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

Jian Chen; Xiaoxiao Zhang; Maud Bernoux; John P Rathjen; Peter N Dodds

doi:10.1016/j.isci.2024.108817

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

iScience. 2024 Jan 24;27(2):108817. doi: 10.1016/j.isci.2024.108817. eCollection 2024 Feb 16.

Authors

Jian Chen^{1

2}, Xiaoxiao Zhang², Maud Bernoux³, John P Rathjen², Peter N Dodds¹

Affiliations

¹ Commonwealth Scientific and Industrial Research Organization, Agriculture and Food, Canberra, ACT 2601, Australia.
² Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia.
³ Laboratoire des interactions plantes-microbes-environnement, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France.

Abstract

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 NbEDS1-NbSAG101b-NbNRG1 signaling pathway in N. benthamiana 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 N. benthamiana. We also find that TIR domains physically associate with NbEDS1, NbPAD4, and NbSAG101 in planta, independently of each other. Furthermore, NbNRG1 associates with NbSAG101b, 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.

Keywords: Biochemistry; Molecular interaction; Molecular plant pathology.