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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A enzima histidinol desidrogenase de mycobacterium tuberculosis como alvo para o desenvolvimento de drogas : caracteriza??o bioqu?mica

Nunes, Jos? Eduardo Sacconi 15 April 2011 (has links)
Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-07-26T14:44:00Z No. of bitstreams: 1 JOSE_EDUARDO_SACCONI_NUNES_DIS.pdf: 1721834 bytes, checksum: 00ef2ffd5994d7fa6e05348a79aaced6 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-31T14:27:33Z (GMT) No. of bitstreams: 1 JOSE_EDUARDO_SACCONI_NUNES_DIS.pdf: 1721834 bytes, checksum: 00ef2ffd5994d7fa6e05348a79aaced6 (MD5) / Made available in DSpace on 2018-07-31T14:47:08Z (GMT). No. of bitstreams: 1 JOSE_EDUARDO_SACCONI_NUNES_DIS.pdf: 1721834 bytes, checksum: 00ef2ffd5994d7fa6e05348a79aaced6 (MD5) Previous issue date: 2011-04-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / In 2009, tuberculosis (TB) was responsible for 1.3 million deaths worldwide. The incidence rates reached 9.4 millions and the World Health Organization (WHO) estimative indicates that one third of the world population is infected by Mycobacterium tuberculosis, the main agent responsible for the disease. The lack of new drugs released on market, the long period treatment presenting side effects (causing the abandon by the patients) and the cases with HIV co-infection contributed to the appearance of multi drug resistant strains (MDR-TB) and extensively drug resistant strains (XDR-TB). It's clear, thus, that the development of new drugs to fight TB is necessary and fundamental to the success in eradicating this disease. The histidine biosynthesis pathway emerge in this context offering attractive targets, given that its present in prokaryotes, lower eukaryotes and plants, but absent in animals. The last enzyme in the route is called Histidinol Dehydrogenase and is responsible for the conversion of L-Histidinol into LHistidine. Its essentiality to the bacilli was confirmed by gene knockout, confirming its potential for the development of inhibitory compounds. In this work, a purification protocol was developed, producing the enzyme in the homogeneous form in quantities sufficient to carry its biochemical characterization. The enzyme needs a divalent metal ion in the active site to catalyze the reaction. The kinetic constants were determined, as well as the mechanism, the pH rate profiles and the interaction of its substrates and products by isothermal titration calorimetry. A tridimensional model for its structure was constructed by sequence homology, allowing the analysis of the interaction of the substrates and metal in the active site. The results obtained will allow the rational design of molecules that act as inhibitors. / Em 2009 a tuberculose (TB) foi respons?vel por 1,3 milh?es de mortes no mundo inteiro. A incid?ncia de casos chegou ao patamar de 9,4 milh?es e as estimativas da Organiza??o Mundial da Sa?de (OMS) indicam que aproximadamente 1/3 da popula??o mundial est? infectada pelo Mycobacterium tuberculosis, principal agente causador da doen?a. A falta de novas drogas no mercado, o tratamento longo e com efeitos colaterais (levando ao abandono por parte dos pacientes) e os quadros de co-infec??o com HIV tem colaborado para o surgimento de novas cepas resistentes as drogas atualmente em uso (MDR-TB e XDR-TB). Fica claro, portanto, que o desenvolvimento de novas drogas para o combate da TB ? necess?rio e fundamental para que se tenha sucesso na erradica??o desta doen?a. A via de bioss?ntese de histidina aparece nesse contexto oferecendo alvos atrativos, visto que est? presente em organismos procari?ticos, em organismos eucari?ticos inferiores e em plantas, mas ausente em animais. A ?ltima enzima pertencente ? via ? chamada de Histidinol Desidrogenase e ? respons?vel pela convers?o de L-Histidinol em L-Histidina. Sua essencialidade para a viabilidade do bacilo foi comprovada atrav?s de nocaute g?nico, confirmando sua potencialidade para o desenvolvimento de compostos inibidores de sua atividade. Neste trabalho, um protocolo depurifica??o foi desenvolvido, produzindo a enzima na forma homog?nea em quantidades suficientes para realizar a caracteriza??o bioqu?mica da mesma. A enzima necessita de um ?on met?lico divalente no s?tio para catalisar a rea??o. Suas constantes cin?ticas foram determinadas, assim como o mecanismo, os perfis de pH, e a intera??o com os substratos e produtos atrav?s de calorimetria de titula??o isot?rmica. Um modelo tridimensional da sua estrutura foi constru?do por homologia de sequ?ncia, permitindo uma an?lise da intera??o dos substratos e do metal no s?tio ativo da enzima. Os resultados obtidos permitir?o o desenho racional de mol?culas que atuem como inibidores.
2

Identifica??o e caracteriza??o das esp?cies de flebotom?neos (Diptera: Psychodidae), infectadas por Leishmania spp., na localidade Praia das Pombas, Viam?o, Rio Grande do Sul, Brasil

