Micorrizas arbusculares: indicadores clave de la eficacia de las fitotecnologías de remediación a largo plazo

A nivel global, la contaminación de los suelos es uno de los mayores problemas ambientales. La degradación del suelo lleva aparejada la alteración de las comunidades vegetales y microbiológicas y, por tanto, de la funcionalidad del ecosistema. Entre las diversas técnicas de recuperación existentes, la fitorremediación surge como la opción más respetuosa con el medio ambiente a la vez que económica. Sin embargo, ¿son estas técnicas realmente eficaces? Y, si lo son, ¿durante cuánto tiempo? Para responder a estas cuestiones pueden utilizarse bioindicadores debido a su sensibilidad a los cambios producidos por actividades humanas. Entre ellos, ¿las micorrizas arbusculares pueden ser una opción adecuada? En esta charla se abordará si estos microorganismos pueden proporcionarnos suficiente información del estado de recuperación de un suelo contaminado y si el análisis de estas comunidades podría emplearse como indicador de la eficacia de la fitorrecuperación.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Departamento de Biología Vegetal, Vicerrectorado de Investigación y Transferencia, Universidad de Málag

Effect of heavy metals and organic matter on root exudates (low molecular weight organic acids) of herbaceous species: An assessment in sand and soil conditions under different levels of contamination

9 páginas.-- 7 figuras.-- 1 tablas.-- 37 referencias.-- Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.envpol.2016.05.080.Bioavailability of heavy metals can be modified by different root exudates. Among them, low molecular weight organic acids (LMWOAs) play an important role in this process. Three plant species (Poa annua, Medicago polymorpha and Malva sylvestris), potentially used for phytoremediation, have been assessed for both metal uptake and LMWOAs excretion in contaminated environments with different concentrations of Cd, Cu and Zn. The experiments have been carried out in washed sand and in three contaminated soils where two organic amendments were added (biosolid compost and alperujo compost). The most abundant LMWOAs excreted by all studied plants were oxalic and malic acids, although citric and fumaric acids were also detected. The general tendency was that plants responded to an increase of heavy metal stress releasing higher amounts of LMWOAs. This is an efficient exclusion mechanism reducing the metal uptake and allowing the plant growth at high levels of contamination. In the experiment using wash sand as substrate, the organic acids composition and quantity depended mainly on plant species and metal contamination. M. polymorpha was the species that released the highest concentrations of LMWOAs, both in sand and in soils with no amendment addition, whereas a decrease of these acids was observed with the addition of amendments. Our results established a clear effect of organic matter on the composition and total amount of LMWOAs released. The increase of organic matter and nutrients, through amendments, improved the soil quality reducing phytotoxicity. As a result, organic acids exudates decreased and were solely composed of oxalic acid (except for M. polymorpha). The release of LMWOAs has proved to be an important mechanism against heavy metal stress, unique to each species and modifiable by means of organic amendment addition.This study was made possible by AGL2011-23617 project supported by the CICYT of the Ministerio de Ciencia e Innovación of Spain and FEDER (EU). MMar Montiel- Rozas acknowledges support from the MINECO, (FPI grant, BES-2012-05339). P. Madejon and E. Madejon are members of the “Unidad Asociada al CSIC de Uso sostenible del suelo y el agua en la agricultura (US-IRNAS)”.Peer reviewe

¿Se puede hablar de un arte queer español?

Until the 1990s, the Spanish artistic and theoretical gender-related production was almost nonexistent. However, it is from that decade on when feminism begins to develop and spread within the borders of the country, and it is also at this time when the Queer theory takes its rsts steps. These studies have developed in such a fast way in just over 20 years, that, already in 2000, we can nd some theorists and artists who are recognized in the international context. This paper re ects on one of the consequences resulting of the celerity of this process and thus whether or not it makes sense to talk about a Spanish Queer Art.  Hasta la llegada de la década de los noventa la producción artística y teórica en España relativa a las cuestiones de género era prácticamente inexistente. No obstante, a partir de dicha década el feminismo comienza a desarrollarse y difundirse dentro de las fronteras nacionales a la par que la teoría queer da sus primeros pasos. En poco más de veinte años estos estudios han avanzado de un modo vertiginoso consiguiendo erigir, ya en el 2000, a algunos teóricos y artistas que son reconocidos a nivel internacional. En este artículo se re exiona sobre una de las consecuencias derivadas de la rapidez con que se ha producido el proceso: si tiene sentido hablar de un arte queer español. 

