The RPS4/RRS1 NLR pair: sensing of pathogen interference and regulation of post-activation signaling
L. DESLANDES (1), J. Parker (2), C. Le Roux (3), M. Escouboué (4), A. Delga (5), G. Huet (4), A. Jauneau (6), Y. Couté (7), A. Kraut (7), K. Niefind (8), R. Berthomé (5), D. Tremousaygue (4), S. Carrere (5) (1) CNRS, France; (2) Max-Planck Institut, Germany; (3) Max-Planck Institut, Germany; (4) CNRS, France; (5) INRA, France; (6) FR3450, France; (7) CEA, France; (8) University of Cologne, Germany

We are studying effector-triggered immunity conditioned by a co-functioning Arabidopsis nuclear ‘sensor-signaling’ NLR pair, RRS1-R (Resistance to RaLStonia Solanacearum1) with RPS4 (RESISTANCE TO PSEUDOMONAS SYRINGAE4). This NLR pair confers resistance to different pathogens including Ralstonia solanacearum bacteria expressing PopP2, a member of the YopJ superfamily of acetyltransferases. PopP2 modifies by acetylation a key lysine within the integrated WRKY domain of RRS1-R receptor leading to the disruption of RRS1-R-DNA association and the activation of RPS4-dependent immunity. PopP2 employs the same lysine acetylation strategy to target multiple defence-promoting WRKY transcription factors, causing loss of WRKY-DNA binding and trans-activating functions needed for defence gene expression and disease resistance. Therefore, the WRKY domain integrated in RRS1-R serves as an effector target ‘decoy’ which betrays the resistance-suppressing actions of PopP2 on its operational targets, the defensive WRKY transcription factors. The nature of NLR dynamics at the DNA and its relation to gene expression changes are not known. We describe the use of a DNA adenine methylation IDentification (DamID) approach to monitor TNL genome-wide associations to chromatin sites and recent advances in this study. We are also exploring how PopP2 virulence functions might involve the targeting of specific chromatin sites through the acetylation of various epigenetic readers.


Abstract Number: P^-5
Session Type: Plenary