title: ZmZHOUPI, an endosperm-specific basic helix-loop-helix transcription factor involved in maize seed development.
abstract: In angiosperm seeds the embryo is embedded within the endosperm, which is in turn enveloped by the seed coat, making inter-compartmental communication essential for coordinated seed growth. In this context the basic helix-loop-helix domain transcription factor AtZHOUPI (AtZOU) fulfils a key role in both the lysis of the transient endosperm and in embryo cuticle formation in Arabidopsis thaliana. In maize (Zea mays), a cereal with a persistent endosperm, a single gene, ZmZOU, falls into the same phylogenetic clade as AtZOU. Its expression is limited to the endosperm where it peaks during the filling stage. In ZmZOU-RNA interference knock-down lines embryo size is slightly reduced and the embryonic suspensor and the adjacent embryo surrounding region show retarded breakdown. Ectopic expression of ZmZOU reduces stomatal number, possibly due to inappropriate protein interactions. ZmZOU forms functional heterodimers with AtICE/AtSCREAM and the closely related maize proteins ZmICEb and ZmICEc, but its interaction is more efficient with the ZmICEa protein, which shows sequence divergence and only has close homologues in other monocotyledonous species. Consistent with the observation that these complexes can trans-activate target gene promoters from Arabidopsis, ZmZOU partially complements the Atzou-4 mutant. However, structural, trans-activation and gene expression data support the hypothesis that ZmZOU and ZmICEa may have coevolved to form a functional complex unique to monocot seeds. This divergence may explain the reduced functionality of ZmZOU in Arabidopsis, and reflect functional specificities which are unique to the monocotyledon lineage.
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Grimault
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Gendrot
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Sophy
authors.initials: S
authors.lastname: Chamot
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Widiez
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Rabillé
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Gérentes
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Creff
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, Versailles, France.
authors.forename: Johanne
authors.initials: J
authors.lastname: Thévenin
authors.affiliation: INRA, UMR1318, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, Versailles, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Dubreucq
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Gwyneth C
authors.initials: GC
authors.lastname: Ingram
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rogowsky
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364, Lyon, France.|INRA, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France.|CNRS, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Depège-Fargeix
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D056625:Endosperm / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D005816:Genetic Complementation Test; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D054046:Plant Stomata / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D055503:Protein Multimerization; D012639:Seeds / Q000235:genetics / Q000254:growth & development*; D003313:Zea mays / Q000235:genetics / Q000254:growth & development*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D010940:Plant Proteins
keywords: Arabidopsis thaliana; Zea mays; development; embryo size; embryo surrounding region; endosperm; suspensor; transcription factor