Fig. 2.
The effect of light on post-transcriptional regulation of clock genes in Arabidopsis. Light is perceived by photoreceptors (PHYB, red light; CRY1 and CRY2; blue light) and this input signal is transmitted to the circadian core loop to entrain the clock. ZTL is also a blue-light photoreceptor, affecting an evening loop, and regulates TOC1 expression together with GIGANTEA (GI). Light also provokes several post-transcriptional events, such as CCA1 mRNA degradation, translational activation of LHY and the enhancement of the amplitude of TOC1 rhythmic expression. PRR7 and PRR9 are PSEUDO RESPONSE REGULATOR 7 and PSEUDO RESPONSE REGULATOR 9.