@article{fdi:010049231,
  title = {{T}he rice yellow mottle virus {P}1 protein exhibits dual functions to suppress and activate gene silencing},
  author = {{L}acombe, {S}{\'e}verine and {B}angratz, {M}artine and {V}ignols, {F}lorence and {B}rugidou, {C}hristophe},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n plants {RNA} silencing is a host defense mechanism against viral infection, in which double-strand {RNA} is processed into 21-24-nt short interfering {RNA} (si{RNA}). {S}ilencing spreads from cell to cell and systemically through a sequence-specific signal to limit the propagation of the virus. {T}o counteract this defense mechanism, viruses encode suppressors of silencing. {T}he {P}1 protein encoded by the rice yellow mottle virus ({RYMV}) displays suppression activity with variable efficiency, according to the isolates that they originated from. {H}ere, we show that {P}1 proteins from two {RYMV} isolates displaying contrasting suppression strength reduced local silencing induced by single-strand and double-strand {RNA} in {N}icotiana benthamiana leaves. {T}his suppression was associated with a slight and a severe reduction in 21- and 24-nt si{RNA} accumulation, respectively. {U}nexpectedly, cell-to-cell movement and systemic propagation of silencing were enhanced in {P}1-expressing {N}icotiana plants. {W}hen transgenically expressed in rice, {P}1 proteins induced specific deregulation of {DCL}4-dependent endogenous si{RNA} pathways, whereas the other endogenous pathways were not affected. {A}s {DCL}4-dependent pathways play a key role in rice development, the expression of {P}1 viral proteins was associated with the same severe developmental defects in spikelets as in dcl4 mutants. {O}verall, our results demonstrate that a single viral protein displays multiple effects on both endogenous and exogenous silencing, not only in a suppressive but also in an enhancive manner. {T}his suggests that {P}1 proteins play a key role in maintaining a subtle equilibrium between defense and counter-defense mechanisms, to insure efficient virus multiplication and the preservation of host integrity.},
  keywords = {gene silencing ; viral suppressor ; rice yellow mottle virus ; rice ; {DCL}4 ; silencing movement},
  booktitle = {},
  journal = {{P}lant {J}ournal},
  volume = {61},
  numero = {3},
  pages = {371--382},
  ISSN = {0960-7412},
  year = {2010},
  DOI = {10.1111/j.1365-313{X}.2009.04062.x},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049231},
}