"Si la tierra tiene sazón..." El conocimiento tradicional campesino como movilizador de procesos de transición agroecológica

Peasant traditional knowledge remains on the basis of agroecological research, considering that within it we can find features of the ecological racionality for natural resource management that peasant societies have developed along the History. Recovery and updating of this knowledge is, in the current context of global ecological crisis, more necessary than never. Peasant traditional knowledge can play as well an aditional role in Agroecological Transition processes at local society level, linking both symbolic and material components of social change. Activating its materiality -traditional seeds and tools or knowledge- we can boost subjective processes of change in the collective imaginarium, necessary to activate dynamics of endogenous, social change to sustainability.To assess the potential of peasant traditional knowledge as mobylizer of Agroecological Transition we have developed a case-study in a peri-urban town in central Spain, with an ancient agrarian tradition but very affected by de-agrarization processes. In this study we have made diverse activities for the recovery of traditional knowledge, and then we have used this information as feed-back for debate with local population in open events which we have called agroecological analyzer-mobylizer. In this paper we try to assess the potential of these actions for activate Agroecological Transition.El conocimiento tradicional campesino se encuentra en la base de la investigación agroecológica, ya que en él podemos encontrar rasgos de la racionalidad ecológica en el manejo de los recursos naturales que las sociedades campesinas han desarrollado a lo largo de la historia. La recuperación y actualización de este conocimiento es, en el contexto actual de crisis ecológica global, más necesario que nunca. El conocimiento tradicional campesino puede además jugar un papel adicional en los procesos de Transición Agroecológica a nivel de sociedad local, ya que éstos deben articular las componentes material y simbólica en los procesos de cambio social. A través de la puesta en acción de su materialidad -las semillas, las herramientas o el saber para transformar el medio físico- podemos activar procesos subjetivos de cambio en el imaginario colectivo, necesarios para activar dinámicas endógenas de cambio social hacia la sustentabilidad.Para evaluar el potencial del conocimiento tradicional campesino como movilizador del potencial agroecológico hemos desarrollado un estudio de caso en un municipio periurbano del centro del Estado Español, con profunda tradición agraria pero muy afectado por los procesos de desagrarización, en el que se han articulado diversas metodologías participativas y etnográficas. En primer lugar, se han realizado diversas actividades de recuperación de conocimiento tradicional campesino. En segundo lugar, el conocimiento y los materiales recuperados se han devuelto a la población local en distintos eventos que hemos denominado analizadores-movilizadores agroecológicos. En el presente artículo tratamos de analizar la potencialidad de estas acciones para dinamizar los procesos de Transición Agroecológica

Pulsed light of near-infrared and visible light wavelengths induces the accumulation of carotenoids in tomato fruits during post-treatment time

Pulsed light (PL) is proposed as a novel strategy for the food industryto enhance the antioxidant potential of fruits and vegetables for industrial uses.The main aim of this work is to evaluate the impact of postharvest PL treatmentsof different spectral ranges on the carotenoid concentration as well as qualityattributes of tomatoes during post-treatment time. Doses of wide-spectrum light(180–1100 nm), full-spectrum without ultraviolet (UV)-C wavelengths (305–1100nm),andvisible(VIS)+near-infraredlight(NIR)(400–1100nm)werecompared.Total carotenoids, lycopene, and chlorophyll contents were spectrophotomet-rically assessed just after treatments and 1, 5, and 10 days post-treatment. PLtreatments accelerated the accumulation of both total carotenoids and lycopeneconcentrations in tomato fruits. Nevertheless, the efficacy of PL depended onthe applied spectral range. Tomato subjected to VIS+NIR treatment exhibitedthe greatest enhancement in total carotenoids (31 %) and lycopene (35 %) con-tent at day 5 post-treatment and quality attributes were not affected. Conversely,UV-light exposure did not enhance carotenoid concentrations. These results evi-denced that VIS+NIR treatments induced a faster accumulation of carotenoidswithout negatively affecting tomato quality attributes.Ministerio de Economía y Competitividad (Spain) reference AGL2013-44851-R and Ministerio de Ciencia, Innovación y Universidades (Spain) grant number RTI2018-095560-B-I00. S.G.C. Agència de Gestió dťAjuts Universitaris i de Recerca (AGAUR)—predoctoral grant

