Plantas transgénicas con alto rendimiento en peso seco y almidón cuyos órganos de reserva presentan elevada textura, elevado contenido en almidón y elevado rendimiento en peso seco

Plantas transgénicas con alto rendimiento en peso seco y almidón cuyos órganos de reserva presentan elevada textura, elevado contenido en almidón y elevado rendimiento en peso seco. La presente invención proporciona plantas transgénicas con alto rendimiento en peso seco y almidón cuyos órganos de reserva presentan elevada textura, elevado contenido en almidón y elevado rendimiento en peso seco.Peer reviewedUniversidad Pública de Navarra OTRI, Consejo Superior de Investigaciones Científicas (España)B1 Patente sin examen previ

Arabidopsis thaliana mutants lacking ADP-glucose pyrophosphorylase can accumulate high levels of starch and ADP-glucose: further evidences for the occurrence of important sources, other than ADP-glucose pyrophosphorylase, of ADP-glucose linked to starch biosynthesis

Póster presentado en la The Annual Plant Biology Meeting, celebrada en Minneapolis del 6 al 10 de agosto de 2011.Peer Reviewe

Compuestos útiles para el tratamiento de infecciones bacterianas, composiciones farmaceúticas que los contienen, procedimiento de identificación de los mismos y sus aplicaciones

La presente invención describe una serie de compuestos útiles para reducir o anular procesos determinantes de la patogenicidad y virulencia bacterianas y de la adherencia bacteriana a superficies inertes o células tales como la producción de adhesinas, la motilidad flagelar y la formación de EPSs y biofilms bacterianos. Estos compuestos pueden usarse para la elaboración de composiciones farmacéuticas antibacterianas o de composiciones antisépticas para el tratamiento de un amplio abanico de infecciones bacterianas, como por ejemplo, E. coli, S. typhi, S. dysenteteriae, V. chlolerae, P. aeruginosa, H. pylori, L. monocytogenes, C. difficile y S. pyogenes. Además, se describe un procedimiento para la identificación de dichos compuestosPeer reviewedConsejo Superior de Investigaciones Científicas, Universidad Pública de NavarraA2 Solicitud de patente sin informe sobre el estado de la técnic

Enhancing the expression of starch synthase class IV results in increased levels of both transitory and long-term storage starch

Starch is an important renewable raw material with an increasing number of applications.Several attempts have been made to obtain plants that produce modified versions of starchor higher starch yield. Most of the approaches designed to increase the levels of starch havefocused on the increment of the amount of ADP-glucose or ATP available for starch biosyn-thesis. In this work, we show that the overexpression of starch synthase class IV (SSIV)increases the levels of starch accumulated in the leaves ofArabidopsisby 30%–40%. In addi-tion,SSIV-overexpressing lines display a higher rate of growth. The increase in starch contentas a consequence of enhancedSSIVexpression is also observed in long-term storage starchorgans such as potato tubers. Overexpression ofSSIVin potato leads to increased tuber starchcontent on a dry weight basis and to increased yield of starch production in terms of tons ofstarch⁄hectare. These results identify SSIV as one of the regulatory steps involved in the con-trol of the amount of starch accumulated in plastids.Comisión Interministerial de Ciencia y Tecnología de España y Fondo Europeo de Desarrollo Regional BIO2009-07040, BIO2007-63915 y PET2008-0106Junta de Andalucía P09-CVI-470

Differential Regulation of Stomatal Conductance as a Strategy to Cope With Ammonium Fertilizer Under Ambient Versus Elevated CO2

