The fungal pathogen Cochliobolus victoriae, the causal agent of Victoria blight, produces a host-selective pathogenicity factor called victorin. In Arabidopsis thaliana, a dominant gene called "supersense" (SSN) confers constitutive victorin sensitivity at very low concentrations. SSN encodes a nucleotide-binding leucine-rich-repeat (NB-LRR) protein. In the SSN-carrying Heiligkreuztal 2 ecotype (TAIR Germplasm...