A chromatin loop represses WUSCHEL expression in Arabidopsis.
Lin Guo, Xiuwei Cao, Yuhao Liu, Jun Li, Yongpeng Li, Dongming Li, Ke Zhang, Caixia Gao, Aiwu Dong, Xigang Liu
Author Information
Lin Guo: State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.
Xiuwei Cao: State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.
Yuhao Liu: State Key Laboratory of Genetic Engineering, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Collaborative Innovation Center for Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Jun Li: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
Yongpeng Li: State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.
Dongming Li: State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.
Ke Zhang: State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China.
Caixia Gao: State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
Aiwu Dong: State Key Laboratory of Genetic Engineering, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Collaborative Innovation Center for Genetics and Development, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China.
Xigang Liu: State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, China. ORCID
WUSCHEL (WUS) is critical for plant meristem maintenance and determinacy in Arabidopsis, and the regulation of its spatiotemporal expression patterns is complex. We previously found that AGAMOUS (AG), a key MADS-domain transcription factor in floral organ identity and floral meristem determinacy, can directly suppress WUS expression through the recruitment of the Polycomb group (PcG) protein TERMINAL FLOWER 2 (TFL2, also known as LIKE HETEROCHROMATIN PROTEIN 1, LHP1) at the WUS locus; however, the mechanism by which WUS is repressed remains unclear. Here, using chromosome conformation capture (3C) and chromatin immunoprecipitation 3C, we found that two specific regions flanking the WUS gene body bound by AG and TFL2 form a chromatin loop that is directly promoted by AG during flower development in a manner independent of the physical distance and sequence content of the intervening region. Moreover, AG physically interacts with TFL2, and TFL2 binding to the chromatin loop is dependent on AG. Transgenic and CRISPR/Cas9-edited lines showed that the WUS chromatin loop represses gene expression by blocking the recruitment of RNA polymerase II at the locus. The findings uncover the WUS chromatin loop as another regulatory mechanism controlling WUS expression, and also shed light on the factors required for chromatin conformation change and their recruitment.
