Many organisms, including some prokaryotes and most eukaryotes, possess an internal timer or circadian clock that allows them to regulate their physiology to better adapt to our continually changing world. These circadian clocks generate roughly 24 hour rhythms in physiology and behavior that are maintained even in the absence of environmental cues. Although the molecular components of circadian clocks are not conserved across higher taxa, in all organisms studied these clocks are cell autonomous oscillators and in diverse eukaryotes are composed of complex transcriptional networks.
The study of circadian rhythms presents a wide range of interesting questions: What is the molecular nature of the circadian clock; that is, how can a cell keep time? What aspects of physiology are under circadian regulation? What are the mechanistic links between the clock network and other signaling pathways? Why does a functional circadian clock provide an adaptive advantage?
The Harmer lab is using the model plant Arabidopsis thaliana to address these fundamental questions. We use forward and reverse genetics, genomics, biochemistry, and physiological studies to better understand the nature of the plant clock and how it helps shape plant responses to the environment.