Disease resistance (R) protein that confers resistance to multiple powdery and downy mildew by promoting cell death (PubMed:24033846, PubMed:31439792). Acts as a NAD(+) hydrolase (NADase): in response to activation, catalyzes cleavage of NAD(+) into ADP-D-ribose (ADPR) and nicotinamide; NAD(+) cleavage triggering a defense system that promotes cell death (PubMed:31439792). Also able to hydrolyze NADP(+), but not other NAD(+)-related molecules (PubMed:31439792). H2O + NAD(+) = ADP-D-ribose + H(+) + nicotinamide H2O + NADP(+) = ADP-D-ribose 2'-phosphate + H(+) + nicotinamide Localizes predominantly to the nucleus. The TIR domain mediates NAD(+) hydrolase (NADase) activity. Self-association of TIR domains is required for NADase activity. Belongs to the disease resistance TIR-NB-LRR family.