VIRION
Virions have short bacilliform or bullet-shaped particles with modal lengths of 100-150 nm and diameters of 40 nm. No envelope structure have been detected, but the presence of a glycoprotein in the genome suggests it could happen.
GENOME
Negative-stranded RNA linear genome, composed of two segments.
GENE EXPRESSION
The viral RNA dependent RNA polymerase binds the encapsidated genome at the leader region, then sequentially transcribes each genes by recognizing start and stop signals flanking viral genes.
ENZYMES
- RNA-dependent RNA polymerase [L]
- Mononega-type capping
- RNA TPase, GTase, N7 Mtase, 2'O Mtase [L]
REPLICATION
NUCLEUS
- Virus penetrates into the cell by effraction or plasmodesmata transport.
- Viral nucleocapsid is transported into the host nucleus
- 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