菜用大豆蔗糖合酶基因鉴定及表达模式分析

Identification and Expression Pattern Analyses of Sucrose Synthase Genes in Vegetable Soybean

蔗糖含量是影响菜用大豆甜味的主要因素。蔗糖合酶(sucrose synthase, SUS)是调控蔗糖代谢的关键酶之一,在作物品质调控等方面发挥重要作用。为了深入了解菜用大豆蔗糖代谢相关GmSUSs基因的分子作用机制,本研究从基因组水平对GmSUSs进行了基因成员鉴定、蛋白理化特性、保守结构域、进化关系、基因结构、启动子元件组成、组织表达模式及激素和胁迫表达谱分析。结果表明:从全基因组水平共鉴定到11个GmSUSs编码蔗糖合酶。蛋白多序列比对显示所有GmSUSs均含有保守的特征结构域:Sucrosesynth和Glycostransf1。进化分析显示GmSUSs主要划分为3个分支。组织表达分析显示不同GmSUSs基因在不同生长发育阶段的表达量具有明显差异。启动子顺式作用元件分析显示GmSUSs基因上游启动子区内激素和胁迫应答元件组成各异。进一步,qRT-PCR分析显示激素(ABA, ACC和NAA)和胁迫(低温,高温和干旱)处理诱导GmSUS11基因表达。以上实验结果为菜用大豆GmSUSs基因功能解析及蔗糖代谢途径改造提供了参考。

Sucrose content is one of the main factors which influence the sweet taste of vegetable soybean. Sucrose synthase(SUS) is one of the key enzymes which are involved in sucrose metabolism. SUSs play key roles as crop quality regulators. To further understand the molecular mechanism of sucrose metabolism related SUSs in vegetable soybean, we performed a systematic analyses of GmSUSs, containing identification of gene members,protein properties, conserved motifs, phylogenetic relationship, responsive elements of gene promoters and expression patterns of different tissues, hormone signals and environment stresses. A total of 11 GmSUS genes were identified from the soybean genome. Protein sequence alignments indicated that all GmSUSs contained the conserved domains: Sucrosesynth and Glycostransf1. Phylogenetic analysis showed that GmSUSs were classfied into three sub-families. Tissue expression analysis revealed that different GmSUSs participated in different growth and development stages with different expression levels. Cis-acting element analysis revealed that the promoter regions of different GmSUSs had distinct number and composition of hormone and abiotic stress responsive elements. Fur ther, qRT-PCR assay indicated that hormone(ABA, ACC and NAA) and stress(low temperature, high temperature and drought) treatments induced the expression changes of GmSUS11. These results provide reference for functional researches of GmSUSs and genetic modification of sucrose metabolism pathway in vegetable soybean.