Concepedia

Orchestrated Transcription of Key Pathways in Arabidopsis by the Circadian Clock

Stacey L. Harmer, John B. Hogenesch, Marty Straume, Hur‐Song Chang, Bin Han, Tong Zhu, Xun Wang, Joel A. Kreps, Steve A. Kay

Science · 2000 · 1.7K citations · 26 references

DOI

TL;DR

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.