Broader functions of TIR domains in Arabidopsis immunity

• DOI: 10.1073/pnas.2220921120
• Publication Date: 2023-03-09T19:09:04Z
• Authors: Pierre Jacob; Junko Hige; Lijiang Song; Adam Bayless; Dor Russ; Vera Bonardi; Farid El Kasmi; Lisa Wünsch; Yu Yang; Connor R. Fitzpat...; Brock J. McKinney; Marc T. Nishimura; Murray R. Grant; Jeffery L. Dangl
• Keywords: Immune receptor

TIR domains are NAD-degrading enzymes that function during immune signaling in prokaryotes, plants, and animals. In most incorporated into intracellular receptors termed TNLs. Arabidopsis, TIR-derived small molecules bind activate EDS1 heterodimers, which turn RNLs, a class of cation channel–forming receptors. RNL activation drives cytoplasmic Ca 2+ influx, transcriptional reprogramming, pathogen resistance, host cell death. We screened for mutants suppress an mimic allele identified TNL, SADR1. Despite being required the autoactivated RNL, SADR1 is not defense triggered by other tested initiated some transmembrane pattern recognition contributes to unbridled spread death lesion simulating disease 1 . Together with regulates gene expression at infection site borders, likely non-cell autonomous manner. cannot sustain this unable prevent beyond localized sites, suggesting corresponds containment mechanism. potentiates RNL-driven only through but also partially independently EDS1. studied EDS1-independent using nicotinamide, NADase inhibitor. Nicotinamide decreased induction from calcium growth restriction, following receptor activation. demonstrate can potentiate influx thus broadly Arabidopsis immunity.