Journal Article

AtrbohD-Mediated Oxidative Burst Elicited by Oligogalacturonides in Arabidopsis Is Dispensable for the Activation of Defense Responses Effective against Botrytis cinerea

Ausubel, Frederick M, Ferrari, Simone, Galletti, Roberta, Gambetta, Stefano, Dewdney, Julia, De Lorenzo, Giulia, Denoux, Carine

2008

Overview

Oligogalacturonides (OGs) are endogenous elicitors of defense responses released after partial degradation of pectin in the plant cell wall. We have previously shown that, in Arabidopsis (Arabidopsis thaliana), OGs induce the expression of PHYTOALEXIN DEFICIENT3 (PAD3) and increase resistance to the necrotrophic fungal pathogen Botrytis cinerea independently of signaling pathways mediated by jasmonate, salicylic acid, and ethylene. Here, we illustrate that the rapid induction of the expression of a variety of genes by OGs is also independent of salicylic acid, ethylene, and jasmonate. OGs elicit a robust extracellular oxidative burst that is generated by the NADPH oxidase AtrbohD. This burst is not required for the expression of OG-responsive genes or for OG-induced resistance to B. cinerea, whereas callose accumulation requires a functional AtrbohD. OG-induced resistance to B. cinerea is also unaffected in powdery mildew resistant4, despite the fact that callose accumulation was almost abolished in this mutant. These results indicate that the OG-induced oxidative burst is not required for the activation of defense responses effective against B. cinerea, leaving open the question of the role of reactive oxygen species in elicitor-mediated defense.

• Publisher: American Society of Plant Biologists
• Subject: Arabidopsis / Arabidopsis - enzymology / Arabidopsis - metabolism / Arabidopsis - microbiology / Arabidopsis thaliana / Biological and medical sciences / Botrytis / Botrytis - pathogenicity / Botrytis cinerea / callose / cell walls / Cyclopentanes / Cyclopentanes - metabolism / enzymology / ethylene / Ethylenes / Ethylenes - metabolism / Fundamental and applied biological sciences. Psychology / Fungal plant pathogens / gene expression / Genes / Hexuronic Acids / Hexuronic Acids - metabolism / Infections / Leaves / metabolism / microbiology / Mitochondrial Proteins / NADP (coenzyme) / Oxidases / Oxidoreductases / Oxidoreductases - metabolism / Oxylipins / Oxylipins - metabolism / pathogenicity / Pathogens / pectins / Phytopathology. Animal pests. Plant and forest protection / Plant cells / Plant physiology and development / Plant Proteins / Plants / Plants Interacting with Other Organisms / powdery mildew / Reactive oxygen species / Respiratory Burst / salicylic acid / Salicylic Acid - metabolism / Seedlings / Signal Transduction