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

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。

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

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.