Separación mediante electrofóresis en 2-D de membranas tilacoidales

4 Pags.- 2 Figs.La deficiencia en hierro disminuye marcadamente la tasa de fotosíntesis. Las hojas deficientes en hierro reducen el número membranas tilacoidales por cloroplasto (Spiller y Terry 1980) y los componentes de las membranas: transportadores electrónicos de la cadena fotosintética (Spiller y Terry 1980), clorofilas y carotenoides (Abadía y Abadía 1993, Morales et al., 1990). Una de las principales características de las hojas deficientes en hierro es la clorosis debida a la baja concentración de clorofilas y carotenoides por área (Morales et al. 1990, 1994; Abadía y Abadía 1993). No todos los pigmentos disminuyen en igual cantidad, ya que existe una pérdida preferente de Chl b y por lo tanto de antena extrínseca LHC. Además Riethman y Sherman 1988 y Burnap et al 1993 publicaron la existencia de un nuevo pigmento-proteína inducido por la deficiencia de hierro en cianobacteria. Todo parece indicar que el patrón polipeptídico de las membranas de hojas deficientes en hierro podría ser distinto al de las membranas de las hojas control. Aunque en nuestro grupo de investigación ya se habían efectuado trabajos sobre electroforesis en 2 D (González-Vallejo, 1999), se han aprovechado los nuevos avances de la proteómica para llevar a cabo esta nueva aproximación.Financiado por los proyectos del Plan Nacional de Investigación AGL2000-1721 a AA, y PB97-1176 y BOS2001-2343 a JA.Peer reviewe

Image techniques: New approaches in metal homeostasis

1 .pdf copia del original presentado por los autores al Meeting.Plant physiological processes take place in a complex cellular environment. Organs are complex structures made up of different tissues with distinct cell types. Traditional biochemistry involves the analysis of bulk samples containing am ixture of heterogeneous tissues, leading to a non correct interpretation of the results. This averaging effect can only be overcome by increasing the spatial resolution of analysis to a tissue-or even cell- specific level, in other words, by using image techniques.This study was supported by MICINN projects AGL2006-1416 and AGL2007-61948,co-financed with FEDER, the European Commission (EU 6th Framework Integrated Project ISAFRUIT, Contract no.FP6-FOOD-CT-2006-016279), and the Aragón Government(groupA03).Peer reviewe

Cambios producidos por el tratamiento de Fe sobre las concentraciones de ácidos orgánicos en xilema de melocotoneros afectados por clorosis férrica

4 Pags.- 3 Figs.La deficiencia de hierro se considera uno de los mayores estreses abióticos que afectan a los frutales cultivados en suelos calcáreos del área mediterránea. Se conoce desde hace décadas que las concentraciones de ácidos orgánicos aumentan en todas las partes de la planta con la clorosis férrica (ver revisión de Abadía et al., 2001). Este aspecto ha sido muy poco estudiado en árboles frutales, en especial por lo que se refiere a la savia de xilema y apoplasto. Chatti (1997) indicó que la concentración de ácidos orgánicos de la savia de melocotonero cambia ligeramente con el grado de clorosis. López-Millán et al., (2001) indicaron que la concentración total de ácidos orgánicos en apoplasto de peral aumenta con el grado de clorosis. También se encontró un aumento de la concentración de ácidos orgánicos en hojas de manzano y peral cloróticos (Sun et al., 1987; López-Millán et al., 2001). Entre los métodos empleados para remediar la clorosis figuran las inyecciones de implantes de Fe en el tronco de los árboles. Se ha descrito que este método es efectivo para aliviar la clorosis, con un efecto duradero por lo menos durante dos o tres años (Hurley et al. 1986). El principal objetivo de este trabajo es investigar los cambios producidos por las inyecciones de implantes de Fe sobre la composición en ácidos orgánicos en xilema de árboles cloróticos.Financiado por los proyectos del Plan Nacional de Investigación AGL2000-1721 a AA, y PB97-1176 y BOS2001-2343 a JA.Peer reviewe