Efectos de la rizosfera y de las enmiendas orgánicas en la fitorecuperación de suelos contaminados con elementos traza

Actualmente, la degradación de los suelos es uno de los problemas ambientales de mayor importancia a nivel global. Desde un punto de vista antropogénico, los suelos además de actuar como soporte físico proveen de servicios ecosistémicos, entre los que destaca la producción de alimentos. Los cambios en sus condiciones físicas, químicas y biológicas, resultado de la actividad humana, provocan su degradación y, consecuentemente, la degradación de los organismos asociados como las comunidades vegetales y microbiológicas. Esta degradación conlleva una alteración de la funcionalidad del ecosistema repercutiendo finalmente, directa o indirectamente, sobre la salud humana. Por todo ello el mantenimiento y la recuperación de la calidad del suelo es fundamental. Los trabajos que componen la presente Tesis doctoral se centran en el estudio de diversos factores relevantes en la recuperación de suelos contaminados por elementos traza. Este tipo de suelos se consideran un importante problema ambiental debido a los altos niveles de elementos traza que presentan y que por tanto pueden entrar en la cadena trófica. De entre las distintas técnicas para la recuperación de suelos contaminados destaca, desde el punto de vista medioambiental, la fitorecuperación, que engloba varias técnicas sostenibles. Entre ellas, la fitoestabilización implica la estabilización de los contaminantes a nivel radicular mediante el uso de plantas y de enmiendas. En esta Tesis se evalúa el efecto de 3 enmiendas orgánicas (compost de biosólidos, compost de alperujo y leonardita) y de distintas especies vegetales potencialmente fitoestabilizadoras sobre la dinámica de los elementos traza en la interfase suelo-planta, centrándose en algunos de los procesos que se producen a nivel de rizosfera. Para ello se han llevado a cabo experimentos tanto a nivel de microcosmos como a nivel de campo. Los suelos de estudio se sitúan en el Corredor Verde del Guadiamar (Sevilla), afectado por el vertido de residuos mineros procedente de la rotura de la balsa de decantación de Aznalcóllar, y en una zona con contaminación crónica por elementos traza cercana a la explotación minera de Tharsis (Huelva). En primer lugar, se evaluó la capacidad de tres especies vegetales ruderales (Poa annua, Medicago polymorpha y Malva sylvestris) para estabilizar elementos traza en el suelo minero de Tharsis y mejorar su calidad. Asimismo, se estudió el efecto de los compost añadidos al suelo. La adición de compost incrementó el pH, el carbono hidrosoluble y la producción de biomasa vegetal. En general, la acumulación de elementos traza en las tres especies vegetales estudiadas estuvo dentro de los intervalos normales en plantas. Las mayores concentraciones de As y Pb se encontraron en P. annua mientras que M. sylvestris fue la que acumuló mayor concentración de Mn y Zn. Salvo alguna excepción, el factor de bioconcentración fue menor que 1 (indicando la idoneidad de estas especies para la fitoestabilización). Entre las especies estudiadas, M. polymorpha fue la que reunió las características más adecuadas para promover la estabilización de elementos traza en la rizosfera y mejorar la calidad del suelo. En segundo lugar, se estudió la exudación de ácidos orgánicos de bajo peso molecular de las tres especies analizadas anteriormente bajo diferentes niveles de Cd, Cu y Zn. Tanto la cantidad como la composición de los exudados variaron según el medio de crecimiento (arena lavada / suelos contaminados), el nivel de contaminación, el contenido en materia orgánica y la especie vegetal. Los ácidos más abundantes fueron el ácido oxálico y el málico, seguidos del cítrico y el fumárico. En general, el aumento de concentración de metales pesados en el medio estuvo relacionado con una mayor concentración de ácidos orgánicos. En los suelos con mayor contenido de materia orgánica se observó una reducción de la cantidad de exudados y de la composición de los mismos, estando compuestos únicamente por ácido oxálico (exceptuando M. polymorpha). En tercer lugar, se identificaron los ecotipos de hongos micorrícicos arbusculares presentes en las tres especies vegetales bajo las mismas condiciones experimentales en los suelos en los que se midió la exudación de ácidos orgánicos. El diferente contenido de materia orgánica, fósforo y elementos traza de los suelos permitió evaluar el cambio en la comunidad fúngica acorde a las condiciones del suelo. La adición de ambas enmiendas (materia orgánica exógena) no afectó a la comunidad endomicorrícica. Sin embargo, el contenido en materia orgánica nativa del suelo fue, junto al contenido en elementos traza, el factor que influyó en mayor medida en la comunidad fúngica. El incremento de la calidad del suelo (es decir, un mayor contenido en materia orgánica y una menor concentración de Cd, Cu y Zn) se tradujo en la disminución de la abundancia de Glomeraceae y en un aumento de la abundancia de Claroideoglomeraceae en la comunidad. Paralelamente a los experimentos en microcosmos, se analizó la diversidad filogenética de las comunidades de hongos micorrícicos arbusculares presentes en suelos enmendados en la parcela “El Vicario” (situada en el Corredor Verde). El proceso de restauración en esta parcela comenzó en 2002 por lo que se evaluó el efecto a largo plazo del compost de biosólidos y de la leonardita sobre estos microorganismos bioindicadores. Además, se identificaron los ecotipos presentes y los cambios de la comunidad en función de las condiciones del suelo. Entre las variables del suelo, la concentración de elementos traza fue el factor que afectó en mayor medida a la composición de la comunidad fúngica. El filtro ambiental causado por este factor se redujo principalmente por la adición de compost de biosólidos, encontrándose en estas parcelas la comunidad más diversa. Finalmente, se evaluó si la aplicación de