Environmental Memory from a Circadian Oscillator: The Arabidopsis thaliana Clock Differentially Integrates Perception of Photic vs. Thermal Entrainment

Abstract

The constraint of a rotating earth has led to the evolution of a circadian clock that drives anticipation of future environmental changes. During this daily rotation, the circadian clock of Arabidopsis thaliana (Arabidopsis) intersects with the diurnal environment to orchestrate virtually all transcriptional processes of the plant cell, presumably by detecting, interpreting, and anticipating the environmental alternations of light and temperature. To comparatively assess differential inputs toward phenotypic and physiological responses on a circadian parameter, we surveyed clock periodicity in a recombinant inbred population modified to allow for robust periodicity measurements after entrainment to respective photic vs. thermal cues, termed zeitgebers. Lines previously thermally entrained generally displayed reduced period length compared to those previously photically entrained. This differential zeitgeber response was also detected in a set of diverse Arabidopsis accessions. Thus, the zeitgebers of the preceding environment direct future behavior of the circadian oscillator. Allelic variation at quantitative trait loci generated significant differences in zeitgeber responses in the segregating population. These were important for periodicity variation dependent on the nature of the subsequent entrainment source. Collectively, our results provide a genetic paradigm for the basis of environmental memory of a preceding environment, which leads to the integrated coordination of circadian periodicity.

Natural variation reveals that intracellular distribution of ELF3 protein is associated with function in the circadian clock

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A Reduced-Function Allele Reveals That EARLY FLOWERING3 Repressive Action on the Circadian Clock Is Modulated by Phytochrome Signals in Arabidopsis

“…LUC expression profiles were monitored and processed as described by Hanano et al (2008) and Boikoglou et al (2011). The gating experiment was performed as described by McWatters et al (2000).…”

Natural diversity in daily rhythms of gene expression contributes to phenotypic variation

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