Significado ecológico de la acumulación de flavonoides en tejidos reproductivos y vegetativos en Silene littorea (Caryophyllaceae)

Programa de Doctorado en Medio Ambiente y SociedadLínea de Investigación: Biodiversidad y Biología de la ConservaciónClave Programa: DAMCódigo Línea: 83Anthocyanins are one of the main pigments conferring color to flowers. These compounds may be also accumulated in vegetative tissues, where perform multiple protective roles against different biotic and abiotic stressors. In the same metabolic route of anthocyanins, other non-anthocyanin flavonoids that confer protection against a wide diversity of environmental stresses are also synthesized. Thus, the study of anthocyanins and other flavonoids is key to understand the importance of these metabolites in the adaptation process of plants to their environments. In this thesis, we investigate the adaptive role of flavonoids analyzing the ecological and evolutionary significance of flavonoid accumulation in reproductive and vegetative tissues of plants, using Silene littorea (Caryophyllaceae) as a model organism. This species is endemic of the Iberian Peninsula, growing at the sea level on coastal ecosystems. The flowers of S. littorea are pink due to the accumulation of anthocyanins. The presence of anthocyanins in calyces, leaves and stems confers a coloration that vary from green to red depending on the concentration of pigments accumulated. In addition, non-anthocyanin flavonoids are also produced in all plant organs. The ability of S. littorea to synthesize anthocyanins and non-anthocyanin flavonoids in the whole plant allow us to study how these compounds are accumulated in different plant tissues, the possible relationships among tissues in flavonoid production and the degree of phenotypic plasticity of this response. We also studied the physiological, biochemical and genetic changes that UV light exposure induces in this species. In addition, S. littorea also displays white plants with localized absence of anthocyanins in petals or a complete absence of these pigments in the whole plant. This feature of the species offers an excellent opportunity to investigate the relevance of these secondary metabolites in plant development and survival. Finally, we develop a fast, efficient and non-invasive method for estimating anthocyanin concentrations in plants by using digital images. In S. littorea, each plant organ exhibited considerable variability in the content of anthocyanins and other flavonoids both within and among populations. At the plant level, the flavonoid content in petals, calyxes, and leaves was not correlated in most of the populations. However, at the population level, the mean amount of anthocyanins in all organs was positively correlated, which suggests that the variable environmental conditions of populations may play a role in anthocyanin accumulation. In populations on the west coast of the Iberian Peninsula, a general pattern of increasing accumulation of flavonoids toward southern latitudes was observed in photosynthetic tissues. This pattern corresponds to a gradual increase of UV-B radiation and temperature, and a decrease of rainfall toward the south. The study of plasticity in flavonoid production revealed that the synthesis of both anthocyanins and flavones is mostly plastic in photosynthetic tissues, being mainly influenced by environmental effects. In addition, flavones exhibited approximately half the degree of phenotypic plasticity compared to anthocyanins. On the other hand, petals showed limited plasticity in flavonoid production. These results suggest that anthocyanins are usually constitutive in petals, yet susceptible to environmental conditions in photosynthetic tissues. We found that UV light stimulated the production of both anthocyanins and flavones, especially these latter in photosynthetic tissues. The synthesis of effective antioxidant flavones in photosynthetic tissues suggest that these compounds may have a key role as antioxidants and a minor role as light filters. In addition, UV light also induced a modest activation of specific transcription factors, decreased the photochemical efficiency of photosystem II and had a negative influence on plant fitness. The study of polymorphism in the flavonoid production showed that loss of anthocyanins, either in petals or in the whole plant, does not influence the ability of this species to synthesize flavones. Flavones have important protective functions for plants, similar to those of anthocyanins. We suggested that lack of anthocyanins may involve deleterious pleiotropic effects for plant survival not associated to their protective functions, which would explain the scarcity of non-pigmented plants in natural populations. Finally, we showed that our method based on digital images can be applied for accurately estimate anthocyanin concentration in photosynthetic and non-photosynthetic tissues. The most accurate estimations were obtained from color indices that stated the ratio of the G channel over the R and/or B channels or that reflect variations in the G channel.Universidad Pablo de Olavide de Sevilla. Departamento de Biología Molecular e Ingeniería BioquímicaPostprin

