蚕豆萎蔫病毒2号板蓝根分离株全基因组序列测定与分析

Identification and Analysis of Genomic Sequence of Broad bean wilt virus 2 Isolated from Isatidis Radix

板蓝根(Isatidis Radix)病毒病害的发生已对其产量和品质造成了严重影响。因此,建立一套灵敏、快速、有效的板蓝根病毒病害检测手段十分重要。本研究利用双链RNA(double-stranded RNA,dsRNA)和非序列依赖PCR扩增(sequence-independent amplification,SIA)等技术对感病板蓝根进行鉴定,确定其被蚕豆萎蔫病毒2号(Broad bean wilt virus 2, BBWV2)所侵染。为明确BBWV2板蓝根分离物(BBWV2-IR)的进化关系,对其全基因组进行序列扩增与分析,获得其RNA1序列全长为5 955 bp,RNA2序列全长为3 602 bp,分别编码由1 870和1 064个氨基酸组成的多聚蛋白质。序列比对发现,BBWV2-IR RNA1与BBWV2-Am分离物的同源性最高,RNA2与BBWV2-SN分离物的同源性最高。全基因组变异情况分析表明,BBWV2-IR RNA1和RNA2分别与其同源性最高的株系存在多个氨基酸变异位点。系统进化分析表明,BBWV2-IR RNA1与BBWV2-Am RNA1聚为一簇,RNA2与BBWV2-SN RNA2聚为一簇,亲缘性最近。本研究获得了BBWV2板蓝根分离株的全基因组序列,并明确其在进化过程中的地位和区域变化情况,为进一步研究BBWV2-IR致病性变异提供一定的理论基础。

The occurrence of the Isatidis Radix virus disease has seriously influences on its yield and quality. Therefore, it is very important to establish a sensitive, rapid and effective detection method for the Isatidis Radix virus disease. In this study, double-stranded RNA(dsRNA) and sequence-independent amplification(SIA) methods were used to identify the pathogens of Isatidis Radix. The results showed that the Isatidis Radix was infected by Broad bean wilt virus 2(BBWV2). In order to clarify the evolutionary relationship of Isatidis Radix isolates of BBWV2, the whole genome sequence was amplified and analyzed. The full length of RNA1 and RNA2 sequences were 5 955 and 3 602 bps, encoding polypeptides of 1 870 and 1 064 amino acids, respectively. The sequence alignment showed that BBWV2-IR RNA1 had the highest homology with BBWV2-Am and RNA2 has the highest homology with BBWV2-SN. Analysis of genome variation showed that BBWV2-IR RNA1 and RNA2 has multiple amino acid variation sites with the most homologous strain, respectively. Phylogenetic analysis showed that BBWV2-IR RNA1 and BBWV2-Am RNA1 clustered together, and RNA2 and BBWV2-SN RNA2 clustered together, which was closely related. In this study, the whole genome sequence of BBWV2-IR was obtained for the first time, and its status and regional changes in the evolutionary process were clarified, which will provided a theoretical basis for further study of pathogenic variation of BBWV2-IR.