Tomato spotted wilt virus
4215281
174119791
2007-11-27T12:20:15Z
83.7.156.23
{{Taxobox
| color=violet
| name = Tomato spotted wilt virus (TSWV)
| virus_group = V: (-) sense RNA Viruses
| familia = [[Bunyaviridae]]
| genus = [[Tospovirus]]
| species = Tomato spotted wilt virus
| synonyms =
}}
The '''Tomato Spotted Wilt Virus''' (TSWV) is a type [[species]] of the [[Tospovirus]] genus which is a member of the [[Bunyaviridae]] family. TSWV is a [[plant virus]] that has a broad host range and can infect over 800 different plant species from 82 different families. Some of the most common hosts are tomato, pepper, many other vegetables and ornamental plants. The TSWV is transmitted from plant to plant by insect vectors that include several species of [[thrips]].
== Genome ==
This virus has a single stranded [[RNA]] [[genome]] with negative polarity, therefore it is classified as a Class V virus ([[(-)ssRNA viruses]]). The structure of the genome resembles that of the genus [[Phlebovirus]]. The genome is linear and is 17.2 kb in size. It is segmented into three segments termed S (2.9kb), M (5.4kb) and L (8.9kb). The M and S RNA segments encode for proteins in an ambisense orientation.
== Disease ==
Early symptoms of infection are difficult to diagnose. In young infected plants the characteristic symptoms consist of inward cupping of leaves and leaves that develop a bronze cast followed by dark spots. As the infection progresses additional symptoms develop which include dark streaks on the main stem and wilting of the top portion of the plant. [[Fruit]] may be deformed, show uneaven ripening and often have raised bumps on the surface. Once a plant becomes infected the disease cannot be controlled.
== Epidemology ==
TSWV is prevalent in warm climates in regions with a high population of thrips. This virus is an agricultural pest in Asia, America, Europe and Africa. Over the past 15 years outbreaks of Tomato spotted wilt disease have become more prevalent in these regions. Therefore TSWV is described as an emerging viral disease of plants. The increased prevalence is largely because of the successful survival of the thrips vector ''[[Frankliniella occidentalis]]''. However, the successfulness of this virus is also attributed to the acquisition of a gene in the M segment of the genome which encodes a [[movement protein]]. This protein allows the virus to infect a range of hosts. The gene encoding this protein was likely acquired by recombination from either a plant host or from another plant virus.
== Prevention of Spotted Wilt disease ==
Control of this disease is difficult. One of the reasons for this is that the wide host range allows the virus to successfully overseason from one crop to the next. To prevent spread of the virus infected plants should be immediately removed away from neighbouring plants to prevent spread of the virus. Control of insects, especially thrips, is important to reduce spread of the virus by vectors.
== References ==
*[http://www.oznet.ksu.edu/dp_hfrr/extensn/problems/tomswv.htm Tomato Spotted Wilt Virus]
*[http://image.fs.uidaho.edu/vide/descr837.htm Plant Viruses Online – Tomato Spotted Wilt tospovirus]
*[http://www.apsnet.org/online/feature/tospovirus/ APSnet feature story on Tospoviruses]
*Raccah. B (2000). ''Plant Virus Transmission by Insects. In: Encyclopedia of Life Sciences''. John Wiley & Sons, Ltd: Chichester. www.els.net [doi:10.1038/npg.els.0000760]
*[http://phene.cpmc.columbia.edu/ICTVdB/00.011.0.05.001.htm ICTVdB - The Universal Virus Database: Tomato spotted wilt virus]
*[http://www.virology.net/Big_Virology/BVFamilyGroup.html Family Groups - The Baltimore Method]
[[Category:Bunyaviruses]]
[[Category:Tomato pathogens and pests]]
[[Category:Plant pathogens and diseases]]
{{virus-plant-disease-stub}}