Metal species involved in long distance metal transport in plants

20 Pags.- 2 Tabls.- 1 Fig. © 2014 Álvarez-Fernández, Díaz-Benito, Abadía, López-Millán and Abadía. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids.This study was supported by the Spanish Ministry of Economy and Competitiveness (projects AGL2010-16515 and AGL2012-31988), and the Aragón Government (group A03). Pablo Díaz-Benito was supported by a MINECO-FPI grant.Peer reviewe

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

Estudio de la homeostasis de Fe y Mn en plantas mediante aproximaciones proteómicas

El Fe y el Mn están clasificados como micronutrientes que participan en funciones esenciales para el desarrollo y crecimiento de las plantas. El organismo no puede crecer sin un suministro adecuado de estos metales, pero por otro lado, si los niveles de exposición son demasiado elevados pueden resultar potencialmente tóxicos. El rango de concentraciones considerado fisiológico para los metales esenciales es muy estrecho y varía en función de la especie, el tejido y las condiciones de crecimiento. El conjunto de mecanismos implicados en el mantenimiento de los niveles adecuados de estos nutrientes es lo que se conoce como homeostasis. Desde un punto de vista fisiológico, la homeostasis de metales requiere la coordinación a nivel de toda la planta de los mecanismos de adquisición en la raíz, translocación a la parte aérea, almacenamiento y su posterior removilización a órganos sumidero. En la regulación de la homeostasis el sistema vascular juega un papel fundamental puesto que participa en la traslocación via xilema, en la removilización via floema y en la distribución y almacenamiento via apoplasto. Cuando este equilibrio se pierde, se producen pérdidas en la productividad causadas por disminuciones tanto en rendimiento como en la calidad de los cultivos que conllevan un alto impacto económico al generar productos con menor valor comercial y nutricional e incrementa los costes en el manejo del cultivo. La disponibilidad de ambos metales en la corteza terrestre depende del pH y las características redox del suelo, de forma que cuando el pH del suelo es elevado ambos metales se encuentran en formas con niveles de solubilidad mínimos que resultan difícilmente asimilables por las plantas. El 30% de los suelos cultivables presentan un pH elevado, indicando que la deficiencia de de estos metales resulta uno de los factores limitantes en el área mediterránea, en cultivos en el centro de Asia, el medio oeste de estados unidos o el sur de Australia. Por otro lado, en el caso del Mn, la cantidad del metal asimilable por las plantas aumenta considerablemente conforme el pH disminuye, de forma que en suelos con pH ácido puede llegar a resultar tóxico. Las actividades antropogénicas, como las actividades mineras y los residuos de incineración o de procesos industriales, han provocado el enriquecimiento en metales del medio ambiente, originándose una acumulación de 100 a 1.000 veces más alta en relación con su proporción natural en la corteza terrestre. La toxicidad de Mn supone un problema agronómico cada vez más común y es prevalentes en zonas del norte de Europa y Asia, el norte de EEUU y Canadá, gran parte de sudamérica o en algunas zonas de Australia. Aunque la información de la homeostasis en metales ha aumentado en los últimos años, todavía hay muchos interrogantes al respecto. Por ello, la proteómica puede resultar una herramienta muy útil a la hora de identificar y caracterizar nuevas proteínas que participan en la homeostasis de metales. El estrés por Fe ha sido más estudiado desde un punto de vista proteómico que el estrés por Mn. Los primeros estudios sobre Fe fueron en tejidos vegetales completos como la raíz y las hojas, y aún hoy en día los trabajos en estos tejidos son mayoritarios. En el caso del Mn, los trabajos publicados hasta el momento a nivel de proteoma se han centrado en plantas con características hiperacumuladoras o en estudios en hoja. Sin embargo, el análisis de subproteomas, entre los que se incluyen los fluidos de la planta, que resultan cruciales para el entendimiento de la homeostasis de estos metales, resultan todavía limitados. Con estos antecedentes el objetivo general de esta Tesis Doctoral ha sido incrementar el conocimiento existente acerca de los efectos que causan las deficiencias de Fe y Mn y la toxicidad por Mn en los proteomas vegetales implicados en la absorción (raíz) y el transporte (savias de xilema y floema y fluido apoplástico) de estos nutrientes mediante la aplicación de aproximaciones proteómicas. El uso de la proteómica diferencial en estos estreses y subproteomas puede proporcionar información sobre los procesos de adaptación de las plantas, así como apuntar hacia posibles estrategias para combatirlos. Además, el uso de técnicas de proteómica clásicas (2-DE) y avanzadas (“shotgun proteomics”) permite llevar a cabo la comparación entre técnicas y establecer las ventajas y limitaciones de ambas en el análisis de estos proteomas.<br /

