Fisiología del cultivo in vitro

The culture procedures described up to the eighties, did not made any mention to the environmental control of in vitro plant development. However, growth rate, development and many of the physiologic-morphologic features of the in vitro grown plants are influenced by the culture vessel. The increasing knowledge about the environmental control of culture vessels under sterile conditions, is helping to change micorpropagation procedures. The in vitro environment with lower rate ventilation, brings about low flow rates of matter and energy, with minimum variations of temperature, high relative humidity and large daily changes of the concentration of CO2 inside the culture vessel. The type of culture vessel (size, shape, fabric and closing system) can influence the evolution of the atmosphere along the time of culture. Although submitted to different stresses factors plant can be grown in vitro, but plants can be faulty in their anatomy, morphology and physiology. As a consequence, these plants shown a phenotype unable to survive to ex vitro conditions. Different strategies can be used to control the atmosphere along the different phases of micropropagation, in heterotrophic, mixotrophic or autotrophic cultures. The election of the best strategy will be based on different factors as species, number of transplantes required, or quality-price relationship.enviromental control, tissue culture, micropropagationKeywords: in vitro enviromental, characteristic physiology,En los procedimientos de cultivo descritos hasta la década de los ochenta, no se hace ninguna referencia al control ambiental en el desarrollo de las plantas in vitro. Sin embargo, las tasas de crecimiento, desarrollo y muchas de las características fisiológicas y morfológicas de las plantas formadas in vitro están influenciadas por el ambiente físico, químico y gaseoso de los recipientes. El incremento de conocimientos acerca del control ambiental del cultivo de tejidos en condiciones estériles, está provocando una evolución de las distintas técnicas empleadas en la micropropagación de plantas. El ambiente in vitro en recipientes con baja tasa de ventilación presenta unas tasas bajas de flujo de materia y energía, con mínimas variaciones de temperatura, elevada humedad relativa y grandes cambios diarios de la concentración de CO2 en el interior de los recipientes. El tipo de recipiente de cultivo (tamaño, forma, material y sistema de cierre) puede condicionar la evolución de la composición gaseosa en su interior durante el período de cultivo. Ante los distintos factores de estrés que tienen que soportar durante las fases de la micropropagación las plantas producidas en recipientes con nulo o escaso intercambio gaseoso, pueden manifestar alteraciones o déficit en cuanto a su estructura anatómica, morfológica y fisiológica. Como consecuencia, estas plantas presentan un fenotipo incapaz de sobrevivir al transplante directo al invernadero o campo. Actualmente se pueden utilizar diferentes métodos para controlar el ambiente en las distintas fases de la micropropagación, ya sean cultivos heterótrofos, mixótrofos o autótrofos. La elección de la mejor estrategia va a depender de varios factores, destacando la especie, el número de transplantes requerido y la relación calidad precio entre otros.Palabras clave: ambiente in vitro, características fisiológicas, control ambiental, cultivo de tejidos, micropropagació

Factors involved in Pinus radiata D. Don. micrografting

A series of micrografting conditions using needle fascicles from trees of different ages as scions have been evaluated for Pinus radiata D. Don. to increase success of in vitro propagation. Micrografting success depended on the quality of the graft process as well as age, location and development stage of the scion and tree age. 11-month-old scions, taken in January from terminal portions of basal branches show the best micrografting-induced response. Responsiveness of scions decreases with the donor tree age, although this could be overcome by optimising micrografting conditions.Facteurs impliqués dans le micro-greffage de Pinus radiata D. Don. Différentes conditions de micro-greffage, utilisant comme greffons des brachyblastes provenant d'arbres d'âges différents, ont été comparées afin d'évaluer les possibilités d'améliorer la propagation in vitro de Pinus radiata. Le succès du micro-greffage dépend tout autant de la qualité du processus de greffage que de l'âge, de la localisation et du stade de développement du greffon, ou que de l'âge de l'arbre. Des greffons de 11 mois prélevés en janvier sur la portion terminale de branches de la base de l'arbre donnent les meilleures réponses au micro-greffage. Cette réponse diminue avec l'âge de l'arbre sur lequel ils sont prélevés, bien que ceci puisse en partie être surmonté en optimisant les conditions du micro-greffage