Lindholz, Catiele Gobetti 27 March 2015 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-03-20T14:23:49Z No. of bitstreams: 1 DIS_CATIELI_GOBETTI_LINDHOLZ_COMPLETO.pdf: 610881 bytes, checksum: 802c9e980339f9212a7fbe652acc4378 (MD5) / Made available in DSpace on 2017-03-20T14:23:49Z (GMT). No. of bitstreams: 1 DIS_CATIELI_GOBETTI_LINDHOLZ_COMPLETO.pdf: 610881 bytes, checksum: 802c9e980339f9212a7fbe652acc4378 (MD5) Previous issue date: 2015-03-27 / The Leishmaniasis is a complex of diseases caused by protozoa of the genus Leishmania spp., observed in the promastigote forms (flagellated, extracellular) in invertebrate hosts, and amastigote forms (no scourge, intracellular required) in vertebrates. Nowadays, these diseases are distributed in 88 countries in the Americas, Africa, India, Asia and the Mediterranean. According to the World Health Organization, 500.000 and 1.5 million new cases, respectively of Visceral Leishmaniasis and Cutaneous Leishmaniasis occur annually, and considered one of the infectious and parasitic diseases of major global impact. Transmitted at the moment the blood feeding by the female sandflies (Diptera: Psychodidae), Leishmaniasis is the shown to expand in all regions of Brazil, placing the country among the five most affected in the world. In Brazil, many studies have been carried out to elucidate the species responsible for the transmission of Leishmania spp., and consequently, prescribe important areas of to public health. However, these approaches are uncommon in the Rio Grande do Sul state. This study aimed to investigate the sandfly species occurring in a rural area in Itapu? district, city of Viam?o, metropolitan region of Porto Alegre, and verify the presence of DNA of Leishmania spp. in captured females. The collections were carried out with CDC light traps in intradomicile, peridomicile and forest remnants to verify possible population or species differences among the sites. The captures occurred for three consecutive nights, from May 2013 to April 2014. The sandflies were identified and females were grouped in pools of five animals each, according to the species. A total of 516 phlebotomines were captured, pertaining belonging to the Lutzomyia neivai (37.2%), Lutzomyia migonei (34.5%), Lutzomyia fischeri (21.7%), and Lutzomyia lanei (6.5%). For DNA extraction, 245 females were used. Fragments of 120 bp of conserved region of Leishmania kinetoplast were amplified from samples of Lutzomyia neivai, L. fischeri and L. migonei. / As Leishmanioses s?o um complexo de doen?as causadas por protozo?rios do g?nero Leishmania spp., observados nas formas promastigota (flagelada, extracelular) nos hospedeiros invertebrados, e forma amastigota (aus?ncia de flagelo, intracelular obrigat?rio) nos vertebrados. Atualmente, estas doen?as encontram-se distribu?das em 88 pa?ses nas Am?ricas, ?frica, ?ndia, ?sia e Mediterr?neo. Segundo a Organiza??o Mundial da Sa?de (OMS), estima-se que 500 mil novos casos de Leishmaniose Visceral (LV) e 1,5 milh?es de novos casos de Leishmaniose Tegumentar Americana (LTA) ocorram anualmente, sendo considerada uma das doen?as infecto-parasit?rias de maior incid?ncia mundial. Transmitidas no momento do repasto sangu?neo pelas f?meas de flebotom?neos (Diptera: Psychodidae), as Leishmanioses se mostram em expans?o em todas as regi?es brasileiras, colocando o pa?s entre os cinco mais afetados no mundo. No Brasil, muitas pesquisas t?m sido desenvolvidas no intuito de esclarecer as esp?cies respons?veis pela transmiss?o de Leishmania spp., e consequentemente, apontar ?reas de import?ncia ? sa?de p?blica. A LTA chegou a capital do RS em 2002 e ainda s?o escassos os estudos de esp?cies transmissoras neste Estado. Este estudo teve como objetivo investigar as esp?cies de flebotom?neos ocorrentes em uma localidade rural no distrito de Itapu?, munic?pio de Viam?o, regi?o metropolitana de Porto Alegre, e verificar, a presen?a de DNA de Leishmania spp. nas f?meas capturadas. As capturas foram realizadas com armadilhas luminosas tipo CDC (Center for Diseases Control) em ambiente intradomiciliar, peridomiciliar e mata, a fim de verificar poss?veis diferen?as populacionais e/ou espec?ficas entre os locais. As capturas ocorreram durante tr?s noites consecutivas, no per?odo de Maio de 2013 a Abril de 2014. Os flebotom?neos coletados foram identificados taxonomicamente e as f?meas foram agrupadas em pools de cinco indiv?duos cada, de acordo com esp?cie. Um total de 516 flebotom?neos foi capturado, pertencentes ?s esp?cies Lutzomyia neivai (37,2%), Lutzomyia migonei (34,5%), Lutzomyia fischeri (21,7%), e Lutzomyia lanei (6,5%). Para extra??o de DNA foram utilizadas 245 f?meas. Foram amplificados fragmentos de 120 pares de bases referentes ? regi?o conservada do kDNA de Leishmania em amostras de Lutzomyia neivai, Lutzomyia fischeri e Lutzomyia migonei.
3

Avalia??o da resposta comportamental, morfofisiol?gica e produ??o de leite de cabras puras e mesti?as da ra?a Saanen no semi-?rido do Rio Grande do Norte

Furtado, Gil Dutra 28 June 2007 (has links)
Made available in DSpace on 2014-12-17T15:36:32Z (GMT). No. of bitstreams: 1 GilDF.pdf: 614986 bytes, checksum: d1c9bd0c9c48f246603e34c3399c231b (MD5) Previous issue date: 2007-06-28 / Goat breeding in the state of Rio Grande do Norte, Brazil has promising economic possibilities, with the proper handling of the natural resources. The introduction of specialized animals has been one of the ways used to improve herd genetics and increase productivity. However, climate has been one of the regional factors that most interferes with the adaptation of the new genetic prevalence resulting from the introduction of exotic breeds, because in their country of origin, the air temperature during most of the year is lower than the animals body temperature. With this in mind, the aim of this study was to characterize behavioral, physiological and morphological profiles and milk production of female Saanen goats belonging to different genetic groups raised in the semi-arid region of Rio Grande do Norte in Northeast Brazil. The study was conducted in the city of Lages (5? 42 00 S and 36? 14 41 W). We used 25 lactating female Saanen goats, distributed into 3 genetic groups: 5 purebred animals, 11 three-quarter bred and 9 half-bred. Behavioral observations were made over three consecutive days in the months of August and September, between 09:00 and 11:30h, when the animals were grazing. Physiological and meteorological data were recorded in the last three days of June, July, August and September at 05:00h and at 16:00h. In the semi-intensive breeding system, the animals from different genetic groups were similar in both field behavior and physiological response patterns. Although the purebred goats had longer hair, they did not show symptoms of thermal discomfort. Their white hair helped to reflect the short wavelength rays and thus eliminate those at the longer wave lengths. We concluded that the animals raised in the semi-intensive milk production system in this study seem to have adapted to the climatic conditions of the semi-arid region of Rio Grande do Norte, Brazil / A caprinocultura do Rio Grande do Norte abrange grande possibilidade econ?mica, com o manejo adequado dos recursos naturais. A introdu??o de animais especializados tem sido uma das maneiras utilizadas para aumentar a produtividade introduzindo uma melhor gen?tica aos rebanhos. Todavia, o clima t?m sido um dos fatores regionais que mais interferem na adapta??o da nova preval?ncia gen?tica com a introdu??o de ra?as ex?ticas, pois em seus pa?ses de origem, geralmente, a temperatura do ar apresenta, na maior parte do ano, valores mais baixos que os do corpo do animal. Neste sentido, o objetivo de presente estudo foi caracterizar a atividade comportamental e perfis fisiol?gicas, morfol?gicas e o desempenho leiteiro de f?meas da ra?a caprina Saanen, pertencentes a diferentes grupos gen?ticos, criados no semi-?rido do Rio Grande do Norte. O trabalho foi conduzido no munic?pio de Lages nas coordenadas geogr?ficas de latitude 5? 42 00 Sul e longitude 36? 14 41 Oeste. Foram utilizadas 25 f?meas em lacta??o da ra?a Saanen, distribu?das em 3 grupos gen?ticos : 5 animais puros, 11 animais ? e 9 animais ?. As observa??es comportamentais foram realizadas durante tr?s dias consecutivos no m?s de agosto e no m?s de setembro, das 09:00 ?s 11:30 horas, per?odo o qual os animais ficavam no pasto. Os dados fisiol?gicos e meteorol?gicos foram registrados nos ?ltimos tr?s dias dos meses de junho, julho, agosto e setembro ?s 05:00 e ?s 16:00 horas. No sistema de cria??o semi-intensiva, os animais de diferentes grupos gen?ticos apresentaram padr?es semelhantes de comportamento em n?vel de campo e em rela??o ?s respostas fisiol?gicas. Quanto aos dados morfol?gicos, embora as cabras puras tenham apresentado p?los de maior comprimento, os animais n?o demonstraram sintomas de desconforto t?rmico. A cor branca do pelo contribuiu para a reflex?o dos raios de onda curta e, conseq?entemente, para a elimina??o dos raios de onda longa. Portanto, os animais criados no sistema semi-intensivo de produ??o de leite deste estudo parecem estar adaptados ?s condi??es clim?ticas do semi-?rido do Rio Grande do Norte
4

