Commercial wood of clones of genus Populus : relationship between growth and density of wood with inorganic nutrients

El objetivo del trabajo fue determinar sobre 10 clones de álamos, provenientes de cruzamientos intraespecíficos de Populus deltoides e interespecíficos de Populus x canadensis, implantados en Teodelina, Santa Fe, Argentina (34°09' S; 61°15' W), la concentración de nutrientes inorgánicos en su corteza y leño, y sus relaciones con los volúmenes comerciales alcanzados a los 9 años de edad y la densidad básica de la madera. Se apearon ejemplares seleccionados, se calculó su volumen comercial individual y se determinaron la densidad básica y las concentraciones de Ca, Mg, P y K en fuste y corteza. Se realizó análisis de la varianza, test de comparación de medias de Tukey y correlación simple de los diferentes parámetros evaluados. Los resultados arrojaron diferentes contenidos de nutrientes por clon y concentraciones más bajas en la madera que en la corteza, en todos los casos. No hubo correlaciones significativas entre el volumen comercial obtenido, los valores de densidad básica de la madera y los nutrientes inorgánicos, indicando eficiencias individuales en el uso de los recursos inorgánicos.The aim of this study carried out on 10 Poplar clones, originated from intraspecific crossings of Populus deltoides and interspecific crossings of Populus x canadensis, planted in Teodelina, Santa Fe, Argentina (34°09' S; 61°15' W), was to determine inorganic nutrient concentration in bark and wood and their relations to comercial volume at the age of 9 and their basic wood density. Selected samples were cut and their comercial volume measured. Their basic wood density and Ca, Mg, P and K concentration were established. Analysis of Variance, Tukey´s test comparison of means and simple correlation of the different evaluated parameters were performed. The results showed differences in nutrient content per clone. There were no significant correlations between the reached commercial volume, basic wood density and inorganic nutrient values, which showed individual efficiencies in the use of inorganic resources. In all analysed cases, the wood showed lower nutrient concentration than the one present in the bark.Fil: Senisterra, Gabriela E..Fil: Marlats, Raúl M..Fil: Ducid, María G.

Efecto del sitio, el origen y el clon sobre el crecimiento y propiedades de la madera de Populus

The objective of this paper was to study site, hybrid cross and clone effects on total height, BHD [Breast height diameter], volume, wood basic density, fibre length and yield, of eleven poplars clones. 10-year-old hybrid poplar clones were sampled at two sites in Argentina (MD and EG). The material studied consisted of two poplar hybrid crosses Populus deltoides x P. deltoides and P. deltoides x P. nigra (P. x canadensis = P. x euramericana), as well as P. deltoides. Sites influenced significantly growth traits and wood density, hybrid influenced tree height, wood density and fibre length and clones influenced all variables. MD trees were 5% higher and 2% denser than EG trees, but EG trees were 7% greater in BDH and 11% more volume than the MD trees. P. deltoides and P. deltoides intra specific crosses were 4% higher and 4% denser than P. x canadensis trees. P. x canadensis fibre length was 3% higher than P. x deltoides. According to all properties, difference between site and hybrid were not very importanThe properties of the clones had different responses regardless of the hybrid crosses. 610-31 and 564-17 clones (P. x deltoides) and 568-1 and Triplo (P. x canadensis) clones were distinguished.El objetivo del trabajo fue estudiar el efecto del sitio, el híbrido y el clon, sobre la altura total, DAP [Diámetro a la altura del pecho], volumen, densidad de la madera, longitud de fibras y rendimiento, de 11 clones de álamos. Se muestrearon ensayos de 10 años en dos sitios de Argentina (MD y EG). Los clones provienen de cruzamientos de P. deltoides, de cruzamientos de P. deltoides x P.nigra (P. x canadensis = P. euramericana) y P.deltoides. El sitio influyó significativamente en el crecimiento y densidad, el híbrido en la altura, densidad y longitud de fibras y los clones en todas las variables. Los árboles del sitio MD resultaron 5% más altos y 2% más densos, pero los ejemplares de EG resultaron con mayor DAP (7%) y volumen (11%). Los híbridos de P. x deltoides resultaron 4% mas altos y 4% más densos que los P. x canadensis. En longitud de fibras los híbridos P. x canadensis fueron 3% superiores. Las diferencias entre sitios y entre híbridos no resultaron tan marcadas considerando el conjunto de las propiedades. Los clones tuvieron diferente respuesta en las propiedades independientemente del cruzamiento del que derivan. Se destacaron los clones 610-31 y 564-17 (P. x deltoides) y 568-1 y Triplo (P. x canadensis)

