title: Targeted cell elimination reveals an auxin-guided biphasic mode of lateral root initiation.
abstract: To sustain a lifelong ability to initiate organs, plants retain pools of undifferentiated cells with a preserved proliferation capacity. The root pericycle represents a unique tissue with conditional meristematic activity, and its tight control determines initiation of lateral organs. Here we show that the meristematic activity of the pericycle is constrained by the interaction with the adjacent endodermis. Release of these restraints by elimination of endodermal cells by single-cell ablation triggers the pericycle to re-enter the cell cycle. We found that endodermis removal substitutes for the phytohormone auxin-dependent initiation of the pericycle meristematic activity. However, auxin is indispensable to steer the cell division plane orientation of new organ-defining divisions. We propose a dual, spatiotemporally distinct role for auxin during lateral root initiation. In the endodermis, auxin releases constraints arising from cell-to-cell interactions that compromise the pericycle meristematic activity, whereas, in the pericycle, auxin defines the orientation of the cell division plane to initiate lateral roots.
authors.affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria;
authors.forename: Peter
authors.initials: P
authors.lastname: Marhavý
authors.affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria;
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Montesinos
authors.affiliation: Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie (VIB), 9052 Gent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium;
authors.forename: Anas
authors.initials: A
authors.lastname: Abuzeineh
authors.affiliation: Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie (VIB), 9052 Gent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium;
authors.forename: Daniel
authors.initials: D
authors.lastname: Van Damme
authors.affiliation: Plant Cell Biology, Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland.
authors.forename: Joop E M
authors.initials: JE
authors.lastname: Vermeer
authors.affiliation: Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie (VIB), 9052 Gent, Belgium; Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium;
authors.forename: Jerôme
authors.initials: J
authors.lastname: Duclercq
authors.affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria;
authors.forename: Hana
authors.initials: H
authors.lastname: Rakusová
authors.affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria;
authors.forename: Petra
authors.initials: P
authors.lastname: Nováková
authors.affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria;
authors.forename: Jiři
authors.initials: J
authors.lastname: Friml
authors.affiliation: Department of Plant Molecular Biology, Biophore, UNIL-Sorge, University of Lausanne, 1015 Lausanne, Switzerland;
authors.forename: Niko
authors.initials: N
authors.lastname: Geldner
authors.affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria;
authors.forename: Eva
authors.initials: E
authors.lastname: Benková
mesh_terms: D055011:Ablation Techniques; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D002450:Cell Communication; D002455:Cell Division; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development*; D021381:Protein Transport; D015398:Signal Transduction
chemical_list: D007210:Indoleacetic Acids
keywords: auxin; lateral root organogenesis; mechanical forces; meristem proliferation activity