Bromovirus is a genus of viruses, in the family Bromoviridae.[3] Plants serve as natural hosts. There are six species in this genus.[1][4]
| Bromovirus | |
|---|---|
 | |
| Transmission electron micrograph of brome mosaic virus (BMV) virions | |
 | |
| Crystal structure of Brome mosaic virus, PDB entry 1js9[2] | |
Virus classification  | |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Orthornavirae |
| Phylum: | Kitrinoviricota |
| Class: | Alsuviricetes |
| Order: | Martellivirales |
| Family: | Bromoviridae |
| Genus: | Bromovirus |
| Species[1] | |
| |
Taxonomy
The following species are assigned to the genus:[1]
- Broad bean mottle virus
- Brome mosaic virus
- Cassia yellow blotch virus
- Cowpea chlorotic mottle virus
- Melandrium yellow fleck virus
- Spring beauty latent virus
Structure
Viruses in the genus Bromovirus are non-enveloped, with icosahedral geometries, and T=3 symmetry. The diameter is around 26 nm. Genomes are linear and segmented, tripartite.[1][4]
| Genus | Structure | Symmetry | Capsid | Genomic arrangement | Genomic segmentation |
|---|---|---|---|---|---|
| Bromovirus | Icosahedral | T=3 | Non-enveloped | Linear | Segmented |
Life cycle
Viral replication is cytoplasmic. 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 internal initiation model of subgenomic RNA transcription is the method of transcription. The virus exits the host cell by tubule-guided viral movement. Plants serve as the natural host. Transmission routes are mechanical and contact.[1][4]
| Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
|---|---|---|---|---|---|---|---|
| Bromovirus | Plants | None | Viral movement; mechanical inoculation | Viral movement | Cytoplasm | Cytoplasm | Mechanical inoculation: insects; contact |
Recombination
Brome mosaic virus (BMV) genomes are able to undergo RNA-RNA homologous recombination upon infection of plant cells.[5] The RNA-dependent RNA polymerase specified by the BMV genome appears to undergo template switching (copy choice) recombination during viral RNA synthesis.[6]