enmiendas orgánicas para la restauración de un suelo degradado (“El Vicario”) podía implicar, además de la mejora física-química del suelo, que éste actuara como un sumidero de C. Los resultados de este estudio mostraron que ambas enmiendas (compost de biosólidos y leonardita) modificaron la composición molecular de la materia orgánica del suelo promoviendo la retención de C. Entre ambas, la opción más adecuada para el secuestro de C a largo plazo en el suelo es la leonardita debido a su composición molecular rica en compuestos aromáticos y derivados de la lignina, relativamente estables.Nowadays, soil degradation is one of the most important global environmental problems. From an anthropogenic point of view, soils act as physical support and provide different ecosystem services (e.g. the food supply). Changes on soil physical, chemical and biological conditions due to human activity cause soil degradation and, consequently, damage the associated organisms such as plants and microbiological communities. Soil degradation alters ecosystem function and affects, directly or indirectly, human health; therefore, it is crucial to maintain and improve soil quality. The experiments carried out in this Thesis are focused on the analysis of several factors affecting the remediation of trace element contaminated soils. These soils constitute an important environmental problem due the possible entrance of trace elements into the food chain. From the environmental point of view, among the different techniques for the remediation of contaminated soils, highlights phytostabilization that is a sustainable technique that involves stabilization of contaminants at root level by using plants and amendments. This Thesis evaluates the effect of three organic amendments (biosolid compost, alperujo compost and leonardite) and different plant species with potential phytostabilizer ability on trace elements dynamics in the soil-plant interface, focusing on some of the rhizosphere processes. The results are based on field and microcosms experiments. The studied soils are located in the Green Corridor of Guadiamar (Sevilla), affected by the spill of the Aznalcóllar mine, and in Tharsis (Huelva), an area presenting chronic contamination by trace elements. Firstly, the ability of three ruderal plant species (Poa annua, Medicago polymorpha and Malva sylvestris) to stabilize trace elements in Tharsis soil and to improve its quality was evaluated. Likewise, the effect of alperujo and biosolid composts on soil properties was also studied. Amendment addition increased pH, water-soluble carbon and plant biomass. In general, trace element accumulation in the studied plants was within normal ranges. Higher As and Pb concentrations were found in P. annua whereas M. sylvestris accumulated the highest concentration of Mn and Zn. With some exception, bioconcentration factor was lower than 1 (indicating the suitability of these species for phytostabilisation). Among the studied plant species, M. polymorpha showed the best characteristics to promote the trace element stabilization in the rhizosphere and improve soil quality. Moreover, the exudation of low molecular weight organic acids by the mentioned plant species was analysed under different Cd, Cu and Zn concentrations. Both amount and composition of exudates varied according to the growing media (washed sand/ contaminated soils), contamination level, organic matter content and plant species. Oxalic and malic were the main acids in the exudates and, in a lesser concentration citric and fumaric acids were also identified. In general, the increase of heavy metal concentrations in the media was related to a higher organic acid concentration in the rhizosphere. A decrease of exudates and a modification of their composition (being composed solely of oxalic acid excepting M.polymorpha) were observed in soils with the highest organic matter content. In addition, with the same plant species and experimental soil conditions of the organic acids exudation experiment, the arbuscular mycorrhizal fungi ecotypes were identified. The different organic matter content, phosphorus and trace elements in the studied soils were keys to evaluate the shift in the fungal community according to the soil conditions. The addition of both amendments (exogenous organic matter) did not affect the arbuscular mycorrhizal fungal community. However, native soil organic matter content was, besides the trace element contents, the most influential factor on fungal community. With an increase in soil quality (i.e., higher organic matter content and lower Cd, Cu and Zn concentration), a decrease of Glomeraceae abundance and an increase of Claroideoglomeraceae occurred. While simultaneously carrying out the microcosm experiments, the phylogenetic diversity of arbuscular mycorrhizal fungal communities in amended soils of “El Vicario” plot (located in the Green Corridor) was analysed. The restoration process began in 2002 allowing the evaluation of the long-term effect of biosolid compost and leonardite on these communities. In addition, the ecotypes and community shifts were related to the soil conditions. Among soil variables, trace elements concentration was the most relevant factor affecting the composition of the fungal community. Environmental filtering caused by this factor was reduced mainly by the biosolid compost addition, and in the plots amended with this compost the most diverse community was found. Finally, the effect of organic amendment applications on the increment of C sink in the Vicario plot was studied. Results showed that both amendments (biosolid compost and leonardite) modified the molecular composition of soil organic matter promoting the C sequestration. Between both, leonardite was the most suitable option for long-term C sequestration in the soil due to its molecular composition rich in aromatics and lignin-derived compounds, with a very slow turnover and low mineralization rate

