Objetivo
The primary objective is to produce basic knowledge on the mechanisms by which a variety of signals control growth and cell differentiation. The secondary objective will be to develop tools at cellular and molecular levels to render morphogenetic events accessible to scientific analysis.
Both the 32 and 64 kD secreted glycoproteins have been purified to homogeneity and tested for their effects on impaired embryo development in the carrot line ts11. The 32 kD protein consistently showed rescue activity allowing the formation of globular and heart stage embryos at the nonpermissive temperature. The effect of the 46 kD protein, resulting in an increase of the number of embryos obtained in ts11, could not be reproduced. Both specific antisera as well as partial complementary deoxyribonucleic acid (cDNA) clones for these proteins have been obtained. Th 32 kD protein has been identified as an acidic endochitinase. A 10 kD seceted lipid transfer protein, that marks the presence of embryonic cells in suspension cultures, has been purified to homogeneity.
Biological tests have been developed employing various cell lines to evaluate the role of secreted glycoproteins on somatic embryogenesis. The results show that embryogenic efficiency can be either increased or decreased upon addition of partially purified glycoproteins to either wild type or variant cell lines. New variant lines obtained are unable to produce even the earliest embryo stages. All these new lines exhibit a greater resistance to auxin when compared with the wild type lines. For many of these new variant lines, the ability to produce smatic embryos can be acquired by preculture in the presence of high concentrations of auxin. In addition, it was shown that auxin induces its own binding sites and that this induction was different in embryogenic cells when compared to nonembryogenic cells.
A secreted arabinogalactan protein (AGP) has been immunoaffinity purified to homogeneity in large amounts from carrot cell suspension medium and is being used for deglycosylation prior to sequencing and antibody production; identification of putative receptor molecules in the extracellular matrix; and high resolution electron microscope (EM) studies and Fourier transform infrared (FTIR) microspectroscopy .
A system for large scale culturing of embrogenic cell suspensions of carrot in a rotating drum fermentor has been developed. Large scale purification of an acidic 32 kD protein has been performed by batch and column anion exchange chromatography, gelfiltration and hydrophobic interaction chromatography. This protein has chitinolytic activity.
The enzyme xyloglucan endotransglycosilase (XET) was found to be present in carrot culture media. The enzyme activity was shown to decrease during the first four days of somatic embryogenesis. Both the 32 and 46 kD as well as previously purified 52/54 kd secreted glycoprotein did not have XET activity. The secreted protein exhibiting high XET activity is noe being purified to homogeneity.
In this proposal we will first focus on the functional analysis of a set of molecular markers that are specific for defined stages in the development of somatic embryos in carrot (Daucus carota L.). These markers are monoclonal antibodies that recognize cell surface proteoglycans, CDNA clones encoding secreted glycoproteins and purified secreted glycoproteins that affect embryo
development. Based on one of the monoclonal antibodies pure
populations of cells with precisely defined embryogenic competence will be prepared for detailed molecular analysis. The secreted glycoproteins will be analyzed by molecular techniques and for their potential enzymic activity on cell walls. secondly, we will relate the markers obtained to the development of zygotic embryos. This approach has already shown itself to be highly profitable, since most of the molecular markers described in this proposal were originally obtained from in-vitro grown cells and were
subsequently shown to be highly specific for various stages of somatic as well as zygotic embryo development. Taken together, we can now begin to answer the question whether parallel molecular events occur during the reprogramming of explant cells finally leading to somatic embryos in tissue culture and during the
reprogramming of cells embarking on the gametophytic pathway. Thirdly, the application of the markers obtained to somatic and zygotic embryogenesis in other plant species will be investigated.
Ámbito científico (EuroSciVoc)
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
- ciencias naturales ciencias biológicas genética ADN
- ciencias naturales ciencias biológicas biología del desarrollo
- ciencias naturales matemáticas matemáticas puras análisis matemático análisis funcional
- ciencias agrícolas biotecnología agrícola genética agrícola clonación de plantas
- ciencias médicas y de la salud medicina clínica embriología
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Programa(s)
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Tema(s)
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Las convocatorias de propuestas se dividen en temas. Un tema define una materia o área específica para la que los solicitantes pueden presentar propuestas. La descripción de un tema comprende su alcance específico y la repercusión prevista del proyecto financiado.
Convocatoria de propuestas
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Datos no disponibles
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Régimen de financiación
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Coordinador
6703 HA WAGENINGEN
Países Bajos
Los costes totales en que ha incurrido esta organización para participar en el proyecto, incluidos los costes directos e indirectos. Este importe es un subconjunto del presupuesto total del proyecto.