title: MYB118 represses endosperm maturation in seeds of Arabidopsis.
abstract: In the exalbuminous species Arabidopsis thaliana, seed maturation is accompanied by the deposition of oil and storage proteins and the reduction of the endosperm to one cell layer. Here, we consider reserve partitioning between embryo and endosperm compartments. The pattern of deposition, final amount, and composition of these reserves differ between the two compartments, with the embryo representing the principal storage tissue in mature seeds. Complex regulatory mechanisms are known to prevent activation of maturation-related programs during embryo morphogenesis and, later, during vegetative growth. Here, we describe a regulator that represses the expression of maturation-related genes during maturation within the endosperm. MYB118 is transcriptionally induced in the maturing endosperm, and seeds of myb118 mutants exhibit an endosperm-specific derepression of maturation-related genes associated with a partial relocation of storage compounds from the embryo to the endosperm. Moreover, MYB118 activates endosperm-induced genes through the recognition of TAACGG elements. These results demonstrate that the differential partitioning of reserves between the embryo and endosperm in exalbuminous Arabidopsis seeds does not only result from developmental programs that establish the embryo as the preponderant tissue within seeds. This differential partitioning is also regulated by MYB118, which regulates the biosynthesis of reserves at the spatial level during maturation.
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Barthole
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: To
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France.
authors.forename: Chloé
authors.initials: C
authors.lastname: Marchive
authors.affiliation: INRA, Unité de Recherche en Génomique Végétale, Génomique Fonctionnelle d'Arabidopsis, Plateforme Transcriptome, UMR1165, INRA-Université d'Evry Val d'Essonne, ERL8196 CNRS, Saclay Plant Sciences, F-91000 Evry, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Brunaud
authors.affiliation: INRA, Unité de Recherche en Génomique Végétale, Génomique Fonctionnelle d'Arabidopsis, Plateforme Transcriptome, UMR1165, INRA-Université d'Evry Val d'Essonne, ERL8196 CNRS, Saclay Plant Sciences, F-91000 Evry, France.
authors.forename: Ludivine
authors.initials: L
authors.lastname: Soubigou-Taconnat
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Berger
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Dubreucq
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Lepiniec
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France AgroParisTech, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, F-78000 Versailles, France sebastien.baud@versailles.inra.fr.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Baud
mesh_terms: D017360:Arabidopsis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D056625:Endosperm / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C539387:MYB118 protein, Arabidopsis; D014157:Transcription Factors