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Uncoupling of sustained MAMP receptor signaling from early outputs in an Arabidopsis endoplasmic reticulum glucosidase II allele
- Source :
- Proceedings of the National Academy of Sciences. 106:22522-22527
- Publication Year :
- 2009
- Publisher :
- Proceedings of the National Academy of Sciences, 2009.
-
Abstract
- Recognition of microbe-associated molecular patterns (MAMPs), conserved structures typical of a microbial class, triggers immune responses in eukaryotes. This is accompanied by a diverse set of physiological responses that are thought to enhance defense activity in plants. However, the extent and mechanisms by which MAMP-induced events contribute to host immunity are poorly understood. Here we reveal Arabidopsis priority in sweet life4 ( psl4 ) and psl5 mutants that are insensitive to the bacterial elongation factor (EF)-Tu epitope elf18 but responsive to flagellin epitope flg22. PSL4 and PSL5, respectively, identify β- and α-subunits of endoplasmic reticulum-resident glucosidase II, which is essential for stable accumulation and quality control of the elf18 receptor EFR but not the flg22 receptor FLS2. We notice that EFR signaling is partially and differentially impaired without a significant decrease of the receptor steady-state levels in 2 weakly dysfunctional gII α alleles, designated psl5 -1 and rsw3 . Remarkably, rsw3 plants exhibit marked supersusceptibility against a virulent bacterial phytopathogen despite nearly intact coactivation of MAPKs, reactive oxygen species, ethylene biosynthesis, and callose deposition in response to elf18, demonstrating that these signaling outputs alone are insufficient to mount effective immunity. However, rsw3 plants fail to maintain high transcript levels of defense-promoting WRKY , PR1, and PR2 genes at late time points (4 to 24 h) after elf18 elicitation. This points to an unexpected separation between initial and sustained activation of EFR-mediated signaling in the absence of proper glucosidase II-mediated endoplasmic reticulum quality control. Our findings strongly suggest the importance of sustained MAMP receptor signaling as a key step in the establishment of robust immunity.
- Subjects :
- 0106 biological sciences
Arabidopsis
Pseudomonas syringae
Endoplasmic Reticulum
Genes, Plant
01 natural sciences
03 medical and health sciences
chemistry.chemical_compound
Receptor
MAMP
Alleles
Plant Diseases
030304 developmental biology
Genetics
0303 health sciences
Multidisciplinary
biology
Arabidopsis Proteins
Endoplasmic reticulum
fungi
Callose
alpha-Glucosidases
Biological Sciences
biology.organism_classification
WRKY protein domain
Cell biology
Protein Subunits
chemistry
Receptors, Pattern Recognition
Host-Pathogen Interactions
Mutation
biology.protein
Signal transduction
Flagellin
Signal Transduction
010606 plant biology & botany
Subjects
Details
- ISSN :
- 10916490 and 00278424
- Volume :
- 106
- Database :
- OpenAIRE
- Journal :
- Proceedings of the National Academy of Sciences
- Accession number :
- edsair.doi.dedup.....adea7a3e5b731382c0d95b08ac24e390