Nanovirus

Nanovirus
Faba bean necrotic yellows virus (FBNYV)
Virus classification
(unranked):	Virus
Realm:	Monodnaviria
Kingdom:	Shotokuvirae
Phylum:	Cressdnaviricota
Class:	Arfiviricetes
Order:	Mulpavirales
Family:	Nanoviridae
Genus:	Nanovirus

Nanovirus is a genus of viruses, in the family Nanoviridae.^[1] Legume plants serve as natural hosts. There are 11 species in this genus. Diseases associated with this genus include: stunting, severe necrosis and early plant death.^[1][2][3]

Taxonomy

The following 11 species are assigned to the genus:^[3]

• Black medic leaf roll virus
• Cow vetch latent virus
• Faba bean necrotic stunt virus
• Faba bean necrotic yellows virus
• Faba bean yellow leaf virus
• Milk vetch dwarf virus
• Parsley severe stunt associated virus
• Pea necrotic yellow dwarf virus
• Pea yellow stunt virus
• Sophora yellow stunt virus
• Subterranean clover stunt virus

Structure and genome

Genome map of species Faba bean necrotic yellows virus (FBNYV) showing 8 segments.

Virions in the genus Nanovirus are non-enveloped, with icosahedral and round geometries, and T=1 symmetry. The diameter is around 18-19 nm.

The genome is multipartite, and the genome components (6 or 8, depending on the genus) are circular, around 1kb in length, essentially carry only one gene, and are individually encapsidated forming small icosahedral virions (18–20 nm).^[2][4]

Genus	Structure	Symmetry	Capsid	Genomic arrangement	Genomic segmentation
Nanovirus	Icosahedral	T=1	Non-enveloped	Circular	Segmented

Life cycle

Viral replication is nuclear. Entry into the host cell is achieved by penetration into the host cell. Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exits the host cell by nuclear pore export, and tubule-guided viral movement. Legume plants serve as the natural host. The virus is transmitted via a vector (the virus does not replicate in this). Transmission routes are vector.^[1][2]

Genus	Host details	Tissue tropism	Entry details	Release details	Replication site	Assembly site	Transmission
Nanovirus	Plants: legumes	Phloem	Viral movement; mechanical inoculation	Secretion; viral movement	Nucleus	Nucleus	Aphids

References

1. "ICTV Report Nanoviridae".
2. "Viral Zone". ExPASy. Retrieved 15 June 2015.
3. "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 12 May 2021.
4. Grigoras, Ioana (May 2014). "Genome diversity and evidence of recombination and reassortment in nanoviruses from Europe". Journal of General Virology. 95: 1178–1191. doi:10.1099/vir.0.063115-0. PMID 24515973.

External links

• ICTV Report: Nanoviridae
• Viralzone: Nanovirus