¹⁴C pulse labeling to estimate external fluxes and turnovers in primary metabolism.
Steady state (13)C-MFA is classically used to measure fluxes in complex metabolic networks. However, the modeling of steady state labeling allows the quantification of internal fluxes only and requires the estimation, by other methods, of the external fluxes, corresponding to substrate uptake (carbon input into the network) and to the production rate of compounds that accumulate within plant cells (network output). Additionally, it is not always possible to discriminate between different pathways that lead to the same label distribution. Methods to measure fluxes, based on direct measurements of pool size and on (14)C short-time labeling experiments, are described in this chapter. To illustrate this approach, we focus on the quantification of sucrose and starch turnovers.
UMR 1332 de Biologie du Fruit et Pathologie, INRA, Villenave d'Ornon, France.
Katia
K
Pianelli
Antoine
A
Monier
Marie-Hélène
MH
Andrieu
Bertrand
B
Beauvoit
Martine
M
Dieuaide-Noubhani
D050260:Carbohydrate Metabolism; D002250:Carbon Radioisotopes; D046508:Culture Techniques; D018551:Solanum lycopersicum / Q000166:cytology / Q000378:metabolism*; D018519:Meristem / Q000166:cytology / Q000378:metabolism; D064688:Metabolic Flux Analysis; D013194:Staining and Labeling; D013213:Starch / Q000302:isolation & purification / Q000378:metabolism; D013395:Sucrose / Q000302:isolation & purification / Q000378:metabolism; D003313:Zea mays / Q000166:cytology / Q000378:metabolism*
D002250:Carbon Radioisotopes; D013395:Sucrose; D013213:Starch