利用小RNA深度测序技术鉴定半夏病毒病病原

Identification of the Pathogens of Pinellia ternata Virus by Small RNA Deep Sequencing

RNA沉默是真核生物体内由病毒来源的干扰小RNA(virus-derived small interfering RNA,vsiRNA)沉默复合物介导目标RNA特异降解的一种保守机制,通过对vsiRNA分析可进行植物病毒病原鉴定。本文利用小RNA深度测序技术对感病半夏叶片进行鉴定,结果发现,表现典型花叶症状的半夏叶片受到大豆花叶病毒(Soybean mosaic virus,SMV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)、芋花叶病毒(Dasheen mosaic virus,Ds MV)、魔芋花叶病毒(Konjac mosaic virus,KoMV)、烟草花叶病毒(Tobacco mosaic virus,TMV)等多种病毒的复合侵染。为明确SMV山西半夏分离物(SMV-SXBX)的进化关系,进行SMV-SXBX全基因组克隆与分析,获得SMV-SXBX全长为9735 nt,编码一个由3 105个氨基酸组成的多聚蛋白质。通过核苷酸与氨基酸序列比对发现,SMVSXBX与半夏分离物P同源性最高,分别为91. 1%和94. 1%,且系统发育分析表明,SMV-SXBX与半夏SMV分离物P聚为一簇。同时,也对vsiRNA进行了系统分析,研究结果有望为半夏SMV的有效防治提供一定科学依据。

RNA silencing is a conservative mechanism of specific degradation of target RNA mediated by virus-derived small interfering RNA (vsiRNA) silencing complex in eukaryotic organisms, which can be used to identify the pathogen of plant viruses by vsiRNA analysis. In this study, a technology of small RNA deep sequencing is used to identify the infected pathogens of the leaves of Pinellia ternata. It was found that the Pinellia ternata leaves with typical mosaic symptoms were infected by Soybean mosaic virus (SMV), Cucumber mosaic virus (CMV), Dasheen mosaic virus (DsMV), Konjac mosaic virus (KoMV), Tobacco mosaic virus (TMV). In order to clarify the evolutionary relationship of isolates of SMV from Pinellia ternate from Shanxi (SMV-SXBX), the SMV-SXBX genome was cloned and analyzed, which is 9 735 nucleotides (nt), encoding a polyprotein of 3 105 amino acids (aa). The nucleotide and amino acid sequence alignment showed that SMV-SXBX had the highest homology with Pinellia ternata isolate P, which were 91.1% and 94.1%, respectively. Phylogenetic analysis showed that SMV-SXBX and Pinellia ternata SMV isolate P clustered together. Meanwhile, we also made a systematic analysis of the virus-derived small interfering RNAs (vsiRNAs), which is expected to provide further evidences for the prevention and control of Pinallia ternata SMV infection.