Priming of plant innate immunity by rhizobacteria and beta-aminobutyric acid: differences and similarities in regulation.
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 demonstrated that priming is associated with the enhanced expression of transcription factors.
Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.84, 3508 TB Utrecht, The Netherlands.|Centre for Biosystems Genomics, PO Box 98, 6700 AB Wageningen, The Netherlands.
Sjoerd
S
Van der Ent
Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.84, 3508 TB Utrecht, The Netherlands.
Marieke
M
Van Hulten
Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.84, 3508 TB Utrecht, The Netherlands.|Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
Maria J
MJ
Pozo
Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany.|CNAP Research Laboratories, Department of Biology (Area 7), University of York, Heslington, PO Box 373, York YO10 5YW, UK.
Tomasz
T
Czechowski
Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Golm, Germany.|Samuel Roberts Noble Foundation, Plant Biology Division, 2510 Sam Noble Pky, Ardmore, OK 73401, USA.
Michael K
MK
Udvardi
Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.84, 3508 TB Utrecht, The Netherlands.|Centre for Biosystems Genomics, PO Box 98, 6700 AB Wageningen, The Netherlands.
Corné M J
CMJ
Pieterse
Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.84, 3508 TB Utrecht, The Netherlands.|Rothamsted Research, Department of Biological Chemistry, West Common, Harpenden, Hertfordshire AL5 2JQ, UK.
Jurriaan
J
Ton
D000613:Aminobutyrates / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002473:Cell Wall / Q000187:drug effects / Q000382:microbiology; D003517:Cyclopentanes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant; D007113:Immunity, Innate / Q000187:drug effects* / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009868:Oomycetes / Q000187:drug effects / Q000502:physiology; D054883:Oxylipins / Q000494:pharmacology; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011551:Pseudomonas fluorescens / Q000187:drug effects / Q000502:physiology*; D044224:Pseudomonas syringae / Q000187:drug effects / Q000472:pathogenicity; D020156:Salicylic Acid / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014774:Virulence / Q000187:drug effects
D000613:Aminobutyrates; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; C105496:NPR1 protein, Arabidopsis; D054883:Oxylipins; D014157:Transcription Factors; C047667:3-aminobutyric acid; C011006:jasmonic acid; D020156:Salicylic Acid