Estresse p?s-traum?tico e tratamento com cetamina em ratos Wistar : an?lise comportamental, histofisiol?gica, bioqu?mica e neurometab?lica

Saur, Lisiani 12 January 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-01T15:01:05Z No. of bitstreams: 1 TES_LISIANI_SAUR_COMPLETO.pdf: 5532574 bytes, checksum: 990865e2748aa19880737e88991ec082 (MD5) / Made available in DSpace on 2017-06-01T15:01:05Z (GMT). No. of bitstreams: 1 TES_LISIANI_SAUR_COMPLETO.pdf: 5532574 bytes, checksum: 990865e2748aa19880737e88991ec082 (MD5) Previous issue date: 2017-01-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul (FAPERGS) / Post-traumatic stress disorder (PTSD) is a neuropsychiatric condition related to exposure to a traumatic event. It is clinically characterized by several debilitating symptoms including frequent re-experiencing of the traumatic event, avoidance bahavior, hypervigilance, and cognitive and mood changes among others. Not all individuals exposed to severe traumatic experiences develop PTSD. This psychopathology affects a vulnerable subpopulation of individuals confronted with a stressful experience that exceeds their capacity to cope. In this sense, it has been argued that PTSD can be considered a fear-related disorder. Thus, the brain regions most widely studied in this psychopathology are the prefrontal cortex, the hippocampus and the amygdala, because they are related to the storage and consolidation of new memories including emotional memories, such as fear and anger. Due to the complex clinical presentation of PTSD and its very variable symptoms, it is considered a condition to treat. Ketamine is an NMDA receptor antagonist that has shown promising effects in the treatment of depression. However, because it produces dissociative and psychotic effects, there is a concern this drug might be related with increased PTSD symptoms. One of the most widely used animal models to mimic the behavioral and neurochemical changes of PTSD is the inescapable footshock. In the first part of this study, we observed significant behavioral and histological changes caused by exposure to footshock. Animals with PTSD exhibited longer freezing bouts when re-exposed to the same aversive context, as well as increased pellet production. In addition, important changes were observed in astrocytes from the hippocampal CA1 region of these animals, such as decreased astrocytic density, ramification and fewer primary processes. Furthermore, the polarity of the astrocytes was also changed when compared to control animals. In the second part of this study, we analyzed the effects of ketamine on this animal model. Since not all animals have the same response during the re-exposure to aversive environment, that is, the animals have individual differences in their susceptibility to traumatic stress, we decided to separate the animals with PTSD into two groups: those with an extreme behavioral response (EBR) and those with a minimal behavioral response (MBR). Furthermore, the glucose metabolism and the BDNF levels in the frontal cortex, hippocampus and amygdala were analyzed 8 and 9 days after PTSD induction, respectively. BDNF levels were analyzed through biochemical assays and glucose metabolism was analyzed by 18F-FDG-microPET, which measures the glucose uptake in tissues, in other words, the metabolic demand. We observed that animals with PTSD classified as EBR showed an increase in freezing behavior and the treatment with ketamine worsened that behavioral response, that is, the ketamine worsened the PTSD symptoms. However, no changes were observed in BDNF levels or glucose metabolism. These results demonstrate that footshock as an animal model of PTSD induced significant behavioral and astrocytic alterations. We also observed that ketamine worsened the PTSD symptoms and that, as is the case with humans, not all individuals that are exposed to a traumatic stress develop PTSD. However, this animal model does not seem to be related to long-term changes in BDNF levels or glucose metabolism. / O transtorno do estresse p?s-traum?tico (Post-Traumatic Stress Disorder - PTSD) ? uma doen?a neuropsiqui?trica relacionada ? exposi??o a um acontecimento traum?tico. O PTSD ? caracterizado clinicamente por uma s?rie de sintomas debilitantes incluindo a reviv?ncia frequente do evento traum?tico, fuga de est?mulos associados ao trauma, hipervigil?ncia, mudan?as de cogni??o e humor entre outros. Nem todos os indiv?duos expostos a graves experi?ncias traum?ticas desenvolvem PTSD, esta psicopatologia afeta uma subpopula??o de indiv?duos vulner?veis cuja exposi??o a uma experi?ncia estressante excede sua capacidade de adapta??o. Neste sentido, foi argumentado que o PTSD pode, pelo menos em parte, ser um dist?rbio relacionado ao medo. Assim, as regi?es encef?licas mais amplamente estudadas nesta psicopatologia s?o o c?rtex pr?-frontal, o hipocampo e a am?gdala, pois s?o regi?es relacionadas com os processos de armazenamento e consolida??o de novas mem?rias incluindo mem?rias emocionais, tais como de medo e raiva. Devido ? complexa apresenta??o cl?nica do PTSD e a sua sintomatologia muito vari?vel esta ainda ? uma doen?a classificada como de dif?cil tratamento. A cetamina ? um f?rmaco antagonista de receptores NMDA que tem demonstrado promissores efeitos no tratamento da depress?o, entretanto, por ser uma droga que produz efeitos dissociativos e psic?ticos, existe a preocupa??o de que esta droga possa estar relacionada com o aumento dos sintomas do PTSD. Um dos modelos animais mais amplamente utilizados para mimetizar as altera??es comportamentais e neuroqu?micas do PTSD ? o choque inescap?vel ?nico. Na primeira parte do trabalho observamos importantes altera??es comportamentais e histol?gicas provocadas pela exposi??o ao choque nas patas. Os animais com PTSD apresentaram um maior comportamento de ?freezing? quando reexpostos ao mesmo contexto aversivo, bem como maior produ??o de bolos fecais. Al?m disso, importantes altera??es foram observadas nos str?citos da regi?o CA1 do hipocampo destes animais como: diminui??o na densidade, arboriza??o e quantidade de processos prim?rios. Ademais, a polaridade astrocit?ria tamb?m foi alterada em rela??o aos animais controle. Na segunda parte do trabalho analisamos os efeitos da cetamina sobre este modelo animal. Como nem todos os animais apresentam a mesma resposta durante a reexposi??o ao contexto aversivo, ou seja, os animais apresentam diferen?as individuais na sua susceptibilidade ao estresse traum?tico, n?s decidimos separar os animais com PTSD em dois grupos: aqueles que apresentaram uma resposta comportamental exagerada (Extreme Behavioral Response - EBR) e aqueles que apresentaram uma resposta comportamental m?nima (Minimal Bahavioral Response - MBR). Al?m disso, o metabolismo da glicose e os n?veis de BDNF no c?rtex frontal, hipocampo e am?gdala foram analisados oito e nove dias ap?s a indu??o do PTSD, respectivamente. Os n?veis de BDNF foram analisamos atrav?s ensaios bioqu?micos e o metabolismo da glicose foi analisado por meio do 18FFDG- microPET que avalia o consumo da glicose nos tecidos. Observamos que os animais com PTSD classificados como EBR apresentaram um aumento no comportamento de freezing e que o tratamento com cetamina piorou a resposta comportamental, ou seja, a cetamina agravou os sintomas do PTSD. Entretanto, nenhuma altera??o foi observada nos n?veis de BDNF e no metabolismo da glicose. Estes resultados demonstram que o choque nas patas, como modelos de PTSD em animais, induz importantes altera??es comportamentais e astrocit?rias. Observamos tamb?m que a cetamina piora os sintomas do PTSD e que, tal qual observado em humanos, nem todos os indiv?duos expostos a um estresse traum?tico desenvolvem os sintomas. Contudo, este modelo experimental de PTSD parece n?o estar relacionado com altera??es de longo-prazo nos n?veis de BDNF e metabolismo da glicose.
5

