Biotechnological approaches to increase biomass production in trees

Nutrient use efficiency is one of the factors influencing growth and therefore of high importance for biomass production in trees. Poplar is a model tree widely used for molecular and functional studies and the characterization of transgenic poplars overexpressing structural and regulatory genes involved in glutamine biosynthesis has provided insights on how glutamine metabolism is involved in N economy and biomass production in woody plant models. Numerous studies have shown the relevance of GS isoenzymes in plant development, biomass production, and yield (Cánovas et al. 2006; Castro-Rodríguez et al. 2015). In this communication two examples of functional analysis of plant genes in poplar, and their potential interest for biotechnological approaches are presented (Pascual et al. 2018; Rueda-López et al. 2017). Overexpression of cytosolic NADP+-isocitrate dehydrogenase (ICDH), one of the major enzymes involved in the production of 2-oxoglutarate for amino acid biosynthesis in plants, yields poplar trees with increased growth and enhanced vascular development in young leaves and apical stems. These plants also show an increased expression of genes associated with vascular differentiation and altered amino acids and organic acids content (Pascual et al. 2018). In other study, we observed that overexpression of Dof5, a transcriptional regulator of lignin production and the carbon-nitrogen balance, produced poplar trees with increased growth and biomass production when N availability in the soil is sufficient (Rueda-López et al. 2017). Taken together, these results suggest a close relationship between carbon and nitrogen metabolism and highlights the relevance of glutamine and glutamate biosynthesis in the control of growth and development. Research supported by Spanish Ministry of Economy and Competitiveness and Junta de Andalucía (Grants BIO2015-69285-R, BIO2012-0474 and research group BIO-114).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Los factores de transcripción Dof en pino y la regulación de la expresión génica

El control transcripcional es el mecanismo más importante por el cual se regulan los niveles, momentos y órganos en los que se expresa un gen. Este control es llevado a cabo por la interacción de factores de transcripción con sus elementos cis específicos localizados en el promotor de los genes diana. De esta forma, un factor de transcripción dado puede desempeñar diversos papeles regulando la expresión de distintos genes en respuesta a los estímulos que la planta percibe o a los propios procesos fisiológicos de ésta. En gimnospermas, concretamente en coníferas, se ha visto que el número de genes que codifican para factores de transcripción es menor que los descritos en angiospermas. Esto sugiere que las divergencias y especializaciones existentes en las familias de factores de transcripción de angiospermas no se han producido en las coníferas. Uno de estos casos es la familia Dof, en la cual se han identificado solo 10 miembros tanto en Pinus pinaster como P. taeda. Cada uno de ellos posee un patrón de expresión único y diferencial a la largo del desarrollo y tejidos de la planta. En un estudio más detallado de uno de estos factores: Dof5, se ha visto que es capaz de regular diferencialmente la expresión de las isoformas de glutamina sintetasa de pino, enzima clave para la asimilación de nitrógeno. Induce la transcripción de GS1b e inhibe la de GS1a. En un intento por determinar cuál podría ser su papel dentro de la planta, se han generado plantas transgénicas de Arabidopsis sobreexpresando este factor de transcripción. Mediante estudios de análisis de metabolitos, actividades enzimáticas y microarray hemos visto que está implicado en la regulación de genes tanto de procesos del metabolismo del carbono como del nitrógeno

Novel Insights into Regulation of Asparagine Synthetase in Conifers

Asparagine, a key amino acid for nitrogen storage and transport in plants, is synthesized via the ATP-dependent reaction catalyzed by the enzyme asparagine synthetase (AS; EC 6.3.5.4). In this work, we present the molecular analysis of two full-length cDNAs that encode asparagine synthetase in maritime pine (Pinus pinaster Ait.), PpAS1, and PpAS2. Phylogenetic analyses of the deduced amino acid sequences revealed that both genes are class II AS, suggesting an ancient origin of these genes in plants. A comparative study of PpAS1 and PpAS2 gene expression profiles showed that PpAS1 gene is highly regulated by developmental and environmental factors, while PpAS2 is expressed constitutively. To determine the molecular mechanisms underpinning the differential expression of PpAS1, the promoter region of the gene was isolated and putative binding sites for MYB transcription factors were identified. Gel mobility shift assays showed that a MYB protein from Pinus taeda (PtMYB1) was able to interact with the promoter region of PpAS1. Furthermore, transient expression analyses in pine cells revealed a negative effect of PtMYB1 on PpAS1 expression. The potential role of MYB factors in the transcriptional regulation of PpAS1 in vascular cells is discussed

