龙眼DlWRKY25基因克隆及在成花进程中的功能分析

Cloning of Longan DIWRKY25Gene and Analysis of ItsFunction in Flowering Process

WRKY是植物中一类至关重要的转录因子,其与植物的生长发育过程以及胁迫响应有着密切的关系。从目前研究结果中得到,在龙眼成花诱导进程中部分WRKY基因也参与了其中,比如DlWRKY25。为了对龙眼WRKY基因的功能有更深入的了解,本研究以‘四季蜜’龙眼cDNA为模板克隆了龙眼DlWRKY25基因,同时对该基因的序列特征、成花发育过程与组织表达模式,亚细胞定位及过表达转DlWRKY25基因拟南芥进行研究。结果表明,龙眼DlWRKY25基因的开放阅读框(open reading frame, ORF)全长为1 056 bp,编码355个氨基酸。氨基酸序列显示DlWRKY25含有典型的WRKY结构域与锌指结构,属于Ⅲ型WRKY蛋白。亚细胞定位的结果显示,细胞核处有明显而又集中的荧光信号,表明DlWRKY25定位于细胞核。RT-qPCR结果显示,该基因在茎中有较高的相对表达量,并在‘四季蜜’龙眼的成花诱导阶段,显示特异下调表达。过表达转基因拟南芥植株结果显示,DlWRKY25在拟南芥中的过量表达能够加快植株的成花过程。

WRKY transcription factors plays an important role in plant growth,development and stress response.Based on a previous study,we found several WRKY genes,such as DIWRKY25,were participated in the process of floral induction and stress response.To further reveal the function of longan WRKY genes,DIWRKY25 was cloned using the leave cDNA of‘Sijimi'longan as the template.Meanwhile,the sequence characteristics,tissue expression patterns,flower development process expression patterns,subcellular localization and overexpress DIWRKY25 in Arabidopsis were also studied.Bioinformatics analysis indicated that the complete open reading frame(ORF)box of DIWRKY25 was 1056 bp,encoding 355 amino acid residues.The amino acid sequence alignment analysis showed that DIWRKY25 contained a typical WRKY domain and a zinc finger structure,belonging to Group Ⅲ.The result of RT-qPCR showed that DIWRKY25 was highly expressed in stem and down-regulate in the floral induction of'Sijimi'longan.The results of subcellular localization showed that DIWRKY25 protein was located in the nucleus.The result of overexpress DIWRKY25 in Arabidopsis showed that DIWRKY25 had the ability to advance flowering.