Figure 6.

Entrainment of the circadian rhythm in leaf (cotyledon) movement by temperature cycles. Upper panel shows individual traces (blue) of the relative cotyledon positions for the two cotyledons of a representative seedling entrained under continuous light to a temperature cycle of 12 hr at 22°C and 12 hr at 18°C and then released into continuous conditions of constant light at 22°C at T=0. The lower panel shows traces (red) for the two cotyledons of a seedling entrained to the antiphase (180° out-of-phase) temperature cycle of 12 hr at 18°C and 12 hr at 22°C. Gray bars indicate subjective night as defined by the cold period of the entraining cycle.