71 research outputs found
Desarrollo de embriones somáticos de alcornoque en biorreactores de inmersión temporal.
El sistema de inmersión temporal (SIT) se basa en el empleo de medio lÃquido y el establecimiento de ciclos de aporte y retirada del medio. Esto permite aprovechar las ventajas del medio lÃquido (favorece la absorción de nutrientes, el crecimiento del material vegetal y la dilución de los metabolitos excretados), al tiempo que reduce sus inconvenientes (suprime el contacto continuo de los explantos con el medio de cultivo, evitando los problemas de asfixia y vitrificación). Por otra parte el SIT facilita el control y el estudio de la nutrición en el cultivo in vitro y puede contribuir al desarrollo óptimo de los explantos. En este trabajo presentamos la puesta a punto de un SIT aplicado a la obtención de embriones somáticos de albaricoque
Diversity in viral anti-PKR mechanisms: A remarkable case of evolutionary convergence
Most viruses express during infection products that prevent or neutralize the effect of the host dsRNA activated protein kinase (PKR). Translation of Sindbis virus (SINV) mRNA escapes to PKR activation and eIF2 phosphorylation in infected cells by a mechanism that requires a stem loop structure in viral 26S mRNA termed DLP to initiate translation in the absence of functional eIF2. Unlike the rest of viruses tested, we found that Alphavirus infection allowed a strong PKR activation and eIF2α phosphorylation in vitro and in infected animals so that the presence of DLP structure in mRNA was critical for translation and replication of SINV. Interestingly, infection of MEFs with some viruses that express PKR inhibitors prevented eIF2α phosphorylation after superinfection with SINV, suggesting that viral anti-PKR mechanisms could be exchangeable. Thus, translation of SINV mutant lacking the DLP structure (ΔDLP) in 26S mRNA was partially rescued in cells expressing vaccinia virus (VV) E3 protein, a known inhibitor of PKR. This case of heterotypic complementation among evolutionary distant viruses confirmed experimentally a remarkable case of convergent evolution in viral anti-PKR mechanisms. Our data reinforce the critical role of PKR in regulating virus-host interaction and reveal the versatility of viruses to find different solutions to solve the same conflict.This work was supported in part from the VIRUS-HOST interaction programme (Comunidad de Madrid) and by grants from the Ministerio de Ciencia e Innovación (SAF2006-09810; SAF2008-02036) and the Fundación Mutua Madrileña (FMM 2008). The institutional support from Fundación Ramón Areces is also acknowledged. E.D was a recipient of VIRUS-HOST programme postdoctoral contract. R.T. was a recipient of the SAF2006-09810 contract and I.V. was a researcher of Ramón y Cajal Programme.Peer Reviewe
Effect of the combination of naa, kinetin and sucrose on the induction of somatic embryogenesis in lulo (solanum quitoense lam.)
Lulo is a species of great importance to the fruticulture of Colombia, but has significant phytosanitary problems that require an aggressive breeding program oriented toward the production of genotypes with tolerance to phytopathogens. These programs need to establish highly efficient mass plant propagation protocols, such as somatic embryogenesis. This study focused on research on the somatic embryogenesis of lulo using kinetin, naphthalene acetic acid-NAA (Plant Growth Regulators, PGRs), and different sucrose concentrations in a MS medium. Two lulo varieties, Solanum quitoense var. septentrionale and S. quitoense var. quitoense, and two explant types (hypocotyl and cotyledon) were used, incubated in dark conditions at 25±2°C. The highest production percentage of the embryos was obtained when 50 μM of NAA were added to the medium with sucrose (50.0 and 263.1 μM) for the two explant types used. In lulo with spines, the highest percentage of embryonic structures (50%) was observed with cotyledonary leaf explants and 50 μM of NAA; while in the spineless lulo, the embryonic structures were observed in the same type of explant with 50 μM of NAA + 263.1 μM of sucrose (32%)
Effect of the combination of naa, kinetin and sucrose on the induction of somatic embryogenesis in lulo (solanum quitoense lam.)
Lulo is a species of great importance to the fruticulture of Colombia, but has significant phytosanitary problems that require an aggressive breeding program oriented toward the production of genotypes with tolerance to phytopathogens. These programs need to establish highly efficient mass plant propagation protocols, such as somatic embryogenesis. This study focused on research on the somatic embryogenesis of lulo using kinetin, naphthalene acetic acid-NAA (Plant Growth Regulators, PGRs), and different sucrose concentrations in a MS medium. Two lulo varieties, Solanum quitoense var. septentrionale and S. quitoense var. quitoense, and two explant types (hypocotyl and cotyledon) were used, incubated in dark conditions at 25±2°C. The highest production percentage of the embryos was obtained when 50 μM of NAA were added to the medium with sucrose (50.0 and 263.1 μM) for the two explant types used. In lulo with spines, the highest percentage of embryonic structures (50%) was observed with cotyledonary leaf explants and 50 μM of NAA; while in the spineless lulo, the embryonic structures were observed in the same type of explant with 50 μM of NAA + 263.1 μM of sucrose (32%)
Effect of the combination of naa, kinetin and sucrose on the induction of somatic embryogenesis in lulo (solanum quitoense lam.)