Biologia de sistemas computacional aplicada ? via metab?lica do chiquimato : enfoque na enzima 3-desidroquinato desidratase (EC 4.2.1.10)

?vila, Maur?cio Boff de 20 March 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-29T13:54:15Z No. of bitstreams: 1 DIS_MAURICIO_BOFF_DE_AVILA_COMPLETO.pdf: 2632464 bytes, checksum: 1a170d33bfad88ea8a7aba65cb0f4bea (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-29T13:54:25Z (GMT) No. of bitstreams: 1 DIS_MAURICIO_BOFF_DE_AVILA_COMPLETO.pdf: 2632464 bytes, checksum: 1a170d33bfad88ea8a7aba65cb0f4bea (MD5) / Made available in DSpace on 2017-06-29T13:54:34Z (GMT). No. of bitstreams: 1 DIS_MAURICIO_BOFF_DE_AVILA_COMPLETO.pdf: 2632464 bytes, checksum: 1a170d33bfad88ea8a7aba65cb0f4bea (MD5) Previous issue date: 2017-03-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Microorganisms, in general, are the major agents of disease in humans. Data from the Brazilian Ministry of Health show bacterial diseases as the main causes of death in the country. In the therapy of these organisms, antibiotics are considered the most successful chemotherapy methods of 21st century medicine, as they represent the first, and only, line of combat against bacterial diseases. The development of new antibiotic drugs is becoming increasingly necessary, as bacterial resistance rates become higher each year. At this point, shikimate pathway is attractive to this type of research, since it is considered an essential pathway for the maintenance of these organisms in the environment, besides being absent in animals. The pathway is responsible for the formation of chorismate, precursor of aromatic amino acids (Phe, Trp and Tyr), folic acid and ubiquinones in the groups of organisms that presents it. The third reaction of the shikimate biosynthetic pathway is performed by the enzyme DHQD. In this step the reversible dehydration of the DHQ molecule is performed aiming to transform into 3-dehydroshikimate, the focus reaction of this study. In the search for new DHQD inhibitors, docking simulations were performed against the three-dimensional structure of a target protein, since it is a process that seeks to find, among possible orientations/conformations of a ligand in the active site, the one that presents the lower binding energy and, consequently, greater affinity. In addition to the docking simulations, machine learning methods were used to formulate polynomial scoring functions, based on the MVD scoring functions, which were able to predict protein/binder affinity. At the end of all the simulations and tests carried out throughout the project, we conclude that the Polscore56 equation was the most skilled to predict the affinity between the active site of DHQD and tested compounds. For this polynomial, the results of test set (? = 0,900; p-value = 0,037), AUC (74,686%), EF1 (540) and EF2 (159,23) were, in most of the categories evaluated, the best, confirming the formulated hypotheses on the equation and indicating it for further studies with the enzyme. / Microrganismos, em geral, apresentam-se como os principais agentes de doen?as em seres humanos. Dados do Minist?rio da Sa?de Brasileiro demonstram doen?as bacterianas como as principais causas de morte no pa?s. Na terap?utica desses organismos, os antibi?ticos s?o considerados os m?todos quimioter?picos de maior sucesso da medicina do s?culo XXI, pois representam a primeira, e ?nica, linha de combate contra doen?as bacterianas. O desenvolvimento de novas drogas antibi?ticas torna-se cada vez mais necess?rio, uma vez que os ?ndices de resist?ncia bacteriana se tornam mais altos a cada ano. Nesse ponto, a rota metab?lica do chiquimato ? atraente a esse tipo de pesquisa, por ser considerada uma via essencial para a manuten??o desses organismos no ambiente, al?m de estar ausente em animais. A via ? respons?vel pela forma??o do corismato, precursor de amino?cidos arom?ticos (Phe, Trp e Tyr), ?cido f?lico e ubiquinonas nos grupos de seres vivos onde est? presente. A terceira rea??o da via biossint?tica do chiquimato ? realizada pela enzima DHQD. Nesse passo ? realizada a desidrata??o revers?vel da mol?cula DHQ visando transform?-la em 3-desidrochiquimato, rea??o foco desse estudo. Na busca por novos inibidores de DHQD foram realizadas simula??es de docking de pequenos ligantes contra a estrutura tridimensional de uma prote?na alvo, pois ? um processo onde se visa encontrar, entre as poss?veis orienta??es/conforma??es de um ligante no s?tio ativo, aquela que apresenta a menor energia de liga??o e, consequente, maior finidade. Al?m das simula??es de docking, foram realizados m?todos de Aprendizagem de M?quina na formula??o de fun??es escores polinomiais, a partir de fun??es escores presentes no MVD, que fossem capazes de prever a afinidade entre prote?na/ligante. Ao final de todas as simula??es e testes realizados ao longo do projeto, chegamos ? conclus?o de que a equa??o Polscore56 apresentou-se como a mais h?bil para prever a afinidade entre o s?tio ativo de DHQD com compostos testados. Para esse polin?mio os resultados de test set (? = 0,900; p-value = 0,037), AUC (74,686%), EF1 (540) e EF2 (159,23) foram, na maioria das categorias avaliadas, os melhores, confirmando as hip?teses formuladas sobre a equa??o e indicando-a para estudos posteriores com a enzima.
6

