VIRION
Virions have rod-shaped particles with modal lengths of 320-360 nm and diameters of 18 nm. They do not have an envelope structure.
GENOME
The genome is segmented; bipartite. After deproteinization of purified virions, both single stranded and double stranded RNA are detected.
GENE EXPRESSION
These viruses contain a single coat protein (CP) with an Mr of approximately 48 kDa and do not possess an envelope structure.
ENZYMES
- RNA-dependent RNA polymerase [L]
- Mononega-type capping
- RNA TPase, GTase, N7 Mtase, 2'O Mtase [L]
REPLICATION
CYTOPLASMIC
- Virus penetrates into the cell by effraction or plasmodesmata transport.
- Sequential transcription , viral mRNAs are capped and polyadenylated by polymerase stuttering in the cytoplasm.
- Replication presumably starts when enough nucleoprotein is present to encapsidate neo-synthetized antigenomes and genomes.
- The ribonucleocapsid can penetrate in neighboring plant cells through plasmodesmata transport