Genome skimming and microsatellite analysis reveal contrasting patterns of genetic diversity in a rare sandhill endemic (Erysimum teretifolium, Brassicaceae)

Barriers between islands often inhibit gene flow creating patterns of isolation by distance. In island species, the majority of genetic diversity should be distributed among isolated populations. However, a self-incompatible mating system leads to higher genetic variation within populations and very little between-population subdivision. We examine these two contrasting predictions in Erysimum teretifolium, a rare self-incompatible plant endemic to island-like sandhill habitats in Santa Cruz County, California. We used genome skimming and nuclear microsatellites to assess the distribution of genetic diversity within and among eight of the 13 remaining populations. Phylogenetic analyses of the chloroplast genomes revealed a deep separation of three of the eight populations. The nuclear ribosomal DNA cistron showed no genetic subdivision. Nuclear microsatellites suggest 83% of genetic variation resides within populations. Despite this, 18 of 28 between-population comparisons exhibited significant population structure (mean FST = 0.153). No isolation by distance existed among all populations, however when one outlier population was removed from the analysis due to uncertain provenance, significant isolation by distance emerged (r2 = 0.5611, p = 0.005). Population census size did not correlate with allelic richness as predicted on islands. Bayesian population assignment detected six genetic groupings with substantial admixture. Unique genetic clusters were concentrated at the periphery of the species’ range. Since the overall distribution of nuclear genetic diversity reflects E. tereifolium’s self-incompatible mating system, the vast majority of genetic variation could be sampled within any individual population. Yet, the chloroplast genome results suggest a deep split and some of the nuclear microsatellite analyses indicate some island-like patterns of genetic diversity. Restoration efforts intending to maximize genetic variation should include representatives from both lineages of the chloroplast genome and, for maximum nuclear genetic diversity, should include representatives of the smaller, peripheral populations

Painting the green canvas: how pigments produce flower colours

Flowering plants are characterized by the production of striking flower colours and these colours are primarily caused by the accumulation of pigments in cells of the floral organs. The extraordinary array of colours displayed in flowers relies on four main pigment groups: chlorophylls, carotenoids, flavonoids and betalains. With thousands of different compounds, flavonoids are the most diverse and widespread pigment group. They include coloured anthocyanins, aurones and chalcones, as well as many flavonoid compounds such as flavones and flavonols that are invisible to humans, but visible to most pollinators since they absorb ultraviolet light (UV). Flowers may exhibit homogenous colours produced by only one type of pigment or extremely complex colour patterns caused by the accumulation of several types of pigments in the same or in different floral organs. Here, we review the ecological biochemistry of pigments affecting flower colour. We also present data of flower colour variation and provide future research directions guided by the physiological functions of floral pigments

Profiles of psychological well-being and coping strategies among university students

[Abstract] In the transactional model of stress, coping responses are the key to preventing the stress response. In this study,the possible role o fpsychological well-being as a personal determinant of coping strategies in th eacademic context wa sanalyzed. Specifically, the study has two objectives: (a) to identify different profiles of students according to their level of psychological well-being; and (b) to analyze the differences between these profiles in the use of three coping strategies (positive reappraisal, supportseeking, and planning). Age, gender, and degree were estimated as covariables. A total of 1,072 university students participated in the study. Latent profile analysis was applied to four indices of psychologica lwell-being: self-acceptance, environmental mastery, purpose in life, and personal growth. An optimal four-profile solution, reflecting significant incremental shifts from low to very high psychological well-being, was obtained. As predicted, the profile membership distinguished between participants in positive reappraisal, support-seeking, and planning. Importantly, the higher the profile of psychological well-being was, the higher the use of the three coping strategies. Gender differences in coping strategies were observed, but no interaction effects with psychological well-being were found. Age and degree were not relevant in explaining the use of coping strategies.These results suggest that psychological well-being stands as an important personal resource to favor adaptive coping strategies for academic stress

