How the spectral properties of dawns impact Arabidopsis developmental programmes

Our previous work identified a gene regulatory network governing a burst of transcriptional activity within minutes of lights being switched on, directed by developmental hub genes such as HY5 and BBX31 (Balcerowicz et al. 2021). However, indoor growth chamber experiments usually involve an unnatural binary on/off light treatment that may cause light stress in plants.

On the other hand, natural dawns expose outdoor plants to gradual changes in irradiance and spectral composition. To address this gap in knowledge, we present here a fine-scale time-series transcriptome where plants were grown under simulated natural dawns inside growth cabinets. By mimicking the gradual increase in light irradiance as well as the changing ratios of wavelengths observed in natural dawns, we can model the gene regulatory network of Arabidopsis as it adapts to dynamic light signals in the early morning.