Abstract
P>Pseudomonas fluorescens WCS417r bacteria and beta-aminobutyric acid can induce disease resistance in Arabidopsis, which is based on priming of defence.
In this study, we examined the differences and similarities of WCS417r- and beta-aminobutyric acid-induced priming.
Both WCS417r and beta-aminobutyric acid prime for enhanced deposition of callose-rich papillae after infection by the oomycete Hyaloperonospora arabidopsis. This priming is regulated by convergent pathways, which depend on phosphoinositide- and ABA-dependent signalling components. Conversely, induced resistance by WCS417r and beta-aminobutyric acid against the bacterial pathogen Pseudomonas syringae are controlled by distinct NPR1-dependent signalling pathways. As WCS417r and beta-aminobutyric acid prime jasmonate- and salicylate-inducible genes, respectively, we subsequently investigated the role of transcription factors. A quantitative PCR-based genome-wide screen for putative WCS417r- and beta-aminobutyric acid-responsive transcription factor genes revealed distinct sets of priming-responsive genes. Transcriptional analysis of a selection of these genes showed that they can serve as specific markers for priming. Promoter analysis of WRKY genes identified a putative cis-element that is strongly over-represented in promoters of 21 NPR1-dependent, beta-aminobutyric acid-inducible WRKY genes.
Our study shows that priming of defence is regulated by different pathways, depending on the inducing agent and the challenging pathogen. Furthermore, we demon-strated that priming is associated with the enhanced expression of transcription factors.
New Phytologist (2009) 183: 419-431doi: 10.1111/j.1469-8137.2009.02851.x.
Original language | English |
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Pages (from-to) | 419-431 |
Number of pages | 13 |
Journal | New Phytologist |
Volume | 183 |
Issue number | 2 |
DOIs | |
Publication status | Published - Jul 2009 |
Keywords
- Arabidopsis thaliana
- callose
- NPR1
- priming
- transcription factors
- WRKY
- SYSTEMIC ACQUIRED-RESISTANCE
- ARABIDOPSIS TRANSCRIPTION FACTOR
- DISEASE RESISTANCE
- BIOCONTROL BACTERIA
- PATHOGEN INFECTION
- GENE-EXPRESSION
- SALICYLIC-ACID
- DOWNY MILDEW
- DEFENSE
- PATHWAY