一个大豆脱水胁迫响应的bHLH类转录因子的克隆及功能分析  

Cloning and functioning analysis of transcription factor GmbHLH response to dehydration stress

作　　者：陈李淼[1,2] 沙爱华[2] 张婵娟[2] 单志慧[2] 张晓娟[2] 陈水莲[2] 朱晓玲[2] 刘宝红[2] 祁琳[2] 周新安[2] 李文滨[1] 

机构地区：[1]东北农业大学大豆生物学教育部重点实验室,农业部东北大豆生物学与遗传育种重点实验室,黑龙江哈尔滨150030 [2]中国农业科学院油料作物研究所,农业部油料作物生物学与遗传育种重点实验室,湖北武汉430062

出　　处：《中国油料作物学报》2013年第6期630-636,共7页Chinese Journal of Oil Crop Sciences

基　　金：转基因生物新品种培育重大专项(2011ZX08004-002);现代农业产业技术体系建设专项(CARS-04-PS08)

摘　　要：为了获得植物在干旱胁迫反应中起关键作用的基因,本研究以大豆耐旱品种和敏感品种为试验材料,利用前期构建的数字基因表达谱,从中筛选出一个在两种材料间存在表达差异的基因,命名为GmbHLH25。采用实时定量PCR对表达谱的结果进行验证,并克隆得到该基因的全长序列。利用ExPASy的ProtParam工具分析发现GmbHLH25蛋白长度为368aa,含有由50aa组成的保守结构域bHLH。进化树分析表明GmbHLH25蛋白与百脉根、苜蓿中的同源蛋白关系最近,处于同一进化分枝。洋葱表皮亚细胞定位结果表明该蛋白在细胞核中表达。PCR和RT-PCR检测表明GmbHLH25基因已经整合到本生烟草的基因组中。在干旱、高盐胁迫下超表达GmbHLH25基因能提高烟草的耐旱、耐盐能力。本研究结果将为进一步分析该基因参与的耐旱信号传导途径,深入研究bHLH转录因子在植物耐逆反应中的分子机理奠定基础。Drought stress seriously affects plant growth and development as well as reduces quality and productivity of crops. In order to gain some key functional genes in response to dehydration/drought stress, a digital gene Expression Tag profile of two drought tolerance and sensitivity materials under dehydration had been constructed in our previous study. In the research, a gene encoding bHLH transcription factor, namely GmbHLH25, was identified from expression profile. This gene was significantly induced in leaves and roots under dehydration and the expression showed an obvious difference between two materials. Expression level of GmbHLH25 gene was validated by real-time quantitative PCR. The CDS sequence of GmbHLH had been cloned from two materials. GmbHLH25 gene encodes 368 aa and contains one basic Helix-Loop-Helix（bHLH） motif comprised of 50 amino acid. The homology tree demonstrated that GmbHLH25 was at the same evolutionary branch with homologous proteins of Lotus corniculatus and Medicago. Subcellular localization revealed that GmbHLH25 was distributed preferentially to nucleus. PCR and RT-PCR results showed that GmbHLH25 gene had been integrated into tobacco genome. Over expression of GmbHLH25 gene improved drought and salt tolerance capacities under water-deficit and high salt conditions. This study will help to clarify the molecular mechanisms of plants response to drought.

关 键 词：干旱胁迫 大豆 表达谱 GmbHLH25 BHLH 本生烟草 超表达 

分 类 号：S565.103[农业科学—作物学]