Politizando el consumo alimentario: estrategias para avanzar en la transición agroecológica/ Politicizing Food Consumption: Strategies for Advancing in Agroecological Transition

The starting point of this paper is the unfeasibility situation of the industrialized agriculture model and the dominant agro-food regime. Building a sustainable alternative is urgently needed. In the last decades, a great number of agroecological experiences have emerged which constitute, by their innovative character, the vanguard of an alternative agro-alimentary system. However, these experiences are not enough to produce a change to upper scales of social organization and even for their own survival as such experiences. The main challenge that Agroecology has raised is to upscaling the agroecological experiences. In this paper we propose a change of focus in the agroecological practice itself, betting on the formation of agro-ecological local food systems that, when winning on a scale, impose a favorable institutional framework. This will only be possible through a social mobilization not only focused on agricultural production or distribution, but on food, weaving social alliances with capacity for change. This can be done by politicizing food consumption.En este artículo se parte de la situación de inviabilidad del modelo de agricultura industrializada y del régimen agroalimentario dominante y de la necesidad de construir alternativas sustentables que reviertan la crisis. En las últimas décadas han aparecido gran cantidad de experiencias que constituyen, por su carácter innovador, la vanguardia de un sistema agroalimentario alternativo. Sin embargo, estas experiencias no son suficientes para producir un cambio a escalas superiores de organización social e incluso para su propia supervivencia como tales experiencias. El reto principal que la Agroecología tiene planteado es el de ampliar la escala de las experiencias agroecológicas. En este artículo proponemos un cambio de enfoque en la propia práctica agroecológica, apostando por la conformación de sistemas agroalimentarios locales de base agroecológica que al ganar en escala impongan un nuevo arreglo institucional favorable. Ello sólo será posible mediante una movilización social no sólo centrada en la producción agraria o en la distribución, sino en la alimentación, tejiendo alianzas sociales con capacidad de cambio. Ello se puede hacer politizando el consumo alimentario

Isolation and transfection of strawverry protoplasts for gene editing

Strawberry is the most economically important soft fruit. The improvement of the organoleptic qualities of ripe fruit and the postharvest shelf life are main objectives of strawberry breeding programs. Fruit softening is mainly due to the disassembly of cell walls and the dissolution of middle lamella. In strawberry, functional analyses of genes encoding polygalacturonases (PGs) indicate that these enzymes play a key role in fruit softening, i.e. the antisense downregulation of PG genes FaPG1 or FaPG2 increased fruit firmness and postharvest shelf life (Paniagua et al., 2020). These results suggest that PG encoding genes are excellent targets for gene editing to improve strawberry fruit quality. Transfection of protoplasts with CRISPR/Cas9 ribonucleoprotein complexes is currently being explored in many species to produce DNA-free edited plants. In this research, a protocol for strawberry protoplasts transfection has been optimized with the final goal of producing non-transgenic strawberry plants with the FaPG1 gene edited. Protoplasts were isolated from 9 weeks old in vitro grown plants of Fragaria x ananassa, cv. ‘Chandler’, micropropagated in Murashige and Skoog (MS) medium supplemented with 2 mg/L of BA. Protoplast extraction and purification was performed as described by Barceló et al. (2019). Using this protocol, a yield of 1 x 105 protoplast/g fresh tissue was obtained and nearly 50-70% of them were viable. Protoplasts were transfected with the plasmid pHBT-sGFP(S65T)-NOS using a PEG-mediated transformation system, as reported by Yoo et al. (2007). To improve the efficiency of protoplast transfection, different variables were evaluated: PEG concentration, time of incubation on PEG and DNA concentration. At 48 h after transfection, the highest percentage of protoplasts showing GFP expression, 18%, was obtained with 15 minutes incubation in 20% of PEG and 5 µg of DNA

Leaf structural changes associated with iron deficiency chlorosis in field-grown pear and peach: physiological implications

