Circadian and environmental signal transduction in a natural population of Arabidopsis

Abstract

AbstractPlants 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. The integration and transduction of circadian and environmental signals within plants growing in natural environments remain poorly understood. To gain insights into the 24 h dynamics of environmental signalling in nature, we performed a field study of cell signalling in a natural population of Arabidopsis halleri. As a representative model signalling pathway, we exploited the transduction of circadian and environmental signals from the nucleus to chloroplasts, by a sigma factor, to study diel cycles of environmental signalling under natural conditions. Using dynamic linear models to interpret the data, we identified that circadian regulation 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 allowed us to identify dynamic integration and transduction of environmental cues, in the cells of plants, under naturally fluctuating diel cycles.