Arabidopsis Chromatin Remodeling Factor PICKLE Interacts with Transcription Factor HY5 to Regulate Hypocotyl Cell Elongation

• Published in: The Plant cell 2013-01, Vol.25 (1), p.242-256
• Main Authors: Jing, Yanjun, Zhang, Dong, Wang, Xin, Tang, Weijiang, Wang, Wanqing, Hual, Junling, Xu, Gang, Chen, Dongqin, Li, Yunliang, Lin, Rongcheng
• Format: Article
• Language: English
• Subjects: Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - physiology; Arabidopsis - radiation effects; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Basic-Leucine Zipper Transcription Factors - genetics; Basic-Leucine Zipper Transcription Factors - metabolism; Biological and medical sciences; Cell growth; Chromatin; Chromatin - genetics; Chromatin - metabolism; Chromatin Assembly and Disassembly; DNA Helicases - genetics; DNA Helicases - metabolism; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Gene Expression Regulation, Plant; Genes; Histones; Histones - genetics; Histones - metabolism; Hypocotyl - genetics; Hypocotyl - growth & development; Hypocotyl - physiology; Hypocotyl - radiation effects; Hypocotyls; Light; Methylation; Models, Molecular; Mutagenesis, Insertional; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Photoreceptors, Plant; Plant cells; Plant physiology and development; Plants; Promoter Regions, Genetic; Recombinant Fusion Proteins; Renovations; Seedlings; Transcription, Genetic; Two-Hybrid System Techniques
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.112.105742

Photomorphogenesis is a critical plant developmental process that involves light-mediated transcriptome changes, histone modifications, and inhibition of hypocotyl growth. However, the chromatin-based regulatory mechanism underlying this process remains largely unknown. Here, we identify ENHANCED PHOTOMORPHOGENIC1 (EPP1), previously known as PICKLE (PKL), an ATP-dependent chromatin remodeling factor of the chromodomain/helicase/DNA binding family, as a repressor of photomorphogenesis in Arabidopsis thaliana. We show that PKL/EPP1 expression is repressed by light in the hypocotyis in a photoreceptor-dependent manner. Furthermore, we reveal that the transcription factor ELONGATED HYPOCOTYL5 (HY5) binds to the promoters of cell elongation—related genes and recruits PKL/EPP1 through their physical interaction. PKL/EPP1 in turn negatively regulates HY5 by repressing trimethylation of histone H3 Lys 27 at the target loci, thereby regulating the expression of these genes and, thus, hypocotyl elongation. We also show that HY5 possesses transcriptional repression activity. Our study reveals a crucial role for a chromatin remodeling factor in repressing photomorphogenesis and demonstrates that transcription factor—mediated recruitment of chromatin-remodeling machinery is important for plant development in response to changing light environments.