@article{fdi:010040914,
  title = {{T}heme and variations in the evolutionary pathways to virulence of an {RNA} plant virus species},
  author = {{P}inel {G}alzi, {A}gn{\`e}s and {R}akotomalala, {M}. and {S}angu, {E}. and {S}orho, {F}. and {K}anyeka, {Z}. and {T}raor{\'e}, {O}. and {S}{\'e}r{\'e}m{\'e}, {D}. and {P}oulicard, {N}ils and {R}abenantoandro, {Y}. and {S}{\'e}r{\'e}, {Y}. and {K}onat{\'e}, {G}. and {G}hesqui{\`e}re, {A}lain and {H}{\'e}brard, {E}ug{\'e}nie and {F}argette, {D}enis},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he diversity of a highly variable {RNA} plant virus was considered to determine the range of virulence substitutions, the evolutionary pathways to virulence, and whether intraspecific diversity modulates virulence pathways and propensity. {I}n all, 114 isolates representative of the genetic and geographic diversity of {R}ice yellow mottle virus ({RYMV}) in {A}frica were inoculated to several cultivars with e{IF}(iso)4{G}-mediated {R}ymv1-2 resistance. {A}ltogether, 41 virulent variants generated from ten wild isolates were analyzed. {N}onconservative amino acid replacements at five positions located within a stretch of 15 codons in the central region of the 79-aa-long protein {VP}g were associated with virulence. {V}irulence substitutions were fixed predominantly at codon 48 in most strains, whatever the host genetic background or the experimental conditions. {T}here were one major and two isolate-specific mutational pathways conferring virulence at codon 48. {I}n the prevalent mutational pathway {I}, arginine ({AGA}) was successively displaced by glycine ({GGA}) and glutamic acid ({GAA}). {S}ubstitutions in the other virulence codons were displaced when {E}48 was fixed. {I}n the isolate-specific mutational pathway {II}, isoleucine ({ATA}) emerged and often later coexisted with valine ({GTA}). {I}n mutational pathway {III}, arginine, with the specific {S}2/{S}3 strain codon usage {AGG}, was displaced by tryptophane ({TGG}). {M}utational pathway {I} never arose in the widely spread {W}est {A}frican {S}2/{S}3 strain because {G}48 was not infectious in the {S}2/{S}3 genetic context. {S}train {S}2/{S}3 least frequently overcame resistance, whereas two geographically localized variants of the strain {S}4 had a high propensity to virulence. {C}odons 49 and 26 of the {VP}g, under diversifying selection, are candidate positions in modulating the genetic barriers to virulence. {T}he theme and variations in the evolutionary pathways to virulence of {RYMV} illustrates the extent of parallel evolution within a highly variable {RNA} plant virus species.},
  keywords = {},
  booktitle = {},
  journal = {{PL}o{S} {P}athogens},
  volume = {3},
  numero = {11},
  pages = {1761--1770 [art. no. e180]},
  ISSN = {1553-7366},
  year = {2007},
  DOI = {10.1371/journal.ppat.0030180},
  URL = {https://www.documentation.ird.fr/hor/fdi:010040914},
}