|
PLANT PHYSIOLOGY , Vol 115, Issue 4 1505-1513, Copyright © 1997 by American Society of Plant Biologists
|
DEVELOPMENT AND GROWTH REGULATION |
Sugar-Starvation-Induced Changes of Carbon Metabolism in Excised Maize Root Tips
M. Dieuaide-Noubhani, P. Canioni and P. Raymond
Station de Physiologie Vegetale, Institut National de la Recherche Agronomique, Centre de Recherches de Bordeaux, BP 81, 33883 Villenave d'Ornon cedex, France (M.D.-N., P.R.)
Excised maize (Zea mays L.) root tips were used to study the early
metabolic effects of glucose (Glc) starvation. Root tips were prelabeled
with [1-13C]Glc so that carbohydrates and metabolic intermediates were
close to steady-state labeling, but lipids and proteins were scarcely
labeled. They were then incubated in a sugar-deprived medium for carbon
starvation. Changes in the level of soluble sugars, the respiratory
quotient, and the 13C enrichment of intermediates, as measured by 13C and
1H nuclear magnetic resonance, were studied to detect changes in carbon
fluxes through glycolysis and the tricarboxylic acid cycle. Labeling of
glutamate carbons revealed two major changes in carbon input into the
tricarboxylic acid cycle: (a) the phosphoenolpyruvate carboxylase flux
stopped early after the start of Glc starvation, and (b) the contribution
of glycolysis as the source of acetyl-coenzyme A for respiration decreased
progressively, indicating an increasing contribution of the catabolism of
protein amino acids, fatty acids, or both. The enrichment of glutamate
carbons gave no evidence for proteolysis in the early steps of starvation,
indicating that the catabolism of proteins was delayed compared with that
of fatty acids. Labeling of carbohydrates showed that sucrose turnover
continues during sugar starvation, but gave no indication for any
significant flux through gluconeogenesis.
This article has been cited by other articles:
|
|
|
|
 
M. J. van der Merwe, S. Osorio, T. Moritz, A. Nunes-Nesi, and A. R. Fernie
Decreased Mitochondrial Activities of Malate Dehydrogenase and Fumarase in Tomato Lead to Altered Root Growth and Architecture via Diverse Mechanisms
Plant Physiology,
February 1, 2009;
149(2):
653 - 669.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Schwender, Y. Shachar-Hill, and J. B. Ohlrogge
Mitochondrial Metabolism in Developing Embryos of Brassica napus
J. Biol. Chem.,
November 10, 2006;
281(45):
34040 - 34047.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. P. Alonso, H. Vigeolas, P. Raymond, D. Rolin, and M. Dieuaide-Noubhani
A New Substrate Cycle in Plants. Evidence for a High Glucose-Phosphate-to-Glucose Turnover from in Vivo Steady-State and Pulse-Labeling Experiments with [13C]Glucose and [14C]Glucose
Plant Physiology,
August 1, 2005;
138(4):
2220 - 2232.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. E. McLAUGHLIN and J. S. BOYER
Sugar-responsive Gene Expression, Invertase Activity, and Senescence in Aborting Maize Ovaries at Low Water Potentials
Ann. Bot.,
November 1, 2004;
94(5):
675 - 689.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Nogues, G. Tcherkez, G. Cornic, and J. Ghashghaie
Respiratory Carbon Metabolism following Illumination in Intact French Bean Leaves Using 13C/12C Isotope Labeling
Plant Physiology,
October 1, 2004;
136(2):
3245 - 3254.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. Tcherkez, S. Nogues, J. Bleton, G. Cornic, F. Badeck, and J. Ghashghaie
Metabolic Origin of Carbon Isotope Composition of Leaf Dark-Respired CO2 in French Bean
Plant Physiology,
January 1, 2003;
131(1):
237 - 244.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. Rontein, M. Dieuaide-Noubhani, E. J. Dufourc, P. Raymond, and D. Rolin
The Metabolic Architecture of Plant Cells. STABILITY OF CENTRAL METABOLISM AND FLEXIBILITY OF ANABOLIC PATHWAYS DURING THE GROWTH CYCLE OF TOMATO CELLS
J. Biol. Chem.,
November 8, 2002;
277(46):
43948 - 43960.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
