黄瓜CsRAX2的克隆与表达分析及原核表达蛋白诱导

Cloning,Expression Analysis and Prokaryotic Protein Induction of CsRAX2 in Cucumber

作为最大的转录因子家族,MYB转录因子广泛参与植物的生长发育以及对胁迫的响应与耐受。CsRAX2是黄瓜MYB转录因子家族成员之一,本研究通过同源克隆法克隆了CsRAX2全长,分析了该转录因子基因的生物信息和表达特征,在原核表达系统中诱导并纯化该蛋白。结果表明,CsRAX2全长939 bp,编码321个氨基酸,定位在3号染色体。CsRAX2蛋白定位在细胞核,与其他物种MYB的进化关系很近,是一个典型的R2R3-MYB转录因子。CsRAX2表达具有组织特异性,且低温处理显著诱导采后黄瓜CsRAX2表达,表明其可能在采后黄瓜低温反应调控中发挥作用。启动子元件分析显示,该基因启动子中含有多个环境和激素响应元件,表明非生物胁迫可能通过激素信号调控CsRAX2表达。原核表达研究表明,培养温度影响原核表达蛋白的诱导效果,降低细菌培养温度能提高上清液中融合表达蛋白产量。本研究结果为进一步研究黄瓜CsRAX2基因的生物学功能及黄瓜耐冷性机理提供了帮助。

As the largest transcription factor family,MYB transcription factors are widely involved in plant growth,development,response and tolerance to stress.CsRAX2 is one of the members of cucumber MYB transcription factor family.In this study,the full length of CsRAX2 was cloned by homologous cloning method.The bioinformatics and expression patterns of CsRAX2 gene were analyzed,and the CsRAX2 protein was induced and purified through prokaryotic expression system.CsRAX2 was 939 bp in length,encoded 321 amino acids and located on chromosome 3.CsRAX2 is a typical R2R3-MYB transcription factor,which is located in the nucleus and showed close evolution relationship with MYB of other plant species.The expression of CsRAX2 showed tissue-specific features,and low temperature treatments significantly induced the expression of CsRAX2 in harvested cucumbers,indicating that it may play a role in the regulation of cucumber fruits in response to low temperatures.Promoter element analysis showed that there were several environmental and hormone responsive elements in the promoter of CsRAX2 gene,which indicated that abiotic stress regulated the expression of CsRAX2 by hormone signaling.Prokaryotic expression suggested that incubation temperature affected the induction effects and reducing of the incubation temperature could enhance the production of fused CsRAX2 protein in the supernatants.The results of this study could be helpful for further study on the biological function of cucumber CsRAX2 gene and the cold tolerance mechanisms of cucumber.