Evaluation of two years aged Populus clones, in two microsites of the pampean region, Argentina

La producción de álamos en la pampa ondulada de la provincia de Buenos Aires podría constituir una actividad alternativa y/o complementaria, debido a zonas ecológicas favorables para su cultivo. En este contexto es importante conocer el comportamiento de los clones en los diversos ambientes para poder definir cuáles de ellos podrían presentar mayor estabilidad para los diferentes sitios. El objetivo del trabajo fue estudiar la interacción existente entre los parámetros de crecimiento y supervivencia de 16 clones de Populus spp. en dos micrositios geomorfológicamente diferentes en la región pampeana, Argentina. Los clones en estudio provienen de cruzamientos intraespecíficos de P. deltoides e interespecíficos de P. deltoides x P. nigra (Populus x canadensis). Se plantaron en dos ensayos, uno por cada situación geomórfica: loma y bajo, y se completó con un análisis estadístico comparando los ensayos en forma individual y conjunta. Cada ensayo se instaló con un diseño de bloques completos al azar. Las variables analizadas fueron la supervivencia, la altura media y el área basal al concluir el segundo año de crecimiento. Para el sitio regional evaluado, la interacción entre los clones y los micrositios fue significativa para las variables altura y supervivencia. La mayor disponibilidad de agua en el micrositio bajo produjo mayores crecimientos clonales con diferencias significativas respecto del micrositio loma. La estabilidad de los atributos de supervivencia y crecimiento frente a los micrositios es un objetivo fundamental en las plantaciones clonales. Siendo los micrositios una realidad ambiental importante, propia como variable no controlable, la reducción de la variabilidad de respuesta ante ellos permitiría la constitución de unidades de manejo más homogéneas.Poplar production in the pampean region of the province of Buenos Aires could become an altenative and/or complementary activity, because of the ecological conditions for its cultivation. It is within this context that is important to know the behaviour of the clones in the different environments, in order to define which ones could present more stability in the different sites. The aim of this work was to study the interaction between the growth and the survival parameters of 16 clones of Populus spp., in two geomorphologycal different micro-sites, in the pampean region of Argentina. The studied clones were planted in two different essays, one for each geomorphic situation: hill and lowland. A statistic analysis was done in order to compare the essays in an individual and in a combined way. Each essay was installed with a randomized block design. The analyzed variables by the end of the second year of growth were survival, mean height and basal area. For the evaluated region, the interaction between clones and micro sites was significant for height and survival. The mayor water availability in the lowland micro-site produced mayor clone growth, with significant differences with the hill micro-site. The stability of survival and growth in the micro-sites is one of the principal objects in a clone plantation. Being the microsite a huge environmental reality, as a non controllable variable, the reduction of variability in the response, will allow the construction of more homogeneous management units.Fil: Senisterra, Gabriela E..Fil: Ducid, María G..Fil: Gaspari, Fernanda J..Fil: Delgado, María Isabel

Susceptibilidad a Septoria musiva de híbridos inter e intraespecíficos de Populus spp. implantados en dos micrositios de la Pampa Húmeda Argentina

