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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Desempenho e atividades enzimáticas em girinos de rã-touro(Pesquisa Agropecuária Brasileira, 2008-11) Oliveira, Maria Goreti Almeida; Moura, Guilherme de Souza; Lanna, Eduardo Teixeira Arruda; Garcia, Silvana Lages Ribeiro; Seixas Filho, José Teixeira de; Silva, Lilia Nogueira daO objetivo deste trabalho foi avaliar o desempenho e as atividades das enzimas digestivas de girinos de rã-touro, alimentados com ração comercial durante 60 dias, com um girino por litro, em caixas com 30 L de água. Os parâmetros medidos quinzenalmente foram: sobrevivência, comprimento, peso final, consumo de ração, e a atividade de amilase, lipase e tripsina. O maior crescimento dos girinos foi do 15º ao 45º dia - 20,61 mm. Durante os primeiros 15 dias, os girinos apresentaram a maior taxa de crescimento específico, 16,73% por dia. Do 45º ao 60º dia, os girinos apresentaram o maior ganho de peso, 3,98±0,73 g, o maior consumo de ração, 14,40±1,14 g, e a melhor conversão alimentar, 3,67:1,0±0,18. Houve aumento significativo da atividade enzimática depois do 30º dia. Observaram-se relações entre as atividades específicas das enzimas e os distintos estágios de desenvolvimento dos girinos.Item Estudo ecogeográfico da poaia [Psychotria ipecacuanha (Brot.) Stokes](Revista Brasileira de Plantas Medicinais, 2009) Oliveira, L. O.; Vieira, I. J. C.; Maia, J. T. L. S.; Martins, E. R.Este estudo foi conduzido com 13 populações amostradas nos estados RJ, MG, ES e BA para a coleta de dados ecogeográficos da poaia (Psychotria ipecacuanha). Foi conduzida a análise de freqüência de ocorrência de características ambientais, tais como: altitude, pluviosidade, temperaturas máxima, média e mínima absolutas, latitude e longitude. A análise etnobotânica consistiu no levantamento de formas terapêuticas, homeopáticas e as crendices relacionadas à utilização da poaia. Os teores dos alcalóides emetina e cefelina foram determinados, utilizando-se cromatografia líquida de alta eficiência (CLAE). Aproximadamente 87% das reboleiras ocorreram em solo distrófico. Dentre os micronutrientes analisados, Fe, Mn, e Cu apresentaram correlações significativas com número de hastes por reboleira (NH) e peso de raízes secas (PR). O comprimento, em 65% das reboleiras, foi inferior a 2 m, sendo que as dimensões médias das reboleiras foram de 1,8 x 1,3 m. A porcentagem da radiação fotossiteticamente ativa variou entre 0,14 e 17%. Dos locais onde ocorreram as reboleiras, cerca de 69% foram consideradas com pequena inclinação. A caracterização química revelou que em cerca de 65% das amostras de raízes analisadas, foram observados teores de emetina entre 1 e 2%, e o teor de cefelina, em 61% das amostras, foi inferior a 0,3%. As características morfológicas e químicas foram analisadas pela técnica de componentes principais, concluindo-se que os resultados obtidos são pouco informativos sobre a diversidade genética, possibilitando o descarte de características cuja variação é pequena e, também, aquelas altamente correlacionadas entre si.Item Reproductive studies in ipecac (Psychotria ipecacuanha (Brot.) stockes; Rubiaceae): pollen development and morphology(Brazilian Archives of Biology and Technology, 2008-09) Oliveira, Luiz Orlando de; Souza, Margarete Magalhães; Martins, Ernane Ronie; Pereira, Telma Nair SantanaThe aim of this work was to carry out the reproductive studies on Brazilian accessions of ipecac, Psychotria ipecacuanha. It presented heterostyly, with brevistylous and longistylous flowers. The pollen development was observed from the sections of the anthers embedded in resin. Anther development was normal as usually observed in dicotyledones, displaying four layers: outer epidermis, endothecium, middle layer and inner tapetum. The pollen was bicellular and filled with starch at the microspore stage. Pollen morphology was studied using SEM, which showed pollen polymorphism within and between the two floral morphs. Five types of pollen with reticulate or perforate exine were identified. The characteristics showed that the sexual process was as important as the vegetative propagation for the reproduction of this species.Item Extracellular nucleotide metabolism in Leishmania: influence of adenosine in the establishment of infection(Microbes and Infection, 2008-07) Fietto, Juliana Lopes Rangel; Marques-da-Silva, Eduardo de Almeida; Oliveira, Jamile Camargos de; Figueiredo, Amanda Braga; Lima Júnior, Djalma de Souza; Carneiro, Cláudia Martins; Afonso, Luís Carlos CroccoLeishmaniasis is a parasitic disease with a variety of clinical forms, which are related to the Leishmania species involved. In the murine model, Leishmania amazonensis causes chronic non-healing lesions in Leishmania braziliensis- or