Photocontrol of anthocyanin synthesis: I. Action of short, prolonged, and intermittent irradiations on the formation of anthocyanins in cabbage, mustard, and turnip seedlings.

Red far red reversibility (phytochrome control) of anthocyanin synthesis can be easily demonstrated for the response induced by short (5 minutes) and relatively short (4 hours) irradiation. Red far red reversibility of the response induced by longer irradiations can be demonstrated by the use of cyclic irradiations alternating short exposures to red and far red light.The level of anthocyanin formed during the dark incubation period following exposure to light depends upon the duration of the irradiation and becomes proportionally smaller as the length of the irradiation increases.Production of anthocyanins under cyclic irradiations depends upon the total energy applied and upon the length of the dark interval between successive irradiations.The relative efficiencies of radiations in various spectral ranges change with changes in the length of the irradiations.