆OSCA家族分为2个亚家族,第一亚家族又分为三组(GroupⅠ~Ⅲ),且各组内成员具有相似的内含子-外显子组成模式。保守性分析结果表明,大豆OSCA基因家族很保守,都包含3个功能结构域(即Late exocytosis,Cytosolic domain of 10TM putative phosphate transporter和Calcium-dependent channel);进一步组织表达分析结果表明,OSCA基因家族在不同组织的表达量不同。盐碱胁迫表达模式分析表明,OSCA3.1上调表达变化倍数最大。进一步的启动子分析结果表明,这些盐碱胁迫应答的基因启动子中存在着多种不同的胁迫响应元件,其中干旱和ABA应答相关的元件较多。以上结果为OSCA基因家族提供了新的有价值的信息,并为后续研究提供了重要参考。

OSCA belongs to the transmembrane calcium - permeable cation channel proteins and plays vital roles in hyperosmotic stress responses. However, up to now, little studies were reported about OSCA gene family, especially in legume crops. In this study, a total of 21 GmOSCA genes were identified from soybean. These OSCA genes were distributed in 15 different chromosomes. Further syntenic analysis revealed that most GmOSCAs p o s -sessed duplication events. The results of Ka （ non - synonymous substitution rate）/Ks （ synonymous substitution rate） ratios suggested that the duplication of GmOSCAs mainly underwent purifying selection. P hylogenetic analysis revealed that 21 GmOSCAs could be divided into 2 subfamilies, and subfamily I could be further divided into 3 groups （ Group I - IH ） - Further analysis demonstrated that OSCA family was conserved in term of gene structure and conserved motif. All these GmOSCAs contained three functional domains （late exocytosis, cytosolic domain of 10TM putative phosphate transporter and calcium - dependent channel） . Tissue expression profile analysis of OSCA genes showed that they were differentially expressed in various tissues. Further saline - alkali stress expression pat-terns analysis showed that 0SCA3. 1 exhibited the maximum upregulation value. Promoter analysis revealed that many different stress responsive elements existed in the promoters of these salt - alkali stress responsive genes. Most of these elements were related to drought and ABA responses. The results would provide new valuable information and important reference for future research.