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

Area of Science:

• Plant Virology
• Molecular Biology
• Genomics

Background:

• Subterranean clover stunt virus (SCSV) is the type species of *Nanovirus*.
• It was the first single-stranded DNA plant virus with a determined multipartite genome.
• SCSV was previously believed to have only six genome components, lacking homologs of DNA-U2 and DNA-U4 found in other nanoviruses.

Purpose of the Study:

• To verify the complete genome composition of Subterranean clover stunt virus (SCSV).
• To determine if SCSV possesses the two previously missing genome components (DNA-U2 and DNA-U4).
• To confirm SCSV's status as a typical member of the *Nanovirus* genus.

Main Methods:

• Analysis of archived SCSV-infected legume plant samples.
• Analysis of recent SCSV-infected legume plant samples.
• Genomic DNA sequencing and component verification.

Main Results:

• The previously missing genome components, DNA-U2 and DNA-U4 homologs, were identified in SCSV.
• Analysis confirmed that SCSV possesses eight genome components, consistent with other nanoviruses.
• SCSV is a typical representative of the *Nanovirus* genus.

Conclusions:

• Subterranean clover stunt virus (SCSV) possesses a complete set of eight genome components.
• SCSV is confirmed as a typical member of the *Nanovirus* genus.
• This finding resolves previous discrepancies in nanovirus genome composition.