RT Journal Article SR Electronic T1 Genetically-clustered antifungal phytocytokines and receptor proteins function together to trigger plant immune signaling JF bioRxiv FD Cold Spring Harbor Laboratory SP 2023.11.27.568785 DO 10.1101/2023.11.27.568785 A1 Lintz, Julie A1 Goto, Yukihisa A1 Bender, Kyle W. A1 Bchini, Raphaƫl A1 Dubrulle, Guillaume A1 Cawston, Euan A1 Zipfel, Cyril A1 Duplessis, Sebastien A1 Petre, Benjamin YR 2023 UL http://biorxiv.org/content/early/2023/11/27/2023.11.27.568785.abstract AB Phytocytokines regulate plant immunity via cell-surface receptors. Populus trichocarpa RUST INDUCED SECRETED PEPTIDE 1 (PtRISP1) exhibits an elicitor activity in poplar, as well as a direct antimicrobial activity against rust fungi. PtRISP1 gene directly clusters with a gene encoding a leucine-rich repeat receptor protein (LRR-RP), that we termed RISP- ASSOCIATED LRR-RP (PtRALR).In this study, we used phylogenomics to characterize the RISP and RALR gene families, and functional assays to characterize RISP/RALR pairs.Both RISP and RALR gene families specifically evolved in Salicaceae species (poplar and willow), and systematically cluster in the genomes. Two divergent RISPs, PtRISP1 and Salix purpurea RISP1 (SpRISP1), induced a reactive oxygen species (ROS) burst and mitogen- activated protein kinases (MAPKs) phosphorylation in Nicotiana benthamiana leaves expressing the respective clustered RALR. PtRISP1 triggers a rapid stomatal closure in poplar, and both PtRISP1 and SpRISP1 directly inhibit rust pathogen growth.Altogether, these results suggest that plants evolved phytocytokines with direct antimicrobial activities, and that the genes coding these phytocytokines co-evolved and physically cluster with their cognate receptors.Competing Interest StatementThe authors have declared no competing interest.