PLANT PHYSIOLOGY (3)

Author: SABINO LOPES MARTA DA SILVA.
Year: 2006.
University: BARCELONA [www.ub.es].
Place of defense: UNIVERSIDAD DE BARCELONA.
Place of preparation: BIOLOGIA VEGETAL, UNIV. FISIOLOGIA VEGETAL.

Author: MUÑOZ BERTOMEU JESÚS.
Year: 2006.
University: VALENCIA [www.uv.es].
Place of defense: FACULTAD DE FARMACIA.
Place of preparation: FACULTAD DE FARMACIA - UNIVERSITAT DE VALÈNCIA.

Summary: The lavender (Lavandula latifolia Medicus) is an aromatic shrub with a high economic value due to its content in essential oils, used in the pharmaceutical, cosmetics, perfume and food processing. The objective of this thesis was to improve the production of essential oil of lavender using conventional methods of improvement and biotechnology (metabolic engineering of biosynthesis monoterpenes, major constituents of the essential oil of lavender). First, we studied the variation of the essential oil between and within 7 populations lavender de la Comunidad Valenciana. The production of oil, provided higher in flowers that leaves varied within and between populations, although the hierarchical analysis of variance showed that the proportion of variance attributable to individuals was significantly greater than that caused by differences between populations. The analysis of the components of oils allowed three distinct groups characterized by a high content, intermediate or low linalol, to be correlated, respectively, with the floors above-, meso-and termo-mediterráneo where populations are located. The improvement was addressed through biotechnology overexpression of both genes encoding enzymes key routes plastidial (Route metileritritol phosphate MEP) and cytosolic (Route mevalonato, MVA), as the final stages of the biosynthesis of monoterpenes (monoterpeno sintasas ). The overexpression of the gene DXS, which encodes the first enzyme (1-deoxi-D-xilulosa phosphate synthase) from the route MEP led to significant increases in the production of essential oil (increments of 101.49 to 359.04% and 17.17 to 74.11% leaves and flowers, respectively). The overexpression of the gene HMG1, which encodes the enzyme HMGR (3-hidroxi-3-metilglutaril CoA reductase), regulating the route MVA also increase the production of essential oil (mean increases of 14.91 to 107.01% and 38.82 to 79.22% on leaves and flowers, respectively) and sterols leaf (median increases of 80.28 and 91.53% in sitosterol and stigmasterol, respectively), but did not alter the accumulation of carotenoids and chlorophylls. These results demonstrate the importance of trade intermediaries between MVA and MEP routes for the synthesis of monoterpenes in the essential oil of lavender. The LS overexpression of the gene, which encodes the enzyme synthase limonene, which transforms the geranil diphosphate in limonene, showed that the leaves of developing transgenic plants containing high levels of limonene (increase of over 450% compared to controls), correlated with the greatest accumulations of transcripts of that gene. Levels of other monoterpenes, especially pinenos, mirceno,? -terpineol And cineol also were significantly altered in such sheets. These results demonstrate that the synthesis of limonene in lavender is regulated during leaf development, as both the post-transcriptional level.

Author: ALONSO SIMÓN ANA.
Year: 2006.
University: LEÓN [www.unileon.es].
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS Y AMBIENTALES.
Place of preparation: FACULTAD DE CIENCIAS BIOLÓGICAS Y AMBIENTALES.

Summary: Cell cultures have been used for bean (Phaseolus vulgaris L.) used herbicide synthesis inhibitors cellulose with the aim of studying plasticity and the dynamics and structure of the cell wall. This has been used numerous techniques biochemical, immunological, microscopy, and so on. By monitoring the habituation to diclobenil of calluses of bean by FTIR spectroscopy associated with multivariate analysis revealed the existence of three different levels of habituation (low, medium and high) and the changes produced by the habituation depended on the concentration of inhibitor and while the cells grew in this concentration. The study of the activity xiloglucano endotransglucosilasa (XET) cells used to diclobenil showed greater activity in the cells accustomed, along with a xiloglucano lower molecular mass, and this could indicate that the increased activity XET work to strengthen the cell wall, weakened by introducing a lower cellulose content. The habituation to diclobenil and subsequent cessation (subculture of cells accustomed in the absence of diclobenil) also led to changes in the molecular mass and structure of xiloglucano, studied through the study of such purification and hemicellulose from cells not accustomed, accustomed and deshabituadas. Purification and characterization of ß-1 ,4-glucano soluble from cells deshabituadas to diclobenil; this glucan filed a molecular mass of 10 kDa half and one or more radical acetyl glucose in the waste, which would enable their greater solubility. It also considered the greater tolerance of cells deshabituadas against other synthesis inhibitors cellulose, and these cells showed a great capacity for habituation to diclobenil already isoxaben, in addition to higher levels of enzyme activity related to the detoxification of xenobiotics. Lastly, habituaron cells bean to quinclorac and marked the cell wall of the cells accustomed. The cell wall of the cells used to quinclorac showed a lower protein content and pectins. In addition, they appeared in extracellular material that responded positively to marking with specific antibodies pectins with high metilesterificación. However, the cellulose content suffered no noticeable changes. We conclude that this herbicide is not an inhibitor of the synthesis of cellulose, and that changes in the cell wall that leads are secondary consequence of their activity auxínica.