COP1 controls light-dependent chromatin remodeling in Arabidopsis [ChIP-Seq]

Light is an environmental factor that influences various aspects of plant development. Phytochromes (phys) as light sensors regulate myriads of downstream genes in response to changes in environmental factors. VIL1 (VIN3-LIKE 1)/VERNALIZATION 5 (VRN5), a Polycomb Repressive Complex 2 (PRC2) - associated protein, mediates vernalization pathway. VIL1 directly interacts with phyB and regulates photomorphogenesis through the formation of repressive chromatin loops at downstream growth-promoting genes in response to light. CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) is an E3 ligase for a number of substrates in light signaling, acting as a central repressor of photomorphogenesis. Here, we show that VIL1 is a substrate of COP1 and COP1 degrades VIL1 through the ubiquitin/26S proteosome system (UPS) in the dark. Our study illustrates that COP1 controls light-dependent formation of chromatin loop by regulating the stability of VIL1 and limits a repressive histone modification to fine-tune expressions of growth-promoting genes during photomorphogenesis. We performed Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for histone modifications H3K27me3 in five Arabidopsis genotypes (Col-0, vil1-1, cop1-4, vil1-1cop1-4 and hy5-215). Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for histone modifications H3K27me3 in five Arabidopsis genotypes (Col-0, vil1-1, cop1-4, vil1-1cop1-4 and hy5-215).