Actualización de inventario de especies de hifomicetos acuáticos en Venezuela

Los hongos Ingoldianos, también conocidos como hifomicetos acuáticos, son un grupo de hongos imperfectos microscópicos que en el ecosistema acuático son potencialmente responsables de degradar la materia vegetal, facilitando así el ciclaje de nutrientes en niveles tróficos superiores. Este rol resalta la importancia de los hifomicetos en dos aspectos: son bioindicadores de calidad de agua en ríos de bajo orden, y en el ámbito biotecnológico, poseen diversas y numerosas enzimas que facilitan su desarrollo en el ambiente acuático. Lo anterior señala la importancia de actualizar las características, el registro e ilustraciones de las especies fúngicas presentes en la franja tropical de América Latina, región del mundo donde son aún pocos los registros de dichos organismos. El objetivo de este trabajo es realizar esa actualización en la República Bolivariana de Venezuela

Caracterización morfo-anatómica de la embriogénesis somática secundaria en Azadirachta indica (Meliaceae)

Background and Aims: Meliaceae species are extremely recalcitrant during germination and in vitro processes. Therefore, this research focuses on characterization and optimization of a highly efficient system by secondary somatic embryogenesis in Azadirachta indica, which is an important step for enhancing secondary metabolite production and regeneration in recalcitrant species.Material and Methods: Leaf and cotyledon sections were induced in MS medium supplemented with benzylaminopurine (BAP) alone, or combined with 1-naphthaleneacetic acid (NAA) and, abscisic acid (BA) with thidiazuron (TDZ).Key results: Azadirachta indica developed primary somatic embryos with BAP. Shoot and root formation occurred at low concentrations of BAP, while somatic embryogenesis was favored under high levels of BAP or TDZ. Primary and secondary somatic embryos were evidenced continuously and asynchronously. The highest amount of somatic embryos was obtained with cytokinins. However, the concentration might be significant to differentiate between primary and secondary embryos. Moreover, the auxins are key for inducing histodifferentiation in embryos. Shoot induction occurred after transfer of the embryos to hormone-free MS medium. The shoots were rooted in MS1/2.Conclusions: The secondary somatic embryos were distinguished and characterized during the whole process and the efficient system was established with cotyledon sections at short term, which offers several advantages such as the production of metabolites.Antecedentes y Objetivos: Las especies de Meliaceae son extremadamente recalcitrantes durante la germinación y en los procesos in vitro. Por lo tanto, este estudio está enfocado en caracterizar y optimizar un sistema altamente eficiente de propagación a través de embriogénesis somática secundaria en Azadirachta indica, paso importante para la producción de metabolitos secundarios, la propagación o regeneración de estas especies recalcitrantes.Materiales y Métodos: Las secciones de hojas y cotiledones fueron inducidos en medio MS suplementado con bencil-aminopurina (BAP) sola o combinada con ácido 1-naftalenacético (NAA) y ácido abscísico (BA) con tidiazuron (TDZ).Resultados clave: Azadirachta indica desarrolla embriones somáticos primarios con BAP. La formación de tallos y raíces ocurre en bajas concentraciones de BAP, mientras la embriogénesis somática es favorecida a altos niveles de BAP o TDZ. Los embriones somáticos primarios y secundarios fueron evidenciados continuamente y sincrónicamente o asincrónicamente. Una gran cantidad de embriones somáticos fueron obtenidos con citoquininas. Sin embargo, la concentración tiene un rol importante en la diferenciación entre embriones primarios y secundarios. Además, las auxinas son la clave para inducir la histo-diferenciación en los embriones. La inducción de tallo ocurrió después de que los embriones somáticos se transfirieron a un medio libre de hormonas (MS). Estos tallos fueron enraizados con MS1/2.Conclusiones: Los embriones somáticos secundarios fueron distinguidos y caracterizados durante todo el proceso y el sistema fue establecido con segmentos de cotiledones en corto tiempo; esto ofrece oportunidades ventajosas como la producción de metabolitos

Establecimiento del sistema de regeneración por embriogénesis somática de Azadirachta Indica A. Juss.