Addition of organic amendments contributes to C sequestration in trace element contaminated soils.

Nowadays, the study of global C cycle and the different natural sinks of C have become especially important in a climate change context. Fluxes of C have been modified by anthropogenic activities and, presently, the global objective is the decrease of net CO2 emission. For this purpose, many studies are being conducted at local level for evaluate different C sequestration strategies. These techniques must be, in addition to safe in the long term, environmentally friendly. Restoration of contaminated and degraded areas is considered as a strategy for SOC sequestration. Our study has been carried out in the Guadiamar Green Corridor (Seville, Spain) affected by the Aznalcóllar mining accident. This accident occurred 16 years ago, due to the failure of the tailing dam which contained 4-5 million m3 of toxic tailings (slurry and acid water). The affected soils had a layer of toxic sludge containing heavy metals as As, Cd, Cu, Pb and Zn. Restoration techniques began to be applied just after the accident, including the removal of the toxic sludge and a variable layer of topsoil (10-30 cm) from the surface. In a second phase, in a specific area (experimental area) of the Green Corridor the addition of organic amendments (Biosolid compost (BC) and Leonardite (LE), a low grade coal rich in humic acids) was carried out to increase pH, organic matter and fertility in a soil which lost its richest layer during the clean-up operation. In our experimental area, half of the plots (A) received amendments for four years (2002, 2003, 2006 and 2007) whereas the other half (B) received amendments only for two years (2002-2003). To compare, plots without amendments were also established. Net balance of C was carried out using values of Water Soluble Carbon (WSC) and Total Organic Carbon (TOC) for three years (2012, 2013 and 2015). To eliminate artificial changes carried out in the plots, amendment addition and withdrawal of biomass were taken into account to calculate balance of kg TOC ha ¯¹. Thus, results revealed the effect of amendments. Values of net balance show an increase in C sequestered in amended plots. The retention of carbon in soluble and total forms was reflected in the increase in time. According to the results, application of leonardite (a more stabilized amendment) seems to entail a greater retention of carbon in soil than in the case of biosolid compost. Restoration strategies have multiple benefits for the ecosystem. In our case, the use of organic amendments decreased trace element toxicity, improved soil structure and microbial communities, and contribute to retain C in terrestrial ecosystems.Peer Reviewe