Investiga??o dos efeitos do pept?deo liberador de gastrina (GRP) e seu antagonista RC-3095 em c?lulas mieloides

Czepielewski, Rafael Sanguinetti 18 March 2016 (has links)
Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2017-07-24T18:23:29Z No. of bitstreams: 1 RAFAEL_SANGUINETTI_CZEPIELEWSKI_TES.pdf: 5487109 bytes, checksum: 88dbb99b9597e08253e2832cc01ccfce (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-07-25T17:50:46Z (GMT) No. of bitstreams: 1 RAFAEL_SANGUINETTI_CZEPIELEWSKI_TES.pdf: 5487109 bytes, checksum: 88dbb99b9597e08253e2832cc01ccfce (MD5) / Made available in DSpace on 2017-07-25T18:00:09Z (GMT). No. of bitstreams: 1 RAFAEL_SANGUINETTI_CZEPIELEWSKI_TES.pdf: 5487109 bytes, checksum: 88dbb99b9597e08253e2832cc01ccfce (MD5) Previous issue date: 2016-03-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Tumor microenvironment and inflammatory diseases promote alterations in our immune system along with their development. Several molecules are implicated in this modulation and are therefore considered therapeutic targets. Gastrin-releasing peptide (GRP) is produced in tumors where it promotes cellular proliferation. It is also correlated with chronic diseases, as in rheumatoid arthritis and asthma, and in the acute condition of sepsis. Recently, our group found a direct GRP action over neutrophils, promoting migration. This work aimed to study the interface between GRP-producing tumors and the recruitment of immune cells, as well as extend the cellular studies about neutrophil activation and migration processes promoted by the peptide. In tumors, we observed that a lung adenocarcinoma cell line does not proliferate in response to GRP. Yet, it is induced to migrate when exposed to the peptide, indicating a potential role for GRP in metastasis of this type of cancer. In our tumor immunology studies, we established a novel in vivo model by overexpressing GRP in a melanoma cell line (B16F10). We observed the augment of infiltrating inflammatory monocytes in the tumor microenvironment of these tumors. In parallel, we verified that reactive oxygen species production and migration in response to GRP is dependent of the NADPH oxidase complex. GRP stimulation promotes an intense activation, which culminates in neutrophil extracellular traps (NETs) release. In addition, the GRP receptor (GRPR) antagonist RC-3095 presented anti-inflammatory potential, inhibiting neutrophil migration towards IL-8 and reducing the extent of acetaminophen-induced liver damage. This effect was due to motility alterations in infiltrating neutrophils within the tissue and reduction of cell adhesion molecules. The results presented herein demonstrate the wide panorama of GRP?s interactions in tumor and immune biology. / O microambiente tumoral e as doen?as inflamat?rias promovem altera??es nas c?lulas do nosso sistema imune ? medida que progridem. Diversas mol?culas est?o envolvidas nessa modula??o, e por isso s?o alvos terap?uticos. O pept?deo liberador de gastrina (GRP) ? produzido por tumores, onde promove prolifera??o celular. Este tamb?m est? correlacionado com doen?as cr?nicas como a artrite reumatoide e asma, e em doen?as agudas, como a sepse. Recentemente, nosso grupo descobriu a??o direta do GRP em neutr?filos, promovendo indu??o de migra??o. O presente trabalho se prop?s a estudar a interface entre tumores produtores de GRP e o recrutamento celular, assim como aprofundar os estudos celulares sobre os processos de ativa??o e migra??o de neutr?filos promovidos pelo pept?deo. Em tumores, observamos que uma linhagem de adenocarcinoma pulmonar n?o prolifera quando exposto ao GRP, por?m ? induzida a migrar quando exposta ao pept?deo, estabelecendo um potencial papel deste na promo??o de met?stases para esse tipo tumoral. Na interface da imunologia tumoral, atrav?s do desenvolvimento de um modelo in vivo de superexpress?o de GRP em melanoma murino (B16F10), observamos que esse aumento do GRP induz a infiltra??o de mon?citos inflamat?rios no microambiente tumoral. Em paralelo, verificamos que a produ??o de esp?cies reativas de oxig?nio e a migra??o em dire??o ao GRP s?o dependentes do complexo NADPH oxidase. Esse est?mulo promove ativa??o intensa, culminando na produ??o de redes extracelulares de neutr?filos (NETs). J? o antagonista do seu receptor, GRPR, apresentou potencial antiinflamat?rio, sendo capaz de inibir a migra??o neutrof?lica via modula??o de IL-8 e reduzindo a extens?o da les?o hep?tica induzida por paracetamol (acetaminofeno), alterando a motilidade dos neutr?filos no tecido e a express?o de mol?culas de ades?o. Assim, os resultados aqui apresentados demonstram um panorama amplo da fun??o do GRP na biologia tumoral e no sistema imune.
7

Efeito da inje??o da prote?na b-amiloide 1-42 em diferentes formas no ventr?culo encef?lico : um modelo de aspectos celulares da doen?a de Alzheimer em zebrafish

