Toll/interleukin-1 receptor (TIR) domain proteins possess NADase activity and trigger plant immunity via their enzymatic products. Two recent studies have elucidated the mechanism by which TIR NADase-derived 2′cADPR and pRib-AMP/ADP activate EDS1–PAD4–ADR1 (EPA) signalling, thereby inducing immune responses in plants.
- Kaihuai Li
- Yan Qiao
- Fengquan Liu