Recognition of the Magnaporthe oryzae effector AVR-Pia by the decoy domain of the rice NLR immune receptor RGA5

Diana Ortiz (1) , Karine de Guillen (2, 3) , Stella Cesari (1, 4) , Veronique Chalvon-Poulier (1) , Jérôme Gracy (2, 3) , André Padilla (2) , Thomas Kroj (1)

1 UMR BGPI - Biologie et Génétique des Interactions Plante-Parasite
2 CBS - Centre de Biochimie Structurale [Montpellier]
3 UM - Université de Montpellier
4 CSIRO

Nucleotide-binding domain and leucine-rich repeat proteins (NLRs) are important receptors in plant immunity that allow recognition of pathogen effectors. The rice NLR RGA5 recognizes the Magnaporthe oryzae effector AVR-Pia through direct interaction. Here, we gained detailed insights into the molecular and structural bases of AVR-Pia-RGA5 interaction and the role of the RATX1 decoy domain of RGA5. NMR titration combined with in vitro and in vivo protein-protein interaction analyses identified the AVR-Pia interaction surface that binds to the RATX1 domain. Structure-informed AVR-Pia mutants showed that, although AVR-Pia associates with additional sites in RGA5, binding to the RATX1 domain is necessary for pathogen recognition, but can be of moderate affinity. Therefore, RGA5-mediated resistance is highly resilient to mutations in the effector. We propose a model that explains such robust effector recognition as a consequence, and an advantage, of the combination of integrated decoy domains with additional independent effector-NLR interactions.

Mots clés: pathogen; recognition; pathogen

Mots clés: magnaporthe oryzae; agent pathogène; amélioration des cultures; reconnaissance; protection des cultures; sélection végétale; magnaporthe oryzae

Domaines: Biologie végétale; Microbiologie et Parasitologie

Diana Ortiz, Karine de Guillen, Stella Cesari, Veronique Chalvon-Poulier, Jérôme Gracy, et al.. Recognition of the Magnaporthe oryzae effector AVR-Pia by the decoy domain of the rice NLR immune receptor RGA5. The Plant cell, 2017, 29 (1), pp.156-168. ⟨10.1105/tpc.16.00435⟩. ⟨hal-01608403⟩