Opinion of the Spectators of a Grand Tour in Spain: A Qualitative Analysis

The objective of this study is to carry out a qualitative analysis of the ratings of tourists and residents attending the road cycling sporting event "La Vuelta" held in Spain in 2019, 2020 and 2021 editions. Methods: The sample consisted of 1,203 comments/observations from tourists and residents in the in situ and post-event phase of each edition. For this qualitative analysis, an open question was used at the end of a quantitative questionnaire on social and tourism impact. Once each comment had been categorised, a summary was made of the responses and frequencies of each idea according to each category, positive and negative comments and the words most used in each type of comment. Nvivo v.10 software (QSR International, Burlington, MA 01803, USA) was used to analyse the comments and frequencies of each idea. Results: Most of the positive comments focus on the positive feelings and emotions generated by attending the event (emotion or enjoyment; 12.4%), great experience (14.8%), atmosphere of the event (10.4%), good organisation of the event (12.1%) and future intentions to return and recommend the event (7.4%). Negative comments mainly refer to the COVID-19 pandemic (11.8%), the advertising caravan (7.4%) and traffic and parking problems (5.9% of comments). Among the words associated with negative comments, the word "advertising caravan" stands out, while the most used words in positive reviews were "experience" and "emotion". Conclusion: Most of the positive comments focus on positive feelings and emotions generated by attending the event (emotion or enjoyment) and the great experience and atmosphere surrounding the sporting event. In the 2020 edition, the COVID-19 pandemic negatively affected the event, although parking problems and traffic congestion are the worst-rated categories

Moluscos de hábitats bentónicos del volcán de fango Gazul (Golfo de Cádiz)

Molluscs from the Gazul mud volcano and its adjacent areas in the northern Gulf of Cádiz were studied using differ­ent sampling methods. This mud volcano has vulnerable deep-sea habitats and a potential high biodiversity. A total of 232 species were identified from the taxocoenosis and thanatocoenosis, of which 86 are new records for the Spanish margin of the Gulf of Cádiz, three of them are new records for Spanish waters and two species are new to science. The high species richness observed could be related to the combination of different sampling methods, the study of the thanatocoenosis, the high habitat heterogeneity and the geographical location of the Gazul mud volcano between different biogeographical regions. The best-represented species were Bathyarca philippiana, Asperarca nodulosa, Leptochiton sp., Astarte sulcata and Limopsis angusta. The thanatocoenosis harboured, with low frequency, species that are typical of northern latitudes, species indicating past seepage, species from the shelf and species restricted to particular hosts. The taxocoenosis found in different areas of Gazul (the mud volcano edifice, erosive de­pression and adjacent bottoms) generally displayed significant differences in multivariate analyses. Furthermore, the environmental parameters related to environmental complexity and food availability displayed the highest linkage with the molluscan fauna.Se estudiaron los moluscos del volcán de fango Gazul y sus zonas adyacentes, en el norte del Golfo de Cádiz, utili­zando diferentes métodos de muestreo. Este volcán de fango destaca por la presencia de hábitats vulnerables de aguas profundas y una alta biodiversidad potencial. Se identificaron un total de 232 especies de la taxocenosis y la tanatocenosis, de las cuales 86 son nuevas citas para el margen español del Golfo de Cádiz, tres de ellas son nuevas citas para aguas españolas y dos especies son nuevas para la ciencia. La alta riqueza de especies detectada podría estar relacionada con la combinación de diferentes mé­todos de muestreo, el estudio de la tanatocenosis, la alta heterogeneidad del hábitat y la ubicación geográfica del volcán de fango Gazul entre diferentes regiones biogeográficas. Las especies mejor representadas fueron Bathyarca philippiana, Asperarca nodulosa, Leptochiton sp., Astarte sulcata y Limopsis angusta. La tanatocenosis contenía, con baja frecuencia, especies típicas de latitudes superiores, especies indicadoras de emisiones pasadas, especies de la plataforma y especies restringidas a huéspedes particulares. La taxocenosis encontrada en las diferentes zonas de Gazul (edificio del volcán de fango, depresión erosiva y fon­dos adyacentes) generalmente mostró diferencias significativas en los análisis multivariantes. Además, los parámetros ambien­tales más vinculados con la malacofauna fueron los relacionados con la complejidad ambiental y la disponibilidad de alimento

A Rat Immobilization Model Based on Cage Volume Reduction: A Physiological Model for Bed Rest?

