侵染红肉火龙果的蟹爪兰X病毒贵州分离物基因组分析

 通过高通量测序和RT-PCR扩增,克隆并分析蟹爪兰X病毒(Zygocactus virus X,ZyVX)贵州分离物ZyVX-GZ基因组序列。对表现病毒病症状的红肉火龙果植株进行高通量测序,获得4条ZyVX相关contig。RT-PCR扩增并拼接获得ZyVX-GZ基因组,全长为 6 567 nt,5′-UTR和 3′-UTR分别为60 nt和70 nt。含有5个ORF,分别编码复制酶蛋白、TGB1、TGB2、TGB3蛋白和外壳蛋白。ZyVX-GZ与P39和B1分离物基因组序列一致性均为91%。TGB1-3、外壳蛋白基因与大多数分离物核苷酸和推导的氨基酸序列一致性分别为95%～99%和96%～100%;复制酶基因的核苷酸和推导的氨基酸序列一致性分别为80%～89%和92%～97%。系统进化分析表明,ZyVX群体的遗传分化与寄主种类、地理分布不存在相关性。本研究结果丰富了ZyVX群体的基因组序列信息,为ZyVX的监测和防控提供了基础。

The genomic sequence analysis of Zygocactus virus X Guizhou isolate infecting the red pitaya

Based on high-throughput sequencing and RT-PCR amplification, the genomic sequence of the ZyVX (Zygocactus virus X) Guizhou isolate ZyVX-GZ was cloned and analyzed. Using high-throughput sequencing for the red pitaya samples, which displayed the virus-like symptoms, four ZyVX-related contigs were obtained. RT-PCR amplification and assembly showed that the full-length genome of ZyVX-GZ was 6 567 nt, of which the 5′-untranslated region (UTR) and 3′-UTR were 60 nt and 70 nt, respectively. ZyVX-GZ genome contained five open reading frames (ORFs), which encoded RNA dependent RNA polymerasease (RdRP), triple gene block 1 (TGB1), TGB2, TGB3 and coat protein (CP). ZyVX-GZ genome shared nucleotide sequence identities of both 91% with P39 and B1 isolates. The nucleotide and deduced amino acid sequence identities of TGB1-3, CP with most ZyVX isolates were 95%-99% and 96%-100%, respectively. The nucleotide and deduced amino acid sequence identities of RdRP with most isolates were 80%-89% and 92%-97%, respectively. Phylogenetic analysis suggested that there was no correlation between the genetic differentiation of the current ZyVX population and host species, geographic distribution. The results of this study enriched the genomic information of the ZyVX population, and provided basis for the monitor and control of ZyVX.