Format

Send to

Choose Destination
J Biol Chem. 2019 Aug 30;294(35):13006-13016. doi: 10.1074/jbc.RA119.007730. Epub 2019 Jul 11.

Cross-reactivity of a rice NLR immune receptor to distinct effectors from the rice blast pathogen Magnaporthe oryzae provides partial disease resistance.

Author information

1
Department of Biological Chemistry, John Innes Centre, Norwich Research Park, NR4 7UH Norwich, United Kingdom.
2
Laboratory of Plant Symbiotic and Parasitic Microbes, Department of Molecular Microbiology, Faculty of Life Sciences, Tokyo University of Agriculture, Tokyo 156-8502, Japan.
3
The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, NR4 7UH Norwich, United Kingdom.
4
Division of Genomics and Breeding, Iwate Biotechnology Research Center, Iwate 024-0003, Japan.
5
Laboratory of Crop Evolution, Graduate School of Agriculture, Kyoto University, Kyoto 606-8501, Japan.
6
Department of Biological Chemistry, John Innes Centre, Norwich Research Park, NR4 7UH Norwich, United Kingdom mark.banfield@jic.ac.uk.

Abstract

Unconventional integrated domains in plant intracellular immune receptors of the nucleotide-binding leucine-rich repeat (NLRs) type can directly bind translocated effector proteins from pathogens and thereby initiate an immune response. The rice (Oryza sativa) immune receptor pairs Pik-1/Pik-2 and RGA5/RGA4 both use integrated heavy metal-associated (HMA) domains to bind the effectors AVR-Pik and AVR-Pia, respectively, from the rice blast fungal pathogen Magnaporthe oryzae These effectors both belong to the MAX effector family and share a core structural fold, despite being divergent in sequence. How integrated domains in NLRs maintain specificity of effector recognition, even of structurally similar effectors, has implications for understanding plant immune receptor evolution and function. Here, using plant cell death and pathogenicity assays and protein-protein interaction analyses, we show that the rice NLR pair Pikp-1/Pikp-2 triggers an immune response leading to partial disease resistance toward the "mis-matched" effector AVR-Pia in planta and that the Pikp-HMA domain binds AVR-Pia in vitro We observed that the HMA domain from another Pik-1 allele, Pikm, cannot bind AVR-Pia, and it does not trigger a plant response. The crystal structure of Pikp-HMA bound to AVR-Pia at 1.9 Å resolution revealed a binding interface different from those formed with AVR-Pik effectors, suggesting plasticity in integrated domain-effector interactions. The results of our work indicate that a single NLR immune receptor can bait multiple pathogen effectors via an integrated domain, insights that may enable engineering plant immune receptors with extended disease resistance profiles.

KEYWORDS:

Nod-like receptor (NLR); effector; host-pathogen interaction; plant biochemistry; plant defense; plant immunity; protein structure; rice; rice blast disease

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center