title: The influence of ascorbate on anthocyanin accumulation during high light acclimation in Arabidopsis thaliana: further evidence for redox control of anthocyanin synthesis.
abstract: Ascorbate and anthocyanins act as photoprotectants during exposure to high light (HL). They accumulate in Arabidopsis leaves in response to HL on a similar timescale, suggesting a potential relationship between them. Flavonoids and related metabolites were identified and profiled by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The ascorbate-deficient mutants vtc1, vtc2 and vtc3 accumulated less anthocyanin than wild-type (WT) during HL acclimation. In contrast, kaempferol glycoside accumulation was less affected by light and not decreased by ascorbate deficiency, while sinapoyl malate levels decreased during HL acclimation. Comparison of six Arabidopsis ecotypes showed a positive correlation between ascorbate and anthocyanin accumulation in HL. mRNA-Seq analysis showed that all flavonoid biosynthesis transcripts were increased by HL acclimation in WT. RT-PCR analysis showed that vtc1 and vtc2 were impaired in HL induction of transcripts of anthocyanin biosynthesis enzymes, and the transcription factors PAP1, GL3 and EGL3 that activate the pathway. Abscisic acid (ABA) and jasmonic acid (JA), hormones that could affect anthocyanin accumulation, were unaffected in vtc mutants. It is concluded that HL induction of anthocyanin synthesis involves a redox-sensitive process upstream of the known transcription factors. Because anthocyanins accumulate in preference to kaempferol glycosides and sinapoyl malate in HL, they might have specific properties that make them useful in HL acclimation.
authors.affiliation: Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Page
authors.forename: Nighat
authors.initials: N
authors.lastname: Sultana
authors.forename: Konrad
authors.initials: K
authors.lastname: Paszkiewicz
authors.forename: Hannah
authors.initials: H
authors.lastname: Florance
authors.forename: Nicholas
authors.initials: N
authors.lastname: Smirnoff
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000064:Acclimatization; D000872:Anthocyanins / Q000378:metabolism*; D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001205:Ascorbic Acid / Q000032:analysis / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism; D060146:Ecotype; D018506:Gene Expression Regulation, Plant / Q000235:genetics* / Q000528:radiation effects; D006027:Glycosides / Q000378:metabolism; D044949:Kaempferols / Q000378:metabolism; D008027:Light; D008293:Malates / Q000378:metabolism; D009154:Mutation; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D054883:Oxylipins / Q000378:metabolism; D000073718:Pancreatitis-Associated Proteins; D010666:Phenylpropionates / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C079164:2-O-sinapoylmalate; D000872:Anthocyanins; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D006027:Glycosides; D044949:Kaempferols; D008293:Malates; D054883:Oxylipins; D000073718:Pancreatitis-Associated Proteins; D010666:Phenylpropionates; D010937:Plant Growth Regulators; C000612141:REG3A protein, human; D014157:Transcription Factors; C011006:jasmonic acid; D000040:Abscisic Acid; C006552:kaempferol; D001205:Ascorbic Acid