Lulo is a species of great importance to the fruticulture of Colombia, but has significant phytosanitary problems that require an aggressive breeding program oriented toward the production of genotypes with tolerance to phytopathogens. These programs need to establish highly efficient mass plant propagation protocols, such as somatic embryogenesis. This study focused on research on the somatic embryogenesis of lulo using kinetin, naphthalene acetic acid-NAA (Plant Growth Regulators, PGRs), and different sucrose concentrations in a MS medium. Two lulo varieties, Solanum quitoense var. septentrionale and S. quitoense var. quitoense, and two explant types (hypocotyl and cotyledon) were used, incubated in dark conditions at 25±2°C. The highest production percentage of the embryos was obtained when 50 μM of NAA were added to the medium with sucrose (50.0 and 263.1 μM) for the two explant types used. In lulo with spines, the highest percentage of embryonic structures (50%) was observed with cotyledonary leaf explants and 50 μM of NAA; while in the spineless lulo, the embryonic structures were observed in the same type of explant with 50 μM of NAA + 263.1 μM of sucrose (32%)
Effect of the combination of naa, kinetin and sucrose on the induction of somatic embryogenesis in lulo (solanum quitoense lam.)
Lulo is a species of great importance to the fruticulture of Colombia, but has significant phytosanitary problems that require an aggressive breeding program oriented toward the production of genotypes with tolerance to phytopathogens. These programs need to establish highly efficient mass plant propagation protocols, such as somatic embryogenesis. This study focused on research on the somatic embryogenesis of lulo using kinetin, naphthalene acetic acid-NAA (Plant Growth Regulators, PGRs), and different sucrose concentrations in a MS medium. Two lulo varieties, Solanum quitoense var. septentrionale and S. quitoense var. quitoense, and two explant types (hypocotyl and cotyledon) were used, incubated in dark conditions at 25±2°C. The highest production percentage of the embryos was obtained when 50 μM of NAA were added to the medium with sucrose (50.0 and 263.1 μM) for the two explant types used. In lulo with spines, the highest percentage of embryonic structures (50%) was observed with cotyledonary leaf explants and 50 μM of NAA; while in the spineless lulo, the embryonic structures were observed in the same type of explant with 50 μM of NAA + 263.1 μM of sucrose (32%)
Nuevos modelos universitarios frente a la expansión de la educación superior. Las nuevas universidades del conurbano bonaerense
Esta ponencia forma parte de un proyecto de investigación que se está desarrollando en la Universidad Nacional de Lanús, desde mediados del año 2016 y cuyo objetivo general es analizar las particularidades que presentan las nuevas universidades que se han desarrollado en el Conurbano Bonaerense, como parte de la expansión de la Educación Superior (en adelante ES), y compararlas con las experiencias de otros paÃses.
La hipótesis de la que se parte en el proyecto referido es que la ampliación de la cobertura de la ES que ha tenido lugar a través de las nuevas universidades del Conurbano Bonaerense, forma parte de la expansión de este nivel educativo que se ha registrado en la mayorÃa de los paÃses.
