title: The Arabidopsis PEPR pathway couples local and systemic plant immunity.
abstract: Recognition of microbial challenges leads to enhanced immunity at both the local and systemic levels. In Arabidopsis, EFR and PEPR1/PEPR2 act as the receptor for the bacterial elongation factor EF-Tu (elf18 epitope) and for the endogenous PROPEP-derived Pep epitopes, respectively. The PEPR pathway has been described to mediate defence signalling following microbial recognition. Here we show that PROPEP2/PROPEP3 induction upon pathogen challenges is robust against jasmonate, salicylate, or ethylene dysfunction. Comparative transcriptome profiling between Pep2- and elf18-treated plants points to co-activation of otherwise antagonistic jasmonate- and salicylate-mediated immune branches as a key output of PEPR signalling. Accordingly, as well as basal defences against hemibiotrophic pathogens, systemic immunity is reduced in pepr1 pepr2 plants. Remarkably, PROPEP2/PROPEP3 induction is essentially restricted to the pathogen challenge sites during pathogen-induced systemic immunity. Localized Pep application activates genetically separable jasmonate and salicylate branches in systemic leaves without significant PROPEP2/PROPEP3 induction. Our results suggest that local PEPR activation provides a critical step in connecting local to systemic immunity by reinforcing separate defence signalling pathways.
authors.affiliation: Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
authors.forename: Annegret
authors.initials: A
authors.lastname: Ross
authors.forename: Kohji
authors.initials: K
authors.lastname: Yamada
authors.forename: Kei
authors.initials: K
authors.lastname: Hiruma
authors.forename: Misuzu
authors.initials: M
authors.lastname: Yamashita-Yamada
authors.forename: Xunli
authors.initials: X
authors.lastname: Lu
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Takano
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tsuda
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Saijo
mesh_terms: D017360:Arabidopsis / Q000276:immunology* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001419:Bacteria / Q000276:immunology; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D057865:Plant Immunity; D011498:Protein Precursors / Q000378:metabolism; D012459:Salicylates / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D011498:Protein Precursors; D012459:Salicylates; C011006:jasmonic acid; C036216:ethylene