313 research outputs found

    Mineral stress affects the cell wall composition of grapevine (Vitis vinifera L.) callus

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    Versão provisória aceite p. publicação na Plant Science (ISSN 0168-9452)em 19-01-2013Grapevine (Vitis vinifera L.) is one of the most economically important fruit crops in the world. Deficit in nitrogen, phosphorus and sulfur nutrition impairs essential metabolic pathways. The influence of mineral stress in the composition of the plant cell wall (CW) has received residual attention. Using grapevine callus as a model system, 6-weeks deficiency of those elements caused a significant decrease in growth. Callus CWs were analyzed by Fourier transform infrared spectroscopy (FT-IR), by quantification of CW components and by immunolocalization of CW epitopes with monoclonal antibodies. PCA analysis of FT-IR data suggested changes in the main components of the CW in response to individual mineral stress. Decreased cellulose, modifications in pectin methyl esterification and increase of structural proteins were among the events disclosed by FT-IR analysis. Chemical analyses supported some of the assumptions and further disclosed an increase in lignin content under nitrogen deficiency, suggesting a compensation of cellulose by lignin. Moreover, polysaccharides of callus under mineral deficiency showed to be more tightly bonded to the CW, probably due to a more extensive cross-linking of the cellulose-hemicellulose network. Our work showed that mineral stress impacts the CW at different extents according to the withdrawn mineral element, and that the modifications in a given CW component are compensated by the synthesis and/or alternative linking between polymers. The overall results here described for the first time pinpoint the CW of Vitis callus different strategies to overcome mineral stress, depending on how essential they are to cell growth and plant development

    Fourier transform mid infrared spectroscopy applications for monitoring the structural plasticity of plant cell walls

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    [EN] Fourier transform mid-infrared (FT-MIR) spectroscopy has been extensively used as a potent, fast and non-destructive procedure for analyzing cell wall architectures, with the capacity to provide abundant information about their polymers, functional groups, and in muro entanglement. In conjunction with multivariate analyses, this method has proved to be a valuable tool for tracking alterations in cell walls. The present review examines recent progress in the use of FT-MIR spectroscopy to monitor cell wall changes occurring in muro as a result of various factors, such as growth and development processes, genetic modifications, exposition or habituation to cellulose biosynthesis inhibitors and responses to other abiotic or biotic stresses, as well as its biotechnological applicationsSIThe authors thank Antonio Encina, Penélope García-Angulo, and María de Castro for their helpful scientific discussion, and to Denise Phelps for the English revision of the manuscrip

    Un Entorno de Modelado Inteligente y Simulación Distribuida de Plantas de Proceso

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    [ES] Se describen un conjunto de aplicaciones informáticas que abordan diferentes aspectos del modelado y simulación de procesos continuos. Primero, se presenta un prototipo universitario SIMPD, que es un generador de código de simulación de sistemas de la industria de proceso y cuyo algoritmo básico trata de emular el modo de razonamiento de un experto en modelado cuando escribe un modelo de simulación. Se compara con otros enfoques y se analizan tanto las ventajas que presenta desde la perspectiva del usuario final como los inconvenientes para el programador que trate de aumentar el conjunto de sistemas modelables. Segundo, se describe tanto una arquitectura de simulación distribuida cuyas comunicaciones se basan en el estándar de facto OPC (OLE for Process Control) como el conjunto de herramientas informáticas desarrolladas para diseñar estos escenarios de simulación. Esta arquitectura se aplica a un proceso industrial, explicando el criterio usado para dividir el modelo de simulación global.Los autores quieren agradecer el soporte financiero de la empresa Ebro Agrícolas así como a la Junta de Castilla y León por medio del proyecto “Desarrollo de un entorno de modelado inteligente y simulación distribuida de plantas de proceso”.Acebes, L.; Alves, R.; Merino, A.; De Prada, C. (2010). Un Entorno de Modelado Inteligente y Simulación Distribuida de Plantas de Proceso. Revista Iberoamericana de Automática e Informática industrial. 1(2):42-48. http://hdl.handle.net/10251/146626OJS42481

    The nuclear receptor LXRα controls the functional specialization of splenic macrophages.

