Carotenoid Synthesis in Leaves of Wheat after Irradiation by Red Light

A short inipulse of red light induces a Carotenoid synthesis in dark‐grown wheat leaves. This effect is particularly evident if the leaves, having received a short light impulse, are kept in darkness for six hours prior to a period of continuous irradiation for six hours. During this second period of irradiation much more carotenoids are formed than during an irradiation period of the same length, but not preceded by a pre‐irradiation. The main increase in pigment contents can be brought back to β‐carotene. For this pigment the short light impulse nearly doubles the pigment synthesis during a subsequent dark and light period of six + six hours as compared to the amount formed during six hours of light without pre‐irradiation.