Glycolysis at the climacteric of bananas.
This work was carried out to investigate the relative roles of phosphofructokinase and pyrophosphate-fructose-6-phosphate 1-phosphotransferase during the increased glycolysis at the climacteric in ripening bananas (Musa cavendishii Lamb ex Paxton). Fruit were ripened in the dark in a continuous stream of air in the absence of ethylene. CO2 production, the contents of glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-bisphosphate, phosphoenolpyruvate and PPi; and the maximum catalytic activities of pyrophosphate-fructose-6-phosphate 1-phosphotransferase, 6-phosphofructokinase, pyruvate kinase and phosphoenolpyruvate carboxylase were measured over a 12-day period that included the climacteric. Cytosolic fructose-1,6- bisphosphatase could not be detected in extracts of climacteric fruit. The peak of CO2 production was preceded by a threefold rise in phosphofructokinase, and accompanied by falls in fructose 6-phosphate and glucose 6-phosphate, and a rise in fructose 1,6-bisphosphate. No change in pyrophosphate-fructose-6-phosphate 1-phosphotransferase or pyrophosphate was found. It is argued that phosphofructokinase is primarily responsible for the increased entry of fructose 6-phosphate into glycolysis at the climacteric.
Ball
K L
KL
Botany School, University of Cambridge, England.
Green
J H
JH
ap Rees
T
T
D002245:Carbon Dioxide / Q000032:analysis; D005638:Fruit; D006019:Glycolysis; D007700:Kinetics; D010730:Phosphoenolpyruvate Carboxylase / Q000378:metabolism; D010732:Phosphofructokinase-1 / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D011770:Pyruvate Kinase / Q000378:metabolism
D002245:Carbon Dioxide; D010770:Phosphotransferases; D010732:Phosphofructokinase-1; D011770:Pyruvate Kinase; C022502:pyrophosphate-fructose 6-phosphate 1-phosphotransferase; D010730:Phosphoenolpyruvate Carboxylase