title: Transcription factor MYC2 is involved in priming for enhanced defense during rhizobacteria-induced systemic resistance in Arabidopsis thaliana.
abstract: Upon appropriate stimulation, plants can develop an enhanced capacity to express infection-induced cellular defense responses, a phenomenon known as the primed state. Colonization of the roots of Arabidopsis thaliana by the beneficial rhizobacterial strain Pseudomonas fluorescens WCS417r primes the leaf tissue for enhanced pathogen- and insect-induced expression of jasmonate (JA)-responsive genes, resulting in an induced systemic resistance (ISR) that is effective against different types of pathogens and insect herbivores. Here the molecular mechanism of this rhizobacteria-induced priming response was investigated using a whole-genome transcript profiling approach. Out of the 1879 putative methyl jasmonate (MeJA)-responsive genes, 442 genes displayed a primed expression pattern in ISR-expressing plants. Promoter analysis of ISR-primed, MeJA-responsive genes and ISR-primed, Pseudomonas syringae pv. tomato DC3000 (Pst DC3000)-responsive genes revealed over-representation of the G-box-like motif 5'-CACATG-3'. This motif is a binding site for the transcription factor MYC2, which plays a central role in JA- and abscisic acid-regulated signaling. MYC2 expression was consistently up-regulated in ISR-expressing plants. Moreover, mutants impaired in the JASMONATE-INSENSITIVE1/MYC2 gene (jin1-1 and jin1-2) were unable to mount WCS417r-ISR against Pst DC3000 and the downy mildew pathogen Hyaloperonospora parasitica. Together, these results pinpoint MYC2 as a potential regulator in priming for enhanced JA-responsive gene expression during rhizobacteria-mediated ISR.
authors.affiliation: Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.56, 3508 TB, Utrecht, the Netherlands.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Pozo
authors.affiliation: Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.56, 3508 TB, Utrecht, the Netherlands.|Center for Biosystems Genomics, PO Box 98, 6700 AB Wageningen, the Netherlands.
authors.forename: Sjoerd
authors.initials: S
authors.lastname: Van Der Ent
authors.affiliation: Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.56, 3508 TB, Utrecht, the Netherlands.
authors.forename: L C
authors.initials: LC
authors.lastname: Van Loon
authors.affiliation: Graduate School Experimental Plant Sciences, Plant-Microbe Interactions, Institute of Environmental Biology, Faculty of Science, Utrecht University, PO Box 800.56, 3508 TB, Utrecht, the Netherlands.|Center for Biosystems Genomics, PO Box 98, 6700 AB Wageningen, the Netherlands.
authors.forename: Corné M J
authors.initials: CMJ
authors.lastname: Pieterse
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000222:Adaptation, Physiological / Q000235:genetics; D000818:Animals; D017360:Arabidopsis / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics*; D003517:Cyclopentanes / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D009868:Oomycetes / Q000472:pathogenicity; D054883:Oxylipins / Q000378:metabolism*; D044742:Peronospora / Q000469:parasitology; D010935:Plant Diseases; D010937:Plant Growth Regulators; D011401:Promoter Regions, Genetic; D011551:Pseudomonas fluorescens / Q000502:physiology; D044224:Pseudomonas syringae / Q000472:pathogenicity; D014157:Transcription Factors
chemical_list: D000085:Acetates; D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D003517:Cyclopentanes; C473611:MYC2 protein, Arabidopsis; D054883:Oxylipins; D010937:Plant Growth Regulators; D014157:Transcription Factors; C072239:methyl jasmonate