title: The transcription factor ABI4 Is required for the ascorbic acid-dependent regulation of growth and regulation of jasmonate-dependent defense signaling pathways in Arabidopsis.
abstract: Cellular redox homeostasis is a hub for signal integration. Interactions between redox metabolism and the ABSCISIC ACID-INSENSITIVE-4 (ABI4) transcription factor were characterized in the Arabidopsis thaliana vitamin c defective1 (vtc1) and vtc2 mutants, which are defective in ascorbic acid synthesis and show a slow growth phenotype together with enhanced abscisic acid (ABA) levels relative to the wild type (Columbia-0). The 75% decrease in the leaf ascorbate pool in the vtc2 mutants was not sufficient to adversely affect GA metabolism. The transcriptome signatures of the abi4, vtc1, and vtc2 mutants showed significant overlap, with a large number of transcription factors or signaling components similarly repressed or induced. Moreover, lincomycin-dependent changes in LIGHT HARVESTING CHLOROPHYLL A/B BINDING PROTEIN 1.1 expression were comparable in these mutants, suggesting overlapping participation in chloroplast to nucleus signaling. The slow growth phenotype of vtc2 was absent in the abi4 vtc2 double mutant, as was the sugar-insensitive phenotype of the abi4 mutant. Octadecanoid derivative-responsive AP2/ERF-domain transcription factor 47 (ORA47) and AP3 (an ABI5 binding factor) transcripts were enhanced in vtc2 but repressed in abi4 vtc2, suggesting that ABI4 and ascorbate modulate growth and defense gene expression through jasmonate signaling. We conclude that low ascorbate triggers ABA- and jasmonate-dependent signaling pathways that together regulate growth through ABI4. Moreover, cellular redox homeostasis exerts a strong influence on sugar-dependent growth regulation.
authors.affiliation: Centre for Plant Sciences, Faculty of Biology, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Pavel I
authors.initials: PI
authors.lastname: Kerchev
authors.forename: Till K
authors.initials: TK
authors.lastname: Pellny
authors.forename: Pedro Diaz
authors.initials: PD
authors.lastname: Vivancos
authors.forename: Guy
authors.initials: G
authors.lastname: Kiddle
authors.forename: Peter
authors.initials: P
authors.lastname: Hedden
authors.forename: Simon
authors.initials: S
authors.lastname: Driscoll
authors.forename: Hélène
authors.initials: H
authors.lastname: Vanacker
authors.forename: Paul
authors.initials: P
authors.lastname: Verrier
authors.forename: Robert D
authors.initials: RD
authors.lastname: Hancock
authors.forename: Christine H
authors.initials: CH
authors.lastname: Foyer
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006706:Homeostasis; D009154:Mutation; D010084:Oxidation-Reduction; D054883:Oxylipins / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome
chemical_list: C470421:ABI4 protein, Arabidopsis; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D005875:Gibberellins; D054883:Oxylipins; D010937:Plant Growth Regulators; D014157:Transcription Factors; C011006:jasmonic acid; D000040:Abscisic Acid; C007842:gibberellic acid; D005978:Glutathione; D001205:Ascorbic Acid