Carlavirus
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 currently 53 species in this genus including the type species Carnation latent virus. Diseases associated with this genus include: mosaic and ringspot symptoms.
Description
Carlavirus is described in the 9th report of the ICTV. The genus is characterised by having six ORFs including a TGB. The viruses are transmitted by insects.Taxonomy
The genus was first proposed in the first report of the ICTV in 1971, as the 'Carnation latent virus group' but was renamed in 1975 as the 'Carlavirus Group', and as the genus Carlavirus in 1995. In 2005 it was placed in the Flexiviridae family, having previously been unassigned. The current position in the 9th report as a genus of the family Betaflexiviridae derives from the subsequent subdivision of Flexiviridae.Group: ssRNA
Virology
The virions are non enveloped, filamentous, 610–700 nanometers and 12–15 nm in diameter.The linear 5.8–9 kilobase genome is positive sense, single-stranded RNA. The 3’ terminus is polyadenylated. In some species the 5’ end is capped. The genome encodes 3 to 6 proteins including a coat protein located at the 3' end and an RNA-dependent RNA polymerase located at the 5' end of the genome.
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 is the method of transcription. The virus exits the host cell by tripartite non-tubule guided viral movement. Plants serve as the natural host.| Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
| Carlavirus | Plants | - | Viral movement; mechanical inoculation | Viral movement | Cytoplasm | Cytoplasm | Mechanical: insects |