Skip to main content
ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #234815
Title: Southern Tomato Virus: The Link between the Families Totiviridae and Partitiviridae

Author
item SABANADZOVIC, S - MISSISSIPPI STATE UNIV
item VLAVERDE, R - LOUISIANA STATE UNIV
item BROWN, J - UNIVERSITY OF ARIZONA
item Martin, Robert
item TZANETAKIS, I - UNIVERSITY OF ARKANSAS

Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2008
Publication Date: 3/1/2009
Citation: Sabanadzovic, S., Vlaverde, R.A., Brown, J.K., Martin, R.R., Tzanetakis, I.E. 2009. Southern tomato virus: the link between the families Totiviridae and Partitiviridae. Virus Research. 140(1-2):130-137.

Interpretive Summary: Three uncharacterized virus-like diseases have been reported in tomato in the Imperial Valley of California, in greenhouse-grown tomatoes in southwestern Mexico and field tomatoes in northeastern Mississippi. Common among the three diseases was the presence of a 3.5 kb dsRNA indicative of virus infection. After initial studies, collaborations were established among the research groups in Arizona, Louisiana, Mississippi and Oregon to compare the viruses identified in each situation. Initial partial sequences determined that the disease in each location was associated with the same dsRNA virus. After completing the sequence of the virus, it became clear that the virus was most closely related to a virus family that is known to infect fungi and protozoa but not plant viruses. Diseased plants tested negative for the presence of endophytic fungi, and the virus was seed transmitted at very high rates. The virus has been tentatively named Southern tomato virus and represents a new lineage in the Totiviridae virus family and a species of a new taxonomic group of plant viruses.

Technical Abstract: A dsRNA virus with a genome of 3.5 kb was isolated from field and greenhouse-grown tomato plants of different cultivars and geographic locations in North America. Cloning and sequencing of the viral genome showed the presence of two partially overlapping open reading frames (ORFs) and a genomic organization resembling members of the family Totiviridae that comprises fungal and protozoan viruses but not plant viruses. The 5’-proximal ORF codes for a 377 amino acid-long protein of unknown function, whereas the product of ORF2 contains typical motifs of an RNA-dependant RNA polymerase and is likely expressed by a +1 ribosomal frame shift. Despite the similarity in the genome organization with members of the family Totiviridae, this virus shared very limited sequence homology with known totiviruses or with other viruses. Repeated attempts to detect the presence of an endophytic fungus as the possible host of the virus failed, supporting its phytoviral nature. The virus was efficiently transmitted by seed but not mechanically and/or by grafting. Phylogenetic analyses revealed that this virus, for which the name Southern tomato virus (STV) is proposed, belongs to a partitivirus-like lineage and represents a species of a new taxon of plant viruses.