Leishmania major-resistant mouse strains. In this study, we investigated the involvement of the pathway of extracellular nucleotide hydrolysis, with special focus on the role of extracellular adenosine, in the establishment of Leishmania infection. Our results show that the more virulent parasite—L. amazonensis—hydrolyzes higher amounts of ATP, ADP and AMP than the two other species, probably due to the higher expression of membrane NTPDase. Corroborating the idea that increased production of adenosine is important to lesion development and establishment of tissue parasitism, we observed that increased 5′-nucleotidase activity in L. braziliensis or addition of adenosine at the moment of infection with this parasite resulted in an increase in lesion size and parasitism as well as a delay in lesion healing. Furthermore, inhibition of adenosine receptor A2B led to decreased lesion size and parasitism. Thus, our results suggest that the conversion of ATP, a molecule with pro-inflammatory activity, into adenosine, which possesses immunomodulatory properties, may contribute to the establishment of infection by Leishmania.Item Protective effect of ions against cell death induced by acid stress in Saccharomyces(FEMS Yeast Research, 2009-08) Sant’Ana, Gilzeane dos Santos; Paes, Lisvane da Silva; Paiva, Argentino F. Vieira; Fietto, Luciano Gomes; Totola, Antônio Helvécio; Trópia, Maria J. Magalhães; Silveira- Lemos, Denise; Lucas, Cândida; Fietto, Juliana L. Rangel; Brandão, Rogelio L.; Castro, Ieso de MirandaSaccharomyces boulardii is a probiotic used to prevent or treat antibiotic-induced gastrointestinal disorders and acute enteritis. For probiotics to be effective they must first be able to survive the harsh gastrointestinal environment. In this work, we show that S. boulardii displayed the greatest tolerance to simulated gastric environments compared with several Saccharomyces cerevisiae strains tested. Under these conditions, a pH 2.0 was the main factor responsible for decreased cell viability. Importantly, the addition of low concentrations of sodium chloride (NaCl) protected cells in acidic conditions more effectively than other salts. In the absence of S. boulardii mutants, the protective effects of Na 1 in yeast viability in acidic conditions was tested using S. cerevisiae Na 1 -ATPases (ena1-4), Na 1 /H 1 antiporter (nha1D) and Na 1 /H 1 antiporter prevacuolar (nhx1D) null mutants, respectively. Moreover, we provide evidence suggesting that this protection is determined by the plasma membrane potential, once altered by low pH and low NaCl concentrations. Additionally, the absence or low expression/activity of Ena proteins seems to be closely related to the basal membrane potential of the cells.Item Complete inventory of soybean NAC transcription factors: Sequence conservation and expression analysis uncover their distinct roles in stress response(Gene, 2009-09-01) Pinheiro, Guilherme L.; Marques, Carolina S.; Costa, Maximiller D.B.L.; Reis, Pedro A. B.; Alves, Murilo S.; Carvalho, Claudine M.; Fietto, Luciano G.; Fontes, Elizabeth P. B.We performed an inventory of soybean NAC transcription factors, in which 101 NAC domain-containing proteins were annotated into 15 different subgroups, showing a clear relationship between structure and function. The six previously described GmNAC proteins (GmNAC1 to GmNAC6) were located in the nucleus and a transactivation assay in yeast confirmed that GmNAC2, GmNAC3, GmNAC4 and GmNAC5 function as transactivators. We also analyzed the expression of the six NAC genes in response to a variety of stress conditions. GmNAC2, GmNAC3 and GmNAC4 were strongly induced by osmotic stress. GmNAC3 and GmNAC4 were also induced by ABA, JA and salinity but differed in their response to cold. Consistent with an involvement in cell death programs, the transient expression of GmNAC1, GmNAC5 and GmNAC6 in tobacco leaves resulted in cell death and enhanced expression of senescence markers. Our results indicate that the described soybean NACs are functionally non-redundant transcription factors involved in response to abiotic stresses and in cell death events in soybean.Item Expression of genes encoding cytosolic and endoplasmic reticulum HSP90 proteins in the aquatic fungus Blastocladiella emersonii(Gene, 2008-03-31) Fietto, Luciano G.; Pugliese, Luciana; Georg, Raphaela C.; Gomes, Suely L.HSP90 proteins are important molecular chaperones involved in multiple cellular processes. This work reports the characterization of cDNAs encoding two distinct HSP90 proteins (named HSP90A and HSP90B) from the chytridiomycete Blastocladiella emersonii. Deduced amino acid sequences of HSP90A and HSP90B exhibit signatures of the cytosolic and endoplasmic reticulum (ER) HSP90 proteins, respectively. A genomic clone encoding HSP90A