title: Danger peptide receptor signaling in plants ensures basal immunity upon pathogen-induced depletion of BAK1.
abstract: Pathogens infect a host by suppressing defense responses induced upon recognition of microbe-associated molecular patterns (MAMPs). Despite this suppression, MAMP receptors mediate basal resistance to limit host susceptibility, via a process that is poorly understood. The Arabidopsis leucine-rich repeat (LRR) receptor kinase BAK1 associates and functions with different cell surface LRR receptors for a wide range of ligands, including MAMPs. We report that BAK1 depletion is linked to defense activation through the endogenous PROPEP peptides (Pep epitopes) and their LRR receptor kinases PEPR1/PEPR2, despite critical defects in MAMP signaling. In bak1-knockout plants, PEPR elicitation results in extensive cell death and the prioritization of salicylate-based defenses over jasmonate-based defenses, in addition to elevated proligand and receptor accumulation. BAK1 disruption stimulates the release of PROPEP3, produced in response to Pep application and during pathogen challenge, and renders PEPRs necessary for basal resistance. These findings are biologically relevant, since specific BAK1 depletion coincides with PEPR-dependent resistance to the fungal pathogen Colletotrichum higginsianum. Thus, the PEPR pathway ensures basal resistance when MAMP-triggered defenses are compromised by BAK1 depletion.
authors.affiliation: Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
authors.forename: Misuzu
authors.initials: M
authors.lastname: Yamashita-Yamada
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Hirase
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tsuda
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Hiruma
authors.affiliation: Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan JST, PRESTO, Kawaguchi, Japan saijo@bs.naist.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Saijo
mesh_terms: D017360:Arabidopsis / Q000276:immunology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020231:Colletotrichum / Q000276:immunology; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C512592:PEPR1 protein, Arabidopsis; D011956:Receptors, Cell Surface; D015534:Trans-Activators; C463660:BAK1 protein, Arabidopsis; C582179:PEPR2 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases
keywords: Arabidopsis; BAK1; DAMP; PEPR; plant immunity