title: The transcription factor OBP4 controls root growth and promotes callus formation.
abstract: Plant growth and development require a continuous balance between cell division and differentiation. In root meristems, differentiated cells acquire specialized functions, losing their mitotic potential. Some plant cells, such as pericycle cells, have a remarkable plasticity to regenerate new organs. The molecular mechanisms underlying cell reprogramming are not completely known. In this work, a functional screening of transcription factors identified Arabidopsis OBP4 (OBF Binding Protein 4) as a novel regulator of root growth and cell elongation and differentiation. Overexpression of OBP4 regulates the levels of a large number of transcripts in roots, many involved in hormonal signaling and callus formation. OBP4 controls cell elongation and differentiation in root cells. OBP4 does not induce cell division in the root meristem, but promotes pericycle cell proliferation, forming callus-like structures at the root tip, as shown by the expression of stem cell markers. Callus formation is enhanced by ectopic expression of OBP4 in the wild-type or alf4-1, but is significantly reduced in roots that have lower levels of OBP4. Our data provide molecular insights into how differentiated root cells acquire the potential to generate callus, a pluripotent mass of cells that can regenerate fully functional plant organs.
authors.affiliation: Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223, Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Ramirez-Parra
authors.affiliation: Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223, Madrid, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Perianez-Rodriguez
authors.affiliation: Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223, Madrid, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Navarro-Neila
authors.affiliation: Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223, Madrid, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Gude
authors.affiliation: Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223, Madrid, Spain.
authors.forename: Miguel A
authors.identifier: http://orcid.org/0000-0002-9794-1450
authors.initials: MA
authors.lastname: Moreno-Risueno
authors.affiliation: Centro de Biotecnología y Genómica de Plantas (CBGP) INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria-Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223, Madrid, Spain.
authors.forename: Juan C
authors.identifier: http://orcid.org/0000-0002-4113-457X
authors.initials: JC
authors.lastname: Del Pozo
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D018519:Meristem / Q000166:cytology / Q000187:drug effects; D010937:Plant Growth Regulators / Q000494:pharmacology; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C000623373:OBP4 protein, Arabidopsis; D010937:Plant Growth Regulators; D014157:Transcription Factors
keywords: Arabidopsis; OBP4; callus formation; cell division and differentiation; roots