Gloria Barrera - Academia.edu (original) (raw)

Papers by Gloria Barrera

Research Square (Research Square), Aug 1, 2022

Archives of Microbiology, Feb 6, 2023

Hyperhydricity can affect the development of plant morphology. A better understanding of the anat... more Hyperhydricity can affect the development of plant morphology. A better understanding of the anatomical and physiological changes of hyperhydric plants is needed to predict and control the occurrence of hyperhydryc conditions. The aim of this study is to demonstrate the role of oxidative stress in hyperhydricity. To this end, the anatomical, physiological and biochemical responses to oxidative stress in shoots of Bambusa vulgaris Schrad. ex Wendl were compared during the in vitro-ex vitro transition. For this propose, we used shoots grown in two different culture systems: liquid static culture medium and temporary immersion system. Our results showed that hyperhydricity was associated with oxidative stress in the shoots. In hyperhydric shoots chlorophyll content decreased when cultured in liquid static culture medium. Moreover, hydrogen peroxide content and malondialdehyde, as well as the activities of catalase and enzymes of ascorbate-glutathione cycle (ascorbate peroxidase, monode...

Corporación colombiana de investigación agropecuaria - AGROSAVIA, 2007

Journal of Microencapsulation, Oct 20, 2009

The aim of this study was to encapsulate the occlusion bodies (OBs) of Spodoptera frugiperda nucl... more The aim of this study was to encapsulate the occlusion bodies (OBs) of Spodoptera frugiperda nucleopolyhedrovirus (SfNPV) in Eudragit S100 microparticles (MPs), considering this technique as a possible alternative to protect them from deleterious environmental conditions. The MPs were prepared by oil-in-oil emulsion (O/O) solvent evaporation method. Experimental conditions were established according to a previous multi-level experimental design involving the core/polymer ratio as independent variable. The effects of these parameters on particle size and process yield were investigated observing that polymer concentration had a significant effect on particle size. After adequate conditions for MPs formation were determined, virus was encapsulated. The virus microparticles presented a particle size between 50-300 microm and concentration was 2.62 x 10(9) OBs g(-1). Microencapsulation efficiency was 53.43% and virus release adjusted to Higuchi model suggesting diffusion as the release mechanism. Evaluated microencapsulation process protected viral particles of UV-inactivation, suggesting its potential for a biopesticide development.

Revista Mexicana De Ingenieria Quimica, Mar 27, 2021

Corporación colombiana de investigación agropecuaria - AGROSAVIA, 2010

Journal of Applied Entomology, 2017

The tomato leafminer Tuta absoluta (Meyrick 1917) (Lepidoptera:Gelechiidae) is a devastating pest... more The tomato leafminer Tuta absoluta (Meyrick 1917) (Lepidoptera:Gelechiidae) is a devastating pest, causing losses of up to 100%. An interesting tool for its control is the use of the insect specific viruses of Baculoviridae family. Despite its high potential, its use on T. absoluta larvae has been poorly studied. In this work, Colombian granuloviruses VG013 and VG003 isolated from T. absoluta and Tecia solanivora (Lepidoptera:Gelechiidae) larvae sampled in tomato and potato crops, respectively, were morphologically, biologically and molecularly characterized. Occlusion bodies showed ovoid shape containing one nucleocapsid. Restriction endonuclease analysis revealed a pattern similar to Phthorimaea operculella granulovirus and bioinformatics studies showed that both isolates are variants of that baculovirus specie. Similar mean lethal concentrations (LC50) on T. absoluta larvae were estimated for both viruses, although VG013 exhibited shorter mean time to death than VG003. The latter...

