This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Beaudry, R. M. Articles by Kays, S. J. Search for Related Content PubMed PubMed Citation Articles by Beaudry, R. M. Articles by Kays, S. J. Agricola Articles by Beaudry, R. M. Articles by Kays, S. J.

Metabolism and Enzymology

Banana Ripening: Implications of Changes in Internal Ethylene and CO₂ Concentrations, Pulp Fructose 2,6-Bisphosphate Concentration, and Activity of Some Glycolytic Enzymes ¹

Department of Horticulture, University of Georgia, Athens, Georgia 30602, Department of Biochemistry, University of Georgia, Athens, Georgia 30602

In ripening banana (Musa acuminata L. [AAA group, Cavandish subgroup] cv. Valery) fruit, the steady state concentration of the glycolytic regulator fructose 2,6-bisphosphate (Fru 2,6-P₂) underwent a transient increase 2 to 3 hours before the respiratory rise, but coincident with the increase in ethylene synthesis. Fru 2,6-P₂ concentration subsequently decreased, but increased again approximately one day after initiation of the respiratory climacteric. This second rise in Fru 2,6-P₂ continued as ripening proceeded, reaching approximately five times preclimacteric concentration. Pyrophosphate-dependent phosphofructokinase glycolytic activity exhibited a transitory rise during the early stages of the respiratory climacteric, then declined slightly with further ripening. Cytosolic fructose 1,6-bisphosphatase activity did not change appreciably during ripening. The activity of ATP-dependent phosphofructokinase increased approximately 1.6-fold concurrent with the respiratory rise. A balance in the simultaneous glycolytic and gluconeogenic carbon flow in ripening banana fruit appears to be maintained through changes in substrate levels, relative activities of glycolytic enzymes and steady state levels of Fru 2,6-P₂.