Effector-binding by integrated decoy domain of immune receptor RGA5 required for resistance activation

Magnaporthe oryzae is the fungus that causes rice blast disease, which is a serious threat to food security. Ortiz et al. explore the interaction between AVR-Pia, a fungal effector protein, and RGA5, a rice NLR (nucleotide-binding domain and leucine-rich repeat protein) immune receptor protein. RGA5 has a C-terminal domain, RATX1, that acts as an integrated target decoy and that has been shown as important for interaction with AVR-Pia. In this study, the authors use NMR and yeast two-hybrid assays to map the interaction between RGA5 and AVR-Pia. They show that activation of resistance requires AVR-Pia interaction with RGA5 in both central and RATX1 domains, and suggest that this interaction provides resilience to mutations in the effector. Plant Cell 10.1105/tpc.16.00435