Hébrard Eugénie, Fargette Denis, Konaté G. (2008). Rice Yellow Mottle Virus. In :
Mahy B.W.J. (ed.), Van Regenmortel M.H.V. (ed.). Encyclopedia of virology. Oxford : Elsevier, p. 485-490. ISBN 978-0-12-374410-4.
Titre du document
Rice Yellow Mottle Virus
Année de publication
2008
Type de document
Partie d'ouvrage
Auteurs
Hébrard Eugénie, Fargette Denis, Konaté G.
In
Mahy B.W.J. (ed.), Van Regenmortel M.H.V. (ed.), Encyclopedia of virology
Source
Oxford : Elsevier, 2008,
p. 485-490 ISBN 978-0-12-374410-4
Rice yellow mottle virus (RYMV) causes the most important rice disease in Africa. RYMV belongs to the genus Sobemovirus. RYMV has icosahedral particles of 25 nm in diameter. The virions contain a single coat protein (CP) of 29 kDa, a genomic RNA, and one subgenomic RNA molecule. The genomic RNA is one single-stranded messenger-sense molecule, 4450 nt in size. The 5′ terminus of the RNAs has a genome-linked protein (VPg), and lacks a poly(A) tail. RYMV often encapsidates, in addition to its genomic RNA, a viroid-like satellite RNA. The RYMV genome is organized in four overlapping open reading frames (ORFs). The ORF1 encodes a protein P1 required for cell-to-cell movement of the virus. P1 is a suppressor of posttranslational gene silencing. The ORF2a contains sequence motifs for the proteinase and the VPg. The ORF2b encodes the RNA-dependent RNA polymerase. The ORF4 is translated from the subgenomic RNA and encodes the CP. The natural host range of RYMV is restricted to a few members of the Poaceae family. Transmission is due to chrysomelidae vectors and to contact during cultural practices. The more efficient resistance called high resistance encodes the translation initiation factor eIF(iso)4G. This resistance is overcome by a point mutation in the VPg. The evolution of RYMV has been inferred from its genetic diversity.
