Subterranean Clover Stunt Virus Revisited: Detection of Two Missing Genome Components

Abstract

Subterranean clover stunt virus (SCSV) is a type species of the genus Nanovirus in the family Nanoviridae. It was the first single-stranded DNA plant virus with a multipartite genome, of which genomic DNA sequences had been determined. All nanoviruses have eight genome components except SCSV, for which homologs of two genome components present in all other nanovirus genomes, DNA-U2 and DNA-U4, were lacking. We analysed archived and more recent samples from SCSV-infected legume plants to verify its genome composition and found the missing genome components. These results indicated that SCSV also has eight genome components and is a typical member of the genus Nanovirus.