Fructose 2,6-Bisphosphate and the Regulation of Pyrophosphate-Dependent Phosphofructokinase Activity in Germinating Pea Seeds

Abstract
The activity of pyrophosphate: d-fructose-6-phosphate-1-phosphotransferase (EC 2.7.1.90, PPi-PFK) in cotyledons and sprouts of germinating pea seeds (Pisum sativum cv Alaska or Green Arrow) increases rapidly during the first 2 to 3 days after imbibition and then declines to a lower activity. The reaction toward fructose 1,6-bisphosphate formation is activated greatly by fructose 2,6-bisphosphate (fru 2,6-P2); however, the sensitivity of the enzyme's activity to fru 2,6-P2 activation changes during germination.