Biology subjects

de Barros Dantas, L. L.

Publications and source records attributed to de Barros Dantas, L. L..

3 recordsLinked to original sources

bioRxiv2026

Circadian entrainment to environmental cues in a natural plant population

Circadian clocks coordinate physiology, development and behaviour with cycles of day and night, which contributes to organismal fitness. For this to occur, the circadian clock must be aligned with the natural daily fluctuations in the environmental conditions. Here, we investigated under natural conditions the role of environmental cues in adjusting the circadian clock, and how this affects clock outputs. By combining novel field-based experimentation in a natural plant population with genome-wide analysis and machine-learning strategies for data interpretation, we inferred that temperature cues change circadian timing under natural conditions. We inferred that low temperature cues can shift circadian phase under naturally fluctuating conditions, and that there are seasonal changes in the effects of temperature upon circadian entrainment. We also identified extensive circadian modulation of temperature responses under field conditions. Therefore, plasticity of circadian timing under natural conditions allows flexible responses of both the clock and its outputs to environmental stimuli.

plant biology↗

bioRxiv2022

Circadian and environmental signal transduction in a natural population of Arabidopsis

Plants sense and respond to environmental cues during 24 h fluctuations in their environment. This requires the integration of internal cues such as circadian timing with environmental cues such as light and temperature to elicit cellular responses through signal transduction. However, the integration and transduction of circadian and environmental signals within plants growing in natural environments remains poorly understood. To gain insights into the 24 h dynamics of environmental signalling in nature, we performed a field study of signalling from the nucleus to chloroplasts in a natural population of Arabidopsis halleri. Using advanced modelling approaches to interpret the data, we identified that the circadian clock and temperature are key regulators of this pathway under natural conditions. We identified potential time-delay steps between pathway components, and diel fluctuations in the response of the pathway to temperature cues that are reminiscent of the process of circadian gating. This approach of combining studies of gene expression in the field with modelling allowed us to identify the dynamic integration and transduction of environmental cues, in plant cells, under naturally fluctuating diel cycles.

plant biology↗

bioRxiv2022

Circadian and diel regulation of photosynthesis in the bryophyte Marchantia polymorpha

Circadian rhythms are 24-hour biological cycles that align metabolism, physiology and development with daily environmental fluctuations. Photosynthetic processes are governed by the circadian clock in both flowering plants and some cyanobacteria, but it is unclear how extensively this is conserved throughout the green lineage. We investigated the contribution of circadian regulation to aspects of photosynthesis in Marchantia polymorpha, a liverwort that diverged from flowering plants early in the evolution of land plants. First, we identified in M. polymorpha the circadian regulation of photosynthetic biochemistry, measured using two approaches (delayed fluorescence, PAM fluorescence). Second, we identified that light-dark cycles synchronize the phase of 24 h cycles of photosynthesis in M. polymorpha, whereas the phases of different thalli desynchronize under free running conditions. This might also be due to masking of the underlying circadian rhythms of photosynthesis by light-dark cycles. Finally, we used a pharmacological approach to identify that chloroplast translation might be necessary for clock control of light harvesting in M. polymorpha. We infer that the circadian regulation of photosynthesis are well-conserved amongst terrestrial plants.

plant biology↗