Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Specific boundaries between the causal agents of the soybean stem canker(Tropical Plant Pathology, 2014-07) Oliveira, Luiz Orlando de; Guillin, Eduardo A.; Grijalba, Pablo E.; Gottlieb, Alexandra M.Pathogens within the Diaporthe complex cause seed decay, stem blight and stem canker on soybean, representing a serious threat for this crop species. We herein utilize worldwide sequence data retrieved from Genbank in order to assess the species boundaries between the soybean stem canker causal agents, and define whether or not they should be regarded as members of the same biological species. These studies were complemented with compatibility tests, in order to validate our findings from a biological standpoint. Species delimitation assays supported the occurrence of a speciation event between D. caulivora and D. phaseolourm var. meridionalis. A speciation hypothesis between D. aspalathi and D. phaseolourm var. meridionalis was also supported, based on three reciprocally monophyletic substitutions at locus EF1-α. Compatibility tests further validated species delimitation assays indicating that D. caulivora has developed barriers to gene exchange with D. phaseolorum var. meridionalis. Clarification of the specific boundaries of the SSC pathogens and related entities will be an important asset to future research in soybean pathology, epidemiology and breeding.Item Specific boundaries between the causal agents of the soybean stem canker(Tropical Plant Pathology, 2014-07) Oliveira, Luiz Orlando de; Guillin, Eduardo A.; Grijalba, Pablo E.; Gottlieb, Alexandra M.Pathogens within the Diaporthe complex cause seed decay, stem blight and stem canker on soybean, representing a serious threat for this crop species. We herein utilize worldwide sequence data retrieved from Genbank in order to assess the species boundaries between the soybean stem canker causal agents, and define whether or not they should be regarded as members of the same biological species. These studies were complemented with compatibility tests, in order to validate our findings from a biological standpoint. Species delimitation assays supported the occurrence of a speciation event between D. caulivora and D. phaseolourm var. meridionalis. A speciation hypothesis between D. aspalathi and D. phaseolourm var. meridionalis was also supported, based on three reciprocally monophyletic substitutions at locus EF1-α. Compatibility tests further validated species delimitation assays indicating that D. caulivora has developed barriers to gene exchange with D. phaseolorum var. meridionalis. Clarification of the specific boundaries of the SSC pathogens and related entities will be an important asset to future research in soybean pathology, epidemiology and breeding.Item Biometric analysis of protein and oil contents of soybean genotypes in different environments(Pesquisa Agropecuária Brasileira, 2014-06) Rodrigues, Josiane Isabela da Silva; Arruda, Klever Márcio Antunes; Cruz, Cosme Damião; Piovesan, Newton Deniz; Barros, Everaldo Gonçalves de; Moreira, Maurilio AlvesThe objective of this work was to identify by biometric analyses the most stable soybean parents, with higher oil or protein contents, cultivated at different seasons and locations of the state of Minas Gerais, Brazil. Forty-nine genotypes were evaluated in the municipalities of Viçosa, Visconde do Rio Branco, and São Gotardo, in the state of Minas Gerais, from 2009 to 2011. Protein and oil contents were analyzed by infrared spectrometry using a FT-NIR analyzer. The effects of genotype, environment, and genotype x environment interaction were significant. The BARC-8 soybean genotype is the best parent to increase protein contents in the progenies, followed by BR 8014887 and CS 3032PTA276-3-4. Selection for high oil content is more efficient when the crossings involve the Suprema, CD 01RR8384, and A7002 genotypes, which show high mean phenotypic values, wide adaptability, and greater stability to environmental variation.Item Insights into the proteome of the spermatheca of the leaf- cutting ant Atta sexdens rubropilosa (Hymenoptera: Formicidae)(Florida Entomologist, 2014-12) Malta, Juliana; Martins, Gustavo Ferreira; Marques, Ana Ermelinda; Games, Patrícia Dias; Zanuncio, José Cola; Baracat- Pereira, Maria Cristina; Salomão, Tânia Maria FernandesFifteen of the 22 differentially expressed proteins in the spermathecae of virgin and inseminated females of the leaf cutting ant Atta sexdens rubropilosa were tentatively identified. The profile of expressed proteins of the spermatheca differed significantly between virgin and fertilized females. Data from this study should contribute to the elucidation of the roles of these various proteins in prolonged storage and maintenance of viable spermatozoa within the female.Item Evidence of horizontal transmission of primary and secondary endosymbionts between maize and rice weevils (Sitophilus zeamais and Sitophilus oryzae) and the parasitoid Theocolax elegans(Journal of Stored Products Research, 2014-10) Carvalho, Gislaine A.; Corrêa, Alberto S.; Oliveira, Luiz O. de; Guedes, Raul Narciso C.Grain weevils are hosts of two cellular endosymbionts: Wolbachia and “Sitophilus Primary Endosymbiont” (SPE). Wolbachia is a facultative endosymbiont, while SPE is an obligatory endosymbiont. Both Wolbachia and SPE are transmitted vertically, that is, from mother to offspring. There are circumstances in which transmission occurs among conspecific organisms or organisms of distinct species (horizontal