EARLY FLOWERING 3: A Nexus for Circadian Timing and Environmental Integration in Plants

Circadian clocks are internal timekeeping devices that integrate environmental stimuli so that biological processes are timed to occur at the optimal time of the day. Close alignment of internal physiology with the external environment subsequently boosts plant fitness. Within the plant circadian clock, EARLY FLOWERING 3 (ELF3) has emerged as a critical regulatory node. The function of ELF3 has been primarily studied in the context of the evening complex (EC), a transcriptional repressor for which ELF3 activity is essential. However, there is now accumulating evidence that ELF3 activity expands beyond the EC. In this review, I discuss these recent advancements, drawing on studies from Arabidopsis and other plant and algal species. I also highlight the latest insights into how ELF3 activity is regulated, focusing on the importance of cellular and sub-nuclear dynamics in controlling ELF3 function. Finally, I discuss outstanding questions and future research directions to understand how ELF3 localisation and structural features may determine its function.