Plant Toll/interleukin-1 receptor/resistance protein domains physically associate with enhanced disease susceptibility1 family proteins in immune signaling.

Plant Toll/interleukin-1 receptor/resistance protein (TIR) type nucleotide-binding and leucine-rich repeat immune receptors (NLRs) require enhanced disease susceptibility 1 (EDS1) family proteins and the helper NLRs NRG1 and ADR1 for immune activation. We show that the EDS1-SAG101b-NRG1 signaling pathway in is necessary for cell death signaling by TIR-NLRs from a range of plant species, suggesting a universal requirement for this module in TIR-NLR-mediated cell death in We also find that TIR domains physically associate with EDS1, PAD4, and SAG101 , independently of each other. Furthermore, NRG1 associates with SAG101b, but not with other EDS1 family members, via its C-terminal EP domain. Physical interaction between activated TIRs and EDS1 signaling complexes may facilitate the transfer of low abundance products of TIR catalytic activity or alter TIR catalytic activity to favor the production of EDS1 heterodimer ligands.