Reliability Improvement in III-V Concentrator Solar Cells by Means of Perimeter Protection

This paper presents the evolution in the strategy to assess the reliability of III-V solar cells and a new thermal ageing test carried out over GaAs single junction solar cells at three different temperatures (130, 150 and 170° C). The perimeter of the solar cells has been protected with silicone, which seems to be an effective way of enhancing the reliability of the solar cells. A preliminary analysis of the results indicates a mean time to failure (MTTF) one order of magnitude larger than the one obtained in a previous thermal test with the perimeter uncoated

Phenotypic plasticity in light-induced flavonoids varies among tissues in Silene littorea (Caryophyllaceae)

Plants respond to environmental stimuli in a diversity of ways including the production of secondary metabolites. Biosynthesis of plant phenolics, including flavonoids, is frequently activated in response to a variety of abiotic and biotic stressors (e.g. extreme temperatures, high radiation, pathogens, etc.). This induced reaction is typically assumed to be a plastic response, but the components attributable to plasticity vs genetic variance in these components are poorly understood. Here, we investigate the variation in flavonoid production (anthocyanins and flavones) in petals and in photosynthetic tissues (calyces, leaves and stems) of Silene littorea. We performed a common garden experiment with maternal families from three populations in which plants were exposed to different light treatments (sun exposure and shade). The concentrations of anthocyanins in photosynthetic tissues increased when plants were exposed to sun, except for leaves that showed very low quantities of anthocyanins in both light treatments; yet flavones are produced constitutively in both sun and shade treatments. The synthesis of both anthocyanins and flavones is mostly plastic, with 25 to 43% of total phenotypic variance explained by light environment. We found significant environmental effects in anthocyanin biosynthesis in calyces and stems, and in flavone production in all photosynthetic tissues. Petals showed considerably less plasticity in anthocyanin production in contrast with the accumulation of these compounds in calyces and stems. Flavones exhibited less than half of the degree of phenotypic plasticity compared to anthocyanins in calyces and stems. Overall, these results provide new insights into the degree of tissue-specific plasticity and flavonoid-specific response. Variable plasticity between flavonoids types in petals and photosynthetic tissues may allow this annual plant to differentially respond to changing light environments, while maintaining constitutive petal color in response to pollinators

Real-time reliability test for a CPV module based on a power degradation model

Models based on degradation are powerful and useful tools to evaluate the reliability of those devices in which failure happens because of degradation in the performance parameters. This paper presents a procedure for assessing the reliability of concentrator photovoltaic (CPV) modules operating outdoors in real-time conditions. With this model, the main reliability functions are predicted. This model has been applied to a real case with a module composed of GaAs single-junction solar cells and total internal reflection (TIR) optic

UV radiation increases flavonoid protection but decreases reproduction in \u3ci\u3eSilene littorea\u3c/i\u3e

Plants respond to changes in ultraviolet (UV) radiation both morphologically and physiologically. Among the variety of plant UV-responses, the synthesis of UV-absorbing flavonoids constitutes an effective non-enzymatic mechanism to mitigate photoinhibitory and photooxidative damage caused by UV stress, either reducing the penetration of incident UV radiation or acting as quenchers of reactive oxygen species (ROS). In this study, we designed a UV-exclusion experiment to investigate the effects of UV radiation in Silene littorea. We spectrophotometrically quantified concentrations of both anthocyanins and UV-absorbing phenolic compounds in petals, calyces, leaves and stems. Furthermore, we analyzed the UV effect on the photosynthetic activity in hours of maximum solar radiation and we tested the impact of UV radiation on male and female reproductive performance. We found that anthocyanin concentrations showed a significant decrease of about 20% with UV-exclusion in petals and stems, and a 30% decrease in calyces. The concentrations of UV-absorbing compounds under UV-exclusion decreased by approximately 25% in calyces and stems, and 12% in leaves. Photochemical efficiency of plants grown under UV decreased at maximum light stress, reaching an inhibition of 58% of photosynthetic activity, but their ability to recover after light-stress was not affected. In addition, exposure to UV radiation did not affect ovule production or seed set per flower, but decreased pollen production and total seed production per plant by 31% and 69%, respectively. Our results demonstrate that UV exposure produced opposing effects on the accumulation of plant phenolic compounds and reproduction. UV radiation increased the concentration of phenolic compounds, suggesting a photoprotective role of plant phenolics against UV light, yet overall reproduction was compromised

