Chemical biology to dissect molecular mechanisms underlying plant circadian clocks

Circadian clocks regulate the diel rhythmic physiological activities of plants, enabling them to anticipate and adapt to day–night and seasonal changes. Genetic and biochemical approaches have suggested that transcription–translation feedback loops (TTFL) are crucial for Arabidopsis clock function. Recently, the study of chemical chronobiology has emerged as a discipline within the circadian clock field, with important and complementary discoveries from both plant and animal research. In this review, we introduce recent advances in chemical biology using small molecules to perturb plant circadian clock function through TTFL components. Studies using small molecule clock modulators have been instrumental for revealing the role of post-translational modification in the clock, or the metabolite-dependent clock input pathway, as well as for controlling clock-dependent flowering time.