title: Auxin minimum defines a developmental window for lateral root initiation.
abstract: Root system architecture depends on lateral root (LR) initiation that takes place in a relatively narrow developmental window (DW). Here, we analyzed the role of auxin gradients established along the parent root in defining this DW for LR initiation. Correlations between auxin distribution and response, and spatiotemporal control of LR initiation were analyzed in Arabidopsis thaliana and tomato (Solanum lycopersicum). In both Arabidopsis and tomato roots, a well defined zone, where auxin content and response are minimal, demarcates the position of a DW for founder cell specification and LR initiation. We show that in the zone of auxin minimum pericycle cells have highest probability to become founder cells and that auxin perception via the TIR1/AFB pathway, and polar auxin transport, are essential for the establishment of this zone. Altogether, this study reveals that the same morphogen-like molecule, auxin, can act simultaneously as a morphogenetic trigger of LR founder cell identity and as a gradient-dependent signal defining positioning of the founder cell specification. This auxin minimum zone might represent an important control mechanism ensuring the LR initiation steadiness and the acropetal LR initiation pattern.
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, 62250 Cuernavaca, Morelos, Mexico.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Dubrovsky
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, 62250 Cuernavaca, Morelos, Mexico.
authors.forename: Selene
authors.initials: S
authors.lastname: Napsucialy-Mendivil
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.|Department of Plant Biotechnology and Genetics, Gent University, 9052 Gent, Belgium.
authors.forename: Jérme
authors.initials: J
authors.lastname: Duclercq
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, 62250 Cuernavaca, Morelos, Mexico.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Shishkova
authors.affiliation: Department of Botany and Plant Pathology, 2082 Cordley Hall, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Ivanchenko
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.|Department of Plant Biotechnology and Genetics, Gent University, 9052 Gent, Belgium.
authors.forename: Jiří
authors.initials: J
authors.lastname: Friml
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Angus S
authors.initials: AS
authors.lastname: Murphy
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.|Department of Plant Biotechnology and Genetics, Gent University, 9052 Gent, Belgium.
authors.forename: Eva
authors.initials: E
authors.lastname: Benková
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D002454:Cell Differentiation; D007210:Indoleacetic Acids / Q000378:metabolism* / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D018613:Microscopy, Confocal; D009024:Morphogenesis; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D021381:Protein Transport; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators