Instituto Universitario Mixto de Biología Molecular y Celular de Plantas

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New C-21 Delta(20) pregnanes, inhibitors of mitochondrial respiratory chain, from Indopacific octocoral Carijoa sp
(Elsevier, 2004-10-04) Ciavatta, M. Letizia; López Gresa, María Pilar; Manzo, Emiliano; Gavagnin, Margherita; Wahidulla, Solimabi; Cimino, Guido; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Dpto. de Biotecnología; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural
[EN] Two new compounds, pregnanes 1 and 2, the known pregnane 3 and a series of known chlorinated prostanoids (4¿9) have been isolated from the Indian octocoral Carijoa sp. Their structures have been elucidated by spectroscopic methods, mainly by 1D and 2D NMR. The new compounds were potent inhibitors of the mitochondrial respiratory chain.
Gibberellins modulate light signalling pathways to prevent seedling de-etiolation in darkness.
(Blackwell Publishing, 2008-01) Alabadí, David; Gallego Bartolomé, Javier; Orlando, Leonardo; García-Cárcel, Laura; Rubio, Vicente; Martínez Sánchez, Mª Cristina; Frigerio, Martín; Iglesias-Pedraz, Juan Manuel; Espinosa, Ana; Wang Deng, Xing; Blazquez Rodriguez, Miguel Angel; Instituto Universitario Mixto de Tecnología Química; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Ministerio de Educación; Ministerio de Educación y Ciencia; European Molecular Biology Organization; Fundación de la Comunitat Valenciana para la Investigación Agroalimentaria, Agroalimed
[EN] In many plants, photomorphogenesis is the default developmental program after seed germination, and provides the key features that allow adaptation to light. This program is actively repressed if germination occurs in the absence of light, through a mechanism dependent on the E3 ubiquitin ligase activity that is encoded in Arabidopsis by COP1 ((CO) under bar NSTITUTIVE (P) under bar HOTOMORPHOGENIC 1), which induces proteolytic degradation of transcription factors necessary for light-regulated development, such as HY5 (LONG (HY) under bar POCOTYL 5) and HYH (LONG (HY) under bar POCOTYL 5 (H) under bar OMOLOG), and stabilization of transcription factors that promote skotomorphogenesis, such as PIF3 ((P) under bar HYTOCHROME (I) under bar NTERACTING (F) under bar ACTOR 3). Seedlings deficient in gibberellin (GA) synthesis or signaling display a de-etiolated phenotype when grown in darkness, equivalent to the phenotype of cop1 mutants, which indicates that the switch between photo- and skotomorphogenesis is also under hormonal control. Here we provide evidence for the existence of crosstalk between GA and the COP1-mediated pathway, and identify HY5 and the PIF family as nodes of a regulatory network. This interaction occurs through distinct molecular mechanisms, based on the observation that GA signaling regulates protein stability of HY5, and the activity of PIF3.
Induction of p-coumaroyidopamine and feruloyidopamine, two novel metabolites, in tomato by the bacterial pathogen Pseudomonas syringae
(Scientific Societies, 2007) Zacarés Sanmartín, Laura; López Gresa, María Pilar; Fayos Febrer, Joaquín; Primo Millo, Jaime; Belles Albert, José María; Conejero Tomás, Vicente; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Dpto. de Biotecnología; Instituto Agroforestal Mediterráneo; Dpto. de Química; Escuela Técnica Superior de Ingeniería Industrial; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural; Ministerio de Ciencia y Tecnología
[EN] Inoculation of tomato plants (Solanum lycopersicum cv. Rutgers) with Pseudomonas syringae pv. tomato led to the production of a hypersensitive-like response in this pathovar of tomato. Accumulation of hydroxycinnamic acid amides (HCAA) of tyramine (p-coumaroyltyramine and feruloyltyramine) and dopamine (p-coumaroyldopamine and feruloyldopamine) was detected after bacterial infection. Two of them, p-coumaroyldopamine and feruloyldopamine, are described for the first time. The accumulation of HCAA was preceded by an increment of hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) gene expression. HCAA also accumulated in transgenic NahG tomato plants overexpressing a bacterial salicylic hydroxylase. However, treatment of plants with the ethylene biosynthesis inhibitor, aminoethoxyvinilglycine, led to a reduction in the accumulation of THT transcripts and HCAA. Together, the results suggest that pathogen-induced induction of ethylene is essential for HCAA synthesis, whereas salicylic acid is not required for this response. In addition, notable antibacterial and antioxidant activities were found for the new HCAA, thus indicating that they could play a role in the defense of tomato plants against bacterial infection.
