''Closterovirus'', also known as beet yellows viral group, is a genus of

viruses 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 Ivanovsky's 1 ...

, in the family ''

Closteroviridae ''Closteroviridae'' is a family of viruses. Plants serve as natural hosts. There are four genera and 59 species in this family, seven of which are unassigned to a genus. Diseases associated with this family include: yellowing and necrosis, parti ...

''. Plants serve as natural hosts. There are 17 species in this genus. Diseases associated with this genus include: yellowing and necrosis, particularly affecting the phloem. This genus has a probably worldwide distribution and includes among other

viral species Virus classification is the process of naming viruses and placing them into a taxonomic system similar to the classification systems used for cellular organisms. Viruses are classified by phenotypic characteristics, such as morphology, nucleic ...

the ''

Beet yellows virus Beet yellows virus (BYV) is a plant pathogenic virus of the family '' Closteroviridae''. Beet yellows virus is transmitted by multiple species of aphid and causes a yellowing disease in ''Beta vulgaris'' and ''Spinacia oleracea Spinach ('' ...

'' (the type species) and ''

Citrus tristeza virus Citrus tristeza virus (CTV) is a viral species of the genus ''Closterovirus'' that causes the most economically damaging disease to its namesake plant genus, ''Citrus''. The disease has led to the death of millions of ''Citrus'' trees all over ...

'', rather economically important plant diseases. At least some species require vectors such as

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 or

mealybug Mealybugs are insects in the family (biology), family Pseudococcidae, unarmored scale insects found in moist, warm habitats. Many species are considered pest (animal), pests as they feed on plant juices of greenhouse plants, house plants and sub ...

s for their transmission from plant to plant.

Taxonomy

The following species are assigned to the genus: * '' Arracacha virus 1'' * '' Beet yellow stunt virus'' * ''

'' * '' Blackcurrant closterovirus 1'' * '' Burdock yellows virus'' * ''

Carnation necrotic fleck virus Carnation necrotic fleck virus (CNFV) is a plant pathogenic virus of the family ''Closteroviridae ''Closteroviridae'' is a family of viruses. Plants serve as natural hosts. There are four genera and 59 species in this family, seven of which ...

'' * '' Carrot closterovirus 1'' * '' Carrot yellow leaf virus'' * ''

'' * ''

Grapevine leafroll-associated virus 2 Grapevine leafroll-associated virus 2 (GRLaV2) is a virus infecting grapevine in the genus '' Closterovirus''. It is associated with rugose wood condition of grapevine.According to Bosciai, 1995, ''grapevine corky bark-associated virus'' (GCBaV) i ...

'' * '' Mint virus 1'' * ''

Raspberry leaf mottle virus The raspberry is the edible fruit of a multitude of plant species in the genus ''Rubus'' of the rose family, most of which are in the subgenus '' Idaeobatus''. The name also applies to these plants themselves. Raspberries are perennial with ...

'' * '' Rehmannia virus 1'' * '' Rose leaf rosette-associated virus'' * '' Strawberry chlorotic fleck-associated virus'' * '' Tobacco virus 1'' * '' Wheat yellow leaf virus''

RNA pseudoknot

The viral RNA molecules of some members of this genus contain four hair-pin structures and a

pseudoknot __NOTOC__ A pseudoknot is a nucleic acid secondary structure containing at least two stem-loop structures in which half of one stem is intercalated between the two halves of another stem. The pseudoknot was first recognized in the turnip yellow ...

in the 3'UTR. These secondary structures have been found to be important in viral RNA replication.

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 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.

Structure

Viruses in ''Closterovirus'' are non-enveloped, with flexuous and filamentous geometries. The diameter is around 10-13 nm, with a length of 1250-2200 nm. Genomes are linear, around 19.3kb in length.

References

External links

ICTV Report: ''Closteroviridea''

* {{Taxonbar, from=Q5135471 Closteroviridae Viral plant pathogens and diseases Virus genera