Pyrophosphate: Fructose-6-phosphate Phosphotransferase and Gluconeogenic Capacity in Germinated Peanut Seeds

Abstract

Maximum activities of phosphofructokinase (PFK), PPi: fructose-6-phosphate 1-phosphotransferase (PFP) and fructose- 1,6-bisphosphatase (FBPase) were determined in desalted extracts from gluconeogenic and non-gluconeogenic tissues from seedlings of peanut, safflower, black gram, green gram, radish and buckwheat. FBPase activity was high only in gluconeogenic tissues, but PFP activity was distributed at significant levels in all tissues examined. PFP activity was always higher than PFK activity. In normal and γ-irradiated peanut cotyledons, the changing pattern of activity of FBPase after germination, but not that of PFP, resembled the changing pattern of gluconeogenic capacity, as estimated by the incorporation of [2-¹⁴C]glycerol to sugars. The minor role of PFP in gluconeogenesis in germinating fatty seeds is discussed.