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 74 species in this genus. 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.The following species are assigned to the genus, listed by scientific name and followed by the exemplar virus of the species:Carlavirus alphacapsici, Pepper virus ACarlavirus alphacliviae, Clivia carlavirus ACarlavirus alphaconiti, Aconite virus ACarlavirus alphaligustri, Ligustrum virus ACarlavirus alpharosae, Rose virus ACarlavirus americanense, American hop latent virusCarlavirus atractylodis, Atractylodes mottle virusCarlavirus betachrysanthemi, Chrysanthemum virus BCarlavirus betagapanthi, Agapanthus carlavirus BCarlavirus betaphlocis, Phlox virus BCarlavirus betarosae, Rose virus BCarlavirus betulae, Birch carlavirusCarlavirus cacti, Cactus virus 2Carlavirus chisolani, Potato virus HCarlavirus chloroipomoeae, Sweet potato chlorotic fleck virusCarlavirus colei, Coleus vein necrosis virusCarlavirus cornutum, Sint-Jan onion latent virusCarlavirus cucumis, Cucumber vein-clearing virusCarlavirus deltasambuci, Sambucus virus DCarlavirus duocacti, Cactus carlavirus 2Carlavirus duopseudostellariae, Pseudostellaria heterophylla carlavirus 2Carlavirus epsilonsambuci, Sambucus virus ECarlavirus fragariae, Strawberry pseudo mild yellow edge virusCarlavirus gammasambuci, Sambucus virus CCarlavirus hellebori, Helleborus mosaic virusCarlavirus humuli, Hop mosaic virusCarlavirus hydrangeae, Hydrangea chlorotic mottle virusCarlavirus ipomoeae, Sweet potato C6 virusCarlavirus jasmini, Jasmine virus CCarlavirus latensaconiti, Aconitum latent virusCarlavirus latensallii, Garlic common latent virusCarlavirus latensascalonici, Shallot latent virusCarlavirus latensbrassicae, Cole latent virusCarlavirus latenscapparis, Caper latent virusCarlavirus latensdianthi, Carnation latent virusCarlavirus latensdioscoreae, Yam latent virusCarlavirus latensgaillardiae, Gaillardia latent virusCarlavirus latenshippeastri, Hippeastrum latent virusCarlavirus latenshumuli, Hop latent virusCarlavirus latenskalanchoe, Kalanchoe latent virusCarlavirus latensnarcissi, Narcissus common latent virusCarlavirus latensnerinis, Nerine latent virusCarlavirus latensolani, Potato latent virusCarlavirus latenspassiflorae, Passiflora latent virusCarlavirus latensverbenae, Verbena latent virusCarlavirus lilii, Lily symptomless virusCarlavirus maculapapayae, Papaya mottle-associated virusCarlavirus melonis, Melon yellowing-associated virusCarlavirus miphlocis, Phlox virus MCarlavirus mirabilis, Mirabilis jalapa mottle virusCarlavirus misolani, Potato virus MCarlavirus mitipapayae, Papaya mild mottle associated virusCarlavirus necroligustri, Ligustrum necrotic ringspot virusCarlavirus necroretis, Helleborus net necrosis virusCarlavirus oleraceae, Cole mild mosaic virusCarlavirus petasitis, Butterbur mosaic virusCarlavirus pisi, Pea streak virusCarlavirus pisolani, Potato virus PCarlavirus populi, Poplar mosaic virusCarlavirus rhochrysanthemi, Chrysanthemum virus RCarlavirus sigmadaphnis, Daphne virus SCarlavirus sigmahelenii, Helenium virus SCarlavirus sigmaphlocis, Phlox virus SCarlavirus sigmascalonici, Shallot virus SCarlavirus sigmasolani, Potato virus SCarlavirus sigmavaccinii, Blueberry virus SCarlavirus trifolii, Red clover vein mosaic virusCarlavirus tripseudostellariae, Pseudostellaria heterophylla carlavirus 3Carlavirus unicacti, Cactus carlavirus 1Carlavirus uniglycinis, Soybean carlavirus 1Carlavirus unipseudostellariae, Pseudostellaria heterophylla carlavirus 1Carlavirus unisteviae, Stevia carlavirus 1Carlavirus vaccinii, Blueberry scorch virusCarlavirus vignae, Cowpea mild mottle virus
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 |