Abstract
Plants utilise intracellular nucleotide-binding, leucine-rich repeat (NLR) immune receptors to detect pathogen effectors and activate local and systemic defence. NRG1 and ADR1 "helper" NLRs (RNLs) cooperate with enhanced disease susceptibility 1 (EDS1), senescence-associated gene 101 (SAG101) and phytoalexin-deficient 4 (PAD4) lipase-like proteins to mediate signalling from TIR domain NLR receptors (TNLs). The mechanism of RNL/EDS1 family protein cooperation is not understood. Here, we present genetic and molecular evidence for exclusive EDS1/SAG101/NRG1 and EDS1/PAD4/ADR1 co-functions in TNL immunity. Using immunoprecipitation and mass spectrometry, we show effector recognition-dependent interaction of NRG1 with EDS1 and SAG101, but not PAD4. An EDS1-SAG101 complex interacts with NRG1, and EDS1-PAD4 with ADR1, in an immune-activated state. NRG1 requires an intact nucleotide-binding P-loop motif, and EDS1 a functional EP domain and its partner SAG101, for induced association and immunity. Thus, two distinct modules (NRG1/EDS1/SAG101 and ADR1/EDS1/PAD4) mediate TNL receptor defence signalling.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Arabidopsis / genetics
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Arabidopsis / metabolism
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Arabidopsis / microbiology
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Arabidopsis Proteins / chemistry
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Arabidopsis Proteins / genetics
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Arabidopsis Proteins / metabolism*
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Carboxylic Ester Hydrolases / chemistry
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Carboxylic Ester Hydrolases / genetics
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Carboxylic Ester Hydrolases / metabolism*
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Cell Death
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DNA-Binding Proteins / chemistry
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism*
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Immunity, Innate
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Neuregulin-1 / chemistry
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Neuregulin-1 / genetics
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Neuregulin-1 / metabolism*
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Nicotiana / genetics
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Nicotiana / metabolism
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Plant Diseases / immunology
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Plant Diseases / microbiology
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Plant Immunity / genetics
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Plant Immunity / physiology*
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Plants, Genetically Modified
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Protein Domains
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Pseudomonas syringae
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Receptors, Immunologic / chemistry
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Receptors, Immunologic / genetics
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Receptors, Immunologic / metabolism*
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Signal Transduction
Substances
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ADR1 protein, Arabidopsis
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Arabidopsis Proteins
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DNA-Binding Proteins
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EDS1 protein, Arabidopsis
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Neuregulin-1
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Receptors, Immunologic
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Carboxylic Ester Hydrolases
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PAD4 protein, Arabidopsis
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SAG101 protein, Arabidopsis