Achieving Full Psychological Functioning: The Dimension of Personal Growth

Sección monográfica: Tecnología digital, test y evaluación[Resumen] Los grandes avances médicos logrados en las últimas décadas han posibilitado un inusitado aumento de la esperanza de vida en buena parte de la población mundial, especialmente en los países desarrollados. Sin embargo, este notable incremento de la salud física de las personas contrasta con las elevadas cifras de enfermedades mentales que asolan en numerosas sociedades contemporáneas. En aras de prevenir y reducir la alta incidencia de problemas de salud mental, en los últimos años estamos asistiendo a un creciente interés por el estudio científico de los recursos psicológicos personales como garante de un funcionamiento psicológico pleno. En consonancia con este planteamiento, numerosos enfoques psicológicos enfatizan la importancia de promover el desarrollo de las capacidades y potencialidades individuales, en la medida en que esta dimensión de crecimiento personal se erige en uno de los factores más genuinos y representativos del bienestar psicológico. El presente trabajo pretende profundizar en la comprensión de este pilar esencial del bienestar humano. En primer lugar, se realiza un sucinto recorrido histórico del constructo crecimiento personal, desde su pionera concepción aristotélica hasta su operativización por parte de psicólogos relevantes como Maslow, Rogers, Jung o Frankl, entre otros. Estas aportaciones conforman la raíz por la que se nutre la psicología contemporánea a la hora de explicar y definir este tópico. En concreto, y apoyándonos en diferentes teorías, enfoques y corrientes psicológicas ampliamente aceptadas en la actualidad, analizamos en este artículo aquellos recursos más estrechamente asociados al crecimiento personal, entre los que se encuentran la autodeterminación, el estado de flujo, el mindfulness, la compasión y el capital psicológico[Abstract] The great medical advances achieved in the last decades have allowed an unusual increase in life expectancy in a large part of the world population, especially in developed countries. However, this remarkable improvement in the physical health of people contrasts with the high numbers of mental illnesses that plague in many contemporary societies. In order to prevent and reduce the high incidence of mental health problems, in recent years we are witnessing a growing interest in the scientific study of personal psychological resources as a guarantor of full psychological functioning. In line with this approach, numerous psychological proposals emphasize the importance of promoting the development of individual capacities and potentialities, to the extent that this dimension of personal growth stands as one of the most genuine and representative factors of psychological well-being. This paper aims to deepen the understanding of this core pillar of human well-being. Firstly, there is a brief historical journey of the personal growth construct, from its pioneering Aristotelian conception to its operationalization by relevant psychologists such as Maslow, Rogers, Jung or Frankl, among others. These contributions constitute the root for which contemporary psychology is nourished when explaining and defining this topic. In particular, and relying on different theories, approaches, and psychological currents widely accepted today, secondly, we analyze in this paper those resources most closely associated with personal growth, among which are self-determination, flow, mindfulness, compassion, and psychological capitalEste trabajo ha sido desarrollado con la financiación de los proyectos EDU2013-44062-P (MINECO), EDU2017-82984-P (MEIC), y Gobierno del Principado de Asturias, España. Fondo Europeo de Desarrollo Regional (Programa de Grupos de Investigación FC-GRUPIN-IDI/2018/000199)Gobierno del Principado de Asturias; FC-GRUPIN-IDI/2018/00019