<p>Cladogram generated using Kimura 2-parameter method. Numbers on nodes indicate their con... more <p>Cladogram generated using Kimura 2-parameter method. Numbers on nodes indicate their consistency expressed as percentages. GenBank sequences used [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184053#pone.0184053.ref022" target="_blank">22</a>] are referred with its accession numbers and are indicated in black letters. Besides, their geographical origins are indicated in green letter. Sequences obtained by this work are indicated in red. Some clades were collapsed to preserve space (number of samples are indicated). DSV05 <i>=</i> DiatraeaSolisVargas05.</p

En los ultimos anos los avances tecnologicos han posibilitado explorar la naturaleza como nunca y... more En los ultimos anos los avances tecnologicos han posibilitado explorar la naturaleza como nunca y, en consecuencia, posicionar la biologia como una ciencia de la informacion. Entre estas nuevas aproximaciones metodologicas de las ciencias de la vida se destacan las disciplinas omicas, cuyo objeto de estudio son conjuntos biomoleculares particulares (adn, arn, proteinas o metabolitos secundarios) analizados mediante procedimientos de alto rendimiento. En este sentido, la genomica (con sus derivados: pangenomica y metagenomica), la transcriptomica, la proteomica y la metabolomica —entre otras disciplinas omicas— conforman lineas de estudio imprescindibles para describir la naturaleza y potenciar la produccion de bienes y servicios biotecnologicos. En este capitulo se hace una recopilacion de los procedimientos empleados para hacer estudios omicos y se resalta su utilidad en la investigacion y el desarrollo de agentes de control biologico para invertebrados plaga y fitopatogenos. Se re...

En este capitulo se sintetizan las posibilidades de uso de virus para controlar los insectos plag... more En este capitulo se sintetizan las posibilidades de uso de virus para controlar los insectos plagas de los cultivos. Desde los primeros trabajos relativamente empiricos hasta los desarrollos actuales, se describe el potencial de diferentes familias de virus para regular las poblaciones de insectos. Sin embargo, solo virus de una familia, los baculovirus, han podido ser registrados como agentes de control biologico. El proceso necesario para llegar del descubrimiento de un aislado viral hasta la produccion de un bioinsecticida se muestra con ejemplos reales. Las estrategias de este uso han conducido, en un caso, a la aparicion de resistencia, lo cual permite plantear las diferencias entre el modo de accion natural y el aplicado en los agroecosistemas, proponiendo nuevas vias de uso, mas sostenibles desde el punto de vista ecologico.

Peruvian Journal of Agronomy

The fique crop has great potential for the development of the natural fiber market as a beneficia... more The fique crop has great potential for the development of the natural fiber market as a beneficial alternative for the protection of the environment. In Colombia, one of the main limitations of fiber production in fique plants is the viral disease Macana caused by Furcraea Necrotic Streak Virus (FNSV). This work aimed to validate the detection of FNSV in asexual planting material from one of the main producing areas and thus contribute to preventing the spread of the disease in the country. The analysis of plants from different geographic altitudes in Cauca, Colombia, showed a positive correlation with the prevalence of Macana disease (being more significant at higher altitudes) but not with the severity of the symptoms. The detection of FNSV on seeds by dot blot immunobinding assay (DBIA) using a polyclonal antibody IgY showed sensitivity (79 %) and specificity (80 %) when sprouts were analyzed, at the same time, for bulbils, the sensitivity was higher (100 %). Moreover, when sprou...

Editorial AGROSAVIA, Oct 17, 2018

Sequence comparisons and structural analysis of homologous regions. The palindromes contained int... more Sequence comparisons and structural analysis of homologous regions. The palindromes contained into the homologous regions (hr) from SfMNPV ColA were analyzed and the consensus sequences represented by Sequence logos. Besides, predictions of the ssDNA secondary structures are shown. 1-A. hr-1 (28 palindromes). 1-B. hr-2 (4 palindromes). 1-C. hr-3 (3 palindromes). 1-D. hr-4 (24 palindromes). 1-E. hr-5 (14 palindromes). 1-F. hr-6 (4 palindromes). 1-G. hr-7 (24 palindromes). 1-H. hr-8 (14 palindromes). 1-I. All palindromes (115 repeats). 2. Largest A + T-rich region in the SfMNPV ColA genome. 2-A. Physical map of hr-1 and location of the largest A + T-rich region. 2-B. Nucleotide sequence detail. 2-C. Local ssDNA secondary structure. (TIF 3246 kb)

Potentially expressed ORFs in the genome of SfMNPV ColA. In bold letter are indicated the core ge... more Potentially expressed ORFs in the genome of SfMNPV ColA. In bold letter are indicated the core genes. (XLSX 32Â kb)