Unveiling the genetic diversity of the genera Enamovirus and Polerovirus through data-driven virus discovery

Enamoviruses and poleroviruses (family Solemoviridae) are plant-infecting icosahedral viruses that have a single-stranded RNA genome. In the present study, we examined plant transcriptome data available in the Sequence Read Archive (SRA) database and identified sequences of 22 putative novel enamo-/enamo-like and poleroviruses. The 13 putative novel enamoviruses that were identified were found in diverse plant species, including gymnospermic hosts, expanding the known genetic diversity of enamoviruses by 0.9-fold and broadening their known host range. Other significant findings of this study include the first identification of a putative polerovirus in a gymnospermic host, identification of a viral genome whose organization resembles that of an enamovirus but clusters phylogenetically with poleroviruses, identification of a phylogenetically divergent enamo-like virus, identification of a novel enamovirus and a polerovirus in the same host sampled from same geographical location, and discovery of a novel tombus-like associated RNA in a plant containing a novel enamovirus. The genome organization of the identified viruses largely resembled those of other members of these genera. Further studies are needed to investigate the properties and distribution of these viruses.