| Tombusvirus | |
|---|---|
Virus classification  | |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Orthornavirae |
| Phylum: | Kitrinoviricota |
| Class: | Tolucaviricetes |
| Order: | Tolivirales |
| Family: | Tombusviridae |
| Subfamily: | Procedovirinae |
| Genus: | Tombusvirus |
Tombusvirus is a genus of viruses, in the family Tombusviridae . Plants serve as natural hosts. There are 17 species in this genus. Symptoms associated with this genus include mosaic. [1] [2] The name of the genus comes from Tomato bushy stunt virus.
The genus contains the following species: [2]
Viruses in Tombusvirus are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. The diameter is around 28-34 nm. Genomes are linear and non-segmented, positive sense, single-stranded RNA, around 4-5.4kb in length. [1] These virions have a regular surface structure and are composed of 17% nucleic acid.
| Genus | Structure | Symmetry | Capsid | Genomic arrangement | Genomic segmentation |
|---|---|---|---|---|---|
| Tombusvirus | Icosahedral | T=3 | Non-enveloped | Linear | Monopartite |
Viral replication is cytoplasmic, and is lysogenic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription, using the premature termination model of subgenomic RNA transcription is the method of transcription. Translation takes place by suppression of termination. The virus exits the host cell by tubule-guided viral movement. Plants serve as the natural host. Transmission routes are mechanical, seed borne, and contact. [1]
| Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
|---|---|---|---|---|---|---|---|
| Tombusvirus | Plants | None | Viral movement; mechanical inoculation | Viral movement | Cytoplasm | Cytoplasm | Mechanical: contact; seed |
The virus uses the cis-regulatory elements, Tombus virus defective interfering (DI) RNA region 3 and Tombusvirus 5' UTR to control expression of defective interfering RNAs and viral RNA replication. [3] [4]
A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major classes: satellite viruses and satellite nucleic acids. Satellite viruses, which are most commonly associated with plants, are also found in mammals, arthropods, and bacteria. They encode structural proteins to enclose their genetic material, which are therefore distinct from the structural proteins of their helper viruses. Satellite nucleic acids, in contrast, do not encode their own structural proteins, but instead are encapsulated by proteins encoded by their helper viruses. The genomes of satellites range upward from 359 nucleotides in length for satellite tobacco ringspot virus RNA (STobRV).
Tombusviridae is a family of single-stranded positive sense RNA plant viruses. There are three subfamilies, 17 genera, and 95 species in this family. The name is derived from Tomato bushy stunt virus (TBSV).
Tobamovirus is a genus of positive-strand RNA viruses in the family Virgaviridae. Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name Tobamovirus comes from the host and symptoms of the first virus discovered.
Furovirus is a genus of viruses, in the family Virgaviridae. Graminae, winter wheat, wheat, triticale, oat, sorghum bicolor, and plants serve as natural hosts. There are six species in this genus. Diseases associated with this genus include: (SBWMV): green and yellow mosaic.
Tomato bushy stunt virus (TBSV) is a virus of the tombusvirus family. It was first reported in tomatoes in 1935 and primarily affects vegetable crops, though it is not generally considered an economically significant plant pathogen. Depending upon the host, TBSV causes stunting of growth, leaf mottling, and deformed or absent fruit. The virus is likely to be soil-borne in the natural setting, but can also transmitted mechanically, for example through contaminated cutting tools. TBSV has been used as a model system in virology research on the life cycle of plant viruses, particularly in experimental infections of the model host plant Nicotiana benthamiana.
Nepovirus is a genus of viruses in the order Picornavirales, in the family Secoviridae, in the subfamily Comovirinae. Plants serve as natural hosts. There are 40 species in this genus. Nepoviruses, unlike the other two genera in the subfamily Comovirinae, are transmitted by nematodes.
Dianthovirus is a genus of viruses, in the family Tombusviridae. Dianthoviruses are plant viruses. There are three species in this genus. The virus probably has a worldwide distribution, and can be transmitted via nematodes, by mechanical inoculation, by grafting of plants and by contact between infected hosts with previously uninfected host.
Tombusvirus 5′ UTR is an important cis-regulatory region of the Tombus virus genome.
Ilarvirus is a genus of positive-strand RNA viruses in the family Bromoviridae. Plants serve as natural hosts. There are 22 species in this genus.
Tobravirus is a genus of viruses, in the family Virgaviridae. Plants serve as natural hosts. There are three species in this genus. Diseases associated with this genus include: SBWMV: green and yellow mosaic.
Carlavirus, formerly known as the "Carnation latent virus group", is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants serve as natural hosts. There are 53 species in this genus. Diseases associated with this genus include: mosaic and ringspot symptoms.
Cucumovirus is a genus of viruses, in the family Bromoviridae. Plants serve as natural hosts. There are four species in this genus.
Alphaflexiviridae is a family of viruses in the order Tymovirales. Plants and fungi serve as natural hosts. There are 65 species in this family, assigned to six genera. Diseases associated with this family include: mosaic and ringspot symptoms.
Betaflexiviridae is a family of viruses in the order Tymovirales. Plants and fungi serve as natural hosts. There are 108 species in this family, assigned to 13 genera in two subfamilies. Diseases associated with this family include mosaic and ringspot symptoms.
Allexivirus is a genus of viruses in the order Tymovirales, in the family Alphaflexiviridae. Shallot, onion, and garlic serve as natural hosts. There are 13 species in this genus, seven of which are assigned to a subgenus. Diseases associated with this genus include: mosaic and ringspot symptoms.
Aureusvirus is a genus of viruses, in the family Tombusviridae. Plants serve as natural hosts. There are six species in this genus.
Foveavirus is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants serve as natural hosts. There are eight species in this genus. Diseases associated with this genus include: mosaic and ringspot symptoms.
Mandarivirus is a subgenus of viruses in the order Tymovirales, family Alphaflexiviridae, genus Potexvirus. There are three species in this subgenus. Diseases associated with this subgenus commonly include yellow ringspot and rapid decline of the tree.
Alphanecrovirus is a genus of viruses, in the family Tombusviridae. Plants serve as natural hosts. There are four species in this genus.
Gallantivirus is a genus of viruses, in the family Tombusviridae. Plants serve as natural hosts. There is only one species in this genus: Galinsoga mosaic virus. Diseases associated with this genus include: chlorotic or necrotic local lesions, systemic mosaic; leaf malformation.