Molecular characterization and identification of Stellaria aquatica virus C, a novel putative member of the genus Closterovirus infecting Stellaria aquatica in South Korea

A novel virus infecting Stellaria aquatica plants, tentatively named "Stellaria aquatica virus C" (StAVC), was identified in Gangwon-do Province, South Korea. Its monopartite genome consists of a single-stranded RNA of 15,024 nucleotides, and it shares 38.24 to 56.2% nucleotide sequence identity with known closterovirus genome sequences. Its genome contains nine hypothetical open reading frames. These encode the multifunctional protein RNA-dependent RNA polymerase (RdRp), hydrophobic protein (P7), heat shock protein 70 homolog (HSP70h), coat protein homolog (CPh), minor coat protein (CPm), and major coat protein (CP), along with proteins involved in suppressing RNA silencing. Phylogenetic analysis reveals that, based on its HSP70h amino acid sequence, StAVC is closely related to members of the genus Closterovirus within the family Closteroviridae. This is the first record of the full genome sequence of StAVC in South Korea.