毛果杨PtAREB9基因启动子的克隆与功能初步分析

Cloning and Functional Identification of Promoter Region of PtAREB9 from Populus trichocarpa

ABF属于碱性亮氨酸拉链(bZIP)转录因子A亚族,受脱落酸(ABA)调控,参与植物生长发育及抗旱耐盐响应。为了研究杨树ABF同源基因的表达规律,利用PCR技术从毛果杨基因组DNA中克隆出PtAREB9基因上游一段1 635 bp序列。使用PLACE和Plant CARE在线软件分析序列,结果表明该序列含有水杨酸(SA)响应元件TCA-element、逆境胁迫响应元件TCrich repeats、干旱胁迫响应元件CCAAT-box和MBS、ABA应答元件CE3。在序列分析的基础上,构建了Pt AREB9基因启动子驱动GUS报告基因的植物表达载体。利用农杆菌介导的花粉管通道法转化拟南芥,结果表明PtAREB9启动子可以驱动GUS基因在拟南芥中表达,ABA、干旱、高盐和SA处理后在叶片和根尖中的表达量较高。说明PtAREB9启动子受SA响应元件调控,与ABA、干旱和高盐胁迫应答相关。

AREB binding factor（ABF） is a member of basic leucine zipper（bZIP） transcription factor A subfamily,which is regulated by ABA and involved in plant growth and drought and salt resistance.A 1 635 bp5＇ flanking sequence of PtAREB9 gene was isolated by PCR from genomic DNA of Populus trichocarpa to study the expression and regulation of ABF.Promoter sequence analysis showed that it contains a salicylic acid（SA）-responsive element（TCA-element）,stress-responsive element（TC-rich repeats）,dehydration-responsive element（CCAAT-box and MBS） and ABA-responsive element（CE3）.Then,the PtAREB9 promoter was fused to the GUS reporter gene to characterize its expression pattern in P.trichocarpa.Agrobacterium mediated transformation of Arabidopsis thaliana showed that the GUS gene was induced in leaves and root tip under ABA,drought,high salt and SA treatments,suggesting that the PtAREB9 promoter was induced by SA-responsive element,and responsed to ABA,drought and high salt stresses.