Abstract
Plastids were separated from extracts of pea (Pisum sativum L.) roots by sucrose-density-gradient centrifugation. The incubation of roots of intact pea seedlings in solutions containing 10 mM KNO3 resulted in increased plastid activity of nitrite reductase and to a lesser extent glutamine synthetase. There were also substantial increases in the activity of glucose-6-phosphate and 6-phosphogluconate dehydrogenases. No other plastid-located enzymes of nitrate assimilation or carbohydrate oxidation showed evidence of increased activity in response to the induction of nitrate assimilation. Studies with [1-14C]-and [6-14C]glucose indicated that there was an increased flow of carbon through the plastid-located pentose-phosphate pathway concurrent with the induction of nitrate assimilation. It is suggested that there is a close interaction through the supply and demand for reductant between the pathway of nitrite assimilation and the pentose-phosphate pathway located in the plastid.
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Emes, M.J., Fowler, M.W. The supply of reducing power for nitrite reduction in plastids of seedling pea roots (Pisum sativum L.). Planta 158, 97–102 (1983). https://doi.org/10.1007/BF00397700
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DOI: https://doi.org/10.1007/BF00397700