Maruta_2025_Mol.Plant_18_192

Plants defend themselves against pathogens by activating two interconnected layers of immunity: pattern- and effector-triggered immunity. Recent studies shed light on a number of unanswered questions in these pathways and demonstrate a conserved structural basis, in monocots and dicots, of signaling through the EDS1:PAD4:ADR1 module, downstream of Toll/interleukin-1 receptor (TIR) domain-containing immune receptors that cleave the dinucleotide nicotinamide adenine dinucleotide (NAD(+)). The studies define a new function for TIR domain proteins in monocots and suggest that the signaling molecule 5''-phosphoribosyl (pRib)-AMP is derived from the TIR product 2'-adenosine diphosphate ribose (2'cADPR). These findings have important implications for developing the strategies to breed resistant crops.