Tobamovirus
Encyclopedia
The genus Tobamovirus contains viruses with a positive sense RNA
genome that infect plants. The most common tobamovirus is probably tobacco mosaic virus
, which infects tobacco
and other plants including potato
, tomato
, and squash. The name Tobamovirus comes from the host and symptoms: Toba for Tobacco
and mo for mosaic. There are four subgroups within this genus; the brassicas
, cucurbits
, malvaceous
and solanaceous
infecting tobamoviruses. The main differences between these groups are genome sequence and range of host plants.
and the read through product which are involved in virus replication, the movement protein which is necessary for the virus to move between cells and the coat protein. The virus is able to replicate without the movement or coat proteins but the other two are essential. The non-structural protein has domains suggesting it is involved in RNA capping and the read through product has a motif for an RNA polymerase. The movement proteins are made very early in the infection cycle and localized to the plasmodesmata
, they are probably involved in host specificity as they are believed to interact with some host cell factors.
methylesterase, a cellular enzyme
important for cell wall metabolism and plant development, with the movement protein has been implicated.
Tentative members of the Tobamovirus genus include:
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
genome that infect plants. The most common tobamovirus is probably tobacco mosaic virus
Tobacco mosaic virus
Tobacco mosaic virus is a positive-sense single stranded RNA virus that infects plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns on the leaves . TMV was the first virus to be discovered...
, which infects tobacco
Tobacco
Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...
and other plants including potato
Potato
The potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
, tomato
Tomato
The word "tomato" may refer to the plant or the edible, typically red, fruit which it bears. Originating in South America, the tomato was spread around the world following the Spanish colonization of the Americas, and its many varieties are now widely grown, often in greenhouses in cooler...
, and squash. The name Tobamovirus comes from the host and symptoms: Toba for Tobacco
Tobacco
Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...
and mo for mosaic. There are four subgroups within this genus; the brassicas
Brassica
Brassica is a genus of plants in the mustard family . The members of the genus may be collectively known either as cabbages, or as mustards...
, cucurbits
Cucurbitaceae
The plant family Cucurbitaceae consists of various squashes, melons, and gourds, including crops such as cucumber, pumpkins, luffas, and watermelons...
, malvaceous
Malvaceae
Malvaceae, or the mallow family, is a family of flowering plants containing over 200 genera with close to 2,300 species. Judd & al. Well known members of this family include okra, jute and cacao...
and solanaceous
Solanaceae
Solanaceae are a family of flowering plants that include a number of important agricultural crops as well as many toxic plants. The name of the family comes from the Latin Solanum "the nightshade plant", but the further etymology of that word is unclear...
infecting tobamoviruses. The main differences between these groups are genome sequence and range of host plants.
Genome
The RNA genome encodes four polypeptides; the non-structural proteinNonstructural protein
In virology, a nonstructural protein is a protein encoded by a virus but it is not part of the viral particle....
and the read through product which are involved in virus replication, the movement protein which is necessary for the virus to move between cells and the coat protein. The virus is able to replicate without the movement or coat proteins but the other two are essential. The non-structural protein has domains suggesting it is involved in RNA capping and the read through product has a motif for an RNA polymerase. The movement proteins are made very early in the infection cycle and localized to the plasmodesmata
Plasmodesmata
Plasmodesmata are microscopic channels which traverse the cell walls of plant cells and some algal cells, enabling transport and communication between them. Species that have plasmodesmata include members of the Charophyceae, Charales and Coleochaetales , as well as all embryophytes, better known...
, they are probably involved in host specificity as they are believed to interact with some host cell factors.
Routes of Infection
The infection is localized to begin with but if the virus remains unchallenged it will spread via the vascular system into a systemic infection. The exact mechanism the virus uses to move throughout the plant is unknown but the interaction of pectinPectin
Pectin is a structural heteropolysaccharide contained in the primary cell walls of terrestrial plants. It was first isolated and described in 1825 by Henri Braconnot...
methylesterase, a cellular enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
important for cell wall metabolism and plant development, with the movement protein has been implicated.
Members
Definitive members of the Tobamovirus genus:- Tobacco mosaic virusTobacco mosaic virusTobacco mosaic virus is a positive-sense single stranded RNA virus that infects plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns on the leaves . TMV was the first virus to be discovered...
(TMV) - Bell pepper mosaic virus (BPeMV)
- Cactus mild mottle virus (CMMoV)
- Cucumber green mottle mosaic virusCucumber green mottle mosaic virusCucumber green mottle mosaic virus is a plant pathogenic virus.In Europe this virus disease is found since 1965–1975. Watermelon and melon are also susceptible to this virus.Symptoms:...
(CGMMV) - Cucumber virus 4 (CV4)
- Frangipani virus (FV)
- Hibiscus latent Fort Pierce virus (HLFPV)
- Hibiscus latent Singapore virus (HLSV)
- Maracuja mosaic virus (MarMV)
- Odontoglossum ringspot virusOdontoglossum ringspot virusOdontoglossum ringspot virus ' is a plant pathogenic virus. It is one of the most common viruses affecting cultivated orchids, perhaps second only to the Cymbidium mosaic virus. It causes spots on leaves and colored streaks on flowers. If a plant is also infected with the Cymbidium mosaic virus,...
(ORSV) - Rattail cactus necrosis associated virus (RCNaV)
- Ribgrass mosaic virus (HRV)
- Sammons' opuntia virus (SOV)
- Sunn-hemp mosaic virus (SHMV)
- Tomato mosaic virusTomato mosaic virusTomato mosaic virus is a plant pathogenic virus. It is found worldwide and affects tomatoes and many other plants.-Symptoms:The foliage of affected tomato plants shows mottling, with alternating yellowish and darker green areas, the latter often appearing thicker and raised giving a blister-like...
(ToMV) and U2 - tobacco mosaic virus (T2MV) - Turnip vein-clearing virus (TVCV)
- Wasabi mottle virus (WMoV)
- Youcai mosaic virus (YoMV) aka oilseed rape mosaic virus (ORMV)
Tentative members of the Tobamovirus genus include:
- BeetBeetThe beet is a plant in the Chenopodiaceae family which is now included in Amaranthaceae family. It is best known in its numerous cultivated varieties, the most well known of which is the purple root vegetable known as the beetroot or garden beet...
necrotic yellow vein virus (BNYVV) - Chara corallina virus (CCV)
- NicotianaNicotianaNicotiana is a genus of herbs and shrubs of the nightshade family indigenous to North and South America, Australia, south west Africa and the South Pacific. Various Nicotiana species, commonly referred to as tobacco plants, are cultivated and grown to produce tobacco. Of all Nicotiana species,...
velutina mosaic virus (NVMV) - PeanutPeanutThe peanut, or groundnut , is a species in the legume or "bean" family , so it is not a nut. The peanut was probably first cultivated in the valleys of Peru. It is an annual herbaceous plant growing tall...
clump virus (PCV) - PotatoPotatoThe potato is a starchy, tuberous crop from the perennial Solanum tuberosum of the Solanaceae family . The word potato may refer to the plant itself as well as the edible tuber. In the region of the Andes, there are some other closely related cultivated potato species...
mop-top virus (PMTV) - Soil-borne wheatWheatWheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
mosaic virus (SBWMV) - Streptocarpus flower break virus (SFBV)
- cucumber green mottle mosaic virus (CGMMV)
- cucumber fruit mottle mosaic virus (CFMMV)