Development of Plant Circadian Clock Modulators

Since the reproductive behavior of plants depends on the circadian clock, artificially controlling the clock timekeeping system could enable improvement in food production and supply of biomass resources. Despite the importance of posttranslational modification in the circadian clock, those in the plant variant are less explored, likely due to genetic redundancy. As such, the modulation of circadian rhythms by small molecules (circadian clock modulators) without genetic modification has received significant attention in recent years. We successfully identified these circadian clock modulators, PHA 767491 and BML-259, to lengthen the circadian rhythm of Arabidopsis thaliana using our developed high-throughput screening. Herein, we described structure-activity relationship studies of PHA767491 and BML-259 and their mechanisms in plant circadian clocks. The development of higher active molecules and the discovery of target proteins have enabled further mechanistic elucidation of the plant circadian clock.