Azadirachta indica, es una planta con múltiples aplicaciones tanto forestal como farmacológica. Por ende, el establecimiento del sistema de cultivo in vitro por embriogénesis somática ofrece diversas y variadas ventajas, tales como obtener plantas altamente productivas en metabolitos. En este estudio, se utilizaron secciones foliares y cotiledonares, inducidas en medios MS (1962) suplementados con: BAP sólo y combinado con ANA / 2,4-D, TDZ sólo y con ABA. La regeneración fue con MS sólo o con K + AIA y BAP + AIA. Como resultado se estableció un sistema eficiente con secciones de cotiledones, observándose organogénesis a bajas concentraciones de BAP, mientras a altos niveles de BAP (2,5 mg.L-1), así como con TDZ + ABA (0,02 + 1 mg.L-1) respectivamente favorecieron la embriogénesis somática primaria y secundaria en un 96 % y 71 % respectivamente. La regeneración fue 71 % con MS, mientras que el enraizamiento fue de 86,67 % con MS½, obteniéndose plantas completas a corto plazo.Azadirachta indica, is a plant with multiple forest and pharmacological application. Therefore, the establishment of in vitro culture system for somatic embryogenesis offers several distinct advantages such as obtaining highly productive plant metabolites. In this study, were used sections cotyledon and leaf, induced on MS medium (1962) supplemented with: BAP alone and combined with NAA / 2,4-D, TDZ alone and ABA. Regeneration was with MS alone or with K + BAP + IAA and IAA. As a result was established an efficient system with cotyledon sections, being observed organogenesis at low concentrations of BAP, while high levels of BAP (2.5 mg.L-1) with 96 % and TDZ + ABA (0.02 + 1 mg.L-1) with 71 %, favoring the primary and secondary somatic embryogenesis. Regeneration was 71 % with MS; rooting was 86.67 % with MS½, presenting whole plants obtained short term

Viability in protoplasts and cell suspensions of Coffea arabica cv. Catimor

Two methods were evaluated in order to assess the viability of protoplasts and cell suspensions of Coffea arabica cv. Catimor used in a protocol of transformation by electroporation. One method consisted of staining with 1 % Evans blue and the other staining with 1% 3-[4,5-dimethyltiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). When Evans blue was applied to viable cells and protoplasts they either did not stain or acquired a faint blue colour. However, it was difficult to distinguish the non-viable cells in the wide spectrum of clear blue tonalities. In contrast, with the MTT assay only the viable cells and protoplasts reduced this salt to the red coloured formazan; viable and non-viable cells were distinguished more clearly with MTT than with Evans blue. The optimal temperature for the reaction with MTT was 37\ub0C . The time of incubation was shown to be important, since longer times improved the reaction; the highest viability value was obtained after incubation for 120 min

Transient gene expression in secondary somatic embryos from coffee tissues electroporated with the genes gus and bar

Different electroporation conditions were evaluated, toward the goal of transformation of Coffea arabica cv. Catimor. The tissues assayed were: embryogenic calli, leaf sections from in vitro plants, and somatic embryos in globular and torpedo stage obtained from cell suspensions. The effect of 1 or 24-hour pretreatment with an enzymatic solution (2% cellulase, 1% macerozyme) and electric field strength (375, 625, 875 V/cm) was evaluated. In all the experiments the tissues were incubated in ASP buffer (potassium aspartate) during three hours, and then one hour with plasmid DNA (pCambia3201, containing gus and bar genes) at room temperature. The electroporation was performed at a capacitance of 900 \u3bc F. The effect of the parameters evaluated was determined by the transient expression of the gus gene. The optimal conditions for electroporation were one hour of enzymatic pretreatment of torpedo shape embryos, electroporation at 375 V and 900 \u3bc F. The culture of electroporated tissues in liquid media with 8 mg/l benzyladenine conducted to maximal regeneration through secondary somatic embryogenesis. The secondary somatic embryos were formed directly in the hypocotyl surface of the electroporated torpedo shape primary somatic embryos, the production of secondary somatic embryos was significantly greater than the production of primary embryos, therefore, this is an excellent method to propagate the products of genetic transformation. The secondary somatic embryos regenerated from electroporated torpedo shape somatic embryos were positive for gus expression, and also in the PCR analysis for the genes gus and bar

Principales promotores utilizados en la transformación genética de plantas

El conocimiento pleno de los promotores determina el éxito en la obtención de nuevos cultivares de plantas a través de técnicas biotecnológicas, ya que dicha secuencia del ADN regula la transcripción de otras regiones adyacentes o cercanas, encontrándose los siguientes promotores: constitutivos, tejido-específicos o estadio-específicos, inducibles y sintéticos. En esta revisión se resume de manera precisa los conceptos, ventajas y limitaciones de los distintos tipos de promotores, con ejemplos claros de ello.Palabras clave: promotor, biotecnología vegetal, transcripción genética.Full knowledge of promoters determines success in obtaining new plant cultivars through biotechnology techniques. This DNA sequence regulates the transcription of adjacent or nearby regions, which are mainly constitutive, tissue-specific or stage-specific, inducible and synthetic. This review summarizes the precise concepts, advantages and limitations of different types of promoters, including clear examples of them.Key words: Promoter; plant biotechnology; gene transcription