En los álamos, una de las enfermedades con mayor influencia en la cantidad y calidad de la madera producida es la cancrosis o r i g i n a d a p o r S e p t o r i a m u s i v a P e c k . El objetivo del trabajo fue determinar en clones híbridos de álamos (Populus spp.) la incidencia y la severidad de la enfermedad producida por Septoria, en dos micrositios de un mismo sitio regional, en Alberti, Buenos Aires, Argentina. Los clones utilizados fueron obtenidos de cruzamientos intraespecíficos de Populus deltoides e interespecíficos de P. deltoides x P. nigra (= P. x canadensis). Se determinó la susceptibilidad a la enfermedad para cada clon/micrositio mediante la estimación de la incidencia, del número de cancros en guías y ramas, y la severidad de daños (ID). Los híbridos inter e intraespecíficos de P. deltoides presentaron respuesta clonal diferencial en la susceptibilidad a la cancrosis en ambas situaciones geomórficas: los híbridos provenientes de cruzamientos intraespecíficos resultaron resistentes, y los provenientes de cruzamientos interespecíficos susceptibles a la enfermedad. Las diferencias significativas entre clones, determinadas para el número de lesiones totales por posición en ambas situaciones geomórficas, no determinaron ID diferentes. El número de cancros identificados en cada posición constituye una herramienta de estimación de la susceptibilidad clonal a la cancrosis más exacta, teniendo en cuenta que los mayores perjuicios ocurren cuando las lesiones se presentan en las guías.En los álamos, una de las enfermedades con mayor influencia en la cantidad y calidad de la madera producida es la cancrosis o r i g i n a d a p o r S e p t o r i a m u s i v a P e c k . El objetivo del trabajo fue determinar en clones híbridos de álamos (Populus spp.) la incidencia y la severidad de la enfermedad producida por Septoria, en dos micrositios de un mismo sitio regional, en Alberti, Buenos Aires, Argentina. Los clones utilizados fueron obtenidos de cruzamientos intraespecíficos de Populus deltoides e interespecíficos de P. deltoides x P. nigra (= P. x canadensis). Se determinó la susceptibilidad a la enfermedad para cada clon/micrositio mediante la estimación de la incidencia, del número de cancros en guías y ramas, y la severidad de daños (ID). Los híbridos inter e intraespecíficos de P. deltoides presentaron respuesta clonal diferencial en la susceptibilidad a la cancrosis en ambas situaciones geomórficas: los híbridos provenientes de cruzamientos intraespecíficos resultaron resistentes, y los provenientes de cruzamientos interespecíficos susceptibles a la enfermedad. Las diferencias significativas entre clones, determinadas para el número de lesiones totales por posición en ambas situaciones geomórficas, no determinaron ID diferentes. El número de cancros identificados en cada posición constituye una herramienta de estimación de la susceptibilidad clonal a la cancrosis más exacta, teniendo en cuenta que los mayores perjuicios ocurren cuando las lesiones se presentan en las guías

On the Mechanism of Action of SJ-172550 in Inhibiting the Interaction of MDM4 and p53

SJ-172550 (1) was previously discovered in a biochemical high throughput screen for inhibitors of the interaction of MDMX and p53 and characterized as a reversible inhibitor (J. Biol. Chem. 2010; 285∶10786). Further study of the biochemical mode of action of 1 has shown that it acts through a complicated mechanism in which the compound forms a covalent but reversible complex with MDMX and locks MDMX into a conformation that is unable to bind p53. The relative stability of this complex is influenced by many factors including the reducing potential of the media, the presence of aggregates, and other factors that influence the conformational stability of the protein. This complex mechanism of action hinders the further development of compound 1 as a selective MDMX inhibitor

Pan-Pathway Based Interaction Profiling of FDA-Approved Nucleoside and Nucleobase Analogs with Enzymes of the Human Nucleotide Metabolism

To identify interactions a nucleoside analog library (NAL) consisting of 45 FDA-approved nucleoside analogs was screened against 23 enzymes of the human nucleotide metabolism using a thermal shift assay. The method was validated with deoxycytidine kinase; eight interactions known from the literature were detected and five additional interactions were revealed after the addition of ATP, the second substrate. The NAL screening gave relatively few significant hits, supporting a low rate of “off target effects.” However, unexpected ligands were identified for two catabolic enzymes guanine deaminase (GDA) and uridine phosphorylase 1 (UPP1). An acyclic guanosine prodrug analog, valaciclovir, was shown to stabilize GDA to the same degree as the natural substrate, guanine, with a ΔTagg around 7°C. Aciclovir, penciclovir, ganciclovir, thioguanine and mercaptopurine were also identified as ligands for GDA. The crystal structure of GDA with valaciclovir bound in the active site was determined, revealing the binding of the long unbranched chain of valaciclovir in the active site of the enzyme. Several ligands were identified for UPP1: vidarabine, an antiviral nucleoside analog, as well as trifluridine, idoxuridine, floxuridine, zidovudine, telbivudine, fluorouracil and thioguanine caused concentration-dependent stabilization of UPP1. A kinetic study of UPP1 with vidarabine revealed that vidarabine was a mixed-type competitive inhibitor with the natural substrate uridine. The unexpected ligands identified for UPP1 and GDA imply further metabolic consequences for these nucleoside analogs, which could also serve as a starting point for future drug design

A cellular chemical probe targeting the chromodomains of Polycomb repressive complex 1

