Secoviridae is a family of viruses in the order Picornavirales. Plants serve as natural hosts. There are 10 genera in the family, four of which are assigned to a subfamily. The family was created in 2009 with the grouping of families Sequiviridae, now dissolved, and Comoviridae, now subfamily Comovirinae, along with the then unassigned genera Cheravirus, Sadwavirus, and Torradovirus.
Taxonomy The family includes the following genera (-virinae denotes subfamily and -virus denotes genus): Comovirinae Comovirus Fabavirus Mersevirus Nepovirus Unassigned to a subfamily: Cheravirus Sadwavirus Sequivirus Stralarivirus Strawberry latent ringspot virus Torradovirus Waikavirus
Structure Viruses in Secoviridae are non-enveloped, with icosahedral geometries, and T=pseudo3 symmetry. The diameter is around 25-30 nm. Genomes are linear and segmented, bipartite, around 24-7kb in length.
Genus Structure Symmetry Capsid Genomic arrangement Genomic segmentationSequivirusIcosahedralPseudo T=3Non-envelopedLinearMonopartiteSadwavirusIcosahedralPseudo T=3Non-envelopedLinearSegmentedNepovirusIcosahedralPseudo T=3Non-envelopedLinearSegmentedFabavirusIcosahedralPseudo T=3Non-envelopedLinearSegmentedComovirusIcosahedralPseudo T=3Non-envelopedLinearSegmentedCheravirusIcosahedralPseudo T=3Non-envelopedLinearSegmentedTorradovirusIcosahedralPseudo T=3Non-envelopedLinearSegmentedWaikavirusIcosahedralPseudo T=3Non-envelopedLinearMonopartite
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.
Genus Host details Tissue tropism Entry details Release details Replication site Assembly site TransmissionSequivirusPlantsNoneViral movement; mechanical inoculationViral movementCytoplasmCytoplasmMechanical inoculation: aphids; Mechanical inoculation: Cavariella aegopodii; Mechanical inoculation: Cavariella pastinacaeSadwavirusPlantsNoneViral movement; mechanical inoculationViral movementCytoplasmCytoplasmNematodes; mites; thripsNepovirusPlantsNoneViral movement; mechanical inoculationViral movementCytoplasmCytoplasmNematodes; mites; thripsFabavirusPlantsNoneViral movement; mechanical inoculationViral movementCytoplasmCytoplasmMechanical inoculation: aphidsComovirusPlantsNoneViral movement; mechanical inoculationViral movementCytoplasmCytoplasmMechanical inoculation: beetlesCheravirusPlantsNoneViral movement; mechanical inoculationViral movementCytoplasmCytoplasmNematodes; mites; thripsTorradovirusPlantsNoneViral movement; mechanical inoculationViral movementCytoplasmCytoplasmUnknownWaikavirusGramineaePhloem; phloem parenchyma; bundle sheathViral movementViral movementCytoplasmCytoplasmMechanical innocuation: aphids; mechanical innocuation: leafhoppers
Evolution The subfamily Comovirinae evolved ~1,000 years ago with extant species diversifying between 50 and 250 years ago. This time period coincides with the intensification of agricultural practices in industrial societies.
The mutation rate has been estimated to be 9.29×10−3 to 2.74×10−3 subs/site/year.
References
External links
Viralzone: Secoviridae UniProt Taxonomy