Regulation of climacteric respiration in ripening avocado fruit.
Ripening of avocado fruit is associated with a dramatic increase in respiration. In vivo(31)P nuclear magnetic resonance spectroscopy revealed large increases in ATP levels accompanying the increase in respiration. Both glycolytic enzymes, phosphofructokinase, and pyrophosphate: fructose-6-phosphate phosphotransferase were present in avocado fruit with the latter activity being highly stimulated by fructose 2,6-bisphosphate. Fructose 2,6-bisphosphate levels increased approximately 90% at the onset of ripening, suggesting that the respiratory increase in ripening avocado fruit may be regulated by the activation of pyrophosphate:fructose-6-phosphate phosphotransferase by an increase in fructose 2,6-bisphosphate.
Bennett
A B
AB
Department of Vegetable Crops, Mann Laboratory, University of California, Davis, California 95616.
Smith
G M
GM
Nichols
B G
BG