title: DEFECTIVE KERNEL 1 promotes and maintains plant epidermal differentiation.
abstract: During plant epidermal development, many cell types are generated from protodermal cells, a process requiring complex co-ordination of cell division, growth, endoreduplication and the acquisition of differentiated cellular morphologies. Here we show that the Arabidopsis phytocalpain DEFECTIVE KERNEL 1 (DEK1) promotes the differentiated epidermal state. Plants with reduced DEK1 activity produce cotyledon epidermis with protodermal characteristics, despite showing normal growth and endoreduplication. Furthermore, in non-embryonic tissues (true leaves, sepals), DEK1 is required for epidermis differentiation maintenance. We show that the HD-ZIP IV family of epidermis-specific differentiation-promoting transcription factors are key, albeit indirect, targets of DEK1 activity. We propose a model in which DEK1 influences HD-ZIP IV gene expression, and thus epidermis differentiation, by promoting cell adhesion and communication in the epidermis.
authors.affiliation: Laboratoire de Reproduction et Développement des Plantes, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, Lyon 69364, Cedex 07, France roberta.galletti@ens-lyon.fr gwyneth.ingram@ens-lyon.fr.
authors.forename: Roberta
authors.initials: R
authors.lastname: Galletti
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Royal Parade, Parkville, Victoria 3010, Australia.
authors.forename: Kim L
authors.initials: KL
authors.lastname: Johnson
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Scofield
authors.affiliation: Laboratoire de Reproduction et Développement des Plantes, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, Lyon 69364, Cedex 07, France.
authors.forename: Rita
authors.initials: R
authors.lastname: San-Bento
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Royal Parade, Parkville, Victoria 3010, Australia.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Watt
authors.affiliation: Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, UK.
authors.forename: James A H
authors.initials: JA
authors.lastname: Murray
authors.affiliation: Laboratoire de Reproduction et Développement des Plantes, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, Lyon 69364, Cedex 07, France roberta.galletti@ens-lyon.fr gwyneth.ingram@ens-lyon.fr.
authors.forename: Gwyneth C
authors.initials: GC
authors.lastname: Ingram
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002154:Calpain / Q000235:genetics / Q000378:metabolism*; D002450:Cell Communication; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D048430:Cell Shape; D018548:Cotyledon / Q000166:cytology / Q000378:metabolism; D035264:Flowers / Q000166:cytology / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D016350:Leucine Zippers; D008870:Microtubules / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D019441:Plant Epidermis / Q000166:cytology*; D011003:Ploidies; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D002154:Calpain; C507125:DEK1 protein, Arabidopsis
keywords: Arabidopsis thaliana; DEK1; Differentiation maintenance; Epidermis