两株黄瓜花叶病毒卫星RNA的竞争与共存研究  

Coexistence and competition of two satellite RNAs of Cucumber mosaic virus in systemic hosts

作　　者：金波[1] 陈集双[1] 

机构地区：[1]浙江理工大学生物工程研究所

出　　处：《微生物学报》2005年第2期209-212,共4页Acta Microbiologica Sinica

基　　金：国家自然科学基金 (3 0 2 70 744 )~~

摘　　要：通过体外转录方法 ,将大小分别为 36 9nt和 385nt的 2个黄瓜花叶病毒 (Cucumbermosaicvirus,CMV)的卫星RNAYi和Yns共同与不含卫星的辅助病毒株CMV_CNa进行假重组 ,接种CMV系统寄主心叶烟。结果表明 :在接种5d的接种叶上同时检测到卫星RNA_Yi和卫星RNA_Yns;在系统叶上 ,接种 5d和 10d亦可同时检测到 2株卫星 ;但接种 15d ,在系统叶组织中只检测到卫星RNA_Yi。再将接种 5d的接种叶扩大接种到几种不同的指示植物后 ,经dsRNA抽提 ,也只获得 1条与卫星RNA_Yi大小相符的条带。通过假重组病毒株中分别获得卫星RNA并测序 ,确定2个卫星RNA的序列没有变化。卫星RNA_Yns和Yi在辅助病毒CMV_CNa作用下 ,表现出明显的竞争性 ,它们在辅助病毒中不能形成稳定的共存关系。Two Cucumber mosaic virus(CMV) satellite RNAs, namely Yns and Yi and of 385nt and 369nt respectively, were introduced to systemic host plants with a satellite RNA-free isolate of CMV (CNa), after in vitro transcription of satellite RNAs from cDNA clones and by co-inoculation with CMV genomic RNAs. The competition and coexistence of the two satellite RNAs were studied by RT-PCR detection, double-stranded RNA analysis and sequencing comparison. The results showed that, in the inoculated leaves of Nicotiana glutinosa, both satellite RNA presented together after inoculated 5 days after pseudo-recombination. In the systemic leaves of N. glutinosa, both satellite RNAs were detected at 5 days and 10 days post first inoculation, however, only the 369nt satellite (Yi) was recovered at 15days post first inoculation and second inoculation transferred from the pseudo-recombination plants. Comparison of full sequences of the satellite RNAs obtained by RT-PCR from pseudo-recombinant virus showed that no mutation and mutual exchange of the satellite genome has been found. The results indicate that both 369nt satellite RNA and 385nt satellite RNA can be introduced to CMV-CNa with in vitro transcription products and both replicated to a high level depending on the helper virus. But after transferring to new systemic plants, only one satellite of 369nt can be kept as co-infection for long with the helper CMV. Co-existence and competition are found between different satellite RNAs in the same plant.

关 键 词：黄瓜花叶病毒 卫星RNA 假重组 竞争与共存 

分 类 号：S436.421[农业科学—农业昆虫与害虫防治]