title: Gibberellins Regulate Ovule Integument Development by Interfering with the Transcription Factor ATS.
abstract: Gibberellins (GAs) are plant hormones that regulate most plant life cycle aspects, including flowering and fruit development. Here, we demonstrate the implication of GAs in ovule development. DELLA proteins, negative GA response regulators, act as positive factors for ovule integument development in a mechanism that involves transcription factor ABERRANT TESTA SHAPE (ATS). The seeds of the della global mutant, a complete loss-of-function of DELLA, and the ats-1 mutant are remarkably similar, with a round shape, a disorganized testa, and viviparism. These defects are the result of an alteration in integuments that fail to fully develop and are shorter than in wild-type plants. ats-1 also shows some GA-related phenotypes, for example, higher germination rates and early flowering. In fact, ats-1 has elevated GA levels due to the activation of GA biosynthesis genes, which indicates that ATS inhibits GA biosynthesis. Moreover, DELLAs and ATS proteins interact, which suggests the formation of a transcriptional complex that regulates the expression of genes involved in integument growth. Therefore, the repression of GA biosynthesis by ATS would result in the stabilization of DELLAs to ensure correct ATS-DELLA complex formation. The requirement of both activities to coordinate proper ovule development strongly argues that the ATS-DELLA complex acts as a key molecular factor. This work provides the first evidence for a role of GAs in ovule and seed development.
authors: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
authors: María Dolores
authors: 0000-0001-9445-2056
authors: MD
authors: Gomez
authors: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
authors: Daniel
authors: 0000-0003-2171-753X
authors: D
authors: Ventimilla
authors: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
authors: Raquel
authors: R
authors: Sacristan
authors: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain mpereza@ibmcp.upv.es.
authors: Miguel A
authors: 0000-0003-4518-3544
authors: MA
authors: Perez-Amador
mesh_terms: D017360:Arabidopsis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D035264:Flowers / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D056771:Ovule / Q000196:embryology* / Q000378:metabolism* / Q000648:ultrastructure; D010641:Phenotype; D011485:Protein Binding; D012639:Seeds / Q000196:embryology / Q000378:metabolism / Q000648:ultrastructure; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D005875:Gibberellins; C511852:KAN4 protein, Arabidopsis; D014157:Transcription Factors