Endogenous rhythmicity and energy transduction. III. Time course of phytochrome action in adenylate kinase, NAD- and NADP-linked glyceraldehyde-3-phosphate dehydrogenase in Chenopodium rubrum

Evidence is presented that phytochrome triggers and maintains the increase in adenylate kinase (AK) as well as NAD- and NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (NAD- and NADP-GPD) activity. After cyclic germination conditions, the time courses of all three enzymes display an endogenous rhythmic increase of their activities in constant far-red light. After germination in constant conditions, NAD- and NADP-GPD activities displayed no rhythm, while AK activity increased rhythmically. Such readiness of AK activity to oscillate was taken as indication of a close functional relationship between the control mechanism(s) of the endogenous rhythm and AK activities. The time courses in NADP-GPD activity demonstrated that phytochrome acted as an on-off switch for the increase in enzyme activity and also controlled enzyme activity depending on the relative concentration of active phytochrome. There is evidence for a function of phytochrome in the "ground state" as well as in an "activated state."It is...