Silva, Natalia Eltz 08 March 2017 (has links)
Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2017-07-11T14:38:07Z No. of bitstreams: 1 NATALIA_ELTZ_SILVA_DIS.pdf: 1036979 bytes, checksum: 23cdf77b8842f9e9ade0b13e6f7bc111 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-07-28T17:40:18Z (GMT) No. of bitstreams: 1 NATALIA_ELTZ_SILVA_DIS.pdf: 1036979 bytes, checksum: 23cdf77b8842f9e9ade0b13e6f7bc111 (MD5) / Made available in DSpace on 2017-07-28T17:47:24Z (GMT). No. of bitstreams: 1 NATALIA_ELTZ_SILVA_DIS.pdf: 1036979 bytes, checksum: 23cdf77b8842f9e9ade0b13e6f7bc111 (MD5) Previous issue date: 2017-03-08 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Aging-related diseases are becoming more common. Alzheimer's disease (AD), the most prevalent form of dementia, includes as initial symptoms cognitive deficits that are attributed to the toxic effects of amyloid? peptide (A?) that accumulates in senile plaques and neurofibrillary tangles composed of hyperphosphorylated tau protein. The amyloid cascade initially proposed to explain the effects of A? pointed to the plaques as the most toxic form of the A? molecule responsible for neuronal dysfunction and death. Recently, several evidences point to the increased toxicity of the soluble forms of the peptide. A better understanding of the dynamics of amyloid aggregation, clearance and toxic potential of the soluble versions may foster significant advances in the understanding AD mechanisms and the identification of potential targets for AD therapies. In this study we used the zebrafish as a model. 24-hour embryos received intracerebroventricular injection of human A?1-42 prepared to have different aggregation potentials: monomeric, oligomeric and plaqueforming. At 5 days post-fertilization (dpf), quantification of A?1-42 levels demonstrated a remnant increase in peptide levels in the animals injected with the solution that favored plaque formation. After monitoring for embryotoxic and teratogenic effects, 5dpf the animals were also evaluated in relation to general physiological aspects and their cognitive ability. Although the injection did not significantly impact animal survival or exploratory ability, the oligomeric solution induced specific cognitive deficits in relation to the vehicleinjected control. Together these results support the revised version of the amyloid cascade in which, although the presence of plaques corresponds to a greater accumulation of A?1- oligomeric forms may induce significant neurotoxic effects and result in cognitive deficits specially at disease?s early stages. / Com o envelhecimento da popula??o, doen?as relacionadas com o envelhecimento v?m se tornando mais comuns. A Doen?a de Alzheimer (DA), a forma prevalente de dem?ncia, inclui como sintomas iniciais deficit cognitivos que s?o atribu?dos a efeitos t?xicos de pept?deo ?- amiloide (A?) que se acumula em placas senis e emaranhados neurofibrilares constitu?dos pela prote?na tau hiperfosforilada. A cascata amiloide inicialmente proposta para explicar os efeitos do A? apontava para as placas de dep?sito de A?1-42 como a forma t?xica da mol?cula respons?vel pela disfun??o e morte neuronal. Recentemente diversas evid?ncias apontam para a toxicidade das vers?es sol?veis do pept?deo antes da agrega??o em placas. O melhor entendimento da din?mica de agrega??o do amiloide, limpeza e potencial t?xico das vers?es sol?veis pode permitir significativos avan?os no conhecimento dos mecanismos da doen?a e a identifica??o de potenciais alvos para terapias da DA. Neste estudo utilizamos o tele?steo zebrafish como modelo para a caracteriza??o destes processos. Embri?es com 24 horas receberam inje??o intracerebroventricular de A?1-42 humano preparado de forma a ter diferentes potenciais de agrega??o: monom?rica, oligom?rica e formadora de placas. Ao atingirem 5 dias p?s-fertiliza??o (dpf), a quantifica??o dos n?veis de A?1-42 demonstrou um aumento remanescente dos n?veis do pept?deo nos animais injetados com a solu??o que favorecia a forma??o de placas. Ap?s monitorarmos eventuais efeitos embriot?xicos e teratog?nicos, ao atingirem 5dpf, os animais foram tamb?m avaliados em rela??o a aspectos fisiol?gicos gerais e sua capacidade cognitiva. Embora a inje??o n?o tenha impactado significativamente a sobreviv?ncia dos animais ou a capacidade explorat?ria, a inje??o da solu??o oligom?rica induziu deficit cognitivos espec?ficos em rela??o ao controle injetado com ve?culo. Juntos, estes resultados suportam a vers?o revisada da cascata amiloide na qual, embora a presen?a de placas corresponda a um maior ac?mulo de A?1-42, a presen?a de vers?es oligom?ricas pode induzir efeitos neurot?xicos significativos e resultar em deficit cognitivos, especialmente nos est?gios iniciais da doen?a.
8

Fenotipagem por DNA - variantes em genes humanos que regulam a pigmenta??o de olhos e de pele : an?lise fenot?pica e genot?pica de indiv?duos sulbrasileiros para fins forenses