Bed rest has been an established treatment in the past prescribed for critically illness or convalescing patients, in order to preserve their body metabolic resource, to prevent serious complications and to support their rapid path to recovery. However, it has been reported that prolonged bed rest can have detrimental consequences that may delay or prevent the recovery from clinical illness. In order to study disuse-induced changes in muscle and bone, as observed during prolonged bed rest in humans, an innovative new model of muscle disuse for rodents is presented. Basically, the animals are confined to a reduced space designed to restrict their locomotion movements and allow them to drink and eat easily, without generating physical stress. The animals were immobilized for either 7, 14, or 28 days. The immobilization procedure induced a significant decrease of food intake, both at 14 and 28 days of immobilization. The reduced food intake was not a consequence of a stress condition induced by the model since plasma corticosterone levels –an indicator of a stress response– were not altered following the immobilization period. The animals showed a significant decrease in soleus muscle mass, grip force and cross-sectional area (a measure of fiber size), together with a decrease in bone mineral density. The present model may potentially serve to investigate the effects of bed-rest in pathological states characterized by a catabolic condition, such as diabetes or cancer

Estrategias metodológicas enfocadas a la mejora del aprendizaje en estudiantes con diversidad

Diseño y desarrollo de estrategias metodológicas que faciliten el aprendizaje de los estudiantes en general y que permitan a los estudiantes con diversidad funcional la integración y participación en el proceso de aprendizaje, que refuercen su inclusión y que favorezcan la adquisición de competencias

Comunidades de coralígeno ligadas a procesos diapíricos de la plataforma española del golfo de Cádiz

The Gulf of Cádiz (GoC) represents an important area of seepage activity and of biological diversity due to the tectonic activity and subsoil fluid mobility, as well as the confluence of Atlantic and Mediterranean water masses and organisms from both basins. Some circalittoral and bathyal areas of the GoC remain still unexplored and they could harbour interesting communities and species that may deserve protection. In summer 2013, a geological expedition carried out between San Fernando and Conil de la Frontera, at water depths between 40 and 55 m and 10 M from Cádiz detected complex coralligenous communities that may be linked to diapiric processes. These communities represent a well preserved 1170 habitat type (Reefs) of the Habitat Directive and also contain ca. 20 spp. of invertebrates that are included in European, National and Local (Andalusian) threatened species lists. The area should be included in the Natura 2000 network as it represents one of the few circalittoral coralligenous communities from Spanish waters of the GoC.Versión del edito

A rat immobilization model based on cage volume reduction: a physiological model for bed rest?

Bed rest has been an established treatment in the past prescribed for critically illness or convalescing patients, in order to preserve their body metabolic resource, to prevent serious complications and to support their rapid path to recovery. However, it has been reported that prolonged bed rest can have detrimental consequences that may delay or prevent the recovery from clinical illness. In order to study disuse-induced changes in muscle and bone, as observed during prolonged bed rest in humans, an innovative new model of muscle disuse for rodents is presented. Basically, the animals are confined to a reduced space designed to restrict their locomotion movements and allow them to drink and eat easily, without generating physical stress. The animals were immobilized for either 7, 14, or 28 days. The immobilization procedure induced a significant decrease of food intake, both at 14 and 28 days of immobilization. The reduced food intake was not a consequence of a stress condition induced by the model since plasma corticosterone levels-an indicator of a stress response- were not altered following the immobilization period. The animals showed a significant decrease in soleus muscle mass, grip force and cross-sectional area (a measure of fiber size), together with a decrease in bone mineral density. The present model may potentially serve to investigate the effects of bed-rest in pathological states characterized by a catabolic condition, such as diabetes or cancer