ScholarWorks@중앙대학교

초록

Background Some plant RNA viruses in the family Betaflexiviridae encode a nucleic acid-binding protein (NABP), which enhances viral infectivity. Until recently, Salvia divinorum RNA virus 1 (SdRV1) was the only known member of the genus Citrivirus to encode a NABP. Objective This study aimed to identify novel Betaflexiviridae genomes encoding NABPs and to investigate their evolutionary origins through comparative and phylogenetic analysis. Methods Publicly available plant transcriptome datasets were screened to identify Betaflexiviridae-like viral sequences. Twelve viral genome contigs corresponding to ten distinct viruses were assembled and annotated. Phylogenetic trees were constructed using replicase and NABP protein sequences. Results Six putative novel species were identified within the genera Citrivirus, Prunevirus, and a potential new genus. Aquilaria sinensis virus 1 (AquSiV1) encoded a NABP, making it the second known Citrivirus with a putative copy of this gene. Hippophae rhamnoides virus 1 (HipRhV1), which also encoded a NABP, formed a distinct lineage, possibly representing a novel genus. Phylogenetic analysis of NABPs revealed topologies incongruent with the replicase phylogeny, suggesting recurrent, independent acquisition events. Conclusion These findings expand the known genomic and taxonomic diversity of the genera Citrivirus and Prunevirus, and support the hypothesis that NABP genes have been independently and repeatedly acquired within the family Betaflexiviridae.

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