title: The Arabidopsis malectin-like leucine-rich repeat receptor-like kinase IOS1 associates with the pattern recognition receptors FLS2 and EFR and is critical for priming of pattern-triggered immunity.
abstract: Plasma membrane-localized pattern recognition receptors such as FLAGELLIN SENSING2 (FLS2) and EF-TU RECEPTOR (EFR) recognize microbe-associated molecular patterns (MAMPs) to activate the first layer of plant immunity termed pattern-triggered immunity (PTI). A reverse genetics approach with genes responsive to the priming agent β-aminobutyric acid (BABA) revealed IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as a critical PTI player. Arabidopsis thaliana ios1 mutants were hypersusceptible to Pseudomonas syringae bacteria. Accordingly, ios1 mutants demonstrated defective PTI responses, notably delayed upregulation of PTI marker genes, lower callose deposition, and mitogen-activated protein kinase activities upon bacterial infection or MAMP treatment. Moreover, Arabidopsis lines overexpressing IOS1 were more resistant to P. syringae and demonstrated a primed PTI response. In vitro pull-down, bimolecular fluorescence complementation, coimmunoprecipitation, and mass spectrometry analyses supported the existence of complexes between the membrane-localized IOS1 and FLS2 and EFR. IOS1 also associated with BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1) in a ligand-independent manner and positively regulated FLS2/BAK1 complex formation upon MAMP treatment. Finally, ios1 mutants were defective in BABA-induced resistance and priming. This work reveals IOS1 as a regulatory protein of FLS2- and EFR-mediated signaling that primes PTI activation upon bacterial elicitation.
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Ching-Wei
authors: CW
authors: Chen
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Dario
authors: D
authors: Panzeri
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Yu-Hung
authors: YH
authors: Yeh
authors: Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom.
authors: Yasuhiro
authors: Y
authors: Kadota
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Pin-Yao
authors: PY
authors: Huang
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Chia-Nan
authors: CN
authors: Tao
authors: Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom.
authors: Milena
authors: M
authors: Roux
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Shiao-Chiao
authors: SC
authors: Chien
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Tzu-Chuan
authors: TC
authors: Chin
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan.
authors: Po-Wei
authors: PW
authors: Chu
authors: Sainsbury Laboratory, Norwich NR4 7UH, United Kingdom.
authors: Cyril
authors: C
authors: Zipfel
authors: Department of Life Science and Institute of Plant Biology, National Taiwan University, Taipei 106, Taiwan lauzim2@ntu.edu.tw.
authors: Laurent
authors: L
authors: Zimmerli
mesh_terms: D000613:Aminobutyrates / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D007930:Leucine / Q000378:metabolism; D009154:Mutation; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000502:physiology; D051192:Receptors, Pattern Recognition / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D000613:Aminobutyrates; D029681:Arabidopsis Proteins; C545106:EFR protein, Arabidopsis; D051192:Receptors, Pattern Recognition; C047667:3-aminobutyric acid; C569619:At1g51800 protein, Arabidopsis; D011494:Protein Kinases; C411853:FLS2 protein, Arabidopsis; D007930:Leucine