This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 19/7/2111    most recent tpc.107.050807v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Perales, M. Articles by Más, P. Search for Related Content PubMed PubMed Citation Articles by Perales, M. Articles by Más, P. Agricola Articles by Perales, M. Articles by Más, P.

A Functional Link between Rhythmic Changes in Chromatin Structure and the Arabidopsis Biological Clock^[W]

Consorcio Consejo Superior de Investigaciones Científicas–Institut de Recerca i Tecnología Agroalimentarias, Laboratory of Plant Molecular Genetics, Institute of Molecular Biology, 08034 Barcelona, Spain

¹ Address correspondence to pmmgmc{at}ibmb.csic.es.

Circadian clocks rhythmically coordinate biological processes in resonance with the environmental cycle. The clock function relies on negative feedback loops that generate 24-h rhythms in multiple outputs. In Arabidopsis thaliana, the clock component TIMING OF CAB EXPRESSION1 (TOC1) integrates the environmental information to coordinate circadian responses. Here, we use chromatin immunoprecipitation as well as physiological and luminescence assays to demonstrate that proper photoperiodic phase of TOC1 expression is important for clock synchronization of plant development with the environment. Our studies show that TOC1 circadian induction is accompanied by clock-controlled cycles of histone acetylation that favor transcriptionally permissive chromatin structures at the TOC1 locus. At dawn, TOC1 repression relies on the in vivo circadian binding of the clock component CIRCADIAN CLOCK ASSOCIATED1 (CCA1), while histone deacetylase activities facilitate the switch to repressive chromatin structures and contribute to the declining phase of TOC1 waveform around dusk. The use of cca1 late elongated hypocotyl double mutant and CCA1-overexpressing plants suggests a highly repressing function of CCA1, antagonizing H3 acetylation to regulate TOC1 mRNA abundance. The chromatin remodeling activities relevant at the TOC1 locus are distinctively modulated by photoperiod, suggesting a mechanism by which the clock sets the phase of physiological and developmental outputs.

This article has been cited by other articles:

				H. Knight, A. J.W. Thomson, and H. G. McWatters SENSITIVE TO FREEZING6 Integrates Cellular and Environmental Inputs to the Plant Circadian Clock Plant Physiology, September 1, 2008; 148(1): 293 - 303. [Abstract] [Full Text] [PDF]

				Compiled by, F. Tooke, T. Chiurugwi, and N. Battey Flowering Newsletter bibliography for 2007 J. Exp. Bot., July 18, 2008; (2008) ern109v1. [Full Text] [PDF]

				Z. Bieniawska, C. Espinoza, A. Schlereth, R. Sulpice, D. K. Hincha, and M. A. Hannah Disruption of the Arabidopsis Circadian Clock Is Responsible for Extensive Variation in the Cold-Responsive Transcriptome Plant Physiology, May 1, 2008; 147(1): 263 - 279. [Abstract] [Full Text] [PDF]