Abstract
The phase responses of the circadian rhythm for a 2-h dark pulse under continuous red light in the transgenic Arabidopsis thaliana CCA1::LUC were investigated using bioluminescence technology. By application of a 2-h dark pulse at subjective dusk, a small phase advance was induced (about 2 h phase advance). In contrast, by the application of a 2-h dark pulse at subjective dawn, a phase delay was induced (about 4 h phase delay). The phase response curve (PRC) was categorized as type-1 PRC and was described by a sinusoidal curve with a second harmonic component. The internal fluctuation of the circadian rhythm under continuous red light was also investigated. In addition, the establishment of a model for the control of the circadian rhythm is discussed.
