The EC night-time repressor plays a crucial role in modulating circadian clock transcriptional circuitry by conservatively double-checking both warm-night and night-time-light signals in a synergistic manner in Arabidopsis thaliana.

During the last decade, significant research progress has been made in Arabidopsis thaliana in defining the molecular mechanisms behind the plant circadian clock. The circadian clock must have the ability to integrate both external light and ambient temperature signals into its transcriptional circuitry to regulate its function properly. We previously showed that transcription of a set of clock genes including LUX (LUX ARRHYTHMO), GI (GIGANTEA), LNK1 (NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED GENE 1), PRR9 (PSEUDO-RESPONSE REGULATOR 9) and PRR7 is commonly regulated through the evening complex (EC) night-time repressor in response to both moderate changes in temperature (Δ6°C) and differences in steady-state growth-compatible temperature (16-28°C).

Ambient temperature signal feeds into the circadian clock transcriptional circuitry through the EC night-time repressor in Arabidopsis thaliana.

An interlocking multiloop model has been generally accepted to describe the transcriptional circuitry of core clock genes, through which robust circadian rhythms are generated in Arabidopsis thaliana. The circadian clock must have the ability to integrate ambient temperature signals into the clock transcriptional circuitry to regulate clock function properly. Clarification of the underlying mechanism is a longstanding subject in the field.