Identification of serum microRNAs as potential biomarkers in Pompe disease

Altres ajuts: This study was supported by a grant from Sanofi-Genzyme (GZ-2015-11342) to Dr. Gallardo and has been registered in Clinicaltrials.gov (identifier NCT03045042).This study was supported by a grant from Sanofi-Genzyme (GZ-2015-11342) to Dr. Gallardo and has been registered in Clinicaltrials.gov (identifier NCT03045042).To analyze the microRNA profile in serum of patients with Adult Onset Pompe disease (AOPD). We analyzed the expression of 185 microRNAs in serum of 15 AOPD patients and five controls using microRNA PCR Panels. The expression levels of microRNAs that were deregulated were further studied in 35 AOPD patients and 10 controls using Real-Time PCR. Additionally, the skeletal muscle expression of microRNAs which showed significant increase levels in serum samples was also studied. Correlations between microRNA serum levels and muscle function test, spirometry, and quantitative muscle MRI were performed (these data correspond to the study NCT01914536 at ClinicalTrials.gov). We identified 14 microRNAs that showed different expression levels in serum samples of AOPD patients compared to controls. We validated these results in a larger cohort of patients and we found increased levels of three microRNAs, the so called dystromirs: miR-1-3p, miR-133a-3p, and miR-206. These microRNAs are involved in muscle regeneration and the expression of these was increased in patients' muscle biopsies. Significant correlations between microRNA levels and muscle function test were found. Serum expression levels of dystromirs may represent additional biomarkers for the follow-up of AOPD patients

Selection on cis-Regulatory Variation at B4galnt2 and Its Influence on von Willebrand Factor in House Mice

The RIIIS/J inbred mouse strain is a model for type 1 von Willebrand disease (VWD), a common human bleeding disorder. Low von Willebrand factor (VWF) levels in RIIIS/J are due to a regulatory mutation, Mvwf1, which directs a tissue-specific switch in expression of a glycosyltransferase, B4GALNT2, from intestine to blood vessel. We recently found that Mvwf1 lies on a founder allele common among laboratory mouse strains. To investigate the evolutionary forces operating at B4galnt2, we conducted a survey of DNA sequence polymorphism and microsatellite variation spanning the B4galnt2 gene region in natural Mus musculus domesticus populations. Two divergent haplotypes segregate in these natural populations, one of which corresponds to the RIIIS/J sequence. Different local populations display dramatic differences in the frequency of these haplotypes, and reduced microsatellite variability near B4galnt2 within the RIIIS/J haplotype is consistent with the recent action of natural selection. The level and pattern of DNA sequence polymorphism in the 5′ flanking region of the gene significantly deviates from the neutral expectation and suggests that variation in B4galnt2 expression may be under balancing selection and/or arose from a recently introgressed allele that subsequently increased in frequency due to natural selection. However, coalescent simulations indicate that the heterogeneity in divergence between haplotypes is greater than expected under an introgression model. Analysis of a population where the RIIIS/J haplotype is in high frequency reveals an association between this haplotype, the B4galnt2 tissue-specific switch, and a significant decrease in plasma VWF levels. Given these observations, we propose that low VWF levels may represent a fitness cost that is offset by a yet unknown benefit of the B4galnt2 tissue-specific switch. Similar mechanisms may account for the variability in VWF levels and high prevalence of VWD in other mammals, including humans

Platelet Derived Growth Factor-AA Correlates With Muscle Function Tests and Quantitative Muscle Magnetic Resonance in Dystrophinopathies

