title: Identification, quantification, spatiotemporal distribution and genetic variation of major latex secondary metabolites in the common dandelion (Taraxacum officinale agg.).
abstract: The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant's highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mgg(-1) range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active.
authors: Department of Biochemistry, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Meret
authors: M
authors: Huber
authors: Department of Biochemistry, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Daniella
authors: D
authors: Triebwasser-Freese
authors: Department of Biochemistry, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Michael
authors: M
authors: Reichelt
authors: Department of Molecular Ecology, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Sven
authors: S
authors: Heiling
authors: Research Group Biosynthesis/NMR, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Christian
authors: C
authors: Paetz
authors: Research Group Biosynthesis/NMR, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Jima N
authors: JN
authors: Chandran
authors: Department of Bioorganic Chemistry, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Stefan
authors: S
authors: Bartram
authors: Research Group Biosynthesis/NMR, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Bernd
authors: B
authors: Schneider
authors: Department of Biochemistry, Max-Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors: Jonathan
authors: J
authors: Gershenzon
authors: Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland. Electronic address: matthias.erb@ips.unibe.ch.
authors: Matthias
authors: M
authors: Erb
mesh_terms: D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D007783:Lactones / Q000032:analysis; D007840:Latex / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018517:Plant Roots / Q000737:chemistry; D012717:Sesquiterpenes / Q000032:analysis; D031205:Taraxacum / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013729:Terpenes / Q000032:analysis
chemical_list: D007783:Lactones; D007840:Latex; D012717:Sesquiterpenes; D013729:Terpenes
keywords: Asteraceae; Common dandelion; Defensive secondary metabolites; GC–MS; HPLC–MS; Latex; Phenolics; Sesquiterpene lactone glycosides; Taraxacum officinale agg.; Triterpene acetates