Accumulation and secretion of coumarinolignans and other coumarins in Arabidopsis thaliana roots in response to iron deficiency at high pH

22 Pags.- 3 Tabls.- 8 Figs. This Document is Protected by copyright and was first published by Frontiers (http://journal.frontiersin.org/journal/373). All rights reserved. it is reproduced with permission.Root secretion of coumarin-phenolic type compounds has been recently shown to be related to Arabidopsis thaliana tolerance to Fe deficiency at high pH. Previous studies revealed the identity of a few simple coumarins occurring in roots and exudates of Fe-deficient A. thaliana plants, and left open the possible existence of other unknown phenolics. We used HPLC-UV/VIS/ESI-MS(TOF), HPLC/ESI-MS(ion trap) and HPLC/ESI-MS(Q-TOF) to characterize (identify and quantify) phenolic-type compounds accumulated in roots or secreted into the nutrient solution of A. thaliana plants in response to Fe deficiency. Plants grown with or without Fe and using nutrient solutions buffered at pH 5.5 or 7.5 enabled to identify an array of phenolics. These include several coumarinolignans not previously reported in A. thaliana (cleomiscosins A, B, C, and D and the 5′-hydroxycleomiscosins A and/or B), as well as some coumarin precursors (ferulic acid and coniferyl and sinapyl aldehydes), and previously reported cathecol (fraxetin) and non-cathecol coumarins (scopoletin, isofraxidin and fraxinol), some of them in hexoside forms not previously characterized. The production and secretion of phenolics were more intense when the plant accessibility to Fe was diminished and the plant Fe status deteriorated, as it occurs when plants are grown in the absence of Fe at pH 7.5. Aglycones and hexosides of the four coumarins were abundant in roots, whereas only the aglycone forms could be quantified in the nutrient solution. A comprehensive quantification of coumarins, first carried out in this study, revealed that the catechol coumarin fraxetin was predominant in exudates (but not in roots) of Fe-deficient A. thaliana plants grown at pH 7.5. Also, fraxetin was able to mobilize efficiently Fe from a Fe(III)-oxide at pH 5.5 and pH 7.5. On the other hand, non-catechol coumarins were much less efficient in mobilizing Fe and were present in much lower concentrations, making unlikely that they could play a role in Fe mobilization. The structural features of the array of coumarin type-compounds produced suggest some can mobilize Fe from the soil and others can be more efficient as allelochemicals.Work supported by the Spanish Ministry of Economy and Competitiveness (MINECO) (grant AGL2013-42175-R, co-financed with FEDER) and the Aragón Government (group A03). PS-T and AL-V were supported by MINECO-FPI contracts.Peer reviewe

Root excretion and accumulation of riboflavin derivatives in iron-deficient Medicago truncatula

