ibclogo XVI International Botanical Congess

Abstract Number: 2584
Session = 20.15.3


SUCROSE TURNOVER AND GLYCOLYTIC FLUXES MEASURED BY AND 1H, 13C, AND 31P NMR


P Raymond, M Dieuaide, D Rontein, D Rolin, C Roby* Physiol Vég, INRA-UVS Bordeaux 2, BP81 33883 Villenave d'O France, *LRMBM, CEA-UJF, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France


Two independent NMR methods were used to quantify carbon fluxes in maize root metabolism, and the effect of sugar starvation or hypoxia. Metabolic modeling of [1-13C]glucose labeling, and 1H- or 13C-NMR analysis of 13C enrichments in key metabolites, provided 20 fluxes including PEP partition into the TCA cycle. Two-dimensional 31P-NMR exchange spectroscopy in vivo provided unidirectional rates of five reactions from sucrose turnover to ATP hydrolysis. Both methods indicated a high ATP consumption by sucrose turnover. We presently use both NMR methods to study the sucrose turnover and PEPcarboxylase fluxes in relation to sugar and organic acid accumulation in tomato fruits and cells.

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