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

Dennis Knierim,Tatiana Timchenko,Bruno Gronenborn,Heinrich-Josef Vetten,Paul Chu,John Thomas,Mark Schwinghamer,Stephan Winter,Quentin Barrière,Ioana Grigoras

doi:10.3390/v11020138

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.

Highlights

Nanovirids, members of the genera Babuvirus and Nanovirus of the Nanoviridae family, are plant viruses with a genome consisting of multiple circular single-stranded DNA molecules that are individually encapsidated in small isometric particles of about 20 nm in diameter [1]
Stem-loop regions of nanovirus DNA-U2 and DNA-U4 share longer stretches of sequence identity, which allowed the design of the primers nanoSTLdir and nanoSTLrev
Amplifications aimed at identifying DNA-U4 yielded three products for isolate 2534B and two products for isolate 3771A, the proportion of the latter differed slightly depending on the annealing temperature during PCR

Summary

Introduction

Nanovirids, members of the genera Babuvirus and Nanovirus of the Nanoviridae family, are plant viruses with a genome consisting of multiple circular single-stranded (ss) DNA molecules that are individually encapsidated in small isometric particles of about 20 nm in diameter [1]. These viruses are transmitted in a circulative persistent (non-propagative) manner by various aphid species [2]. Three other DNA molecules, DNA-U1, DNA-U2 and DNA-U4, are typical constituents of a nanovirus genome, the function of the proteins they encode are hitherto not known.

Methods

Results

Conclusion