Varicosavirus
From MicrobeWiki, the student-edited microbiology resource
A Viral Biorealm page on the genus Varicosavirus
Contents |
Baltimore Classification
Higher order taxa
Virus; dsRNA viruses; (no assigned family); varicosavirus
Species
Lettuce big-vein associated virus, Tobacco stunt virus, Camellia yellow mottle virus, and Freesia leaf necrosis virus
Description and Significance
Varicosaviruses cause infections in plants. The genus Varicosavirus is named for the swollen (or varicose) veins that Lettuce big-vein associated virus (the type member of the genus) was thought to cause. Recent studies have shown, however, that this symptom might also be caused by Mirafiori lettuce virus, which is in the genus Ophiovirus. (sources: Descriptions of Plant Viruses, Sasaya et al.)
Genome Structure
The varicosavirus genome consists of bipartite, linear, double-stranded RNA. The genome is segmented and is 11980-12740-13500 nucleotides in length. The segments are distributed among two particle types of the RNA. RNA-1 is sequenced, and complete sequence is about 6350-6675-7000 nucleotides in length. RNA-2 is sabout 5630-6065-6500 nucleotides in length. (source: ICTVdB)
Virion Structure of a Varicosavirus
Varacosavirus virions consist of a non-enveloped rod-shaped capsid. The capsid has helical symmetry, is 120-360nm long, and is 18-22-30nm wide. (source: ICTVdB)
Reproduction Cycle of a Varicosavirus in a Host Cell
Viral Ecology & Pathology
Varicosaviruses infect plants. The virus is transmitted through soil by the spores of the fungus Olpidium brassicae (order Chytridiales). Control of varicosaviruses is difficult once soil is contaminated because the virus is stably retained in resting spores. This is the only way of transmission of varicosaviruses. (sources: Sasaya et al., ICTVdB, Descriptions of Plant Viruses)
References
Descriptions of Plant Viruses: Notes on Genus: Varacosavirus
ICTVdB - The Universal Virus Database, version 4. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/
Sasaya et al. "The Nucleotide Sequence of RNA1 of Lettuce big-vein virus, Genus Varicosavirus, Reveals Its Relation to Nonsegmented Negative-Strand RNA Viruses." Virology 297.2 (2002): 289-297.