Double-stranded RNA interferes in a sequence-specific manner with the infection of representative members of the two viroid families
(Elsevier, 2008-02-05) Carbonell Olivares, Alberto; Martínez de Alba, Ángel-Emilio; FLORES PEDAUYE, RICARDO; Gago, Selma; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Generalitat Valenciana; Ministerio de Educación y Ciencia; Consejo Superior de Investigaciones Científicas
[EN] Infection by viroids, non-protein-coding circular RNAs, occurs with the accumulation of 21¿24 nt viroid-derived small RNAs (vd-sRNAs) with characteristic properties of small interfering RNAs (siRNAs) associated to RNA silencing. The vd-sRNAs most likely derive from dicer-like (DCL) enzymes acting on viroid-specific dsRNA, the key elicitor of RNA silencing, or on the highly structured genomic RNA. Previously, viral dsRNAs delivered mechanically or agroinoculated have been shown to interfere with virus infection in a sequence-specific manner. Here, we report similar results with members of the two families of nuclear- and chloroplast-replicating viroids. Moreover, homologous vd-sRNAs codelivered mechanically also interfered with one of the viroids examined. The interference was sequence-specific, temperature-dependent and, in some cases, also dependent on the dose of the co-inoculated dsRNA or vd-sRNAs. The sequence-specific nature of these effects suggests the involvement of the RNA induced silencing complex (RISC), which provides sequence specificity to RNA silencing machinery. Therefore, viroid titer in natural infections might be regulated by the concerted action of DCL and RISC. Viroids could have evolved their secondary structure as a compromise between resistance to DCL and RISC, which act preferentially against RNAs with compact and relaxed secondary structures, respectively. In addition, compartmentation, association with proteins or active replication might also help viroids to elude their host RNA silencing machinery.
First report of Tomato torrado virus on weed hosts in Spain
(Scientific Societies, 2008-05) Alfaro Fernández, Ana Olvido; Córdoba-Sellés, C.; Cebrián, M.C; Herrera-Vásquez, J.A.; Sanchez Navarro, Jesus Angel; Juárez, M.; Espino, A.; Martín, R.; Jordá, C.; Dpto. de Ecosistemas Agroforestales; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Instituto Agroforestal Mediterráneo; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural
Obtención de marcadores moleculares para su aplicación a la mejora genética del albaricoquero
(Universitat Politècnica de València, 2009-06-16T12:33:07Z) Hurtado Ruiz, Monica Asuncion; Moreno Ferrero, Vicente; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Dpto. de Biotecnología; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural
La especie albaricoquero (P. armeniaca L.), originaria de China y Asia Central, se cultiva en España principalmente en Murcia y Valencia. La aparición y extensión del virus de la Sharka ha puesto de manifiesto la necesidad de obtener nuevas variedades resmoleculares que se han definido útiles en los procesos de selección en programas de mejora: RFLPs (Restriction Fragment Lenght Polimorphism), RAPDs (Random Amplified Polimorphic DNA) y AFLPs (Amplified Fragment Length Polimorphism).Con ellos se ha realizado un estudio de diversidad genética, utilizando 16 variedades de albaricoquero procedentes de Francia, España y Norteamérica, que incluyen variedades resistentes y susceptibles a Sharka. Algunas de ellas se están utilizando como genitores en el programa de mejora del IVIA. Se ha elaborado el primer mapa genómico de la especie albaricoquero, basado en los marcadores moleculares RAPDs y AFLPs. Se ha estudiado la herencia del carácter resistencia a Sharka, y se ha establecido la hipótesis de herencia basada en 2 genes independientes.Con el fin de obtener marcadores moleculares ligados a los caracteres autoincompatibilidad y androesterilidad en albaricoquero, se ha utilizado la técnica del Bulk Segregation Analysis (BSA) combinada con marcadores tipo RAPD.
Identificación de mutantes de Arabidopsis thaliana resistentes a norespermidina. Clonación y caracterización de una sulfidril oxidasa
(Universitat Politècnica de València, 2008-05-07T07:10:06Z) Alejandro Martínez, Santiago; Serrano Salom, Ramón; Rodríguez Egea, Pedro Luís; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas
La salinidad es uno de los estreses ambientales que más incide en la productividad agrícola, especialmente en las regiones semiáridas como la zona mediterránea, donde se ubica la Comunidad Valenciana. Para poder mitigar los efectos perjudiciales de los estreses abióticos resulta necesario conocer las bases moleculares de los fenómenos investigados, ya que soló entonces podrán ser manipulados de la manera más conveniente. En el caso de la tolerancia a la salinidad se conocen una serie de aspectos claves que han contribuido a mejorar las plantas cultivadas, pero es necesaria mucha más investigación para poder obtener resultados adecuados para la practica agrícola. En este trabajo se ha planteado un nuevo abordaje consistente en el uso de norespermidina, una poliamina no metabolizable, como agente de selección para encontrar individuos resistentes a cationes tóxicos. Para ello se ha utilizado una colección de semillas de Arabidopsis mutadas por inserción de un activador transcripcional. Con este abordaje se aisló el mutante par1-1D (polyamine resistant) que presenta un fenotipo pleiotrópico de resistencia a cationes tóxicos como Na+, Li+, norespermidina y espermidina. par1-1D es un mutante dominante que presenta un aumento en la expresión del locus At1g15020. Este locus codifica una proteína perteneciente a la familia de las quiescina sulfidril oxidasas (existen 2 proteínas homólogas de esta familia en Arabidopsis) por lo que se propuso el nombre de QSO2 (quiescina sulfidril oxidasa) para denominar al locus At1g15020. Mediante un análisis de RT-PCR en diferentes partes de la planta se encontró que QSO2 se expresa principalmente en la raíz y el polen, además al expresar de forma transitoria la construcción QSO2::GFP en la epidermis de hojas de N. benthamiana, la expresión de QSO2 se localizó en la pared celular. Por otro lado, se expresó y purificó en S. cerevisae la proteína recombinante QSO2 y se demostró su actividad sulfidril oxidasa. Finalmente, en plántulas y pl
Production and fungitoxic activity of Sch 642305, a secondary metabolite of Penicillium canescens
(Springer-Verlag, 2007) Nicoletti, Rosario; López Gresa, María Pilar; Manzo, Emiliano; Carella, Angela; Ciavatta, M. Letizia; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Dpto. de Biotecnología; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural
[EN] Production of fungitoxic extrolites was evaluated in culture filtrates of several isolates belonging to Penicillium canescens and P. janczewskii that showed some extent of inhibitory activity against the plant pathogenic fungus Rhizoctonia solani. In addition to griseofulvin and dechlorogriseofulvin that are already known in these species, curvulinic acid, previously unreported in Penicillium, was produced by all isolates assayed. Another extrolite recently characterized from a P. verrucosum strain by the name of Sch 642305 was detected in 5 isolates of P. canescens only. The purified compound completely inhibited mycelial growth of isolates of Rhizoctonia solani and other plant pathogenic fungi in vitro. The role of this extrolite as a possible biochemical determinant of antagonism toward plant pathogenic fungi, and implications concerning chemotaxonomy are discussed.
