Aspiviridae

[[File:{{{image}}}|250px|alt=|]] Authority:

Aspiviridae
Kingdom:	Orthornavirae
Phylum:	Kitrinoviricota
Class:	Flasuviricetes
Order:	Martellivirales
Family:	Aspiviridae

Aspiviridae is a family of positive-sense single-stranded RNA viruses that infect a variety of hosts, including plants and fungi. This family is part of the order Martellivirales and is classified under the class Flasuviricetes. The family Aspiviridae is known for its unique genomic and structural characteristics, which distinguish it from other virus families.

Characteristics

Aspiviridae viruses have a single-stranded RNA genome that is positive-sense, meaning that the viral RNA can directly serve as mRNA for protein synthesis. The genome is typically monopartite, meaning it is composed of a single segment of RNA. The size of the genome can vary, but it generally ranges from 8 to 12 kilobases.

The virions of Aspiviridae are non-enveloped and have an icosahedral capsid structure. The capsid is composed of multiple copies of a single type of protein, which assembles into a symmetrical shell that protects the viral RNA.

Replication Cycle

The replication cycle of Aspiviridae viruses begins with the attachment of the virion to a host cell receptor, followed by entry into the cell. Once inside, the viral RNA is released into the cytoplasm, where it is translated by the host's ribosomes to produce viral proteins. These proteins include the RNA-dependent RNA polymerase, which is essential for replicating the viral genome.

The replication of the viral RNA occurs in the cytoplasm, where the RNA-dependent RNA polymerase synthesizes a complementary negative-sense RNA strand, which then serves as a template for the production of new positive-sense RNA genomes. These new genomes are packaged into newly assembled capsids, forming progeny virions that are released from the host cell to infect new cells.

Host Range and Transmission

Aspiviridae viruses primarily infect plants and fungi. The transmission of these viruses can occur through various means, including mechanical transmission, vector transmission by insects, and through seeds or pollen in the case of plant hosts.

Taxonomy

The family Aspiviridae is divided into several genera, each containing multiple species. The classification is based on genetic and structural similarities among the viruses. The exact number of genera and species is subject to change as new viruses are discovered and classified.

Research and Importance

Research on Aspiviridae is important for understanding the biology and evolution of RNA viruses. These viruses can have significant impacts on agriculture due to their ability to infect crops, leading to economic losses. Understanding their replication and transmission can aid in developing strategies to control viral diseases in plants.

Also see

• Martellivirales
• Positive-sense single-stranded RNA virus
• Virus classification
• Plant virus