Complete genome sequence of a novel closterovirus isolated from Dregea volubilis.

The complete genome sequence of a putative novel closterovirus, tentatively named "Dregea volubilis closterovirus 1" (DvCV1, GenBank accession no. MZ779122), infecting Dregea volubilis in China was determined using high-throughput sequencing (HTS). The complete genome sequence of DvCV1 consists of 16,165 nucleotides (nt) and contains nine ORFs. The genome structure of DvCV1 is typical of members of the genus Closterovirus. Complete genome sequence analysis showed that DvCV1 shares 41.4-48.4% nucleotide sequence identity with other known closteroviruses. The putative RNA-dependent RNA polymerase (RdRp), heat shock protein 70-like protein (HSP70h), and coat protein (CP) of DvCV1 share 46.80-62.65%, 31.06-51.80%, and 28.34-37.37% amino acid sequence identity, respectively, with the RdRp, HSP70h and CP of other closteroviruses. Phylogenetic analysis based on HSP70h aa sequences placed DvCV1 alongside other members of the genus Closterovirus in the family Closteroviridae. These results suggest that DvCV1 is a new member of the genus Closterovirus. This is the first report of a closterovirus infecting D. volubilis.