TIR-NB-LRR receptor-like protein that confers resistance to the pathogen Leptosphaeria maculans (blackleg disease). H2O + NAD(+) = ADP-D-ribose + H(+) + nicotinamide The TIR domain mediates NAD(+) hydrolase (NADase) activity. Self-association of TIR domains is required for NADase activity. No visible phenotype under normal growth conditions, but mutant plants are susceptible to the pathogen Leptosphaeria maculans.