title: Arabidopsis lysin-motif proteins LYM1 LYM3 CERK1 mediate bacterial peptidoglycan sensing and immunity to bacterial infection.
abstract: Recognition of microbial patterns by host pattern recognition receptors is a key step in immune activation in multicellular eukaryotes. Peptidoglycans (PGNs) are major components of bacterial cell walls that possess immunity-stimulating activities in metazoans and plants. Here we show that PGN sensing and immunity to bacterial infection in Arabidopsis thaliana requires three lysin-motif (LysM) domain proteins. LYM1 and LYM3 are plasma membrane proteins that physically interact with PGNs and mediate Arabidopsis sensitivity to structurally different PGNs from gram-negative and gram-positive bacteria. lym1 and lym3 mutants lack PGN-induced changes in transcriptome activity patterns, but respond to fungus-derived chitin, a pattern structurally related to PGNs, in a wild-type manner. Notably, lym1, lym3, and lym3 lym1 mutant genotypes exhibit supersusceptibility to infection with virulent Pseudomonas syringae pathovar tomato DC3000. Defects in basal immunity in lym3 lym1 double mutants resemble those observed in lym1 and lym3 single mutants, suggesting that both proteins are part of the same recognition system. We further show that deletion of CERK1, a LysM receptor kinase that had previously been implicated in chitin perception and immunity to fungal infection in Arabidopsis, phenocopies defects observed in lym1 and lym3 mutants, such as peptidoglycan insensitivity and enhanced susceptibility to bacterial infection. Altogether, our findings suggest that plants share with metazoans the ability to recognize bacterial PGNs. However, as Arabidopsis LysM domain proteins LYM1, LYM3, and CERK1 form a PGN recognition system that is unrelated to metazoan PGN receptors, we propose that lineage-specific PGN perception systems have arisen through convergent evolution.
authors: Department of Plant Biochemistry, Center for Plant Molecular Biology,  University of Tübingen, 72076 Tübingen,  Germany.
authors: Roland
authors: R
authors: Willmann
authors: Heini M
authors: HM
authors: Lajunen
authors: Gitte
authors: G
authors: Erbs
authors: Mari-Anne
authors: MA
authors: Newman
authors: Dagmar
authors: D
authors: Kolb
authors: Kenichi
authors: K
authors: Tsuda
authors: Fumiaki
authors: F
authors: Katagiri
authors: Judith
authors: J
authors: Fliegmann
authors: Jean-Jacques
authors: JJ
authors: Bono
authors: Julie V
authors: JV
authors: Cullimore
authors: Anna K
authors: AK
authors: Jehle
authors: Friedrich
authors: F
authors: Götz
authors: Andreas
authors: A
authors: Kulik
authors: Antonio
authors: A
authors: Molinaro
authors: Volker
authors: V
authors: Lipka
authors: Andrea A
authors: AA
authors: Gust
authors: Thorsten
authors: T
authors: Nürnberger
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001419:Bacteria / Q000254:growth & development / Q000276:immunology / Q000378:metabolism*; D060467:Disease Resistance / Q000235:genetics / Q000276:immunology; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions / Q000276:immunology; D015151:Immunoblotting; D018613:Microscopy, Confocal; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010457:Peptidoglycan / Q000276:immunology / Q000378:metabolism*; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013211:Staphylococcus aureus / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D059467:Transcriptome
chemical_list: D029681:Arabidopsis Proteins; C570721:LYM1 protein, Arabidopsis; C570722:LYM3 protein, Arabidopsis; D010457:Peptidoglycan; D049452:Green Fluorescent Proteins; C525882:CERK1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases