Poulicard N., Galzi Agnès, Fargette Denis, Hébrard Eugénie. (2014). Alternative mutational pathways, outside the VPg, of rice yellow mottle virus to overcome eIF(iso)4G-mediated rice resistance under strong genetic constraints. Journal of General Virology, 95 (1), p. 219-224. ISSN 0022-1317.
Titre du document
Alternative mutational pathways, outside the VPg, of rice yellow mottle virus to overcome eIF(iso)4G-mediated rice resistance under strong genetic constraints
Année de publication
Poulicard N., Galzi Agnès, Fargette Denis, Hébrard Eugénie
Journal of General Virology, 2014,
95 (1), p. 219-224 ISSN 0022-1317
The adaptation of rice yellow mottle virus (RYMV) to rymv1-mediated resistance has been reported to involve mutations in the viral genome-linked protein (VPg). In this study, we analysed several cases of rymv1-2 resistance breakdown by an isolate with low adaptability. Surprisingly, in these rarely occurring resistance-breaking (RB) genotypes, mutations were detected outside the VPg, in the ORF2a/ORF2b overlapping region. The causal role of three mutations associated with rymv1-2 resistance breakdown was validated via directed mutagenesis of an infectious clone. In resistant plants, these mutations increased viral accumulation as efficiently as suboptimal RB mutations in the VPg. Interestingly, these mutations are located in a highly conserved, but unfolded, domain. Altogether, our results indicate that under strong genetic constraints, a priori unfit genotypes can follow alternative mutational pathways, i.e. outside the VPg, to overcome rymv1-2 resistance.
Plan de classement
Sciences du monde végétal 
Fonds IRD [F B010062393]