Maeda, A. E. | Search bioRxiv

bioRxiv2026

The circadian clock gates lateral root development

Lateral root (LR) formation remodels root architecture, yet how temporal information integrates with hormonal cues remains unclear. We show that the circadian clock component EARLY FLOWERING 3 (ELF3) acts as a temporal gatekeeper of root organogenesis in Arabidopsis thaliana. Time-resolved transcriptomics, imaging, and genetics reveal that ELF3 restrains hormone-induced pericycle proliferation by maintaining rhythmic expression of key regulators under callus-inducing conditions. Loss of ELF3 disrupts rhythmic gene expression, enhancing callus growth and accelerating LR development. ELF3 functions through its target LNK1 to regulate the MADS-box genes AGL14 and AGL20. Notably, callus-inducing signals partially restore rhythmicity in elf3 mutants, revealing feedback from hormonal signaling to the circadian system. These findings identify ELF3 as an integrator of circadian and hormonal inputs that temporally constrains root developmental plasticity.

plant biology↗

bioRxiv2025

Quantitative manipulation of the photoperiodic flowering by a small-molecule clock modulator

Photoperiodism, a seasonal response mechanism that relies on day-length measurement by the circadian clock, is a major regulator of flowering time 1. The external coincidence model proposes that the alignment between the internal circadian phase and external light signals triggers photoperiodic responses 2. It has been challenging to establish robust models for the quantitative relationship between clock and flowering time, due to a lack of tools to modulate clock quantitatively. Here, using a circadian period-lengthening small molecule, we demonstrated the quantitative modulation of the critical day length for flowering in monocots.

plant biology↗