Focusing on the nuclear and subnuclear dynamics of light and circadian signalling

Circadian clocks provide organisms the ability to synchronise theirinternal physiological responses with the external environment. Thisprocess, termed entrainment, occurs through the perception of internaland external stimuli. As with other organisms, in plants the perception oflight is a critical for the entrainment and sustainment of circadianrhythms. Red, blue, far-red and UV-B light is perceived by the oscillatorthrough the activity of photoreceptors. Four classes of photoreceptorssignal to the oscillator: phytochromes, cryptochromes, UVR8 and LOV-KELCH domain proteins. In most cases, these photoreceptors localise tothe nucleus in response to light and can associate to subnuclearstructures to initiate downstream signalling. In this review, we willhighlight the recent advances made in understanding the mechanismsfacilitating the nuclear and subnuclear localisation of photoreceptors andthe role these subnuclear bodies have in photoreceptor signalling,including to the oscillator. We will also highlight recent progress that hasbeen made in understanding the regulation of the nuclear andsubnuclear localisation of components of the plant circadian clock.