1 .pdf (43 Pags.) copia de la presentación original de los autores en el Simposio Internacional. Se adjunta también 1 .pdf con copia del "abstract" oficial.When grown in hydroponics under Fe deficiency, some Strategy I plant species develop yellow roots and cause a yellowing of the solution [1-2]. This phenomenon, first reported in the 60’s, is due to root accumulation and excretion of riboflavin and/or riboflavin derivatives such as riboflavin sulphates [3]. The function these compounds play in plant Fe efficiency is still not known, although roles in facilitating electron flow to the root Fe reductase and as antimicrobial agents in the rhizosphere have been hypothesized [4]. Any of these mechanisms may contribute to increase plant Fe efficiency. The aim of this work was to study flavin compounds present in roots of Fe-deficient Medicago truncatula. Plants were grown in Fe-sufficient nutrient solution (45 µM Fe) and in two Fe-deficient (0 µM Fe) nutrient solutions, either with CaCO3 (pH 8.0) or without CaCO3 (pH 5.5). Roots from Fe-sufficient plants were white and roots from Fe-deficient plants were yellow. Root morphology in the two Fe-deficient treatments was different, with swollen yellow tips at pH 8.0, and swollen tips (only some of them yellow) and yellow patches along their length at pH 5.5. A yellow colour was observed only in the Fe-deficient nutrient solution without CaCO3. Flavin compounds in the nutrient solution were concentrated in C18 Sep-Pack cartridges and eluted in methanol, and those in roots were extracted by grinding them with 100 mM ammonium acetate, pH 6.1. Flavin derivatives in root extracts and nutrient solution concentrates were separated by high performance liquid chromatography, and identification was carried out by ultraviolet-visible photodiode array spectrophotometry and electrospray ionization mass spectrometry, using time of flight (TOF) and quadrupole time of flight (QTOF) instruments. Root flavin accumulation and excretion depended on the plant Fe status and the presence of CaCO3 in the nutrient solution.In root extracts from Fe-sufficient plants only riboflavin was detected, whereas in roots of plants grown in both Fe deficiency treatments riboflavin and three different riboflavin derivatives were detected. Two of these derivatives were identified as 7α-hydroxyriboflavin and (E)-5-(4,5-dimethyl-2-((3R,4S)-2,3,4,5-tetrahydroxypentylamino)phenylimino)pyrimidine-2,4(3H,5H)-dione, the latter compound originated from the partial rupture of the riboflavin's isoalloxazine ring. In nutrient solutions, riboflavin and derivatives were detected only in Fe deficiency treatments, and the concentrations were much higher in nutrient solutions without CaCO3 than in those with CaCO3. As a conclusion, Fe-deficient M. truncatula roots accumulated and excreted riboflavin and three riboflavin derivatives different from those previously reported in plants. Further investigation is under way to identify the third flavin compound found.This study was supported by the Spanish Ministry of Science and Education (projects AGL2006-1416 and AGL2007-61948, co-financed with FEDER), the European Commission (EU 6th Framework Integrated Project ISAFRUIT), and the Aragón Government (group A03).Peer reviewe

Effects of Fe deficiency on the protein profiles and lignin composition of stem tissues from Medicago truncatula in absence or presence of calcium carbonate

