甜瓜CmRDR基因家族的鉴定及其对CGMMV侵染的表达分析

Identification of Melon CmRDR Gene Family and Its Expression Analysis on CGMMV Infection

RNA依赖性RNA聚合酶(RDRs)是RNA沉默途径中一类重要的蛋白,能够以单链核糖核酸(ssRNA)为模板合成双链核糖核酸(dsRNAs),启动新一轮的RNA沉默。众所周知,RDR基因在植物抵御病毒侵染中发挥重要的作用,而甜瓜作为一种易受到病害侵染的经济作物,其RDR基因的鉴定尚未见报道。因此,本研究利用生物信息学手段,在全基因组水平对甜瓜RDR基因进行了鉴定,分析其序列特征、亚细胞定位、进化关系和启动子上的逆境和激素响应元件。此外,利用RT-qPCR对甜瓜CmRDR基因的表达特征进行了分析,结果发现,接种黄瓜绿斑驳花叶病毒(CGMMV)后,大部分甜瓜CmRDR基因的表达显著下调。本研究首次鉴定了甜瓜RDRs家族基因的特性,初步揭示了CmRDR基因在CGMMV病毒响应中的功能,为后期甜瓜抗病育种提供了一定的理论依据。

RNA dependent RNA polymerases(RDRs)are the key proteins in the RNA silencing pathway.They are responsible for the synthesis of double stranded ribonucleic acids(dsRNAs)using single stranded ribonucleic acid(ssRNA)as template,thus initiating a new round of RNA silencing.It is well known that RDR genes play very important roles in response to plant virus infection.However,RDR genes in melon has not been reported.Therefore,in this study,seven CmRDR genes in melon were identified at the genome-wide level by bioinformatics,and their protein and gene structure,subcellular localization and evolutionary relationship were predicted and analyzed.The cis-acting elements involved in stress response and hormone response were also analyzed.In addition,the expression patterns of 7 CmRDR genes in melon were analyzed via RT-qPCR.The results showed that most CmRDR genes were significantly repressed by Cucumber green mottle mosaic virus(CGMMV)infection.This study was the first to identify RDRs gene family in melon and preliminarily revealed the roles of CmRDR gene in CGMMV infection,which provided an effective basis for disease resistance breeding in melon.