title: The impact of chromatin dynamics on plant light responses and circadian clock function.
abstract: Research on the functional properties of nucleosome structure and composition dynamics has revealed that chromatin-level regulation is an essential component of light signalling and clock function in plants, two processes that rely extensively on transcriptional controls. In particular, several types of histone post-translational modifications and chromatin-bound factors act sequentially or in combination to establish transcriptional patterns and to fine-tune the transcript abundance of a large repertoire of light-responsive genes and clock components. Cytogenetic approaches have also identified light-induced higher-order chromatin changes that dynamically organize the condensation of chromosomal domains into sub-nuclear foci containing silenced repeat elements. In this review, we report recently identified molecular actors that establish chromatin state dynamics in response to light signals such as photoperiod, intensity, and spectral quality. We also highlight the chromatin-dependent mechanisms that contribute to the 24-h circadian gene expression and its impact on plant physiology and development. The commonalities and contrasts of light- and clock-associated chromatin-based mechanisms are discussed, with particular emphasis on their impact on the selective regulation and rapid modulation of responsive genes.
authors: Environmental and Evolutionary Genomics Section, Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, Paris, F-75005 France Inserm, U1024, Paris, F-75005 France CNRS, UMR 8197, Paris, F-75005 France barneche@biologie.ens.fr.
authors: Fredy
authors: F
authors: Barneche
authors: Center for Research in Agricultural Genomics (CRAG), Consortium CSIC-IRTA-UAB-UB, Parc de Recerca UAB, Bellaterra (Cerdanyola del Vallés), 08193 Barcelona, Spain.
authors: Jordi
authors: J
authors: Malapeira
authors: Center for Research in Agricultural Genomics (CRAG), Consortium CSIC-IRTA-UAB-UB, Parc de Recerca UAB, Bellaterra (Cerdanyola del Vallés), 08193 Barcelona, Spain.
authors: Paloma
authors: P
authors: Mas
mesh_terms: D002843:Chromatin / Q000378:metabolism*; D057906:Circadian Clocks / Q000528:radiation effects*; D008027:Light; D008954:Models, Biological; D018521:Plant Physiological Phenomena / Q000528:radiation effects*; D010944:Plants / Q000235:genetics* / Q000528:radiation effects*
chemical_list: D002843:Chromatin
keywords: Chromatin; circadian clock; gene expression; histone modifications; light signalling; plant.