RESUMEN
The molecular mechanisms underlying the initiation and maintenance of the embryonic pathway in plants are largely unknown. To obtain more insight into these processes, we used subtractive hybridization to identify genes that are upregulated during the in vitro induction of embryo development from immature pollen grains of Brassica napus (microspore embryogenesis). One of the genes identified, BABY BOOM (BBM), shows similarity to the AP2/ERF family of transcription factors and is expressed preferentially in developing embryos and seeds. Ectopic expression of BBM in Arabidopsis and Brassica led to the spontaneous formation of somatic embryos and cotyledon-like structures on seedlings. Ectopic BBM expression induced additional pleiotropic phenotypes, including neoplastic growth, hormone-free regeneration of explants, and alterations in leaf and flower morphology. The expression pattern of BBM in developing seeds combined with the BBM overexpression phenotype suggests a role for this gene in promoting cell proliferation and morphogenesis during embryogenesis.
Asunto(s)
Brassica napus/genética , Proteínas de Plantas/genética , Semillas/genética , Factores de Transcripción/genética , Secuencia de Aminoácidos , Arabidopsis/embriología , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassica napus/embriología , Brassica napus/crecimiento & desarrollo , División Celular , Proteínas de Unión al ADN , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Hibridación in Situ , Datos de Secuencia Molecular , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Fenotipo , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Semillas/crecimiento & desarrollo , Homología de Secuencia de Aminoácido , Factores de Transcripción/metabolismoRESUMEN
The introduction of hybrid crop varieties has enabled spectacular increases in productivity owing to hybrid vigor and increased uniformity. To produce hybrid seeds, a pollination control system is required to prevent unwanted self-pollination. In crop species with hermaphrodite flowers, this can be a major challenge. Over the past decade, new pollination control systems have been developed with the aid of genetic engineering, mainly based on the generation of nuclear-encoded male sterility. The successful application of these systems for large-scale hybrid seed production depends on whether the male-sterile female parent line can be multiplied efficiently and economically. In spite of its relevance, the propagation of the male-sterile line has often been overlooked in the development of pollination control systems.