was also characterized indicating the presence of a single intron of 184 bp interrupting the coding region, located near the amino-terminus of the protein. Expression of both HSP90A and HSP90B genes increases significantly during heat shock at 38 °C, with highest induction ratios observed in cells stressed during germination of the fungus. Changes in the amount of HSP90A transcript were also evaluated during B. emersonii life cycle at physiological temperature (27 °C), and its levels were found to increase both during germination and sporulation of the fungus. HSP90A protein levels were analyzed during B. emersonii life cycle and significant changes were observed only during sporulation. Furthermore, during heat stress a large increase in the amount of HSP90A protein was observed. Induction of HSP90A and HSP90B genes during heat stress indicates the importance of both genes in the response to high temperature in B. emersonii.Item Treatment of soy milk with Debaryomyces hansenii cells immobilised in alginate(Food Chemistry, 2009-05-15) Souza Júnior, Waldeck Campanha de; Rezende, Sebastião Tavares de; Viana, Pollyanna Amaral; Falkoski, Daniel Luciano; Reis, Angélica Pataro; Machado, Solimar Gonçalves; Barros, Everaldo Gonçalves de; Guimarães, Valéria MontezeWhole cells of Debaryomyces hansenii UFV-1 were permeabilised with ethanol and immobilised in calcium alginate hydrogel. The optimum pH and temperature for α-galactosidase activities of permeabilised free (PFC) and permeabilised immobilised cells (PIC) were 4.5 and 60 °C; and 4.0 and 70 °C, respectively. PIC α-galactosidase was more stable than that of PFC. The incubation of PIC at 60 and 70 °C promoted an increase in α-galactosidase activity. The α-galactosidase activity was maintained when PIC was used in three repeated batches. The Km values for PIC and PFC α-galactosidases, with ρNPαGal, were 0.82 mM and 0.30 mM, respectively. Soy milk treatment with PIC for 6 h at 60 °C promoted 100% hydrolysis of raffinose oligosaccharides.Item Adaptação da lagarta de soja Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) ao inibidor de protease Benzamidina(Revista Ceres, 2009-11) Pilon, Anderson Martins; Oliveira, Maria Goreti Almeida; Pilon, Franciny Martins; Guedes, Raul Narciso Carvalho; Oliveira, Joel Antônio; Fazollo, AndersonO inibidor de serino protease benzamidina inibe a hidrólise protéica das proteases digestivas do tipo tripsina, no intestino médio das larvas de Anticarsia gemmatalis. No presente trabalho, lagartas de A. gemmatalis recém-eclodidas foram alimentadas com o inibidor de tripsina benzamidina nas concentrações 0; 0,25; 0,50; e 0,75% (p/p de dieta artificial). As diferentes concentrações do inibidor causaram impactos negativos ao desenvolvimento larval do inseto, como aumento do período larval e maior porcentagem de mortalidade. Entretanto, observou-se que, mesmo nas maio- res concentrações testadas de benzamidina, o inseto consegue se adaptar ao inibidor por remodelagem na quantidade e no tipo de enzima presentes durante a digestão da dieta artificial.Item Contribution of gut bacteria to digestion and development of the velvetbean caterpillar, Anticarsia gemmatalis(Journal of Insect Physiology, 2008-10-29) Viôtto, L.E.; Oliveira, M.G.A.; Guedes, R.N.C.; Ribon, A.O.B.; Good-God, P.I.V.Bacteria colonies from gut homogenates of fifth instar velvetbean caterpillars (Lepidoptera: Noctuidae) were subjected to antibiotic sensitivity experiments using discs containing 22 antibiotics. The antibiotic tetracycline provided the best results, followed by chloramphenicol. Tetracycline also provided higher inhibition of colony forming units than chloramphenicol and was therefore provided to the caterpillars in increasing diet concentrations to assess the contribution of gut bacteria to their digestion and development. The activity of proteases (general), serine-proteinases and lipases were significantly suppressed by tetracycline. Concentration–inhibition curves were successfully established for tetracycline and this antibiotic was effective in suppressing them, particularly serine-proteinases, suggesting that gut bacteria may significantly contribute with lipid- and mainly protein-digestion in velvetbean caterpillars. Increased diet concentrations of tetracycline led only to mild increase in insect mortality (ca. 20%), with the surviving insects showing faster development (≤4 days) and higher pupa weight (<0.04 mg) with increased concentrations of tetracycline. Therefore, the gut bacteria inhibited by tetracycline does not seem to play a crucial role in the survival and development of the velvetbean caterpillar, but may be important in the adaptation of this pest species to hosts rich in protease inhibitors, such as soybean.
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