title: Novel positive regulatory role for the SPL6 transcription factor in the N TIR-NB-LRR receptor-mediated plant innate immunity.
abstract: Following the recognition of pathogen-encoded effectors, plant TIR-NB-LRR immune receptors induce defense signaling by a largely unknown mechanism. We identify a novel and conserved role for the SQUAMOSA PROMOTER BINDING PROTEIN (SBP)-domain transcription factor SPL6 in enabling the activation of the defense transcriptome following its association with a nuclear-localized immune receptor. During an active immune response, the Nicotiana TIR-NB-LRR N immune receptor associates with NbSPL6 within distinct nuclear compartments. NbSPL6 is essential for the N-mediated resistance to Tobacco mosaic virus. Similarly, the presumed Arabidopsis ortholog AtSPL6 is required for the resistance mediated by the TIR-NB-LRR RPS4 against Pseudomonas syringae carrying the avrRps4 effector. Transcriptome analysis indicates that AtSPL6 positively regulates a subset of defense genes. A pathogen-activated nuclear-localized TIR-NB-LRR like N can therefore regulate defense genes through SPL6 in a mechanism analogous to the induction of MHC genes by mammalian immune receptors like CIITA and NLRC5.
authors.affiliation: Department of Plant Biology and The Genome Center, College of Biological Sciences, University of California, Davis, CA, USA.
authors.forename: Meenu S
authors.initials: MS
authors.lastname: Padmanabhan
authors.forename: Shisong
authors.initials: S
authors.lastname: Ma
authors.forename: Tessa M
authors.initials: TM
authors.lastname: Burch-Smith
authors.forename: Kirk
authors.initials: K
authors.lastname: Czymmek
authors.forename: Peter
authors.initials: P
authors.lastname: Huijser
authors.forename: Savithramma P
authors.initials: SP
authors.lastname: Dinesh-Kumar
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D007113:Immunity, Innate; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D044224:Pseudomonas syringae / Q000502:physiology; D015398:Signal Transduction; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000276:immunology* / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D059467:Transcriptome
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; C000596391:SPL6 protein, Arabidopsis; D014157:Transcription Factors