title: RBOH-mediated ROS production facilitates lateral root emergence in Arabidopsis.
abstract: Lateral root (LR) emergence represents a highly coordinated process in which the plant hormone auxin plays a central role. Reactive oxygen species (ROS) have been proposed to function as important signals during auxin-regulated LR formation; however, their mode of action is poorly understood. Here, we report that Arabidopsis roots exposed to ROS show increased LR numbers due to the activation of LR pre-branch sites and LR primordia (LRP). Strikingly, ROS treatment can also restore LR formation in pCASP1:shy2-2 and aux1 lax3 mutant lines in which auxin-mediated cell wall accommodation and remodeling in cells overlying the sites of LR formation is disrupted. Specifically, ROS are deposited in the apoplast of these cells during LR emergence, following a spatiotemporal pattern that overlaps the combined expression domains of extracellular ROS donors of the RESPIRATORY BURST OXIDASE HOMOLOGS (RBOH). We also show that disrupting (or enhancing) expression of RBOH in LRP and/or overlying root tissues decelerates (or accelerates) the development and emergence of LRs. We conclude that RBOH-mediated ROS production facilitates LR outgrowth by promoting cell wall remodeling of overlying parental tissues.
authors.affiliation: Université Catholique de Louvain, Earth and Life Institute, Louvain-la-Neuve B-1348, Belgium Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium Department of Plant Systems Biology, VIB, Ghent B-9052, Belgium.
authors.forename: Beata
authors.identifier: 0000-0002-7171-2473
authors.initials: B
authors.lastname: Orman-Ligeza
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium Department of Plant Systems Biology, VIB, Ghent B-9052, Belgium.
authors.forename: Boris
authors.identifier: 0000-0003-1445-6925
authors.initials: B
authors.lastname: Parizot
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium Department of Plant Systems Biology, VIB, Ghent B-9052, Belgium.
authors.forename: Riet
authors.initials: R
authors.lastname: de Rycke
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium Department of Plant Systems Biology, VIB, Ghent B-9052, Belgium.
authors.forename: Ana
authors.initials: A
authors.lastname: Fernandez
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium Department of Plant Systems Biology, VIB, Ghent B-9052, Belgium.
authors.forename: Ellie
authors.initials: E
authors.lastname: Himschoot
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium Department of Plant Systems Biology, VIB, Ghent B-9052, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Van Breusegem
authors.affiliation: Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Sutton Bonington LE12 5RD, UK.
authors.forename: Malcolm J
authors.identifier: 0000-0003-0475-390X
authors.initials: MJ
authors.lastname: Bennett
authors.affiliation: PhytoSYSTEMS, Laboratory of Plant Physiology, University of Liège, Sart Tilman Campus, 4 Chemin de la Vallée, Liège B-4000, Belgium.
authors.forename: Claire
authors.initials: C
authors.lastname: Périlleux
authors.affiliation: Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent B-9052, Belgium Department of Plant Systems Biology, VIB, Ghent B-9052, Belgium Tom.Beeckman@psb.ugent.be.
authors.forename: Tom
authors.identifier: 0000-0001-8656-2060
authors.initials: T
authors.lastname: Beeckman
authors.affiliation: Université Catholique de Louvain, Earth and Life Institute, Louvain-la-Neuve B-1348, Belgium.
authors.forename: Xavier
authors.identifier: 0000-0002-3637-3330
authors.initials: X
authors.lastname: Draye
mesh_terms: D017360:Arabidopsis / Q000378:metabolism* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism* / Q000502:physiology*; D002473:Cell Wall / Q000378:metabolism / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018517:Plant Roots / Q000378:metabolism* / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species
keywords: Auxin; Auxin-mediated cell wall remodeling; Lateral root emergence; Reactive oxygen species; Respiratory burst oxidase homologs