The ELF4–ELF3–LUX complex links the circadian clock to diurnal control of hypocotyl growth

In plants, the circadian clock functions as an endogenous pacemaker that anticipates and responds to a changing environment in order to optimize the timing of physiological and developmental events. Nusinow et al. elucidate the mechanism by which the circadian clock controls growth of the model plant Arabidopsis thaliana. A novel trimeric complex called the evening complex is regulated by the clock and has a peak of expression at dusk. The complex represses the expression of two transcription factors, PIF4 and PIF5, which are part of a light-signalling cascade that controls the timing of plant growth in response to light conditions.