May play an important role in maintaining the flux of carbon towards starch formation. May also be involved in a sugar-sensing pathway. ATP + D-fructose = ADP + D-fructose 6-phosphate + H(+) Inhibited at high fructose. Glycan biosynthesis; starch biosynthesis. Expressed in roots, at higher levels in stems, and hardly detectable in leaves. High expression 7 days after pollination (DAP), gradually declines after 15 DAP and becomes undetectable by 29 DAP. Belongs to the carbohydrate kinase PfkB family.