While nitrogen (N) derived from ammonium would be energetically less expensive than nitrate-derived N, the use of ammonium-based fertilizer is limited by the potential for toxicity symptoms. Nevertheless, previous studies have shown that exposure to elevated CO2 favors ammonium assimilation in plants. However, little is known about the impact of different forms of N fertilizer on stomatal opening and their consequent effects on CO2 and H2O diffusion in wheat plants exposed to ambient and elevated CO2. In this article, we have examined the response of the photosynthetic machinery of durum wheat (Triticum durum, var. Amilcar) grown with different types of N fertilizer (NO3−, NH4+, and NH4NO3) at 400 versus 700 ppm of CO2. Alongside gas exchange and photochemical parameters, the expression of genes involved in CO2 (PIP1.1 and PIP2.3) and H2O (TIP1) diffusion as well as key C and N primary metabolism enzymes and metabolites were studied. Our results show that at 400 ppm CO2, wheat plants fertilized with ammonium as the N source had stress symptoms and a strong reduction in stomatal conductance, which negatively affected photosynthetic rates. The higher levels of PIP1.1 and PIP2.3 expression in ammonium-fertilized plants at 400 ppm CO2 might reflect the need to overcome limitations to the CO2 supply to chloroplasts due to restrictions in stomatal conductance. This stomatal limitation might be associated with a strategy to reduce ammonium transport toward leaves. On the other hand, ammonium-fertilized plants at elevated CO2 did not show stress symptoms, and no differences were detected in stomatal opening or water use efficiency (WUE). Moreover, similar gene expression of the aquaporins TIP1, PIP1.1, and PIP2.3 in ammonium-fertilized plants grown at 700 ppm compared to nitrate and ammonium nitrate plants would suggest that an adjustment in CO2 and H2O diffusion is not required. Therefore, in the absence of a stress context triggered by elevated CO2, ammonium- and ammonium nitrate-fertilized plants were able to increase their photosynthetic rates, which were translated eventually into higher leaf protein content

HPLC-MS/MS Analyses Show That the Near-Starchless aps1 and pgm Leaves Accumulate Wild Type Levels of ADPglucose: Further Evidence for the Occurrence of Important ADPglucose Biosynthetic Pathway(s) Alternative to the pPGI-pPGM-AGP Pathway

In leaves, it is widely assumed that starch is the end-product of a metabolic pathway exclusively taking place in the chloroplast that (a) involves plastidic phosphoglucomutase (pPGM), ADPglucose (ADPG) pyrophosphorylase (AGP) and starch synthase (SS), and (b) is linked to the Calvin-Benson cycle by means of the plastidic phosphoglucose isomerase (pPGI). This view also implies that AGP is the sole enzyme producing the starch precursor molecule, ADPG. However, mounting evidence has been compiled pointing to the occurrence of important sources, other than the pPGI-pPGM-AGP pathway, of ADPG. To further explore this possibility, in this work two independent laboratories have carried out HPLC-MS/MS analyses of ADPG content in leaves of the near-starchless pgm and aps1 mutants impaired in pPGM and AGP, respectively, and in leaves of double aps1/pgm mutants grown under two different culture conditions. We also measured the ADPG content in wild type (WT) and aps1 leaves expressing in the plastid two different ADPG cleaving enzymes, and in aps1 leaves expressing in the plastid GlgC, a bacterial AGP. Furthermore, we measured the ADPG content in ss3/ss4/aps1 mutants impaired in starch granule initiation and chloroplastic ADPG synthesis. We found that, irrespective of their starch contents, pgm and aps1 leaves, WT and aps1 leaves expressing in the plastid ADPG cleaving enzymes, and aps1 leaves expressing in the plastid GlgC accumulate WT ADPG content. In clear contrast, ss3/ss4/aps1 leaves accumulated ca. 300 fold-more ADPG than WT leaves. The overall data showed that, in Arabidopsis leaves, (a) there are important ADPG biosynthetic pathways, other than the pPGI-pPGM-AGP pathway, (b) pPGM and AGP are not major determinants of intracellular ADPG content, and (c) the contribution of the chloroplastic ADPG pool to the total ADPG pool is low.This research was partially supported by the grants [BIO2010-18239] from the Comisión Interministerial de Ciencia y Tecnología and Fondo Europeo de Desarrollo Regional (Spain) and [IIM010491.RI1] from the Government of Navarra, and by Iden Biotechnology. This research was also supported by Scientific Research on Innovative Areas [22114507] and Grants-in-Aid for Scientific Research (B) [22380186] from the Ministry of Education, Culture, Sports, Science and Technology, Japan.Peer Reviewe