Notes on Family: Secoviridae
This family contains all the plant-infecting members of the order Picornavirales
. The viruses included all have icosahedral particles and monopartite or bipartite genomes, which are translated as polyproteins for subsequent processing.
Virions isometric, icosahedral, not enveloped and about 30 nm in diameter.
Mono- or bi-partite with linear, single-stranded positive sense RNA. Total genome 9000-12000 nucleotides long. The 5'-terminus has a genome-linked protein (VPg) and a poly (A) tract is present almost invariably at the 3'-end. The genomic RNA(s) have a large open reading frame which is translated into a polyprotein for subsequent processing.
Genera in the Family
Classification into genera depends upon genome organisation and some biological properties, supported by phylogenetic analysis. The current genera are:
|Nos of coat proteins||Vector||Other features|
| Subfamily Comovirinae:|
| Other genera:|
|Sequivirus||1||-||3||Aphids||Requires helper virus for transmission. Genome may lack a 3'-polyA tail.|
|Torradovirus||2||134||3||Whiteflies?|| Extra partially overlapping ORF at 5'-end of RNA2|
|Waikavirus||1||-||3||Beetles||Two small additional ORFs at 3'-end|