Introduction: Duchenne (DMD) and Becker (BMD) muscular dystrophy are X-linked muscular disorders produced by mutations in the DMD gene which encodes the protein dystrophin. Both diseases are characterized by progressive involvement of skeletal, cardiac, and respiratory muscles. As new treatment strategies become available, reliable biomarkers and outcome measures that can monitor disease progression are needed for clinical trials. Methods: We collected clinical and functional data and blood samples from 19 DMD patients, 13 BMD patients, and 66 healthy controls (8 pediatric and 58 adult controls), and blood samples from 15 patients with dysferlinopathy (DYSF) and studied the serum concentration of 4 growth factors involved in the process of muscle fibrosis. We correlated the serum concentration of these growth factors with several muscle function tests, spirometry results and fat fraction identified by quantitative Dixon muscle MRI. Results: We found significant differences in the serum concentration of Platelet Derived Growth Factor-AA (PDGF-AA) between DMD patients and pediatric controls, in Connective Tissue Growth Factor (CTGF) between BMD patients and adult controls, and in and Transforming Growth Factor- β1 (TGF-β1) between BMD and DYSF patients. PDGF-AA showed a good correlation with several muscle function tests for both DMD and BMD patients and with thigh fat fraction in BMD patients. Moreover, PDGF-AA levels were increased in muscle biopsies of patients with DMD and BMD as was demonstrated by immunohistochemistry and Real-Time PCR studies. Conclusion: Our study suggests that PDGF-AA should be further investigated in a larger cohort of DMD and BMD patients because it might be a good biomarker candidate to monitor the progression of these diseases

PDGF-BB serum levels are decreased in adult onset Pompe patients

Adult onset Pompe disease is a genetic disorder characterized by slowly progressive skeletal and respiratory muscle weakness. Symptomatic patients are treated with enzymatic replacement therapy with human recombinant alfa glucosidase. Motor functional tests and spirometry are commonly used to follow patients up. However, a serological biomarker that correlates with the progression of the disease could improve follow-up. We studied serum concentrations of TGFβ, PDGF-BB, PDGF-AA and CTGF growth factors in 37 adult onset Pompe patients and 45 controls. Moreover, all patients performed several muscle function tests, conventional spirometry, and quantitative muscle MRI using 3-point Dixon. We observed a statistically significant change in the serum concentration of each growth factor in patients compared to controls. However, only PDGF-BB levels were able to differentiate between asymptomatic and symptomatic patients, suggesting its potential role in the follow-up of asymptomatic patients. Moreover, our results point to a dysregulation of muscle regeneration as an additional pathomechanism of Pompe disease

Platelet Derived Growth Factor-AA Correlates With Muscle Function Tests and Quantitative Muscle Magnetic Resonance in Dystrophinopathies

Introduction: Duchenne (DMD) and Becker (BMD) muscular dystrophy are X-linked muscular disorders produced by mutations in the DMD gene which encodes the protein dystrophin. Both diseases are characterized by progressive involvement of skeletal, cardiac, and respiratory muscles. As new treatment strategies become available, reliable biomarkers and outcome measures that can monitor disease progression are needed for clinical trials.Methods: We collected clinical and functional data and blood samples from 19 DMD patients, 13 BMD patients, and 66 healthy controls (8 pediatric and 58 adult controls), and blood samples from 15 patients with dysferlinopathy (DYSF) and studied the serum concentration of 4 growth factors involved in the process of muscle fibrosis. We correlated the serum concentration of these growth factors with several muscle function tests, spirometry results and fat fraction identified by quantitative Dixon muscle MRI.Results: We found significant differences in the serum concentration of Platelet Derived Growth Factor-AA (PDGF-AA) between DMD patients and pediatric controls, in Connective Tissue Growth Factor (CTGF) between BMD patients and adult controls, and in and Transforming Growth Factor- β1 (TGF-β1) between BMD and DYSF patients. PDGF-AA showed a good correlation with several muscle function tests for both DMD and BMD patients and with thigh fat fraction in BMD patients. Moreover, PDGF-AA levels were increased in muscle biopsies of patients with DMD and BMD as was demonstrated by immunohistochemistry and Real-Time PCR studies.Conclusion: Our study suggests that PDGF-AA should be further investigated in a larger cohort of DMD and BMD patients because it might be a good biomarker candidate to monitor the progression of these diseases