We report the design and characterization of UNC3866, a potent antagonist of the methyllysine (Kme) reading function of the Polycomb CBX and CDY families of chromodomains. Polycomb CBX proteins regulate gene expression by targeting Polycomb repressive complex 1 (PRC1) to sites of H3K27me3 via their chromodomains. UNC3866 binds the chromodomains of CBX4 and CBX7 most potently, with a K d of â ∼1/4100 nM for each, and is 6-to 18-fold selective as compared to seven other CBX and CDY chromodomains while being highly selective over >250 other protein targets. X-ray crystallography revealed that UNC3866's interactions with the CBX chromodomains closely mimic those of the methylated H3 tail. UNC4195, a biotinylated derivative of UNC3866, was used to demonstrate that UNC3866 engages intact PRC1 and that EED incorporation into PRC1 is isoform dependent in PC3 prostate cancer cells. Finally, UNC3866 inhibits PC3 cell proliferation, consistent with the known ability of CBX7 overexpression to confer a growth advantage, whereas UNC4219, a methylated negative control compound, has negligible effects

Exploring the Trypanosoma brucei Hsp83 Potential as a Target for Structure Guided Drug Design

Human African trypanosomiasis is a neglected parasitic disease that is fatal if untreated. The current drugs available to eliminate the causative agent Trypanosoma brucei have multiple liabilities, including toxicity, increasing problems due to treatment failure and limited efficacy. There are two approaches to discover novel antimicrobial drugs--whole-cell screening and target-based discovery. In the latter case, there is a need to identify and validate novel drug targets in Trypanosoma parasites. The heat shock proteins (Hsp), while best known as cancer targets with a number of drug candidates in clinical development, are a family of emerging targets for infectious diseases. In this paper, we report the exploration of T. brucei Hsp83--a homolog of human Hsp90--as a drug target using multiple biophysical and biochemical techniques. Our approach included the characterization of the chemical sensitivity of the parasitic chaperone against a library of known Hsp90 inhibitors by means of differential scanning fluorimetry (DSF). Several compounds identified by this screening procedure were further studied using isothermal titration calorimetry (ITC) and X-ray crystallography, as well as tested in parasite growth inhibitions assays. These experiments led us to the identification of a benzamide derivative compound capable of interacting with TbHsp83 more strongly than with its human homologs and structural rationalization of this selectivity. The results highlight the opportunities created by subtle structural differences to develop new series of compounds to selectively target the Trypanosoma brucei chaperone and effectively kill the sleeping sickness parasite

Erratum: Addendum: A cellular chemical probe targeting the chromodomains of Polycomb repressive complex 1 (Nature chemical biology (2016) 12 3 (180-187))

[No abstract available

The Cryptosporidium parvum Kinome

<p>Abstract</p> <p>Background</p> <p>Hundreds of millions of people are infected with cryptosporidiosis annually, with immunocompromised individuals suffering debilitating symptoms and children in socioeconomically challenged regions at risk of repeated infections. There is currently no effective drug available. In order to facilitate the pursuit of anti-cryptosporidiosis targets and compounds, our study spans the classification of the <it>Cryptosporidium parvum </it>kinome and the structural and biochemical characterization of representatives from the CDPK family and a MAP kinase.</p> <p>Results</p> <p>The <it>C</it>. <it>parvum </it>kinome comprises over 70 members, some of which may be promising drug targets. These <it>C. parvum </it>protein kinases include members in the AGC, Atypical, CaMK, CK1, CMGC, and TKL groups; however, almost 35% could only be classified as OPK (other protein kinases). In addition, about 25% of the kinases identified did not have any known orthologues outside of <it>Cryptosporidium spp</it>. Comparison of specific kinases with their <it>Plasmodium falciparum </it>and <it>Toxoplasma gondii </it>orthologues revealed some distinct characteristics within the <it>C. parvum </it>kinome, including potential targets and opportunities for drug design. Structural and biochemical analysis of 4 representatives of the CaMK group and a MAP kinase confirms features that may be exploited in inhibitor design. Indeed, screening <it>Cp</it>CDPK1 against a library of kinase inhibitors yielded a set of the pyrazolopyrimidine derivatives (PP1-derivatives) with IC₅₀values of < 10 nM. The binding of a PP1-derivative is further described by an inhibitor-bound crystal structure of <it>Cp</it>CDPK1. In addition, structural analysis of <it>Cp</it>CDPK4 identified an unprecedented Zn-finger within the CDPK kinase domain that may have implications for its regulation.</p> <p>Conclusions</p> <p>Identification and comparison of the <it>C. parvum </it>protein kinases against other parasitic kinases shows how orthologue- and family-based research can be used to facilitate characterization of promising drug targets and the search for new drugs.</p