The Ry sto immune receptor recognises a broadly conserved feature of potyviral coat proteins.

Knowledge of the immune mechanisms responsible for viral recognition is critical for understanding durable disease resistance and successful crop protection. We determined how potato virus Y (PVY) coat protein (CP) is recognised by Ry sto , a TNL immune receptor. We applied structural modelling, site-directed mutagenesis, transient overexpression, co-immunoprecipitation, infection assays and physiological cell death marker measurements to investigate the mechanism of Ry sto -CP interaction. Ry sto associates directly with PVY CP in planta that is conditioned by the presence of a CP central 149 amino acids domain. Each deletion that affects the CP core region impairs the ability of Ry sto to trigger defence. Point mutations in the amino acid residues Ser 125 , Arg 157 , and Asp 201 of the conserved RNA-binding pocket of potyviral CP reduce or abolish Ry sto binding and Ry sto -dependent responses, demonstrating that appropriate folding of the CP core is crucial for Ry sto -mediated recognition. Ry sto recognises the CPs of at least 10 crop-damaging viruses that share a similar core region. It confers immunity to plum pox virus and turnip mosaic virus in both Solanaceae and Brassicaceae systems, demonstrating potential utility in engineering virus resistance in various crops. Our findings shed new light on how R proteins detect different viruses by sensing conserved structural patterns.