In vitro culture physiology

The culture procedures described up to the eighties, did not made any mention to the environmental control of in vitro plant development. However, growth rate, development and many of the physiologic-morphologic features of the in vitro grown plants are influenced by the culture vessel. The increasing knowledge about the environmental control of culture vessels under sterile conditions, is helping to change micorpropagation procedures. The in vitro environment with lower rate ventilation, brings about low flow rates of matter and energy, with minimum variations of temperature, high relative humidity and large daily changes of the concentration of CO 2 inside the culture vessel. The type of culture vessel (size, shape, fabric and closing system) can influence the evolution of the atmosphere along the time of culture. Although submitted to different stresses factors plant can be grown in vitro, but plants can be faulty in their anatomy, morphology and physiology. As a consequence, these plants shown a phenotype unable to survive to ex vitro conditions. Different strategies can be used to control the atmosphere along the different phases of micropropagation, in heterotrophic, mixotrophic or autotrophic cultures. The election of the best strategy will be based on different factors as species, number of transplantes required, or quality-price relationship

Analysis of the expression of putative heat-stress related genes in relation to thermotolerance of cork oak

Cork oak (Quercus suber L.) is a research priority in the Mediterranean area and because of cork oaks' distribution these stands are experiencing daily stress. Based on projections of intensifying climate change and considering the key role of exploring the recovery abilities, cork oak seedlings were subjected to a cumulative temperature increase from 25°C to 55°C and subsequent recovery. CO2 assimilation rate, chlorophyll fluorescence, anthocyanins, proline and lipid peroxidation were used to evaluate plant performance, while the relative abundance of seven genes encoding for proteins of cork oak with a putative role in thermal/stress regulation (POX1, POX2, HSP10.4, HSP17a.22, CHS, MTL and RBC) was analyzed by qPCR (quantitative Polymerase Chain Reaction). A temperature change to 35°C showed abundance alterations in the tested genes; at 45°C, the molecular changes were associated with an antioxidant response, possibly modulated by anthocyanins. At 55°C, HSP17a.22, MTL and proline accumulation were evident. After recovery, physiological balance was restored, whereas POX1, HSP10.4 and MTL abundances were suggested to be involved in increased thermotolerance. The data presented here are expected to pinpoint some pathways changes occurring during such stress and further recovery in this particular Mediterranean species

Natural variation of DNA methylation and gene expression may determine local adaptations of Scots pine populations

Abstract Long-lived conifers are vulnerable to climate change because classical evolutionary processes are slow in developing adaptive responses. Therefore, the capacity of a genotype to adopt different phenotypes is important. Gene expression is the primary mechanism that converts genome-encoded information into phenotypes, and DNA methylation is employed in the epigenetic regulation of gene expression. We investigated variations in global DNA methylation and gene expression between three Scots pine (Pinus sylvestris L.) populations located in northern and southern Finland using mature seeds. Gene expression levels were studied in six DNA methyltransferase (DNMT) genes, which were characterized in this study, and in 19 circadian clock genes regulating adaptive traits. In embryos, expression diversity was found for three DNMT genes, which maintain DNA methylation. The expression of two DNMT genes was strongly correlated with climate variables, which suggests a role for DNA methylation in local adaptation. For adaptation-related genes, expression levels showed between-population variation in 11 genes in megagametophytes and in eight genes in embryos, and many of these genes were linked to climate factors. Altogether, our results suggest that differential DNA methylation and gene expression contribute to local adaptation in Scots pine populations and may enhance the fitness of trees under rapidly changing climatic conditions

El siglo de Oro en escena

Del teatro de Sánchez de Badajoz (siglo xvi) al de Bances Candamo (finales del xvii), de las múltiples riquezas de la comedia lopesca a las excelencias del teatro calderoniano, de la prosa cervantina a la de un Mateo Alemán, del Pinciano al maestro Correas, y «trecientas cosas más»: los artículos reunidos en este libro componen un extenso panorama de los más recientes resultados de la investigación internacional sobre toda la literatura española del Siglo de Oro, ofrecidos al profesor Marc Vitse por sus más destacados discípulos, amigos y admiradores.À Marc,Odett

Pictavia Aurea

Este volumen, titulado Pictavia aurea, reúne 131 estudios que constituyen una granada muestra de los debates y las presentaciones en torno a la cultura hispánica del Siglo de Oro que entre los días 11 y 15 de julio de 2011 se dieron en la ciudad de Poitiers (Francia) en el marco del IX congreso de la Asociación Internacional “Siglo de Oro”. Auspiciada por la Universidad de Poitiers, a través del Centro de Estudios de la Literatura española de Entre Siglos (siglos xvii-xviii) (CELES XVII-XVIII) y el laboratorio «Formes et Représentations en Linguistique et Littérature» (FoReLL), la convocatoria reunió en la ciudad francesa a 276 participantes y a un centenar de asistentes en la novena edición del Congreso de la Asociación, que celebró entonces la efeméride del 450o aniversario del nacimiento de Luis de Góngora.A Isaías Lerner, maestro de la filología hispánic