Sawitzki, Fernanda Rosa 07 November 2017 (has links)
Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-02-26T11:20:29Z No. of bitstreams: 1 FERNANDA_ROSA_SAWITSKI_TES.pdf: 5519043 bytes, checksum: d8234f6f341fd9d5f2c4a39db88b714c (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-02-26T20:03:16Z (GMT) No. of bitstreams: 1 FERNANDA_ROSA_SAWITSKI_TES.pdf: 5519043 bytes, checksum: d8234f6f341fd9d5f2c4a39db88b714c (MD5) / Made available in DSpace on 2018-02-26T20:08:29Z (GMT). No. of bitstreams: 1 FERNANDA_ROSA_SAWITSKI_TES.pdf: 5519043 bytes, checksum: d8234f6f341fd9d5f2c4a39db88b714c (MD5) Previous issue date: 2017-11-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Genes related to externally visible characteristics (EVC) present a great importance for the prediction of skin and eye colors in humans. In this study, we tested the ability of a set of SNPs in pigment-related genes to predict skin and eye colors in an admixed south Brazilian population. First, we used the Cinderella - Tiana - Snow White model to analyze the allelic distribution of eight biallelic SNPs in pigment-related. Cinderella and Tiana patterns have respectively low and high melanin content in skin and eyes; Cinderella has white skin and blue eyes (low melanin content; LMC) and Tiana has dark skin and eyes (high melanin content; HMC). Comparative investigation between frequencies of genetic variants in Cinderella-Like versus Tiana-Like subjects may indicate which polymorphic variant is associated with melanin synthesis in skin and eyes. Coordinately, studies with Snow White-Like subjects may be informative to reveal any tissue-specific expression, since these individuals have both white skin (LMC) and dark eyes (HMC). Based on allele frequencies of different human popullations, allele ?L? was used for the alleles associated with low melanin content populations (Cinderela-like subjects), and allele ?H? was used for the alleles associated with high melanin content populations (Tiana-like subjects). Allelic distribution of eight SNPs showed that 100% of Cinderella- like subjects (N= 73) had less than eight H alleles, and 82% of Tiana-Like subjects (N= 61) had eight or more H alleles. The AUC (Area Under the Receiver Operating Characteristic Curve) value was 0.99, and the calculation of PGL (Pathway Genetic Load) and GP (Genetic Probability) showed that the SNP set presented 93% and 91% concordance between DNA genotype and phenotypes, respectively. Factorial discriminant analyses (FDA) performed in the Snow White group (light skin and dark eyes; N= 116) showed an association between SNPs rs16891982 (SLC45A2), rs8045560 (MC1R), rs1426654 (SLC24A5), rs2733832 (TYRP1), and rs1042602 (TYR) and the Cinderella cluster for skin phenotype, and an association between SNPS rs4778138 (OCA2), rs12913832 (HERC2), and rs916977 (HERC2) and the Tiana cluster for eye phenotype. Lastly, we studied 436 South Brazilian subjects with different skin and eye colors to construct a multinomial logistic regression model able to predict phenotype. The model was tested in 40 random subjects to measure the efficiency of the prediction. The data presented 93% concordance between the predicted and the observed phenotype, showing the successful phenotype prediction of the model in South Brazilian individuals. This is important since Brazil has an ethnically mixed population in which genomic structure may favor epistatic and pleiotropic effects not observed in populations that are more homogeneous. The analyses presented here are an important contribution to forensic DNA phenotyping scenario. / Os genes relacionados a caracter?sticas externamente vis?veis (EVC) apresentam grande import?ncia para a previs?o de cores de pele e olho em humanos. Neste estudo, testamos a capacidade de um conjunto de SNPs em genes relacionados ? s?ntese de pigmento melanina para prever cores de pele e olho em uma popula??o sul-brasileira. Inicialmente, utilizamos o modelo Cinderela - Tiana - Neve Branca para analisar a distribui??o al?lica de oito SNPs bial?licos associados ? produ??o da melanina. Os padr?es Cinderela e Tiana possuem respectivamente baixo e alto conte?do de melanina na pele e nos olhos; Cinderela tem pele branca e olhos azuis (baixo conte?do de melanina, LMC) e Tiana tem pele e olhos escuros (alto conte?do de melanina, HMC). A investiga??o comparativa entre frequ?ncias de variantes gen?ticas em indiv?duos com Cinderela-Like versus Tiana-Like pode indicar qual variante polim?rfica est? associada ? s?ntese de melanina na pele e nos olhos. De forma coordenada, os estudos com indiv?duos Branca de Neve-Like podem ser informativos para revelar a express?o tecido-espec?fica, uma vez que esses indiv?duos t?m pele branca (LMC) e olhos escuros (HMC). Com base em frequ?ncias de alelos de diferentes popula??es humanas, o nome alelo "L" foi utilizado para os alelos associados a popula??es de baixo conte?do de melanina (indiv?duos Cinderela-Like) e o nome alelo "H" foi utilizado para os alelos associados a popula??es de alto conte?do de melanina (Indiv?duos Tiana-Like). A distribui??o al?lica de oito SNPs mostrou que 100% de indiv?duos com Cinderela-Like (N= 73) tinham menos de oito alelos H e 82% de indiv?duos Tiana-Like (N= 61) tinham oito ou mais alelos H. O valor AUC (Area Under the Receiver Operating Characteristic Curve) foi de 0,99 e o c?lculo de PGL (Pathway Genetic Load) e GP (Probabilidade Gen?tica) mostrou que o conjunto de SNP apresentou concord?ncia de 93% e 91% entre gen?tipo e fen?tipo, respectivamente. As an?lises discriminantes fatoriais (FDA) realizadas no grupo Branca de Neve-Like (pele clara e olhos escuros; N= 116) mostraram associa??o positiva entre SNPs rs16891982 (SLC45A2), rs8045560 (MC1R), rs1426654 (SLC24A5), rs2733832 (TYRP1) e rs1042602 (TYR) e o cluster de Cinderela para o fen?tipo da pele, e associa??o positiva entre SNPS rs4778138 (OCA2), rs12913832 (HERC2) e rs916977 (HERC2) e o cluster Tiana para o fen?tipo dos olhos. Por fim, estudamos 436 sujeitos sul-brasileiros com diferentes cores de pele e de olhos para construir um modelo de regress?o log?stica multinomial capaz de prever o fen?tipo. O modelo foi testado em 40 indiv?duos aleat?rios para medir a efici?ncia da predi??o. Os dados apresentaram concord?ncia de 93% entre o fen?tipo previsto e observado, mostrando a previs?o fenot?pica bem-sucedida do modelo em indiv?duos sul-brasileiros. Isso ? importante, uma vez que o Brasil tem uma popula??o etnicamente mista, na qual a estrutura gen?mica pode favorecer os efeitos epistaticos e pleiotr?picos n?o observados em popula??es mais homog?neas. As an?lises aqui apresentadas s?o uma importante contribui??o para a ?rea da fenotipagem por DNA.
9

Rizobact?rias Streptomyces no crescimento e na defesa de plantas de Solanum lycopersicum (L.)

Leite, Andressa Von Wurmb Helrighel 25 August 2017 (has links)
Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-03-06T18:10:51Z No. of bitstreams: 1 ANDRESSA_VON_WURMB_HELRIGUEL_LEITE_DIS.pdf: 1584575 bytes, checksum: 5f9a44ec42089e160df54cc84eaadb9a (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-03-07T14:04:49Z (GMT) No. of bitstreams: 1 ANDRESSA_VON_WURMB_HELRIGUEL_LEITE_DIS.pdf: 1584575 bytes, checksum: 5f9a44ec42089e160df54cc84eaadb9a (MD5) / Made available in DSpace on 2018-03-07T14:11:58Z (GMT). No. of bitstreams: 1 ANDRESSA_VON_WURMB_HELRIGUEL_LEITE_DIS.pdf: 1584575 bytes, checksum: 5f9a44ec42089e160df54cc84eaadb9a (MD5) Previous issue date: 2017-08-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Tomato (Solanum lycopersicum) cultures are frequently attacked by many pathogens, leading to yield losses. Among the pathogens, the fungus Alternaria solani (?Early blight? disease) can cause significant yield reductions and decreases the fruit quality. Due to the high susceptibility of tomato to fungal pathogens, the agricultural practices include the intensive use of agrochemicals, which may result in fruits with high levels of residual pesticides and higher production costs. The promotion of plant defense system represents an additional tool for disease control and plant growth management. Some rhizobacteria have been shown the ability to affect plant development and modulate plant defense against pathogens. Among those bacteria, the genus Streptomyces is able to synthesize molecules that directly interfere with growth, through auxin and ACC deaminase production, and indirectly, through antibiotics and siderophores synthesis. The aim of this work was to select Streptomyces (CLV04, CLV05 and CLV07) with the ability to promote seed germination and plant growth, as well as improve tomato plant resistance against A. solani. Results showed that CLV07 delayed the initial seed germination, but it did not impair the final germination process. However, CLV04, CLV05 and CLV07 reduced the early root and shoot growth. All these rhizobacteria produced high auxin levels. CLV07 was efficient for inducing plant resistance against A. solani. Furthermore, all CLVs showed antagonism by competition, decreasing the A. solani growth. Taking together all results, Streptomyces tested were deleterious for seed and initial plant growth, but CLV07 showed a potential to be used for inducing plant resistance. However, the inoculation of these rhizobacteria on seeds is not recommended. / O tomateiro (Solanum lycopersicum) ? constantemente atacado por diversos pat?genos, levando a perdas de produtividade. Dentre os principais pat?genos, destaca-se o fungo Alternaria solani que causa a doen?a ?pinta-preta? (?Early blight?), capaz de reduzir a produ??o e/ou levar ? forma??o de frutos de baixa qualidade. Devido ? grande susceptibilidade do tomateiro a pat?genos, as pr?ticas agr?colas incluem o uso intensivo de agroqu?micos que resultam, frequentemente, em tomates com altos n?veis residuais de pesticidas. A promo??o do crescimento e da defesa vegetal utilizando microrganismos representa uma ferramenta para o manejo do tomateiro. Dentre as diversas rizobact?rias com capacidade de modular o crescimento e a defesa vegetal, o g?nero Streptomyces vem se destacando. Estas bact?rias s?o capazes de sintetizar mol?culas que interferem tanto diretamente no crescimento, como a auxina e a ACC desaminase, quanto indiretamente, atrav?s da produ??o de antibi?ticos e sider?foros. Pretendeu-se, neste trabalho, selecionar isolados de Streptomyces (CLV04, CLV05 e CLV07) com capacidade de promover a germina??o e o crescimento de plantas de tomate, al?m de aumentar a resist?ncia vegetal contra A. solani. Os resultados demonstram que o CLV07 causou retardo na germina??o, mas n?o reduziu a taxa final de germina??o. Apesar das rizobact?rias CLV04, CLV05 e CLV07 produzirem elevados n?veis de auxina, elas causaram a redu??o do crescimento tanto da raiz quanto da parte a?rea de pl?ntulas de tomate cultivadas in vitro. O CLV07 foi eficiente na promo??o da defesa de plantas de tomate contra A. solani. Todas as rizobact?rias apresentaram antagonismo por competi??o, reduzindo o crescimento do mic?lio do fungo A. solani. Considerando todos os resultados, as diferentes bact?rias Streptomyces foram prejudiciais ? germina??o e ao crescimento inicial de pl?ntulas de tomate. Desta forma, n?o ? recomend?vel a utiliza??o destas bact?rias em sementes e pl?ntulas jovens. Contudo, o CLV07 apresenta potencial para ser utilizado para a indu??o de resist?ncia de plantas de tomate contra o pat?geno A. solani.
10

