Some effects of oxygen concentration on levels of respiratory intermediates in buckwheat seedlings

Changes in levels of glycolytic and some related respiratory intermediates in young seedlings of buckwheat (Fagopyrum esculentum) following transfer A) from air to anoxia, B) from air to 1.5% O₂, C) from 1.5% O₂ to anoxia and D) from anoxia to air, are recorded and discussed in relation to other measurements made with these seedlings.

On transfer from air to anoxia the changes are similar to those recorded for pea seeds in which it is inferred that glycolysis is faster in anoxia than in air. The results with buckwheat however can be explained in terms of a decreased rate of glycolysis in anoxia. An alternative hypothesis is developed which states that glycolysis is faster in anoxia than in air and that it is the contribution of the pentose phosphate cycle to the total respiratory catabolism which decreases as the oxygen concentration is reduced towards zero.