title: Selective regulation of the chitin-induced defense response by the Arabidopsis receptor-like cytoplasmic kinase PBL27.
abstract: Recognition of microbe-associated molecular patterns (MAMPs) initiates pattern-triggered immunity in host plants. Pattern recognition receptors (PRRs) and receptor-like cytoplasmic kinases (RLCKs) are the major components required for sensing and transduction of these molecular patterns. However, the regulation of RLCKs by PRRs and their specificity remain obscure. In this study we show that PBL27, an Arabidopsis ortholog of OsRLCK185, is an immediate downstream component of the chitin receptor CERK1 and contributes to the regulation of chitin-induced immunity in Arabidopsis. Knockout of PBL27 resulted in the suppression of several chitin-induced defense responses, including the activation of MPK3/6 and callose deposition as well as in disease resistance against fungal and bacterial infections. On the other hand, the contribution of PBL27 to flg22 signaling appears to be very limited, suggesting that PBL27 selectively regulates defense signaling downstream of specific PRR complexes. In vitro phosphorylation experiments showed that CERK1 preferentially phosphorylated PBL27 in comparison to BIK1, whereas phosphorylation of PBL27 by BAK1 was very low compared with that of BIK1. Thus, the substrate specificity of the signaling receptor-like kinases, CERK1 and BAK1, may determine the preference of downstream RLCKs.
authors.affiliation: Department of Life Sciences, School of Agriculture, Meiji University, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan; Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Shinya
authors.forename: Koji
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Desaki
authors.forename: Kenta
authors.initials: K
authors.lastname: Yamada
authors.forename: Tomoko
authors.initials: T
authors.lastname: Narisawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Kanako
authors.initials: K
authors.lastname: Maeda
authors.forename: Maruya
authors.initials: M
authors.lastname: Suzuki
authors.forename: Takumi
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Jun
authors.initials: J
authors.lastname: Takeda
authors.forename: Masato
authors.initials: M
authors.lastname: Nakashima
authors.forename: Ryota
authors.initials: R
authors.lastname: Funama
authors.forename: Mari
authors.initials: M
authors.lastname: Narusaka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Narusaka
authors.forename: Hanae
authors.initials: H
authors.lastname: Kaku
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Naoto
authors.initials: N
authors.lastname: Shibuya
mesh_terms: D000528:Alternaria / Q000502:physiology; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002686:Chitin / Q000378:metabolism; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D005936:Glucans / Q000378:metabolism; D008954:Models, Biological; D010766:Phosphorylation; D010935:Plant Diseases / Q000276:immunology*; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D051192:Receptors, Pattern Recognition; D015398:Signal Transduction; D013379:Substrate Specificity; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D005936:Glucans; D017382:Reactive Oxygen Species; D018160:Receptors, Cytoplasmic and Nuclear; D051192:Receptors, Pattern Recognition; D002686:Chitin; C048306:callose; C000595437:PBL27 protein, Arabidopsis; D011494:Protein Kinases; C463660:BAK1 protein, Arabidopsis; C525882:CERK1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases
keywords: Arabidopsis thaliana; CERK1; PBL27; chitin; microbe-associated molecular pattern; plant immunity; receptor; receptor-like cytoplasmic kinase