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    Macrophages are professional phagocytic cells that orchestrate innate immune responses and have considerable phenotypic diversity at different anatomical locations. However, the mechanisms that control the heterogeneity of tissue macrophages are not well characterized. Here we found that the nuclear receptor LXRα was essential for the differentiation of macrophages in the marginal zone (MZ) of the spleen. LXR-deficient mice were defective in the generation of MZ and metallophilic macrophages, which resulted in abnormal responses to blood-borne antigens. Myeloid-specific expression of LXRα or adoptive transfer of wild-type monocytes restored the MZ microenvironment in LXRα-deficient mice. Our results demonstrate that signaling via LXRα in myeloid cells is crucial for the generation of splenic MZ macrophages and identify an unprecedented role for a nuclear receptor in the generation of specialized macrophage subsets

    Cólico nefrítico como presentación clínica de un aneurisma complicado. A propósito de un caso

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    A 76-year-old man presented to the emergency department four hours after the onset of colic pain in the left flank and genital irradiation. Three hours after being discharged with diagnosis of non complicated renal colic, he came back presenting symptoms and signs of shock. Laboratory evaluation revealed leukocytosis, anemia, hematuria and elevated serum creatinine. Two abdominal ultrasonographies were performed with no demonstration of specific pathology. Eventually, a Computed Tomography was needed to confirm the diagnosis of complicated hypogastric artery aneurysm. Several conditions may mimic renal colic caused by lithiasis such as ectopic pregnancy, intestinal obstruction, acute mesenteric ischemia, pyelonephritis, aortic aneurysm, etc. Most of them have a great mortality rate without an early diagnosis and management.Paciente de 76 años que acude por dolor lumbar tipo cólico irradiado a genitales de 4 horas de evolución. Tres horas después de ser diagnosticado y de cólico nefrítico no complicado, volvió a Urgencias con síntomas y signos de shock. Se objetiva leucocitosis, anemia, hematuria y elevación de creatinina plasmática. Dos ecografías abdominales que fueron inespecíficas. Finalmente se requirió la realización de una tomografía computarizada (TC) para confirmar el diagnóstico de aneurisma de arteria hipogástrica izquierda complicado. Muchas patologías como embarazo ectópico, obstrucción intestinal, isquemia mesentérica aguda, pielonefritis, aneurismas aórticos, etc., pueden simular un cólico nefrítico por litiasis. La mayoría de estas patologías tienen una elevada tasa de mortalidad sin un diagnóstico y tratamiento precoces

    Production of Encecalin in Cell Cultures and Hairy Roots of Helianthella quinquenervis (Hook.) A. Gray

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    Plant cell and organ cultures of Helianthella quinquenervis, a medicinal plant whose roots are used by the Tarahumara Indians of Chihuahua, Mexico, to relieve several ailments, were established to identify and quantify some chromenes with biological activity, such as encecalin, and to evaluate their potential for biotechnological production. Gas chromatography-mass spectrometry (GC-MS) analysis corroborated the presence of quantifiable amounts of encecalin in H. quinquenervis cell cultures (callus and cell suspensions). In addition, hairy roots were obtained through three transformation protocols (prick, 45-s sonication and co-culture), using wild type Agrobacterium rhizogenes A4. After three months, cocultivation achieved the highest percentage of transformation (66%), and a comparable production (FW) of encecalin (110 g/g) than the sonication assay (120 g/g), both giving far higher yields than the prick assay (19 g/g). Stable integration of rolC and aux1 genes in the transformed roots was confirmed by polymerase chain reaction (PCR). Hairy roots from cocultivation (six months-old) accumulated as much as 1086 g/g (FW) of encecalin, over three times higher than the cell suspension cultures. The production of encecalin varied with growth kinetics, being higher at the stationary phase. This is the first report of encecalin production in hairy roots of H. quinquenervis, demonstrating the potential for a future biotechnological production of chromenes

