Identification and complete genome sequence of honeysuckle-associated cytorhabdovirus in China

Abstract

A putatively novel cytorhabdovirus, tentatively named "honeysuckle-associated cytorhabdovirus" (HaCV), was identified by high-throughput sequencing in honeysuckle plants exhibiting chlorosis and mottling symptoms. Five isolates were obtained in this study, all of which were found to have a similar genome structure, ranging in length from 13,891 to 13,930 nucleotides and containing eight open reading frames (ORFs). In addition to ORFs encoding the five canonical proteins N, P, M, G, and L, these isolates had an ORF within the P gene, one between the P and M genes, and one between the G and L genes, encoding the putative proteins P′, P3, and P6, respectively. Although phylogenetic analysis showed that all five isolates were most closely related to triticum alphacytorhabdovirus 1 (TriACRV1), genome sequence comparisons showed that the level of sequence identity of isolate FQ3 to TriACRV1 and the other isolates was below the threshold for species demarcation in the genus Cytorhabdovirus (< 75%), whereas the other four isolates– FQ1, FQ2, FQ4, and FQ5– exhibited greater than 75% sequence identity to TriACRV1. Thus, according to the current criteria, the isolates FQ1, FQ2, FQ4, and FQ5 should be considered isolates of TriACRV1, while isolate FQ3 should be classified as a member of a new species.