Interactions of metals ions with two Quinolones Antimicrobial agents (cinoxacin and ciprofloxacin): Spectroscopic and X-Ray structural characterization. Antibacterial Studies
(Elsevier, 2002-09) López Gresa, María Pilar; Ortiz, R.; Perelló, L.; Latorre, J.; Liu-González, M.; García-Granda, S.; Pérez-Priede, M.; Cantón, E.; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Dpto. de Biotecnología; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural; Ministerio de Educación y Cultura
[EN] Several novel metal-quinolone compounds have been synthesized and characterized by analytical, spectroscopic and X-ray diffraction methods. The crystal structure of the four compounds, Na2[(Cd(Cx)3)(Cd(Cx)3(H2O))]·12H2O, [Co(Cp)2(H2O)2]·9H2O, [Zn(Cp)2(H2O)2]·8H2O and [Cd(HCp)2(Cl)2]·4H2O, is presented and discussed: HCx=1-ethyl-1,4-dihydro-4-oxo(1,3)-dioxolo(4,5-g)cinnoline-3-carboxylic acid and HCp=1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid. In all these compounds the quinolone acts as a bidentate chelate ligand that binds through one carboxylate oxygen atom and the exocyclic carbonyl oxygen atom. Complexes of ciprofloxacin were screened for their activity against several bacteria, showing activity similar to that of the ligand. In addition, the number of bacteria killed after 3 h of incubation with the ligand, [Co(Cp)2(H2O)2]·9H2O, Ni(Cp)2·10H2O and Cu(Cp)2·6H2O, was determined against S. aureus ATCC25923. There is a direct relationship between the growth rate and the lethal rate. Against growing bacteria, the ligand is the most bactericidal and Cu(Cp)2·6H2O is the less bactericidal. On the contrary, against non-dividing bacteria, the complexes were more bactericidal than the ligand, with Cu(Cp)2·6H2O the most bactericidal compound.
Hormonal regulation of temperature-induced growth in Arabidopsis
(Blackwell Publishing, 2009-11) Stavang, Jon A.; Gallego Bartolomé, Javier; Gómez Jiménez, Maria Dolores; Yoshida, Shigeo; Asami, Tadao; Olsen, Jorunn E.; García-Martínez, José L.; Alabadí Diego, David; Blazquez Rodriguez, Miguel Angel; Instituto Universitario Mixto de Biología Molecular y Celular de Plantas; Research Council of Norway; Ministerio de Educación y Ciencia; Ministerio de Ciencia e Innovación
[EN] Successful plant survival depends upon the proper integration of information from the environment with endogenous cues to regulate growth and development. We have investigated the interplay between ambient temperature and hormone action during the regulation of hypocotyl elongation, and we have found that gibberellins (GAs) and auxin are quickly and independently recruited by temperature to modulate growth rate, whereas activity of brassinosteroids (BRs) seems to be required later on. Impairment of GA biosynthesis blocked the increased elongation caused at higher temperatures, but hypocotyls of pentuple DELLA knockout mutants still reduced their response to higher temperatures when BR synthesis or auxin polar transport were blocked. The expression of several key genes involved in the biosynthesis of GAs and auxin was regulated by temperature, which indirectly resulted in coherent variations in the levels of accumulation of nuclear GFP-RGA (repressor of GA1) and in the activity of the DR5 reporter. DNA microarray and genetic analyses allowed the identification of the transcription factor PIF4 (phytochrome-interacting factor 4) as a major target in the promotion of growth at higher temperature. These results suggest that temperature regulates hypocotyl growth by individually impinging on several elements of a pre-existing network of signaling pathways involving auxin, BRs, GAs, and PIF4.