Bacterial Effector HopF2 Suppresses Arabidopsis Innate Immunity at the Plasma Membrane
Open Access
- 1 May 2011
- journal article
- research article
- Published by Scientific Societies in Molecular Plant-Microbe Interactions®
- Vol. 24 (5), 585-593
- https://doi.org/10.1094/mpmi-07-10-0150
Abstract
Many bacterial pathogens inject a cocktail of effector proteins into host cells through type III secretion systems. These effectors act in concert to modulate host physiology and immune signaling, thereby promoting pathogenicity. In a search for additional Pseudomonas syringae effectors in suppressing plant innate immunity triggered by pathogen or microbe-associated molecular patterns (PAMPs or MAMPs), we identified P. syringae tomato DC3000 effector HopF2 as a potent suppressor of early immune-response gene transcription and mitogen-activated protein kinase (MAPK) signaling activated by multiple MAMPs, including bacterial flagellin, elongation factor Tu, peptidoglycan, lipopolysaccharide and HrpZ1 harpin, and fungal chitin. The conserved surface-exposed residues of HopF2 are essential for its MAMP suppression activity. HopF2 is targeted to the plant plasma membrane through a putative myristoylation site, and the membrane association appears to be required for its MAMP-suppression function. Expression of HopF2 in plants potently diminished the flagellin-induced phosphorylation of BIK1, a plasma membrane–associated cytoplasmic kinase that is rapidly phosphorylated within one minute upon flagellin perception. Thus, HopF2 likely intercepts MAMP signaling at the plasma membrane immediately of signal perception. Consistent with the potent suppression function of multiple MAMP signaling, expression of HopF2 in transgenic plants compromised plant nonhost immunity to bacteria P. syringae pv. Phaseolicola and plant immunity to the necrotrophic fungal pathogen Botrytis cinerea.Keywords
This publication has 62 references indexed in Scilit:
- Differential innate immune signalling via Ca2+ sensor protein kinasesNature, 2010
- The type III effector HopF2
Pto
targets Arabidopsis RIN4 protein to promote Pseudomonas syringae virulenceProceedings of the National Academy of Sciences of the United States of America, 2010
- Salmonella takes control: effector-driven manipulation of the hostCurrent Opinion in Microbiology, 2009
- Bacterial Effectors Target the Common Signaling Partner BAK1 to Disrupt Multiple MAMP Receptor-Signaling Complexes and Impede Plant ImmunityCell Host & Microbe, 2008
- Pathogen virulence factors as molecular probes of basic plant cellular functionsCurrent Opinion in Plant Biology, 2007
- The receptor-like kinase SERK3/BAK1 is a central regulator of innate immunity in plantsProceedings of the National Academy of Sciences of the United States of America, 2007
- The plant immune systemNature, 2006
- Arabidopsis RIN4 Is a Target of the Type III Virulence Effector AvrRpt2 and Modulates RPS2-Mediated ResistanceCell, 2003
- RIN4 Interacts with Pseudomonas syringae Type III Effector Molecules and Is Required for RPM1-Mediated Resistance in ArabidopsisCell, 2002
- MAP kinase signalling cascade in Arabidopsis innate immunityNature, 2002