CHEMICAL CHARACTERIZATION OF BARK COMPOUNDS FROM CAATINGA SPECIES

This study aimed to chemically characterize the bark extracts from three tree species: Anacardium occidentale L., Ziziphus joazeiro Mart. and Mimosa caesalpiniaefolia Benth., in addition to obtaining the soluble extract content in water, alcohol and hexane from the bark of these species. The bark was collected from branches of the three species and subsequently pre-dried and milled. The extract content was then determined using the Sohxlet method aiming to quantify the total extractives in the samples, and determine the extract content soluble in water, ethyl alcohol and hexane. The extracts were further analyzed by Near Infrared Spectroscopy (NIRS) analysis to determine their chemical composition. The extract contents in the three species behaved in a similar way, with hexane being the solvent which extracted more compounds and juazeiro the species that displayed the highest total extract content. With the chemical characterization of the extracts, it was possible to identify the presence of functional groups characteristic of carbohydrates and proteins in the aqueous extracts; the presence of characteristic hydroxyl group, for example in alcohols, aldehydes, ketones and ethers in the ethanolic extracts; and the presence of fatty acids and aromatic compounds (essential oils) in hexanolic extracts. The essential oils were the compounds which presented larger quantities, and can be exploited by the pharmaco-chemical industry

Religion and health: to transform absence in presence

O artigo analisa percepções de profissionais de uma unidade básica de saúde a respeito das relações entre religião e saúde para apreender como os modos de considerar a religião nas práticas de saúde podem produzir equidades ou iniquidades. Trata-se de um estudo exploratório de abordagem qualitativa desenvolvido a partir de entrevistas estruturadas individuais, analisadas com o intuito de detectar práticas de sentido relevantes para a discussão de equidade em saúde. Os resultados destacam: uma concepção negativa da influência da religião dos usuários sobre os cuidados e as agências interessadas na redução dessa interferência da religião; as dificuldades e desconfortos relacionados ao modo de o profissional lidar com a própria religião no exercício do cuidado e na relação interprofissional; que o Sistema Único de Saúde não considera a dimensão religiosa, fazendo-se necessárias políticas públicas específicas ou transformações culturais profundas; e a falta de conhecimento de características das religiões afrobrasileiras que demandem cuidados específicos. Tais resultados sugerem que a negligência em relação à questão religiosa mantém oculta uma prática proativa de apagamento das diferenças, conduzindo a uma reflexão sobre o que, em se tratando de equidades e iniquidades, tem produzido a epistème moderna no âmbito das práticas instituídas na atenção básica.T h e a r t i c l e a n a l y z e s t h e p e r c e p t i o n s o f professionals of a basic health unit regarding the relationship between religion and health in order to apprehend how the ways of considering religion in health practices can produce equities or iniquities. It is an exploratory study of qualitative approach developed from individual structured interviews, analyzed with the intention of detecting signification practices relevant to the discussion of equity in health. The results highlight: a negative conception of the influence of the user’s religion on care and agency interested in reducing this interference of religion; the difficulties and discomforts related to the way the professional deals with their own religion in the exercise of care and in the interprofessional relationship; that the Brazilian National Health System does not consider the religious dimension, creating the need for specific public policies or deep cultural transformations; and the lack of knowledge of the characteristics of Afro-Brazilian religions that demand specific care. These results suggest that negligence of the religious question conceals a proactive practice of erasing differences, which leads to a reflection on what, in the case of equities and iniquities, has produced the modern epistème within the framework of the practices instituted in the Primary Health Care

ANTIFUNGAL POTENTIAL OF BARK EXTRACTS FROM BRAZILIAN SEMI-ARID TREE SPECIES AGAINST Ganoderma spp.

Tree native species of the Caatinga (a Brazilian semi-arid biome) have characteristics of interest for the use of their wood and non-wood products, especially regarding their natural chemical compounds. The aim of this study was to evaluate the antifungal action of different bark extracts of Anacardium occidentale, Ziziphus joazeiro and Mimosa caesalpiniifolia against Ganoderma lobatum and G. multiplicatum by in vitro mycelial inhibition. The extractions from the bark of the trees were carried out with a Soxhlet extractor, using water, ethanol and hexane as solvents. The potential of mycelia inhibition of each extract was tested against fungi of the Ganoderma genus. The hexane extracts of the bark had activity against G. multiplicatum, unlike the aqueous and ethanol extracts. Even though the hexane-based extracts had a small mycelial inhibition effect against G. lobatum, there were no satisfactory results of extracts against this fungus species