Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/2/2005
Publication Date: 6/1/2005
Citation: Tzanetakis, I.E., Postman, J.D., Martin, R.R. 2005. a member of the closteroviridae from mint with similarities to all three genera of the family.. Plant Disease. 89(6):654-658. Interpretive Summary: int (Mentha sp.) is a member of the family Lamiaceae and consists of about 30 species. Mint has been cultivated for thousands of years for the volatile oils that give the plant its unique fragrance and several species are used in the food and medical industry while some are grown as ornamentals. Several Mentha clones in the National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon, exhibited symptoms typical of virus infection. One of the ornamental clones, M. × gracilis ‘Variegata’ (NCGR MEN 454.001) had dramatic vein-banding symptoms that were graft-transmissible and could be eliminated by heat therapy and apical meristem culture. Symptoms become less dramatic during summer months. These observations indicated that symptomatology may be virus-induced. Double-stranded RNA (dsRNA) was extracted and cloned from NCGR clone MEN 454.001. Three viruses were identified in this clone: Strawberry latent ringspot virus, Mint virus X, a newly described potexvirus, and a newly identified virus belonging to the family Closteroviridae, which is described in this paper. The virus was partially sequenced and a method for rapid detection was developed. The virus was also found in other clones and species of mint at the NCGR as well as from nurseries in the United States. This virus was unique in that it showed homology with members of all three genera of the closteroviruses, suggesting that it may be a progenitor of the virus family.
Technical Abstract: Mentha × gracilis ‘Variegata’ described more than 200 years ago, is still being used as an ornamental. The bright vein-banding symptoms that confer the ornamental value to ‘Variegata’ clones is graft transmissible and can be eliminated after heat therapy and apical meristem culture. This observation led us to investigate the possibility that symptoms are virus-induced. Double-stranded RNA extracted from a ‘Variegata’ clone was cloned. One of the viruses identified was a member of the Closteroviridae family. This virus designated as Mint vein-banding associated virus, shares sequence similarities with all three genera of the family making it an important link between the genera of the Closteroviridae. A detection protocol has been developed that readily detects the virus in other mint clones that also exhibit vein-banding symptoms.