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 mosaic and ringspot symptoms.

Betaflexiviridae
TEM showing CPMMV particles in sap of symptomatic yardlong bean leaf. Bar = 100 nm
Virus classification
(unranked):	Virus
Realm:	Riboviria
Kingdom:	Orthornavirae
Phylum:	Kitrinoviricota
Class:	Alsuviricetes
Order:	Tymovirales
Family:	Betaflexiviridae
Subtaxa
See text

The following subfamilies and genera are recognized:

• Quinvirinae
  • Carlavirus
  • Foveavirus
  • Robigovirus
  • Plus three unassigned species:
    • Banana mild mosaic virus
    • Banana virus X
    • Sugarcane striate mosaic-associated virus
• Trivirinae
  • Capillovirus
  • Chordovirus
  • Citrivirus
  • Divavirus
  • Prunevirus
  • Ravavirus
  • Tepovirus
  • Trichovirus
  • Vitivirus
  • Wamavirus

Viruses in Betaflexiviridae are non-enveloped, with flexuous and Filamentous geometries. The diameter is approximately 12–13 nm. Genomes are linear, around 6.5–9kb in length. The genome codes for 2 to 6 proteins.

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, and tubule-guided viral movement. Plants and fungi serve as the natural host. The virus is transmitted via a vector (insects). Transmission routes are vector and mechanical.