谷子GH5基因家族全基因组鉴定和表达分析

糖苷水解酶5(GH5)属于最大的糖苷水解酶家族,在细胞壁合成与降解过程中发挥重要作用。为解读谷子GH5基因家族特性,通过生物信息学方法对谷子进行全基因组扫描,鉴定并分析谷子GH5家族成员。结果表明,谷子具有18个GH5基因(命名为SiGH5-1~SiGH5-18),不均匀分布在8条染色体上。SiGH5蛋白具有保守结构域,叠合比对发现不同物种GH5蛋白结构高度保守。多物种系统发育树分析表明,GH5蛋白具有种属特异性特点。基因结构分析发现,同一分支的GH5蛋白具有相似的基序分布,GH5成员具有外显子改组现象。表达谱分析发现,谷子GH5家族基因属诱导型表达,其中,SiGH5-8、SiGH5-17在谷子各器官和非生物胁迫过程中均具有较高表达量。启动子分析鉴定到大量激素类响应元件,暗示GH5家族成员通过响应植物内源激素发挥调控作用。

Identification and expression analysis of millet GH5 gene family

Glycoside hydrolase 5 (GH5) belonged to the largest family of glycoside hydrolyases involved in the cell wall synthesis and degradation in plant. To identify and systematically characterize GH5 gene family, whole genome scan and bio-informatics analysis in millet were performed. In this study, total 18 GH5 genes were identified in millet, which unevenly distributed on eight chromosomes. By the gene structure and evolutionary analysis, SiGH5 proteins had a conserved domain, and overlapping alignment found that GH5 protein structures were highly conserved. Multi-species phylogenetic tree analysis indicated that GH5 proteins had species-specific characteristics. Gene structure analysis showed that the 18 GH5 genes contained exons and introns structure, some gene had the exon shuffling phenomenon. Expression analysis revealed that millet GH5 genes were specifically expressed in one or more organs, and significantly induced under different abiotic stress. In addition, a large number of hormone-responsive elements were identified in promoter region,which implied millet GH5 genes might play important role in response to plant growth and stresses.