The final version is available at: http://www.springerlink.com/content/y62g0r6712184032/fulltext.pdfPlants grown in calcareous, high pH soils develop Fe deficiency chlorosis. While the physiological parameters of Fe-deficient leaves have been often investigated, there is a lack of information regarding structural leaf changes associated with such abiotic stress. Iron-sufficient and Fe-deficient pear and peach leaves have been studied, and differences concerning leaf epidermal and internal structure were found. Iron deficiency caused differences in the aspect of the leaf surface, which appeared less smooth in Fe-deficient than in Fe-sufficient leaves. Iron deficiency reduced the amount of soluble cuticular lipids in peach leaves, whereas it reduced the weight of the abaxial cuticle in pear leaves. In both plant species, epidermal cells were enlarged as compared to healthy leaves, whereas the size of guard cells was reduced. In chlorotic leaves, bundle sheaths were enlarged and appeared disorganized, while the mesophyll was more compacted and less porous than in green leaves. In contrast to healthy leaves, chlorotic leaves of both species showed a significant transient opening of stomata after leaf abscission (Iwanoff effect), which can be ascribed to changes found in epidermal and guard cells. Results indicate that Fe-deficiency may alter the barrier properties of the leaf surface, which can significantly affect leaf water relations, solute permeability and pest and disease resistance.This study was supported by the Spanish Ministry of Science and Education (MEC, grants AGL2006-01416 and AGL2007-61948, co-financed with FEDER), the European Commission (ISAFRUIT project, Thematic Priority 5-Food Quality and Safety of the 6th Framework Programme of RTD; Contract no. FP6-FOOD-CT-2006-016279) and the Aragón Government (group A03). V.F. was supported by a “Juan de la Cierva”-MEC post-doctoral contract, co-financed by the European Social Fund. T.E. was supported by the CAI Europa XXI for a short term stay at the EEAD-CSIC.Peer reviewe

Poligalacturonasa FaPG1 y CRISPR/Cas9: Editando la firmeza del fruto de fresa

El uso de la técnica CRISPR/Cas9 para la edición de genomas vegetales ha sido ampliamente estudiado y referido en los últimos años. En trabajos recientes, se ha empleado esta técnica para mejorar la vida postcosecha y características organolépticas de frutos modelo como el tomate; sin embargo, los trabajos de edición génica en otros frutos como la fresa son muy escasos. Los cambios en las características y/o composición de las paredes celulares durante la maduración son el principal factor que contribuye a la pérdida de la firmeza del fruto. Estos cambios están promovidos por la inducción de genes que codifican enzimas modificadoras de los polímeros de la pared celular. En el caso de la fresa, trabajos anteriores demostraron que el silenciamiento de genes de poligalacturonasa alarga la vida postcosecha del fruto. En este trabajo se ha evaluado el efecto de la edición del gen de poligalacturonasa FaPG1 mediante el sistema CRISPR/Cas9 en fresa, con el fin último de desarrollar plantas editadas no transgénicas con una vida postcosecha más larga. Para ello, se diseñaron cebadores para amplificar el RNA guía específico para este gen utilizando la aplicación http://crispr.hzau.edu.cn/CRISPR2/ y el genoma de F. vesca v4.0 como referencia. Se transformaron discos de hoja del cv. Chandler mediante A. tumefaciens portando el vector binario pDe-CAS9 que contiene la secuencia codificante de Cas9 y el gen bar para selección en fosfinotricina. Se obtuvieron un total de 40 líneas transgénicas independientes. En el 50% de las plantas analizadas, se comprobó la edición del gen diana mediante el ensayo de la endonucleasa T7. Los productos de amplificación para la zona editada están siendo secuenciados mediante la plataforma Illumina para determinar los patrones de edición que han tenido lugar. Estas líneas serán aclimatadas para su posterior cultivo y evaluación fenotípica en invernadero.AGL2017-86531-C2-1-R; Fondos FEDER; Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tec

High-throughput mapping of cell wall glycans to unveil cell wall disassembly, a key process determining strawberry fruit softening

