''Carlavirus'', formerly known as the "

Carnation latent virus Carnation latent virus (CLV, or Carlavirus) is a plant pathogenic virus A viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter suscepti ...

group", is a genus of

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

es in the order ''

Tymovirales ''Tymovirales'' is an order of viruses with five families. The group consists of viruses which have positive-sense, single-stranded RNA genomes. Their genetic material is protected by a special coat protein. Description Tymoviruses are mainly ...

'', in the family ''

Betaflexiviridae ''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 mosa ...

''. Plants serve as natural hosts. There are 53 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 (2009). The genus is characterised by having six ORFs (

open reading frame In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible readin ...

s) including a TGB ( Triple Gene Block). 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 (6th report). In 2005 (8th report) it was placed in the '' Flexiviridae'' family, having previously been unassigned. The current position in the 9th report (2009) as a genus of the family ''Betaflexiviridae'' derives from the subsequent subdivision of ''Flexiviridae''.ICTV
CTV Taxonomy history: ''Carlavirus''
/ref> The following species are assigned to the genus: *'' Aconitum latent virus'' *''

American hop latent virus ''American hop latent virus'' (AHLV) is a plant pathogenic virus of the family '' Betaflexiviridae''. Its genome is about 8,600 nucleotides in length with a 3'-polyadenylate tail that contains a total of six open reading frame In molecular b ...

'' *'' Atractylodes mottle virus'' *'' Blueberry scorch virus'' *'' Butterbur mosaic virus'' *'' Cactus virus 2'' *'' Caper latent virus'' *''

'' *'' Chrysanthemum virus B *'' Cole latent virus'' *'' Coleus vein necrosis virus'' *''

Cowpea mild mottle virus Cowpea mild mottle virus (CPMMV) is a plant pathogenic virus of the family '' Betaflexiviridae'' that infects yardlong beans, soybeans and peanut The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or ...

'' *'' Cucumber vein-clearing virus'' *''

Daphne virus S Daphne virus S (DVS) is a plant virus that infects daphnes. Infection causes leaf distortion and chlorotic spot disease symptoms. Its genome is about 8,700 nucleotides in length and contains six open reading frames that encode for a viral repli ...

'' *'' Gaillardia latent virus'' *''

Garlic common latent virus ''Garlic common latent virus'' (GarCLV) is a plant virus member of the genus ''Carlavirus'' that has been found infecting garlic globally. Detection of the virus in leek and onion has also been reported. Epidemiology GarCLV main transmission is ...

'' *''

Helenium virus S Helenium virus S (HVS) is a plant pathogenic virus. External links Carlaviruses Viral plant pathogens and diseases {{Virus-plant-disease-stub ...

'' *'' Helleborus mosaic virus'' *'' Helleborus net necrosis virus'' *''

Hippeastrum latent virus ''Hippeastrum'' () is a genus of about 90 species and over 600 hybrids and cultivars of perennial herbaceous bulbous plants. They generally have large fleshy bulbs and tall broad leaves, generally evergreen, and large red or purple flowers. ...

'' *''

Hop latent virus A hop is a type of jump. Hop or hops may also refer to: Arts and entertainment * ''Hop'' (film), a 2011 film * Hop! Channel, an Israeli TV channel * '' House of Payne'', or ''HOP'', an American sitcom * Lindy Hop, a swing dance of the 1920s an ...

'' *''

Hop mosaic virus Hop mosaic virus (HpMV) is a pathogenic plant virus Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a hos ...

'' *''

Hydrangea chlorotic mottle virus ''Hydrangea'', () commonly named the hortensia, is a genus of over 75 species of flowering plants native to Asia and the Americas. By far the greatest species diversity is in eastern Asia, notably China, Korea, and Japan. Most are shrubs tall, ...

'' *''

Kalanchoe latent virus ''Kalanchoe'' , also written ''Kalanchöe'' or ''Kalanchoë'', is a genus of about 125 species of tropical, succulent plants in the stonecrop family Crassulaceae, mainly native to Madagascar and tropical Africa. A ''Kalanchoe'' species was one ...

'' *'' Ligustrum necrotic ringspot virus'' *'' Ligustrum virus A'' *'' Lily symptomless virus'' *'' Melon yellowing-associated virus'' *'' Mirabilis jalapa mottle virus'' *'' Narcissus common latent virus'' *'' Nerine latent virus'' *'' Passiflora latent virus'' *'' Pea streak virus'' *'' Phlox virus B'' *'' Phlox virus M'' *'' Phlox virus S'' *'' Poplar mosaic virus'' *'' Potato latent virus'' *'' Potato virus H'' *'' Potato virus M'' *'' Potato virus P'' *''

Potato virus S Potato virus S (PVS) is a plant pathogenic virus. It was first reported in Netherlands. PVS causes mild or no symptoms in most potato varieties. It is common in potatoes in many regions and does not cause significant yield losses. Field-grown pot ...

'' *'' Red clover vein mosaic virus'' *'' Sambucus virus C'' *'' Sambucus virus D'' *'' Sambucus virus E'' *'' Shallot latent virus'' *'' Sint-Jan onion latent virus'' *'' Strawberry pseudo mild yellow edge virus'' *'' Sweet potato C6 virus'' *'' Sweet potato chlorotic fleck virus'' *'' Verbena latent virus'' *'' Yam latent virus''

Virology

The virions are non enveloped, filamentous, 610–700 nanometers (nm) 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.

Transmission

Infection is at times spread by

aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

s in a semi-persistent mode, that is, the vector is infective for a number of hours.(Pimentel) Some species are transmitted by ''

Bemisia tabaci The silverleaf whitefly (''Bemisia tabaci'', also informally referred to as the sweet potato whitefly) is one of several species of whitefly that are currently important agriculture, agricultural pest (animal), pests. A review in 2011 concluded t ...

'' in a semi-persistent mode or through the seed.Astier S. Principles of Plant Virology p78 Most species infect only a few hosts and cause infections with few or no symptoms, for example, American hop latent virus and lily symptomless virus. Some, such as blueberry scorch virus and poplar mosaic virus, cause serious illnesses. (Foster)

References

Bibliography

*
Astier, S. ''Principles of Plant Virology''

Foster, Gary. "Carlavirus Isolation and RNA Extraction." Foster, Gary D. and Sally C. Taylorin. ''Plant Virology Protocols: From Virus Isolation to Transgenic Resistance.'' Page 145. 1998. Humana Press. Online. February 13, 2008.

Pimentel, David. ''Encyclopedia of Pest Management.''Page 407. CRC Press. 2002/ Google Books. Online February 13, 2008.
*

External links

The Taxonomicon. Online. February 28, 2008.

ICTV
{{Taxonbar, from=Q2939048 Carlaviruses Virus genera Viral plant pathogens and diseases