GhWRKY48负调控棉花对大丽轮枝菌的抗性

Resistance of GhWRKY48 Negatively Regulated Cotton Against Verticillium dahlia

为了防治棉花黄萎病对棉花生产的危害,利用抗病基因培育抗病品种是最经济有效的方法。从陆地棉中克隆了1个WRKY转录因子基因,命名为GhWRKY48;其编码序列全长为882 bp,编码293个氨基酸残基,预测分子质量和等电点分别为32.68 ku和6.10。qPCR组织特异性表达分析结果表明,GhWRKY48在根、茎和叶中均表达,而在茎中为优势表达;同时GhWRKY48表达受到大丽轮枝菌、茉莉酸和水杨酸的诱导。通过病毒诱导基因沉默技术获得GhWRKY48基因沉默植株。对基因沉默植株接种大丽轮枝菌进行抗病性分析,结果显示,沉默植株的病株率和病指均低于对照植株,表明沉默GhWRKY48基因能够提高棉株抗病性。综上所述,GhWRKY48是一个负调控转录因子,抑制下游抗病基因的表达,从而参与棉花对大丽轮枝菌的抗性;因此,GhWRKY48基因可以作为一个理想的候选基因用于棉花的抗病育种。

Since Verticillium wilt causes great loss in cotton production every year,it is an economical and effective method to identify resistance genes for breeding new varieties to control Verticillium wilt.A WRKY transcription factor gene was cloned from upland cotton,named GhWRKY48.The full-length of GhWRKY48 cDNA was 882 bp,encoding 293 amino acid residues with a predicted molecular mass of 32.68 ku and an isoelectric point(pI)of 6.10.qPCR analyses showed that GhWRKY48 gene constitutively expressed in root,stem and leaf,and preferentially done in stem.In addition,GhWRKY48 expression could be induced by V.dahliae infection,jasminic acid and salicylic acid.To dissect the defense function,GhWRKY48-silenced plants were developed by virus-induced gene silencing techniques,which were then inoculated with V.dahliae.The results showed that the resistance of these silenced plants significantly increased compared to the control.The rates of diseased plants and disease index in GhWRKY48-silenced plants were lower than in the control.All together,GhWRKY48 was a negative transcription factor participating in plant resistance to V.dahliae.Therefore,the GhWRKY48 gene could be used as an ideal candidate gene for cotton defense breeding.