Nuclear activity of MLA immune receptors links isolate-specific and basal disease-resistance responses.
Plant immune responses are triggered by pattern recognition receptors that detect conserved pathogen-associated molecular patterns (PAMPs) or by resistance (R) proteins recognizing isolate-specific pathogen effectors. We show that in barley, intracellular mildew A (MLA) R proteins function in the nucleus to confer resistance against the powdery mildew fungus. Recognition of the fungal avirulence A10 effector by MLA10 induces nuclear associations between receptor and WRKY transcription factors. The identified WRKY proteins act as repressors of PAMP-triggered basal defense. MLA appears to interfere with the WRKY repressor function, thereby de-repressing PAMP-triggered basal defense. Our findings reveal a mechanism by which these polymorphic immune receptors integrate distinct pathogen signals.
Shen
Qian-Hua
QH
Department of Plant Microbe Interactions, Max-Planck-Institut für Züchtungsforschung, Carl-von-Linné-Weg 10, D-50829 Köln, Germany.
Saijo
Yusuke
Y
Mauch
Stefan
S
Biskup
Christoph
C
Bieri
Stéphane
S
Keller
Beat
B
Seki
Hikaru
H
Ulker
Bekir
B
Somssich
Imre E
IE
Schulze-Lefert
Paul
P
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001203:Ascomycota / Q000254:growth & development / Q000276:immunology*; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D001467:Hordeum / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D009154:Mutation; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051192:Receptors, Pattern Recognition / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D005656:Fungal Proteins; C433105:MLA1 protein, Hordeum vulgare; C430705:MLA6 protein, Hordeum vulgare; D010940:Plant Proteins; D011971:Receptors, Immunologic; D051192:Receptors, Pattern Recognition; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C464509:WRKY18 protein, Arabidopsis; C512070:WRKY40 protein, Arabidopsis; C512071:WRKY60 protein, Arabidopsis