Metabolism of glucose 6-phosphate by plastids from developing pea embryos


The aim of this work was to investigate the metabolism of glucose 6-phosphate by plastids isolated from developing pea (Pisum sativum L.) embryos. Plastids metabolise exogenously supplied glucose 6-phosphate via the pathway of starch synthesis and the oxidative pentose-phosphate pathway. The flux through the latter pathway is greatly stimulated by the provision of glutamine and 2-oxoglutarate — the substrates of glutamate synthase — indicating that it is regulated by the demand for reductant within the plastid. Flux in the presence of glutamine and 2-oxoglutarate is about 20% of the maximum flux through the pathway of starch synthesis. There is no competition for glucose 6-phosphate between the two pathways at concentrations which are saturating for both. Isolated plastids do not convert glucose 6-phosphate to amino acids or fatty acids at significant rates under the conditins of our experiments.

DOI: 10.1007/BF00195670

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@article{Foster2004MetabolismOG, title={Metabolism of glucose 6-phosphate by plastids from developing pea embryos}, author={Jonathan M. Foster and Alison M Smith}, journal={Planta}, year={2004}, volume={190}, pages={17-24} }