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. The name of the genus comes from Tomato bushy stunt virus.
Taxonomy
The genus contains the following species, listed by scientific name and followed by their common names:Tombusvirus algeriaense, Grapevine Algerian latent virusTombusvirus bulgariaense, Cucumber Bulgarian latent virusTombusvirus cucumis, Cucumber necrosis virusTombusvirus cymbidii, Cymbidium ringspot virusTombusvirus cynarae, Artichoke mottled crinkle virusTombusvirus dianthi, Carnation Italian ringspot virusTombusvirus havelfluminis, Havel River virusTombusvirus latofluminis, Lato River virusTombusvirus limonii, Limonium flower distortion virusTombusvirus lycopersici, Tomato bushy stunt virusTombusvirus melongenae, Eggplant mottled crinkle virusTombusvirus moroccoense, Moroccan pepper virusTombusvirus neckarfluminis, Neckar River virusTombusvirus necropelargonii, Pelargonium necrotic spot virusTombusvirus pelargonii, Pelargonium leaf curl virusTombusvirus petuniae, Petunia asteroid mosaic virusTombusvirus siktefluminis, Sikte waterborne virusStructure
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. 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 |
Life cycle
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.| Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
| Tombusvirus | Plants | - | 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.