title: 13CO2 as a universal metabolic tracer in isotopologue perturbation experiments.
abstract: A tobacco plant was illuminated for 5h in an atmosphere containing (13)CO(2) and then maintained for 10 days under standard greenhouse conditions. Nicotine, glucose, and amino acids from proteins were isolated chromatographically. Isotopologue abundances of isolated metabolites were determined quantitatively by NMR spectroscopy and mass spectrometry. The observed non-stochastic isotopologue patterns indicate (i) formation of multiply labeled photosynthetic carbohydrates during the (13)CO(2) pulse phase followed by (ii) partial catabolism of the primary photosynthetic products, and (iii) recombination of the (13)C-labeled fragments with unlabeled intermediary metabolites during the chase period. The detected and simulated isotopologue profiles of glucose and amino acids reflect carbon partitioning that is dominated by the Calvin cycle and glycolysis/glucogenesis. Retrobiosynthetic analysis of the nicotine pattern is in line with its known formation from nicotinic acid and putrescine via aspartate, glyceraldehyde phosphate and alpha-ketoglutarate as basic building blocks. The study demonstrates that pulse/chase labeling with (13)CO(2) as precursor is a powerful tool for the analysis of quantitative aspects of plant metabolism in completely unperturbed whole plants.
authors.affiliation: Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Römisch-Margl
authors.forename: Nicholas
authors.initials: N
authors.lastname: Schramek
authors.forename: Tanja
authors.initials: T
authors.lastname: Radykewicz
authors.forename: Christian
authors.initials: C
authors.lastname: Ettenhuber
authors.forename: Eva
authors.initials: E
authors.lastname: Eylert
authors.forename: Claudia
authors.initials: C
authors.lastname: Huber
authors.forename: Lilla
authors.initials: L
authors.lastname: Römisch-Margl
authors.forename: Christine
authors.initials: C
authors.lastname: Schwarz
authors.forename: Maria
authors.initials: M
authors.lastname: Dobner
authors.forename: Norbert
authors.initials: N
authors.lastname: Demmel
authors.forename: Bernhard
authors.initials: B
authors.lastname: Winzenhörlein
authors.forename: Adelbert
authors.initials: A
authors.lastname: Bacher
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Eisenreich
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D002245:Carbon Dioxide / Q000737:chemistry / Q000378:metabolism*; D002247:Carbon Isotopes; D003198:Computer Simulation; D005947:Glucose / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013058:Mass Spectrometry; D009538:Nicotine / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D010788:Photosynthesis; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D014026:Nicotiana / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D002247:Carbon Isotopes; D002245:Carbon Dioxide; D009538:Nicotine; D005947:Glucose