Induction of rapid chlorophyll accumulation in dark grown seedlings. III. Transport model for phytochrome action

An explanation is proposed for the differences between completely dark grown and de-etiolated seedlings of some higher plants in their sensitivity to far red inductive light and red-far red photoreversibility. It is based upon the idea that the morphogenic pigment phytochrome is transported during the process of de-etiolation to certain receptor sites of restricted capacity within the plant cell which sites then become activated to initiate the physiological photoresponse.