title: The Arabidopsis SWI2/SNF2 chromatin Remodeler BRAHMA regulates polycomb function during vegetative development and directly activates the flowering repressor gene SVP.
abstract: The chromatin remodeler BRAHMA (BRM) is a Trithorax Group (TrxG) protein that antagonizes the functions of Polycomb Group (PcG) proteins in fly and mammals. Recent studies also implicate such a role for Arabidopsis (Arabidopsis thaliana) BRM but the molecular mechanisms underlying the antagonism are unclear. To understand the interplay between BRM and PcG during plant development, we performed a genome-wide analysis of trimethylated histone H3 lysine 27 (H3K27me3) in brm mutant seedlings by chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq). Increased H3K27me3 deposition at several hundred genes was observed in brm mutants and this increase was partially supressed by removal of the H3K27 methyltransferase CURLY LEAF (CLF) or SWINGER (SWN). ChIP experiments demonstrated that BRM directly binds to a subset of the genes and prevents the inappropriate association and/or activity of PcG proteins at these loci. Together, these results indicate a crucial role of BRM in restricting the inappropriate activity of PcG during plant development. The key flowering repressor gene SHORT VEGETATIVE PHASE (SVP) is such a BRM target. In brm mutants, elevated PcG occupancy at SVP accompanies a dramatic increase in H3K27me3 levels at this locus and a concomitant reduction of SVP expression. Further, our gain- and loss-of-function genetic evidence establishes that BRM controls flowering time by directly activating SVP expression. This work reveals a genome-wide functional interplay between BRM and PcG and provides new insights into the impacts of these proteins in plant growth and development.
authors.affiliation: Agriculture and Agri-Food Canada, Southern Crop Protection and Food Research Centre, London, Ontario, Canada; Department of Biology, Western University, London, Ontario, Canada.
authors.forename: Chenlong
authors.initials: C
authors.lastname: Li
authors.affiliation: Agriculture and Agri-Food Canada, Southern Crop Protection and Food Research Centre, London, Ontario, Canada; Department of Biology, Western University, London, Ontario, Canada.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California Riverside, Riverside, California, United States of America.
authors.forename: Lei
authors.initials: L
authors.lastname: Gao
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South ChinaBotanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong, China.
authors.forename: Songguang
authors.initials: S
authors.lastname: Yang
authors.affiliation: Agriculture and Agri-Food Canada, Southern Crop Protection and Food Research Centre, London, Ontario, Canada.
authors.forename: Vi
authors.initials: V
authors.lastname: Nguyen
authors.affiliation: Clinical Genomics Centre, The UHN/MSH Gene Profiling Facility Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Xuejiang
authors.initials: X
authors.lastname: Shi
authors.affiliation: Clinical Genomics Centre, The UHN/MSH Gene Profiling Facility Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Katherine
authors.initials: K
authors.lastname: Siminovitch
authors.affiliation: Department of Biology, Western University, London, Ontario, Canada.
authors.forename: Susanne E
authors.initials: SE
authors.lastname: Kohalmi
authors.affiliation: School of Life Sciences, Guangdong Provincial Key Laboratory of Plant Resource, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Shangzhi
authors.initials: S
authors.lastname: Huang
authors.affiliation: Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, Taiwan.
authors.forename: Keqiang
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California Riverside, Riverside, California, United States of America; Howard Hughes Medical Institute, University of California Riverside, Riverside, California, United States of America.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Chen
authors.affiliation: Agriculture and Agri-Food Canada, Southern Crop Protection and Food Research Centre, London, Ontario, Canada; Department of Biology, Western University, London, Ontario, Canada.
authors.forename: Yuhai
authors.initials: Y
authors.lastname: Cui
mesh_terms: D000251:Adenosine Triphosphatases / Q000096:biosynthesis* / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D006657:Histones / Q000235:genetics; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D063146:Polycomb-Group Proteins / Q000235:genetics*; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; C000597307:FRG1 protein, Arabidopsis; D006657:Histones; D063146:Polycomb-Group Proteins; C407549:SVP protein, Arabidopsis; D014157:Transcription Factors; D000251:Adenosine Triphosphatases; C514541:BRM protein, Arabidopsis