title: Metabolic flux analysis of the phenylpropanoid pathway in wound-healing potato tuber tissue using stable isotope-labeled tracer and LC-MS spectroscopy.
abstract: The metabolic flux of two phenylpropanoid metabolites, N-p-coumaroyloctopamine (p-CO) and chlorogenic acid (CGA), in the wound-healing potato tuber tissue was quantitatively analyzed by a newly developed method based upon the tracer experiment using stable isotope-labeled compounds and LC-MS. Tuber disks were treated with aqueous solution of L-phenyl-d(5)-alanine, and the change in the ratio of stable isotope-labeled compound to non-labeled (isotope abundance) was monitored for p-CO and CGA in the tissue extract by LC-MS. The time-dependent change in the isotope abundance of each metabolite was fitted to an equation that was derived from the formation and conversion kinetics of each compound. Good correlations were obtained between the observed and calculated isotope abundances for both p-CO and CGA. The rates of p-CO formation and conversion (i.e. fluxes) were 1.15 and 0.96 nmol (g FW)(-1) h(-1), respectively, and for CGA, the rates 4.63 and 0.42 nmol (g FW)(-1) h(-1), respectively. This analysis enabled a direct comparison of the biosynthetic activity between these two compounds.
authors.affiliation: Division of Applied Life Sciences, Department of Agriculture, Kyoto University, Kyoto, 606-8502 Japan. matsuda@kais.kyoto-u.ac.jp
authors.forename: Fumio
authors.initials: F
authors.lastname: Matsuda
authors.forename: Keiko
authors.initials: K
authors.lastname: Morino
authors.forename: Masahiro
authors.initials: M
authors.lastname: Miyashita
authors.forename: Hisashi
authors.initials: H
authors.lastname: Miyagawa
mesh_terms: D000465:Algorithms; D002726:Chlorogenic Acid / Q000378:metabolism*; D002853:Chromatography, Liquid; D003373:Coumaric Acids / Q000378:metabolism; D007553:Isotope Labeling / Q000379:methods; D013058:Mass Spectrometry; D008954:Models, Biological; D009655:Octopamine / Q000031:analogs & derivatives* / Q000096:biosynthesis*; D010649:Phenylalanine / Q000494:pharmacology; D018547:Plant Stems / Q000187:drug effects / Q000378:metabolism*; D020005:Propanols / Q000378:metabolism*; D011849:Radioactive Tracers; D011198:Solanum tuberosum / Q000187:drug effects / Q000378:metabolism*; D013314:Stress, Mechanical
chemical_list: D003373:Coumaric Acids; C410948:N-4-coumaroyloctopamine; D020005:Propanols; D011849:Radioactive Tracers; C439395:1-phenylpropanol; D009655:Octopamine; D002726:Chlorogenic Acid; D010649:Phenylalanine