title: The cytokinin response factors modulate root and shoot growth and promote leaf senescence in Arabidopsis.
abstract: The cytokinin response factors (CRFs) are a group of related AP2/ERF transcription factors that are transcriptionally induced by cytokinin. Here we explore the role of the CRFs in Arabidopsis thaliana growth and development by analyzing lines with decreased and increased CRF function. While single crf mutations have no appreciable phenotypes, disruption of multiple CRFs results in larger rosettes, delayed leaf senescence, a smaller root apical meristem (RAM), reduced primary and lateral root growth, and, in etiolated seedlings, shorter hypocotyls. In contrast, overexpression of CRFs generally results in the opposite phenotypes. The crf1,2,5,6 quadruple mutant is embryo lethal, indicating that CRF function is essential for embryo development. Disruption of the CRFs results in partially insensitivity to cytokinin in a root elongation assay and affects the basal expression of a significant number of cytokinin-regulated genes, including the type-A ARRs, although it does not impair the cytokinin induction of the type-A ARRs. Genes encoding homeobox transcription factors are mis-expressed in the crf1,3,5,6 mutant, including STIMPY/WOX9 that is required for root and shoot apical meristem maintenance roots and which has previously been linked to cytokinin. These results indicate that the CRF transcription factors play important roles in multiple aspects of plant growth and development, in part through a complex interaction with cytokinin signaling.
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
authors.forename: Tracy
authors.initials: T
authors.lastname: Raines
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
authors.forename: Carly
authors.initials: C
authors.lastname: Shanks
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
authors.forename: Chia-Yi
authors.initials: CY
authors.lastname: Cheng
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
authors.forename: Duncan
authors.initials: D
authors.lastname: McPherson
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
authors.forename: Cristiana T
authors.initials: CT
authors.lastname: Argueso
authors.affiliation: Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA.
authors.forename: Hyo J
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Unidad de Genómica and Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma, 28049, Madrid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Franco-Zorrilla
authors.affiliation: Unidad de Genómica and Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma, 28049, Madrid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: López-Vidriero
authors.affiliation: Unidad de Genómica and Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma, 28049, Madrid, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Solano
authors.affiliation: Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR, Rozvojová 263, 165 02, Prague, Czech Republic.
authors.forename: Radomíra
authors.initials: R
authors.lastname: Vaňková
authors.affiliation: Department of Biological Sciences, Dartmouth College, Hanover, NH, 03755, USA.
authors.forename: G Eric
authors.initials: GE
authors.lastname: Schaller
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC, 27599, USA.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Kieber
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003583:Cytokinins / Q000378:metabolism*; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D009154:Mutation; D010641:Phenotype; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D018398:Homeodomain Proteins; D010937:Plant Growth Regulators; D014157:Transcription Factors
keywords: cell division; cytokinin; plant development; root meristem; senescence; transcription factors; two-component signaling