Influence of pH upon the Warburg Effect in Isolated Intact Spinach Chloroplasts
- 1 April 1977
- journal article
- research article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 59 (4), 530-534
- https://doi.org/10.1104/pp.59.4.530
Abstract
The influence of pH upon the O2 inhibition of 14CO2 photoassimilation (Warburg effect) was examined in intact spinach (Spinacia oleracea) chloroplasts. With conditions which favored the Warburg effect, i.e. rate-limiting CO2 and 100% O2, O2 inhibition was greater at pH 8.4 to 8.5 than at pH 7.5 to 7.8. At pH 8.5, as compared with 7.8, there was an enhanced 14C-labeling of glycolate, and a decrease of isotope in some phosphorylated Calvin cycle intermediates, particularly triose-phosphate. The 14C-labeling of starch was also more inhibited by O2 at higher pH. The enhanced synthesis of glycolate during 14CO2 assimilation at higher pH resulted in a diminution in the level of phosphorylated intermediates of the Calvin cycle, and this was apparently a causal factor of the increased severity of the Warburg effect. The 14C-labeling profiles have been interpreted in terms of a “CO2”-sensitive as well as a “CO2”-insensitive mechanism for glycolate synthesis. Both mechanisms functioned optimally at the higher pH and both responded to O2.This publication has 15 references indexed in Scilit:
- Uptake of Bicarbonate Ion in Darkness by Isolated Chloroplast Envelope Membranes and Intact Chloroplasts of SpinachPlant Physiology, 1974
- Ribulose Diphosphate Carboxylase from Freshly Ruptured Spinach Chloroplasts Having an in Vivo Km[CO2]Plant Physiology, 1974
- Sequence of Formation of Phosphoglycolate and Glycolate in Photosynthesizing Chlorella pyrenoidosaPlant Physiology, 1973
- The Effect of pH on the Products of Photosynthesis in 14CO2 by Chloroplast Preparations from Acetabularia mediterraneaPlant Physiology, 1971
- PHOTORESPIRATION, WARBURG EFFECT AND GLYCOLATE*Annals of the New York Academy of Sciences, 1969
- Inhibition of Photosynthesis by Oxygen in Isolated Spinach ChloroplastsPlant Physiology, 1969
- The Relation of Glycolic Acid Synthesis to the Primary Photosynthetic Carboxylation Reaction in LeavesJournal of Biological Chemistry, 1965
- RATE OF HYDRATION OF CARBON DIOXIDE AND DEHYDRATION OF CARBONIC ACID AT 25 DEGREES1963
- The effect of oxygen on the reduction of CO2 to glycolic acid and other products during photosynthesis by ChlorellaBiochemical and Biophysical Research Communications, 1962
- OXYGEN AS A FACTOR IN PHOTOSYNTHESISBiological Reviews, 1962