Quilis J. auteur aut IRD Penas G. auteur aut IRD Messeguer J. auteur aut IRD Brugidou Christophe auteur aut IRD Segundo B. S. auteur aut IRD text journalArticle eng text/pdf born digital access The nonexpressor of pathogenesis-related (PR) genes (NPR1) protein plays an important role in mediating defense responses activated by pathogens in Arabidopsis. In rice, a disease-resistance pathway similar to the Arabidopsis NPR1-mediated signaling pathway one has been described. Here, we show that constitutive expression of the Arabidopsis NPRI (AtNPR1) gene in rice confers resistance against fungal and bacterial pathogens. AtNPR1 exerts its protective effects against fungal pathogens by priming the expression of salicylic acid (SA)-responsive endogenous genes, such as the PR1b, TLP (PR5). PR10, and PBZ1. However, expression of AtNPR1 in rice has negative effects on viral infections. The AtNPR1-expressing rice plants showed a higher susceptibility to infection by the Rice yellow mottle virus (RYMV) which correlated well with a misregulation of RYMV-responsive genes, including expression of the SA-regulated RNA-dependent RNA polymerase 1 gene (OsRDR1). moreover, AtNPR1 negatively regulates the expression of genes playing a role in the plant response to salt and drought stress (rab21, salT, and dipI), which results in a higher sensitivity of AtNPR1 rice to the two types of abiotic stress. These observations suggest that AtNPR1 has both positive and negative regulatory roles in mediating defense responses against biotic and abiotic stresses. specialized Erwinia chrysanthemi Fusarium verticillioides Magnoporthe oryzae Oryza saliva 076 020 21 9 1215-1231 2008 0894-0282 https://www.documentation.ird.fr/hor/fdi:010044227 10.1094/mpmi-21-9-1215 0894-0282 [F B010044227] https://www.documentation.ird.fr/hor/fdi:010044227 https://www.documentation.ird.fr/intranet/publi/2009/02/010044227.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2009-03-06 2017-08-23 fdi:010044227 fre