Temporal spectroscopy of plant development reveals subcircadian response bands
Phys. Rev. E 114, 044404 – Published 9 October, 2026
DOI: https://doi.org/10.1103/8l7d-rzxg
Abstract
Biological development is governed by internal clocks and feedback processes with characteristic response times. While circadian ( h) and ultradian () rhythms are well established, the existence and functional relevance of regulatory processes operating on characteristic subcircadian timescales remain largely unexplored. Here we treat a living organism as a driven dynamical system and introduce a temporal spectroscopy approach to probe its intrinsic regulatory timescales. Using Arabidopsis thaliana as a model system, we apply square-wave light-dark forcing with systematically varied periods spanning 5 s to 5400 s, while conserving the total daily photon dose. The organismal response is strongly nonmonotonic in forcing period and reveals three discrete, highly responsive frequency bands centered on seconds (10.5–42 s), minutes (168–336 s), and hours (1350–5400 s). Forcing within these bands induces sharp transitions in morphology and life-history trajectories, including programmable reallocation of growth between root and shoot systems, suppression of lateral root emergence, and frequency-dependent extension of lifespan by up to 60% without loss of final biomass. These responses are not consistent with simple photon integration or stress accumulation, but instead are consistent with a hypothesis of frequency-selective coupling between external forcing and internal regulatory processes. The characteristic frequencies align with known kinetic timescales of ion fluxes, membrane potential dynamics, photoreceptor signaling, metabolic turnover, and circadian gating, suggesting a hierarchical architecture of biological timescales. Our results uncover a temporal structure underlying development and establish frequency as an independent physical control parameter for reprogramming biological systems. More broadly, this work demonstrates that oscillatory environmental forcing can be used as a discovery tool to map the internal timescales governing complex living matter.
