| Potyviridae | |
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| Genome ofplum pox virus of genusPotyvirus withtransmission electron micrograph and model ofvirions | |
Virus classification | |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Orthornavirae |
| Phylum: | Pisuviricota |
| Class: | Stelpaviricetes |
| Order: | Patatavirales |
| Family: | Potyviridae |
| Genera | |
Potyviridae is a family ofpositive-strand RNA viruses that encompasses more than 30% of knownplant viruses,[1][2] many of which are of great agricultural significance. The family contains 13 genera that contain 259 species.[3][4][5][6]
Potyvirid virions are nonenveloped,flexuous filamentous, rod-shaped particles. The diameter is around 11–20 nm, with a length of 650–950 nm.[4][5]
Genomes are linear and usually nonsegmented, around 8–12kb in length,[4][5] consisting of positive-sense RNA, which is surrounded by a protein coat made up of a single viral encoded protein called acapsid. All induce the formation of virusinclusion bodies called cylindrical inclusions (‘pinwheels’) in their hosts. These consist of a single protein (about 70kDa) made in their hosts from a single viral genome product.[citation needed]
Member viruses encode large polypeptides that are cleaved into matureproteins. In 5'–3' order these proteins are
There may be some variation in the number of the proteins depending on the genera and species.[7] For instance some genera lack P1, some virus of the genusIpomovirus lack HC and have a P1 tandem. Pretty interesting sweet potato potyviral ORF (PISPO), alkylation B (AlkB), andinosine triphosphate pyrophosphatase (known as ITPase or HAM1) are protein domains identified in atypical members.[7][8]
Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration. Replication follows the positive-stranded RNA virus replication model. Positive-stranded RNA virus transcription is the method of transcription. Translation takes place by −1 ribosomal frameshifting. The virus exits the host cell by tubule-guided viral movement.[4][5] Plants serve as the natural host. The virus is transmitted via a vector (often an insect or mite). Transmission routes are vector and mechanical.[4][5]
Potyvirus is the largest genus in the family, with 183 known species.[9] These viruses are 720–850 nm in length and are transmitted byaphids. They can also be easily transmitted by mechanical means. These viruses shared a common ancestry 6,600 years ago[10] and are transmitted by over 200 species of aphids.[citation needed]
The species in the genusMacluravirus are 650–675 nm in length and are also transmitted by aphids. The plant viruses in the genusIpomovirus are transmitted bywhiteflies and they are 750–950 nm long.Tritimovirus and theRymovirus viruses are 680–750 nm long and are transmitted byeriophydid mites. (The rymoviruses are closely related to the potyviruses and may eventually be merged with the potyviruses.[11]) TheBymovirus genome consists of two particles instead of one (275 and 550 nm) and these viruses are transmitted by thechytrid fungus,Polymyxa graminis.[citation needed]
The family contains the following genera:[6]
Authority control databases: National |
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