The short shelf life of strawberry fruit is a major limitation that produces important economic losses related to postharvest spoiling. Fruit texture of fleshy fruits is a complex trait but mainly rely on mechanical properties of parenchyma cell walls. Several studies support the relevance of cell wall modifying enzymes on cell wall deconstruction, decreasing cell wall strength and cell to cell adhesion, and ultimately producing the softening of the fruit at macroscopic level. Previous studies on our group showed that transgenic silencing of ripening-specific genes encoding some of these enzymes reduced softening and increased postharvest shelf life in strawberry (Fragaria × ananassa, cv. ‘Chandler’) fruits. In this research, to further investigate the cell wall remodelling process associated to strawberry softening a high-throughput analysis of cell wall composition based on monoclonal antibodies against different polysaccharide epitopes has been performed. To this purpose, cell walls were isolated from non-transgenic fruits at different developmental stages as well as from ripe fruits of selected transgenic lines with genes involved in metabolism of pectins (pectate lyase, polygalacturonase, β-galactosidase, pectin acetil esterase), hemicellulose/cellulose (endo-β-glucanase) or lignin (cinnamyl alcohol dehydrogenase) down-regulated. These transgenic lines showed a large variability in fruit firmness at ripening. Cell walls were fractionated and subjected to a carbohydrate microarray. The results obtained unveiled a common pattern of cell wall composition on those transgenic lines with firmer phenotypes, specially defined by the higher content of pectins on those cell wall fractions more imbricated in the matrix, which can be interpreted as a less degraded cell wall structure.This research was supported by FEDER EU Funds and the Ministerio de Economía y Competitividad of Spain (grant reference AGL2017-86531-C2-1-R). Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Downregulation of NAC transcription factors modifies cell wall composition and increases strawberry fruit firmness

The strawberry is a soft fruit with a very short post-harvest shelf life. The changes in texture during fruit ripening are mainly due to the dissolution of the middle lamellae, reducing cell-to-cell adhesion, and the weakening of parenchymal cell walls as result of the action of cell wall modifying enzymes. At present, no master regulator of this process has been discovered yet. NAC transcription factors have been involved in numerous physiological processes, including fruit ripening. In strawberry, the NAC family comprises more than 110 genes, and at least 6 of them are expressed during fruit development. In this research, we performed a functional analysis of two ripening-related NAC genes, FaNAC2 and FaNAC3, in Fragaria x ananassa Duch. cv. Chandler. Several RNAi transgenic lines showing low FaNAC2 or FaNAC3 mRNA levels in fruit were obtained through Agrobacterium-mediated transformation. These lines produced fruits significantly firmer than control at the ripe stage, being the increase in firmness higher in FaNAC2 silenced plants. Cell walls were extracted from ripe transgenic fruits and characterized by ELISA and Epitope Detection Chromatography (EDC), using monoclonal antibodies against different polysaccharide epitopes. FaNAC2 transgenic lines showed more extensive changes than FaNAC3; these modifications involved increased amounts of demethylated pectins (LM19) in water and CDTA fractions and an alteration of the lateral branches of RG-I, decreasing the amount of arabinan epitopes and increasing galactan epitopes detected by LM6 and LM5, respectively. The amount of arabinogalactan proteins recognized by the JIM13 antibody was also affected, decreasing in the Na2CO3 fraction and increasing in the 4M KOH and cellulase fraction of the transgenic lines.The results obtained indicate that NAC genes could be involved in the regulation of cell wall disassembly associated to strawberry fruit softening.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Histological and ultrastructural comparison of cauterization and thrombosis stroke models in immune-deficient mice

<p>Abstract</p> <p>Background</p> <p>Stroke models are essential tools in experimental stroke. Although several models of stroke have been developed in a variety of animals, with the development of transgenic mice there is the need to develop a reliable and reproducible stroke model in mice, which mimics as close as possible human stroke.</p> <p>Methods</p> <p>BALB/Ca-RAG2^-/-γc^-/-mice were subjected to cauterization or thrombosis stroke model and sacrificed at different time points (48hr, 1wk, 2wk and 4wk) after stroke. Mice received BrdU to estimate activation of cell proliferation in the SVZ. Brains were processed for immunohistochemical and EM.</p> <p>Results</p> <p>In both stroke models, after inflammation the same glial scar formation process and damage evolution takes place. After stroke, necrotic tissue is progressively removed, and healthy tissue is preserved from injury through the glial scar formation. Cauterization stroke model produced unspecific damage, was less efficient and the infarct was less homogeneous compared to thrombosis infarct. Finally, thrombosis stroke model produces activation of SVZ proliferation.</p> <p>Conclusions</p> <p>Our results provide an exhaustive analysis of the histopathological changes (inflammation, necrosis, tissue remodeling, scarring...) that occur after stroke in the ischemic boundary zone, which are of key importance for the final stroke outcome. This analysis would allow evaluating how different therapies would affect wound and regeneration. Moreover, this stroke model in RAG 2^-/-γC ^-/-allows cell transplant from different species, even human, to be analyzed.</p