12 Pags.- 2 Tabls.- 5 Figs.- Supp. Data.Iron deficiency is a yield-limiting factor with major implications for crop production, especially in soils with high CaCO3. Because stems are essential for the delivery of nutrients to the shoots, the aim of this work was to study the effects of Fe deficiency on the stem proteome of Medicago truncatula. Two-dimensional electrophoresis separation of stem protein extracts resolved 276 consistent spots in the whole experiment. Iron deficiency in absence or presence of CaCO3 caused significant changes in relative abundance in 10 and 31 spots, respectively, and 80% of them were identified by mass spectrometry. Overall results indicate that Fe deficiency by itself has a mild effect on the stem proteome, whereas Fe deficiency in the presence of CaCO3 has a stronger impact and causes changes in a larger number of proteins, including increases in stress and protein metabolism related proteins not observed in the absence of CaCO3. Both treatments resulted in increases in cell wall related proteins, which were more intense in the presence of CaCO3. The increases induced by Fe-deficiency in the lignin per protein ratio and changes in the lignin monomer composition, assessed by pyrolysis-gas chromatography–mass spectrometry and microscopy, respectively, further support the existence of cell wall alterations. Biological significance: In spite of being essential for the delivery of nutrients to the shoots, our knowledge of stem responses to nutrient deficiencies is very limited. The present work applies 2-DE techniques to unravel the response of this understudied tissue to Fe deficiency. Proteomics data, complemented with mineral, lignin and microscopy analyses, indicate that stems respond to Fe deficiency by increasing stress and defense related proteins, probably in response of mineral and osmotic unbalances, and eliciting significant changes in cell wall composition. The changes observed are likely to ultimately affect solute transport and distribution to the leaves.Work supported by the Spanish Ministry of Science and Competitiveness (MINECO; projects AGL2012-31988, AGL2011-25379 and AGL2013-42175-R, co-financed by FEDER), the Aragón Government (group A03), and the US Department of Agriculture, Agricultural Research Service (under Agreement number 58-6250-0-008 to MAG). Support was obtained by contracts I3P-CSIC (JRC), FPI-MINECO (GL and LC-L), JAE-PRE-CSIC (EG-C) and JAE-DOC-CSIC (JR), co-financed by the European Social Fund.Peer reviewe

75 años como referente de la investigación agraria y medioambiental española en condiciones de clima mediterráneo [Sitio Web]

1 .pdf con imagen de acceso al “website”, su url y los créditos relacionados con su creación y diseño.-- Créditos: Organización, Estación Experimental de Aula Dei (EEAD-CSIC); Dirección, Jesús Val Falcón; Coordinación, Ana Álvarez-Fernandez, Jorge Álvaro-Fuentes, Ernesto Igartua; Contenido, Anunciación Abadía, Javier Abadía, Carlos Albiñana, Miguel Alfonso, Arancha Arbeloa, Raúl Arbués, Isabel Armillas, Manuel Becana, Santiago Beguería, Carmen Castañeda, Ana Castillo, José Cavero, Bruno Contreras, Azahara Díaz, Edgar García, Elena García, Juan Manuel Gascuñana, Leticia Gaspar, Yolanda Gogorcena, Juan Herrero, Victoria Lafuente, María Victoria López, Juan Antonio Marín, José Martínez, José Carlos Martínez-Giménez, Ana Pilar Mata, Manuel Matamoros, Pierre Mignard, María Ángeles Moreno, Paula Murillo, Ana Navas, Antonio Pérez, Rafael Picorel, María Pilar Vallés, Irene Villar, Inmaculada Yruela, Nery Zapata, Isabel Zarazaga; Diseño y programación: DigitalWorks (Juanjo Ascaso y Asun Dieste); Vídeo, Delegación del CSIC en Aragón (Sara Gutiérrez y Yolanda Hernáiz); Fotografía, Archivo EEAD-CSIC, Anunciación Abadía, Jorge Álvaro-Fuentes, Arancha Arbeloa, Juanjo Ascaso, Santiago Beguería, Elena García, Ernesto Igartua, Ignasi Iglesias, José Manuel Lasa, José Carlos Martínez-Giménez, Pierre Mignard, María Ángeles Moreno, Rubén Sancho, Kosana Suvocarev, María Pilar Vallés, Nery Zapata."Sitio web" de nueva creación y conmemorativo del 75 Aniversario de la EEAD-CSIC que contiene: 1) Foto esférica de su personal en activo; 2) Recopilación de sus hitos históricos más destacados, en orden cronológico; 3) Un vídeo con participación de su personal y muestra de algunas de sus instalaciones; 4) Un mapa con la distribución geográfica de los egresado del Instituto; 5) Algunas fotos, destacando las tomadas a su personal en las celebraciones del 25 y 50 Aniversarios de la EEAD-CSIC.Presentado durante la "Jornada. 75 Aniversario EEAD-CSIC (Zaragoza, Patio de la Infanta. 30 octubre 2019)".Financiación: CSIC, Vicepresidencia Adjunta de Organización y Cultura Científica.N