title: Programmed cell death controlled by ANAC033/SOMBRERO determines root cap organ size in Arabidopsis.
abstract: BACKGROUND
  The root cap is a plant organ that ensheathes the meristematic stem cells at the root tip. Unlike other plant organs, the root cap shows a rapid cellular turnover, balancing constant cell generation by specific stem cells with the disposal of differentiated cells at the root cap edge. This cellular turnover is critical for the maintenance of root cap size and its position around the growing root tip, but how this is achieved and controlled in the model plant Arabidopsis thaliana remains subject to contradictory hypotheses.
  
  
  RESULTS
  Here, we show that a highly organized cell death program is the final step of lateral root cap differentiation and that preparation for cell death is transcriptionally controlled by ANAC033/SOMBRERO. Precise timing of cell death is critical for the elimination of root cap cells before they fully enter the root elongation zone, which in turn is important in order to allow optimal root growth. Root cap cell death is followed by a rapid cell-autonomous corpse clearance and DNA fragmentation dependent on the S1-P1 type nuclease BFN1.
  
  
  CONCLUSIONS
  Based on these results, we propose a novel concept in plant development that recognizes programmed cell death as a mechanism for maintaining organ size and tissue homeostasis in the Arabidopsis root cap.
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
authors.forename: Matyáš
authors.initials: M
authors.lastname: Fendrych
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Van Hautegem
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
authors.forename: Matthias
authors.initials: M
authors.lastname: Van Durme
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
authors.forename: Yadira
authors.initials: Y
authors.lastname: Olvera-Carrillo
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
authors.forename: Marlies
authors.initials: M
authors.lastname: Huysmans
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium.
authors.forename: Mansour
authors.initials: M
authors.lastname: Karimi
authors.affiliation: Bio Imaging Core, VIB, 9052 Ghent, Belgium; Inflammation Research Center, VIB, 9052 Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.
authors.forename: Saskia
authors.initials: S
authors.lastname: Lippens
authors.affiliation: Bio Imaging Core, VIB, 9052 Ghent, Belgium; Inflammation Research Center, VIB, 9052 Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, 9052 Ghent, Belgium.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Guérin
authors.affiliation: Plant Developmental Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Krebs
authors.affiliation: Plant Developmental Biology, Centre for Organismal Studies, University of Heidelberg, 69120 Heidelberg, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Schumacher
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Ghent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Ghent, Belgium. Electronic address: moritz.nowack@vib.be.
authors.forename: Moritz K
authors.initials: MK
authors.lastname: Nowack
mesh_terms: D017360:Arabidopsis / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D001329:Autolysis; D016923:Cell Death / Q000235:genetics*; D049109:Cell Proliferation; D053938:DNA Fragmentation; D003851:Deoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006706:Homeostasis; D009929:Organ Size; D063245:Plant Development; D018518:Plant Root Cap / Q000254:growth & development* / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; C513622:BFN1 protein, Arabidopsis; C534299:SOMBRERO protein, Arabidopsis; D014157:Transcription Factors; D003851:Deoxyribonucleases