A Mathematical Model in Absolute Units for the Arabidopsis Circadian Oscillator

Arabidopsis thaliana presents circadian oscillations in more than 30% of its transcriptome. These dynamics are generated by a biochemical oscillator made of a collection of interlocked feedback loops. Mathematical modeling has been fundamental for understanding how circadian rhythms emerge form molecular interactions. However, up to now, models have lacked absolute units on the mass scale. The advent of genome editing tools requires a new type of modeling were DNA sequences inform the parameter values in models and how changes in sequence impact the dynamics of genetic circuits. Here we present how absolute quantifications of clock transcription factors using a state of the art bioluminescent reporter combined with biophysical models of transcription factor binding is a first step for incorporating sequence information into dynamical models. We provide a framework for exploring the possible implications of editing cis-elements on the dynamics of the Arabidopsis circadian clock.