毛竹MYB转录因子PeMYB2的克隆与功能分析  

Cloning and functional analysis of Phyllostachys edulis MYB tran scription factor PeMYB2

作　　者：肖冬长[1] 张智俊[1] 徐英武[1] 杨丽[1] 张凤雪[1] 王超莉[1] 

机构地区：[1]浙江农林大学,亚热带森林培育国家重点实验室培育基地,临安311300

出　　处：《遗传》2013年第10期1217-1225,共9页Hereditas（Beijing)

基　　金：国家重点基础研究发展计划(973计划)项目(编号:2011CB111500);浙江农林大学基础基金项目(编号:2010FR072);浙江省自然科学基金项目(编号:Y307469)资助

摘　　要：MYB类转录因子在调控逆境应答基因的表达起着重要的作用,是最大的植物转录因子之一。文章通过同源基因克隆方法和RACE(Rapid-amplification of cDNA ends)技术,以毛竹幼苗为材料,获得一个MYB类转录因子,命名PeMYB2。氨基酸序列分析表明,PeMYB2具有典型的R2R3-MYB特征,N端含有两个串联重复保守结构域,C端含有一个膜蛋白DUF3651;进化树分析表明,PeMYB2与水稻OsMYB18序列相似性最高,达到85.98%;酵母单杂实验表明,PeMYB2具有转录激活功能。将PeMYB2转化拟南芥对其功能进行分析,获得7株转基因纯合体植株。比较转基因和野生型拟南芥表型发现,PeMYB2的过量表达使转基因拟南芥出现矮化、晚花的现象;非生物胁迫处理(盐胁迫、干旱胁迫、低温胁迫)结果表明,转基因拟南芥中PeMYB2的过量表达,导致转基因植株对盐胁迫和低温胁迫有更高的耐性,但是对低温胁迫的耐受性没有明显的变化;进一步通过盐胁迫信号通路相关Marker基因(NXH1、SOS1、RD29A、COR15A)的定量PCR实验验证,发现PeMYB2对下游这些抗逆基因的表达具有调控作用。上述实验结果表明,毛竹PeMYB2可参与非生物胁迫调控,对毛竹盐胁迫和低温胁迫的响应起着重要的作用。MYB-type transcription factor is one of the largest families in plants, which plays important roles in accepting stress signals from environment and regulating the expression of stress-tolerant genes. In this paper, using homologous cloning and RACE technology, a MYB-type transcription factor, designated PeMYB2, was cloned from Phyl- lostachys edulis. The results of bioinformatics showed that PeMYB2 is a typical R2R3-MYB. It contained two tandem re- peats in its N-terminus, and a membrane protein DUF3651 in its C-terminus. In addition, phylogenetic analysis indicated that PeMYB2 shared the highest homology with 85.98% to OsMYB18 protein from Oryza sativa spp. Japonica. In addition,a yeast one-hybrid assay showed that PeMYB2 could activate the expression of downstream genes. After PeMYB2 was transformed into Arabidopsis thaliana, seven PeMYB2 transgenic Arabidopsis lines were obtained. Phenotypic analysis of the transgenic and wild-type Arabidopsis showed that over-expression of PeMYB2 caused delayed flower or dwarfism in transgenic Arabidopsis. Under the abiotic stress conditions, such as salt and cold stresses, the over-expression of PeMYB2 in Arabidopsis had higher survival rate than the wild-type Arabidopsis. Expression analysis of saline stress response marker genes in the transgenic and wild-type plants under the salt stress condition showed that PeMYB2 regulated the expression of NXH1, SOS1, RD29A, and COR15A. As the result, PeMYB2 might play an important role in various responses to abiotic stresses in P. edulis.

关 键 词：毛竹 PeMYB2 非生物胁迫 转基因 

分 类 号：S795.7[农业科学—林木遗传育种] Q943.2[农业科学—林学]