Spatial Regulation of the Plant Circadian Clock.

The plant circadian clock enables the precise timing of physiological processes across the day-night cycle by generating endogenous 24-h rhythms in gene expression. In Arabidopsis, an iteration between experiments and modeling has uncovered a core oscillator comprising interlocked transcriptional feedback loops. However, emerging techniques now reveal that circadian dynamics vary across organs, tissues, and even individual cells, highlighting the need for spatially resolved clock models. In this review, we explore evidence for spatial variation in clock regulation, including differences in sensitivity to environmental cues, the timing of clock components, and the nature of downstream outputs. We discuss how local cellular rhythms are coordinated to achieve robust organism-level timing and consider how spatial regulation of the clock may contribute to the control of diverse developmental processes.