Activities of the glycolytic enzymes were determined in seedlings, callus cultures and cell sus pension cultures of spruce (Picea abies) (L.) (Karst). The rate-limiting enzymes of the pathway were the hexokinases, ATP: phosphofructo-kinase, fructose-1,6-bisphosphatase and pyruvate kinase. Two phosphofructokinases were found: ATP : fructose-6-phosphate 1-phosphotransferase (PFK) and pyrophosphate :fructose-6-phosphate 1-phosphotransferase (PFP). In the presence of its activator fructose-2,6-bisphos-phate, PFP had a 4 -5-fold higher specific activity than PFK. PFP could be activated about 20-fold by fructose-2,6-bisphosphate at saturating concentrations of the substrates (fructose-6-phosphate and pyrophosphate). The increase of V max was accompanied by a strong increase in the apparent affinity of the enzyme for the substrates. Km for fructose-6-phosphate and pyrophosphate was 0.44 mM and 24 μM, respectively. K a for fructose-2,6-bisphosphate was 24 nM. In seedlings, specific activity of the glycolytic enzymes was 30-300 percent higher in the hypocotyls, except for fructose-1,6-bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase, their activity being 100-150percent higher in the cotyledons, This distribution remained unchanged during periods of 2 -16 weeks of cultivation of the seedlings. In callus cultures and in cell suspension cultures, grown mixotrophically with different car bohydrates, all enzymes were between 1-and 7-fold higher than in autotrophically grown seed lings. Incubation of seedlings in mineral salt mixture containing a carbohydrate resulted in a rapid coordinate increase of the activities to the levels of callus-or cell suspension cultures. This induction required a carbohydrate and oxygen. During prolonged cultivation of cell suspension cultures, when carbohydrate became limiting, activity of the enzymes slowly declined.