Complete sequence and genome characterization of a new potexvirus isolated from Chaenostoma cordatum.

Leaves from the ornamental plant Chaenostoma cordatum (Thunb.) Benth. expressing virus-like symptoms were collected for pathogen testing. A virus with features consistent with those of members of the genus Potexvirus was identified by high-throughput sequencing. The genome sequence was confirmed and completed using RT-PCR, cloning, rapid amplification of cDNA ends kits, and Sanger sequencing, revealing a complete viral genome of 6,071 nucleotides, excluding the poly-A tail. Phylogenetic analysis of the RNA-dependent RNA polymerase sequence from the viral genome indicated that its closest relative is Plantago asiatica mosaic virus. Further analysis of the nucleotide and amino acid sequences revealed that it had diverged enough from other potexviruses to be considered a member of a new species.