芒果HMGR家族基因的鉴定、系统进化和表达分析

Identification, Phylogenetic Evolution and Expression Analysis of the Mango(Mangifera indica) HMGR Family Genes

羟甲基戊二酰辅酶A还原酶(HMGR)是甲羟戊酸(MVA)途径的第一个限速酶。为了探索HMGR家族基因在芒果中的作用,本研究鉴定了芒果HMGR家族基因,并对HMGR家族基因的理化性质、系统发育及在芒果中的表达量进行了分析。结果显示,芒果HMGR家族蛋白序列均包含完整的HMG-CoAred结构域,且HMGR家族蛋白均为疏水性蛋白。系统发育树显示,HMGR家族基因是从苔藓植物开始形成的,且芒果HMGR家族基因均聚在双子叶植物的分支,与物种进化历程一致。HMGR家族基因在芒果品种‘贵妃’和‘台农’成熟果果肉中的表达量结果显示,Mi15g11840.1和Mi19g11720.1基因在‘贵妃’中的表达量显著高于‘台农’,Mi18g12500.1基因在‘贵妃’中的表达量显著低于‘台农’,而Mi04g11220.1基因在两个品种中的表达量差异不显著。本研究为进一步研究芒果HMGR家族基因在MVA途径中的作用提供了科学依据。

3-hydroxy-3-methylglutaryl-CoA reductase(HMGR) is the first rate-limiting enzyme in the mevalonate pathway. In order to study the function of HMGR family genes in mango, the protein domains, physical-chemical properties, phylogeny and the expression levels were analyzed. The results showed that mango HMGR family protein sequences all contained the complete HMG-CoAred domain, and HMGR family proteins are hydrophobic proteins. Phylogenetic analysis showed that HMGR family genes could be trace back to bryophytes in plant, and the mango HMGR family genes were all cluster in the branches of dicotyledon, which were consistent with the evolutionary history of species. The expression analysis showed that the expression levels of Mi15 g11840.1 and Mi19 g11720.1 genes in the flesh of mature fruit of ’Guifei’ was significantly higher than ’Tainong’, the expression level of Mi18 g12500.1 gene in the flesh of mature fruit of ’Guifei’ was significantly lower than ’Tainong’. The expression level of Mi04 g11220.1 gene in the flesh of mature fruits of the two varieties were not significantly different. The study provide scientific basis for further study the role of mango HMGR family genes in MVA pathway.