Sodium pyruvate and dinitrophenol stimulated O(2) uptake of freshly cut phloem parenchyma from carrot roots by 63 and 120% at optimal concentrations, indicating that production of pyruvate by glycolysis regulates over-all respiratory rate. Adding 0.5 to 6.7 mm Na(3)ADP and Na(3)ATP to slices rapidly stimulates respiration rate by 20 to 85%. The effect is greater at the lower end of this concent...

Ethylene treatment of carrot roots elicits a developmental program encompassing an increase in respiration rate and changes in gene expression. Both phenomena are potentiated when ethylene is administered in O(2). Our previous studies showed that both respiration and a number of ethylene specific mRNAs increase together in response to ethylene through some 21 hours, whereas thereafter respirati...

Mitochondria incubated with substrate and orthophosphate show a low rate of respiration in the absence of ADP. Addition of ADP leads to a considerable increase in the rate of respiration (1, 2). From 2to 8-fold increases in rate are commonly observed; the extent of the increase depends on the source of the mitochondria and on the mode of their preparation. If the amount of ADP added is small, t...