Orchestrated Transcription of Key Pathways in <i>Arabidopsis</i> by the Circadian Clock

TLDR

Plants possess endogenous biological clocks that synchronize internal processes with the external environment. The authors profiled Arabidopsis gene expression with high‑density microarrays, finding that ~6 % of >8,000 genes cycle, and computationally identified a conserved promoter motif essential for circadian regulation. The study demonstrates that circadian‑regulated genes cluster in light‑response and key metabolic pathways, identifies a conserved promoter motif required for circadian control, and offers a comprehensive view of how the clock temporally organizes physiological pathways.

Abstract

Like most organisms, plants have endogenous biological clocks that coordinate internal events with the external environment. We used high-density oligonucleotide microarrays to examine gene expression in Arabidopsis and found that 6% of the more than 8000 genes on the array exhibited circadian changes in steady-state messenger RNA levels. Clusters of circadian-regulated genes were found in pathways involved in plant responses to light and other key metabolic pathways. Computational analysis of cycling genes allowed the identification of a highly conserved promoter motif that we found to be required for circadian control of gene expression. Our study presents a comprehensive view of the temporal compartmentalization of physiological pathways by the circadian clock in a eukaryote.