Targeted cell elimination reveals an auxin-guided biphasic mode of lateral root initiation
- Peter Marhavý1,6,
- Juan Carlos Montesinos1,
- Anas Abuzeineh2,3,7,
- Daniel Van Damme2,3,
- Joop E.M. Vermeer5,
- Jerôme Duclercq2,3,8,
- Hana Rakusová1,
- Petra Nováková1,6,
- Jiři Friml1,
- Niko Geldner4 and
- Eva Benková1
- 1Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria;
- 2Department of Plant Systems Biology, Vlaams Instituut voor Biotechnologie (VIB), 9052 Gent, Belgium;
- 3Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium;
- 4Department of Plant Molecular Biology, Biophore, UNIL-Sorge, University of Lausanne, 1015 Lausanne, Switzerland;
- 5Plant Cell Biology, Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland
- Corresponding author: eva.benkova{at}ist.ac.at
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.
Keywords
Footnotes
-
Supplemental material is available for this article.
-
Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.276964.115.
- Received December 23, 2015.
- Accepted December 30, 2015.
This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date (see http://genesdev.cshlp.org/site/misc/terms.xhtml). After six months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.