A rapid increase in spinach leaf fructose 2,6-bisphosphate occurs during a light to dark transition

Spinach leaf fructose 2,6-bisphosphate levels increase rapidly during the first 15 minutes of a normal dark period followed by a gradual decline during the next 5 hours. The regulatory mechanism responsible for the dark-induced rise in fructose 2,6-bisphosphate levels can be counteracted by a brief exposure to light intensities greater than 1 microeinstein per square meter per second.