Barley yellow dwarf (BYD) is the most widespread and economically important virus disease of cereals. The viruses causing BYD were initially grouped based on common biological properties, including persistent and often strain-specific transmission by aphids and induction of yellowing symptoms. The severity and distribution of BYD infections are dependent on the sensitivity of host plants and meteorological conditions that favor movement and reproduction of vector aphids. Initially the viruses causing BYD were considered strains of barley yellow dwarf virus (BYDV) and named after their principal aphid vectors. With the advent of serological detection techniques and nucleotide sequence analysis, the viruses were separated into two genera, Luteovirus and Polerovirus, within the family Luteoviridae. Currently, these species, BYDV-MAV, BYDV-PAS, BYDV-PAV, BYDV-RMV and BYDV-SGV, and cereal yellow dwarf virus-RPS (CYDV-RPS) and CYDV-RPV are recognized. BYDVs and CYDVs share a common particle morphology (nonenveloped 25 nm icosahedra), with virus particles composed of one major and one minor capsid protein and a single molecule of positive-sense single-stranded RNA. BYDVs and CYDVs genomic RNAs are about 5.6 kbp in length and contain five to six open-reading frames (ORFs). The ORFs are expressed through multiple strategies, including frameshifting, leaky scanning, termination codon readthrough, and long-distance RNA-RNA interactions. Even though capsid proteins of BYDVs and CYDVs are highly conserved, RNA-dependent RNA polymerases of the BYDVs and CYDVs are distantly related evolutionarily.
- Aphid transmission
- Leaky scanning
- Subgenomic RNA
ASJC Scopus subject areas
- Immunology and Microbiology(all)