Bidirectional regulation between circadian clock and ABA signaling

Circadian clock ensures coordination of rhythmic biological processes with environmental cycles. Correct matching of internal and external rhythmic cycles maximizes plant fitness and environmental adaptation capability and also ensures efficient energy consumption through circadian gating of a variety of physiological processes. Accumulating evidences support that circadian oscillator components extensively participate in circadian gating of output processes. Here, we provide remarkable examples illustrating molecular mechanisms underlying circadian gating of environmental sensitivity. In addition, bidirectional interactions between circadian oscillator and output pathways have been observed in abscisic acid (ABA)-related physiological processes, emphasizing the biological relevance of extensive crosstalk surrounding circadian clock in acute time-of-day responses.