Signaling in the Circadian Clock

Abstract

The plant circadian clock in is an internal-timing mechanism that provides adaption to daily environmental changes. Successive changes in light and temperature are able to reset the oscillator. The most prominent signal studied is light; temperature is a signal that is less well characterized. A complex network consisting of interconnected loops was revealed in Arabidopsis thaliana on the basis of genetic data of a light-dark entrained oscillator. The basic loop generates the 24-h rhythmicity of the oscillating mechanism, whereas the morning and evening loops are fine-tuned rhythmicity in a temporal-specific manner. Here, we review the current understanding of the A. thaliana circadian clockwork with regards to the signaling of the input pathways to the oscillator, and from there, to downstream processes that converge on evolvability of the oscillator.