ISSN:
1432-2048
Keywords:
Embryo conditions (pea)
;
Oxidative pentose phosphate pathway
;
Pisum (plastid)
;
Plastid (pea embryo)
;
Starch synthesis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00195670
Permalink
