Outline of the Arabidopsis circadian clock based on Figure 1 in . The morning and evening loop elements are represented by white and grey boxes respectively. The solid lines indicate transcriptional regulation and the short dashed lines indicate post-translational regulation of TOC1 and EC by GI, ZTL and COP1. An arrow signifies activation and a block inhibition. The EC protein complex formation is denoted by the short-long dashed line. Flashes represent acute light responses and asterisks post-translational regulation by light.