Avalia??o do crescimento e da imunidade de plantas de Solanum tuberosum (L.) tratadas com rizobact?rias

Vilches, Patr?cia Fernanda da Silva 30 March 2017 (has links)
Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-03-15T13:05:33Z No. of bitstreams: 1 PATRICIA_FERNANDA_DASILVA_VILCHES_DIS.pdf: 1829625 bytes, checksum: d4b53df7fed69d5202d5bafec96aaa13 (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2018-03-23T12:17:26Z (GMT) No. of bitstreams: 1 PATRICIA_FERNANDA_DASILVA_VILCHES_DIS.pdf: 1829625 bytes, checksum: d4b53df7fed69d5202d5bafec96aaa13 (MD5) / Made available in DSpace on 2018-03-23T12:22:01Z (GMT). No. of bitstreams: 1 PATRICIA_FERNANDA_DASILVA_VILCHES_DIS.pdf: 1829625 bytes, checksum: d4b53df7fed69d5202d5bafec96aaa13 (MD5) Previous issue date: 2017-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Potatoes (Solanum tuberosum L.) are the third most consumed crop in the world, after rice and wheat. Among the diseases affecting potato, the blackleg and tuber soft rot, caused by phytobacteria Pectobacterium spp., lead to significant losses in the yield crop. Several studies have been exploring the use of plant defense inducers as a strategy to control plant diseases. The use of plant growth-promoting rhizobacteria (PGPR) in agriculture can lead to plant growth and enhancement of plant defense through the promotion of induced systemic resistance (ISR). However, the mechanisms involved in promoting ISR are still poorly understood. This study aimed to screen rhizobacteria of the genus Streptomyces with capacity to promote plant growth and induce Solanum tuberosum innate immunity. To achieve these objectives, we evaluated: i) the ability of Streptomyces isolates to produce auxin (3-indoleacetic acid), ACC deaminase (1-aminocyclopropane-1-carboxylic acid deaminase) and siderophores; ii) their capacity to promote the growth of potato plants; iii) the induction of resistance in potato plants challenged with Pectobacterium carotovorum subsp. brasiliensis and iv) the expression of genes related to defense pathways in S. tuberosum, promoted by Streptomyces and P. carotovorum. Results indicated that the CLV163 isolate presents PGPR features, such as high auxin and siderophores production, and promoted plant defense against P. carotovorum. Although CLV145 showed the highest auxin and siderophores production, it reduced the shoot dry mass and was inefficient in promoting plant defense. Moreover, the ability of Streptomyces in producing ACC deaminase was not critical for promoting plant growth. The CLV163 isolate induced a priming state in potato plants that has occurred through the activation of the AS and ET pathways, and its interaction with S. tuberosum plants did not impair the plant growth. / A batata (Solanum tuberosum L.) ? a terceira cultura agr?cola mais consumida no mundo, ficando atr?s somente do arroz e do trigo. Dentre as diversas doen?as que afetam esta cultura, a canela-preta e a podrid?o-mole, causadas pela fitobact?ria Pectobacterium spp., levam a importantes perdas na produ??o. Neste contexto, v?rios trabalhos v?m explorando o uso de indutores da defesa vegetal como estrat?gia para o controle de doen?as. O uso de rizobact?rias promotoras do crescimento vegetal (PGPR) na agricultura pode promover tanto o crescimento quanto o aumento da defesa das plantas atrav?s da indu??o da resist?ncia sist?mica induzida (ISR). Contudo, ainda s?o pouco conhecidos os mecanismos envolvidos na promo??o da ISR. Este estudo visou selecionar rizobact?rias do g?nero Streptomyces com caracter?sticas de promotoras de crescimento e indutoras da imunidade inata de Solanum tuberosum. Para tanto, foram avaliadas: i) a capacidade de isolados de Streptomyces produzirem auxina (?cido 3- indolac?tico), ACC desaminase (?cido 1-aminociclopropano-1-carbox?lico desaminase) e sider?foros; ii) a capacidade destas rizobact?rias em promover o crescimento das plantas; iii) a promo??o da resist?ncia em plantas de batata desafiadas com Pectobacterium carotovorum subsp. brasiliensis e iv) a express?o de genes relacionados a vias de sinaliza??o de respostas de defesa em S. tuberosum, promovida por Streptomyces sp e a fitobact?ria P. carotovorum. Os resultados indicam que o isolado CLV163 apresenta caracter?sticas de PGPR, sendo capaz de produzir auxina e sider?foros, al?m de promover o aumento da resist?ncia das plantas contra P. carotovorum. Contudo, a rizobact?ria CLV145, com a maior produ??o de auxina e sider?foros, causou a diminui??o da mat?ria seca de parte a?rea e n?o promoveu a defesa das plantas. A capacidade dos Streptomyces em produzirem ACC desaminase n?o foi determinante para a promo??o de crescimento vegetal. O isolado CLV163 induziu um estado de priming nas plantas de S. tuberosum L. atrav?s da ativa??o das vias do AS e ET e a sua intera??o com as plantas de batata n?o comprometeu o crescimento vegetal.

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