    Cellulose Biosynthesis Inhibitors: Comparative Effect on Bean Cell Cultures

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    The variety of bioassays developed to evaluate different inhibition responses for cellulose biosynthesis inhibitors makes it difficult to compare the results obtained. This work aims (i) to test a single inhibitory assay for comparing active concentrations of a set of putative cellulose biosynthesis inhibitors and (ii) to characterize their effect on cell wall polysaccharides biosynthesis following a short-term exposure. For the first aim, dose-response curves for inhibition of dry-weight increase following a 30 days exposure of bean callus-cultured cells to these inhibitors were obtained. The compound concentration capable of inhibiting dry weight increase by 50% compared to control (I50) ranged from subnanomolar (CGA 325′615) to nanomolar (AE F150944, flupoxam, triazofenamide and oxaziclomefone) and micromolar (dichlobenil, quinclorac and compound 1) concentrations. In order to gain a better understanding of the effect of the putative inhibitors on cell wall polysaccharides biosynthesis, the [14C]glucose incorporation into cell wall fractions was determined after a 20 h exposure of cell suspensions to each inhibitor at their I50 value. All the inhibitors tested decreased glucose incorporation into cellulose with the exception of quinclorac, which increased it. In some herbicide treatments, reduction in the incorporation into cellulose was accompanied by an increase in the incorporation into other fractions. In order to appreciate the effect of the inhibitors on cell wall partitioning, a cluster and Principal Component Analysis (PCA) based on the relative contribution of [14C]glucose incorporation into the different cell wall fractions were performed, and three groups of compounds were identified. The first group included quinclorac, which increased glucose incorporation into cellulose; the second group consisted of compound 1, CGA 325′615, oxaziclomefone and AE F150944, which decreased the relative glucose incorporation into cellulose but increased it into tightly-bound cellulose fractions; and the third group, comprising flupoxam, triazofenamide and dichlobenil, decreased the relative glucose incorporation into cellulose and increased it into a pectin rich fraction

    Evolutionary winners are ecological losers among oceanic island plants

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    Aim Adaptive radiation, in which successful lineages proliferate by exploiting untapped niche space, provides a popular but potentially misleading characterization of evolution on oceanic islands. Here we analyse the respective roles of members of in situ diversified vs. non-diversified lineages in shaping the main ecosystems of an archipelago to explore the relationship between evolutionary and ecological ‘success’. Location Canary Islands. Taxon Vascular plants. Methods We quantified the abundance/rarity of the native flora according to the geographical range (number of islands where present and geographical extent of the range), habitat breadth (climatic niche) and local abundance (cover) using species distribution data based on 500 × 500 m grid cells and 2000 vegetation inventories located all over the archipelago. Results Species of diversified lineages have significantly smaller geographic ranges, narrower climatic niches and lower local abundances than those of non-diversified lineages. Species rarity increased with the degree of diversification. The diversified Canarian flora is mainly comprised by shrubs. At both archipelagic and island level, the four core ecosystems (Euphorbia scrub, thermophilous woodlands, laurel forest and pine forest) were dominated by non-diversified lineages species, with diversified lineages species providing <25% cover. Species of diversified lineages, although constituting 54% of the archipelagic native flora, were only abundant in two rare ecosystems: high mountain scrub and rock communities. Main conclusions Radiated species, endemic products of in situ speciation, are mostly rare in all three rarity axes and typically do not play an important role in structuring plant communities on the Canaries. The vegetation of the major ecosystem types is dominated by plants representing non-diversified lineages (species that derive from immigration and accumulation), while species of evolutionarily successful lineages are abundant only in marginal habitats and could, therefore, be considered ecological losers. Within this particular oceanic archipelago, and we posit within at least some others, evolutionary success in plants is accomplished predominantly at the margins.publishedVersio
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