title: The Chromatin-Remodeling Factor PICKLE Integrates Brassinosteroid and Gibberellin Signaling during Skotomorphogenic Growth in Arabidopsis.
abstract: Plant cell elongation is controlled by endogenous hormones, including brassinosteroid (BR) and gibberellin (GA), and by environmental factors, such as light/darkness. The molecular mechanisms underlying the convergence of these signals that govern cell growth remain largely unknown. We previously showed that the chromatin-remodeling factor PICKLE/ENHANCED PHOTOMORPHOGENIC1 (PKL/EPP1) represses photomorphogenesis in Arabidopsis thaliana. Here, we demonstrated that PKL physically interacted with PHYTOCHROME-INTERACTING FACTOR3 (PIF3) and BRASSINAZOLE-RESISTANT1 (BZR1), key components of the light and BR signaling pathways, respectively. Also, this interaction promoted the association of PKL with cell elongation-related genes. We found that PKL, PIF3, and BZR1 coregulate skotomorphogenesis by repressing the trimethylation of histone H3 Lys-27 (H3K27me3) on target promoters. Moreover, DELLA proteins interacted with PKL and attenuated its binding ability. Strikingly, brassinolide and GA3inhibited H3K27me3 modification of histones associated with cell elongation-related loci in a BZR1- and DELLA-mediated manner, respectively. Our findings reveal that the PKL chromatin-remodeling factor acts as a critical node that integrates light/darkness, BR, and GA signals to epigenetically regulate plant growth and development. This work also provides a molecular framework by which hormone signals regulate histone modification in concert with light/dark environmental cues.
authors.affiliation: Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Jing
authors.affiliation: Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China National Center for Plant Gene Research, Beijing 100093, China rclin@ibcas.ac.cn.
authors.forename: Rongcheng
authors.identifier: http://orcid.org/0000-0001-8346-3390
authors.initials: R
authors.lastname: Lin