title: Soybean NDR1-like proteins bind pathogen effectors and regulate resistance signaling.
abstract: Nonrace specific disease resistance 1 (NDR1) is a conserved downstream regulator of resistance (R) protein-derived signaling. We identified two NDR1-like sequences (GmNDR1a, b) from soybean, and investigated their roles in R-mediated resistance and pathogen effector detection. Silencing GmNDR1a and b in soybean shows that these genes are required for resistance derived from the Rpg1-b, Rpg3, and Rpg4 loci, against Pseudomonas syringae (Psg) expressing avrB, avrB2 and avrD1, respectively. Immunoprecipitation assays show that the GmNDR1 proteins interact with the AvrB2 and AvrD1 Psg effectors. This correlates with the enhanced virulence of Psg avrB2 and Psg avrD1 in GmNDR1-silenced rpg3 rpg4 plants, even though these strains are not normally more virulent on plants lacking cognate R loci. The GmNDR1 proteins interact with GmRIN4 proteins, but not with AvrB, or its cognate R protein Rpg1-b. However, the GmNDR1 proteins promote AvrB-independent activation of Rpg1-b when coexpressed with a phosphomimic derivative of GmRIN4b. The role of GmNDR1 proteins in Rpg1-b activation, their direct interactions with AvrB2/AvrD1, and a putative role in the virulence activities of Avr effectors, provides the first experimental evidence in support of the proposed role for NDR1 in transducing extracellular pathogen-derived signals.
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY, 40546, USA.
authors.forename: Devarshi
authors.initials: D
authors.lastname: Selote
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY, 40546, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Shine
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY, 40546, USA.
authors.forename: Guillaume P
authors.initials: GP
authors.lastname: Robin
authors.affiliation: Department of Plant Pathology, University of Kentucky, Lexington, KY, 40546, USA.
authors.forename: Aardra
authors.initials: A
authors.lastname: Kachroo
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D044224:Pseudomonas syringae / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D015398:Signal Transduction; D030262:Soybean Proteins / Q000235:genetics* / Q000378:metabolism; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
chemical_list: D029681:Arabidopsis Proteins; C100931:AvrB protein, Pseudomonas syringae; D001426:Bacterial Proteins; D002352:Carrier Proteins; C109369:NDR1 protein, Arabidopsis; D030262:Soybean Proteins; D014157:Transcription Factors; C087017:AvrD protein, Pseudomonas syringae
keywords: bacterial blight; nondisease resistance 1; pathogen effector; resistance protein; soybean defense