En esta ponencia, y conforme con los avances parciales efectuados hasta el presente en el desarrollo de la investigación, se brindarán algunos argumentos en favor de hipótesis mencionada: en primer término, se hará referencia a los procesos de expansión de la ES ocurridos en otras latitudes; luego, a las caracterÃsticas que ese proceso ha tenido en nuestro paÃs y se procurará reparar en sus particularidades y, por último, se formularán algunas consideraciones sobre el lugar que ocupan las universidades del Conurbano en ese proceso.Mesa 42: Homo Academicus. DesafÃos actuales de la UniversidadFacultad de Humanidades y Ciencias de la Educació
Growth data from a field trial of Quercus suber plants regenerated from selected trees and their half-sib progenies by somatic embryogenesis
The development of reliable clonal propagation technologies is a requisite for performing Multi-Varietal Forestry (MVF). Somatic embryogenesis is considered the tissue culture based method more suitable for operational breeding of forest trees. Vegetative propagation is very difficult when tissues are taken from mature donors, making clonal propagation of selected trees almost impossible. We have been able to induce somatic embryogenesis in leaves taken from mature oak trees, including cork oak (Quercus suber). This important species of the Mediterranean ecosystem produces cork regularly, conferring to this species a significant economic value. In a previous paper we reported the establishment of a field trial to compare the growth of plants of somatic origin vs zygotic origin, and somatic plants from mature trees vs somatic plants from juvenile seedlings. For that purpose somatic seedlings were regenerated from five selected cork oak trees and from young plants of their half-sib progenies by somatic embryogenesis. They were planted in the field together with acorn-derived plants of the same families. After the first growth period, seedlings of zygotic origin doubled the height of somatic seedlings, showing somatic plants of adult and juvenile origin similar growth. Here we provide data on height and diameter increases after two additional growth periods. In the second one, growth parameters of zygotic seedlings were also significantly higher than those of somatic ones, but there were not significant differences in height increase between seedlings and somatic plants of mature origin. In the third growth period, height and diameter increases of somatic seedlings cloned from the selected trees did not differ from those of zygotic seedlings, which were still higher than data from plants obtained from somatic embryos from the sexual progeny. Therefore, somatic seedlings from mature origin seem not to be influenced by a possible ageing effect, and plants from somatic embryos tend to minimize the initial advantage of plants from acorn
Somatic embryogenesis as a regeneration method for clonal propagation of Mediterranean forest species
La mejora y conservación de recursos genéticos en especies forestales lleva siglos de retraso con respecto a las especies agrÃcolas. Los recursos forestales se han considerado tradicionalmente como recursos �mineros�, en los que primaba la mera extracción dejando exclusivamente a la regeneración natural la labor de sostenibilidad en los montes y dehesas o montados. Hoy en dÃa, el necesario desarrollo del medio rural obliga a la explotación racional de los recursos como medio de garantizar su sostenibilidad. Por ello se está empezando a extender el criterio de que las especies forestales se pueden y deben �cultivar� en determinados espacios.
Las caracterÃsticas biológicas de las especies forestales las hacen, a menudo, recalcitrantes a las técnicas de mejora y conservación de recursos genéticos tradicionalmente aplicadas a especies agrÃcolas. En particular, la propagación vegetativa se ha utilizado ampliamente en muchos cultivos leñosos como una herramienta muy poderosa para capturar todo el potencial genético de combinaciones genéticas valiosas. En especies forestales, en particular en las mediterráneas, esta posibilidad raramente se ha podido aplicar debido a la baja capacidad morfogénica de estas especies y la fuerte influencia de la maduración o cambio de fase.
En los últimos años la biotecnologÃa forestal ha tenido un desarrollo espectacular. En particular las técnicas de regeneración clonal de plantas basadas en técnicas de cultivo in vitro, fundamentalmente vÃa embriogénesis somática, se están ya aplicando por muchas empresas privadas e instituciones públicas a nivel semi-operativo con diversas especies, para la conservación de material selecto y el establecimiento de ensayos clonales.
Nuestros grupos de trabajo están desarrollando protocolos de regeneración por embriogénesis somática en distintas especies forestales. En esta comunicación se presenta el estado actual de los conocimientos en dos especies tÃpicamente mediterráneas, el alcornoque (Quercus suber L.) y el pino piñonero (Pinus pinea L.), destacando los principales cuellos de botella para su aplicación a gran escala
Differentiation of bee pollen samples according to the apiary of origin and harvesting period based on their amino acid content
Producción CientÃficaBee pollen is currently one of the most widely consumed dietary supplements due to its high nutritional value and its potentially beneficial effects on health. Unfortunately, in recent years an increase in the fraudulent marketing of this product has been detected, mainly in terms of adulteration with pollen from other sources. This has made it necessary to seek new tools to ensure its authentication. Therefore, this study investigates the use of free amino acids as markers of the geographical origin and harvesting period of bee pollen. To demonstrate their potential as biomarkers, 72 samples from four apiaries (Pistacho, TÃo Natalio, Monte and Fuentelahiguera), located in the same geographical area (Marchamalo, Guadalajara, Spain), were analyzed by liquid chromatography-fluorescence detection, with the data obtained undergoing canonical discriminant analysis. Variable amounts and numbers of free amino acids were found in the samples analyzed; proline predominated in all of them, in a concentration range of 298–569989 mg/kg. The differences observed in amino acid composition could be attributed to the flowering plants from which the bee pollen samples originated. In addition, it was possible to statistically assign over 75% of the samples to the corresponding apiary of origin, the best results being obtained for the Fuentelahiguera and TÃo Natalio apiaries (100%); this classification was even superior in the case of the harvesting periods, as more than 90% of the samples were correctly assigned, and in one period (June) a 100% rate was obtained.Ministerio de EconomÃa, Industria y Competitividad (projects RTA 2015-00013-C03-01 and RTA 2015-00013-C03-03
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