Arabidopsis proteins important for modulating defense responses to Pseudomonas syringae that secrete HopW1-1.
Plant infection responses result from the interaction of pathogen-derived molecules with host components. For the bacterial pathogen Pseudomonas syringae, these molecules are often effector proteins (Hops) that are injected into plant cells. P. syringae carrying hopW1-1 have restricted host range on some Arabidopsis thaliana accessions. At least two Arabidopsis genomic regions are important for the natural variation that conditions resistance to P. syringae/hopW1-1. HopW1-1 elicits a resistance response, and consequently the accumulation of the signal molecule salicylic acid (SA) and transcripts of HWI1 (HopW1-1-Induced Gene1). This work identified three HopW1-1-interacting (WIN) plant proteins: a putative acetylornithine transaminase (WIN1), a protein phosphatase (WIN2) and a firefly luciferase superfamily protein (WIN3). Importantly, WIN2 and WIN3 are partially required for HopW1-1-induced disease resistance, SA production and HWI1 expression. The requirement for WIN2 is specific for HopW1-1-induced resistance, whereas WIN3 is important for responses to several effectors. Overexpression of WIN2 or WIN3 confers resistance to virulent P. syringae, which is consistent with these proteins being defense components. Several known genes important for SA production or signaling are also partially (EDS1, NIM1/NPR1, ACD6 and ALD1) or strongly (PAD4) required for the robust resistance induced by HopW1-1, suggesting a key role for SA in the HopW1-1-induced resistance response. Finally, WIN1 is an essential protein, the overexpression of which over-rides the resistance response to HopW1-1 (and several other defense-inducing effectors), and delays SA and HWI1 induction. Thus, the WIN proteins have different roles in modulating plant defense.
Lee
Min Woo
MW
Department of Molecular Genetics and Cell Biology, The University of Chicago, 1103 East 57th Street EBC410, Chicago, IL 60637, USA.
Jelenska
Joanna
J
Greenberg
Jean T
JT
D017487:Ankyrins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D007113:Immunity, Innate / Q000235:genetics; D049409:Luciferases, Firefly / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D044224:Pseudomonas syringae / Q000254:growth & development / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D000637:Transaminases / Q000235:genetics / Q000378:metabolism / Q000502:physiology
D017487:Ankyrins; D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D049409:Luciferases, Firefly; D020156:Salicylic Acid; D015534:Trans-Activators; D000637:Transaminases; C480953:ACD6 protein, Arabidopsis; C118837:EDS1 protein, Arabidopsis; C105496:NPR1 protein, Arabidopsis; C487812:WIN1 protein, Arabidopsis; C487185:AGD2-LIKE DEFENSE RESPONSE PROTEIN1, Arabidopsis; C523087:At5g13320 protein, Arabidopsis