title: FAR-RED ELONGATED HYPOCOTYL3 activates SEPALLATA2 but inhibits CLAVATA3 to regulate meristem determinacy and maintenance in Arabidopsis.
abstract: Plant meristems are responsible for the generation of all plant tissues and organs. Here we show that the transcription factor (TF) FAR-RED ELONGATED HYPOCOTYL3 (FHY3) plays an important role in both floral meristem (FM) determinacy and shoot apical meristem maintenance in Arabidopsis, in addition to its well-known multifaceted roles in plant growth and development during the vegetative stage. Through genetic analyses, we show that WUSCHEL (WUS) and CLAVATA3 (CLV3), two central players in the establishment and maintenance of meristems, are epistatic to FHY3 Using genome-wide ChIP-seq and RNA-seq data, we identify hundreds of FHY3 target genes in flowers and find that FHY3 mainly acts as a transcriptional repressor in flower development, in contrast to its transcriptional activator role in seedlings. Binding motif-enrichment analyses indicate that FHY3 may coregulate flower development with three flower-specific MADS-domain TFs and four basic helix-loop-helix TFs that are involved in photomorphogenesis. We further demonstrate that CLV3, SEPALLATA1 (SEP1), and SEP2 are FHY3 target genes. In shoot apical meristem, FHY3 directly represses CLV3, which consequently regulates WUS to maintain the stem cell pool. Intriguingly, CLV3 expression did not change significantly in fhy3 and phytochrome B mutants before and after light treatment, indicating that FHY3 and phytochrome B are involved in light-regulated meristem activity. In FM, FHY3 directly represses CLV3, but activates SEP2, to ultimately promote FM determinacy. Taken together, our results reveal insights into the mechanisms of meristem maintenance and determinacy, and illustrate how the roles of a single TF may vary in different organs and developmental stages.
authors.affiliation: 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 050021, China; Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; School of Life Sciences, Lanzhou University, Lanzhou 730000, China;
authors.forename: Dongming
authors.initials: D
authors.lastname: Li
authors.affiliation: Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China;
authors.forename: Xing
authors.initials: X
authors.lastname: Fu
authors.affiliation: 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 050021, China; Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China;
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521; Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, Hunan, China;
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Huang
authors.affiliation: 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 050021, China; Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
authors.forename: Yongpeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: 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 050021, China; Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
authors.forename: Zishan
authors.initials: Z
authors.lastname: He
authors.affiliation: 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 050021, China; Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
authors.forename: Xiuwei
authors.initials: X
authors.lastname: Cao
authors.affiliation: 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 050021, China; College of Life Sciences, South China Agricultural University, Guangzhou 510642, China;
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Ma
authors.affiliation: 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 050021, China; Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China;
authors.forename: Meicheng
authors.initials: M
authors.lastname: Zhao
authors.affiliation: College of Life Sciences, South China Agricultural University, Guangzhou 510642, China;
authors.forename: Guohui
authors.initials: G
authors.lastname: Zhu
authors.affiliation: Hunan Provincial Key Laboratory of Phytohormones and Growth Development, Hunan Agricultural University, Changsha 410128, Hunan, China;
authors.forename: Langtao
authors.initials: L
authors.lastname: Xiao
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
authors.forename: Haiyang
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California, Riverside, CA 92521; Howard Hughes Medical Institute, University of California, Riverside, CA 92521.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Chen
authors.affiliation: Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China; ryliu@sibs.ac.cn xgliu@sjziam.ac.cn.
authors.forename: Renyi
authors.initials: R
authors.lastname: Liu
authors.affiliation: 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 050021, China; Hebei Collaboration Innovation Center for Cell Signaling, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; ryliu@sibs.ac.cn xgliu@sjziam.ac.cn.
authors.forename: Xigang
authors.identifier: 0000-0003-4473-2900
authors.initials: X
authors.lastname: Liu
mesh_terms: D017360:Arabidopsis / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology*; D035264:Flowers / Q000254:growth & development; D018398:Homeodomain Proteins / Q000502:physiology; D018519:Meristem / Q000254:growth & development*; D010834:Phytochrome / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
chemical_list: C118167:AT2G27250 protein, Arabidopsis; D029681:Arabidopsis Proteins; C452847:FHY3 protein, Arabidopsis; D018398:Homeodomain Proteins; C587509:SEPALLATA protein, Arabidopsis; D014157:Transcription Factors; C116421:WUSCHEL protein, Arabidopsis; D010834:Phytochrome
keywords: CLV3; FHY3; SEP2; meristem determinacy; meristem maintenance