transmission), and both vertical and horizontal transmissions play significant roles in shaping the host's ecology and evolution. We found molecular evidence for the horizontal transfer of Wolbachia between the maize weevil (Sitophilus zeamais Motschulsky) and the rice weevil (Sitophilus oryzae (L.)) and evidence of horizontal transfer of Wolbachia and SPE between the maize weevil and the parasitoid Theocolax elegans Westwood (Hymenoptera: Pteromalidae). Using 16S rRNA fragments of both symbionts, we verified the co-existence of two Wolbachia strains in maize weevil individuals from a Mexican population, one of which is typically from this species, while the other is from rice weevils. This finding provides evidence of the horizontal transmission of the endosymbiont between maize and rice weevil and supports the contention of similarity and relatedness between these weevil species. We also observed 100% similarity of 16S rRNA fragments between Wolbachia and SPE sequenced from the weevil parasitoid T. elegans and the maize weevil. This evidence suggests the horizontal transmission of both endosymbionts from the maize weevil to its parasitoid T. elegans. In addition to the importance of these findings for the ecology and evolution of weevils, the potential use of endosymbionts in innovative tactics of arthropod pest management in stored products also deserves attention and remains virtually unexplored.Item E-NTPDase (ecto-nucleoside triphosphate diphosphohydrolase) of Leishmania amazonensis inhibits macrophage activation(Microbes and Infection, 2014-12-30) Souza Vasconcellos, Raphael de; Gomes, Rodrigo Saar; Carvalho, Luana Cristina Faria de; Fietto, Juliana Lopes Rangel; Afonso, Luís Carlos CroccoLeishmania amazonensis, the causal agent of diffuse cutaneous leishmaniasis, is known for its ability to modulate the host immune response. Because a relationship between ectonucleotidase activity and the ability of Leishmania to generate injury in C57BL/6 mice has been demonstrated, in this study we evaluated the involvement of ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDase) activity of L. amazonensis in the process of infection of J774-macrophages. Our results show that high-activity parasites show increased survival rate in LPS/IFN-γ-activated cells, by inhibiting the host-cell NO production. Conversely, inhibition of E-NTPDase activity reduces the parasite survival rates, an effect associated with increased macrophage NO production. E-NTPDase activity generates substrate for the production of extracellular adenosine, which binds to A2B receptors and reduces IL-12 and TNF-α produced by activated macrophages, thus inhibiting NO production. These results indicate that E-NTPDase activity is important for survival of L. amazonensis within macrophages, showing the role of the enzyme in modulating macrophage response and lower NO production, which ultimately favors infection. Our results point to a new mechanism of L. amazonensis infection that may pave the way for the development of new treatments for this neglected disease.Item Moving towards the immunodiagnosis of staphylococcal intramammary infections(European Journal of Clinical Microbiology & Infectious Diseases, 2014-06-20) Fabres-Klein, M. H.; Aguilar, A. P.; Silva, M. P.; Silva, D. M.; Ribon, A. O. B.Bovine mastitis is the primary disease of dairy cattle that has a great impact on the dairy industry. It is estimated that worldwide economic losses due to mastitis range between US$82 and US$131 per cow/year. A fast and efficient diagnosis of the disease remains a major bottleneck that directly influences the speed with which treatment decisions and management are undertaken. Microbiological culture remains the gold standard in the identification of bacteria that cause mastitis, but the method has inherent limitations, such as a delay in obtaining results and cost, and requires special care during the collection and processing of the sample. For this reason, multiple groups have devoted efforts to develop alternative methods that, preferably, can be easily accomplished in the field. The specificity of the antigen–antibody reaction has enabled the emergence of major diagnostic methods used in clinical practice, such as immunoassays, which have significant advantages in terms of speed, sensitivity, specificity, and portability. Commercially, immunodiagnostics have been used in the detection of various diseases in cattle. However, in several cases, only a presumptive diagnosis can be made, which requires confirmation using culture-based methods. This review discusses the immunological-based assays developed since the 1990s for the detection of Staphylococcus aureus, which is considered the primary pathogen of contagious bovine mastitis. Although no ideal antigens ensure the accurate performance of tests and the costs need to be reduced to allow for good market competitiveness, immunoassays, particularly lateral flow immunoassay and immunoagglutination, have emerged as promising tests to be used in the field.Item Bioatividade de três espécies vegetais nativas da Floresta Atlântica brasileira frente ao microcrustáceo Artemia salina(Revista Brasileira de Plantas Medicinais, 2014-02-27) Pompilho, W.M; Marcondes, H.C; Oliveira, T.TEste trabalho teve por objetivo a investigação fitoquímica e propriedades antioxidantes de extratos das folhas de Trigynaea oblongifolia Schltdl (Annonaceae), Ottonia frutescens Trel (Piperaceae), e Bathysa australis (St Hill) Hooz (Rubiaceae), bem como avaliar, in vitro, a letalidade frente ao microcrustáceo Artemia salina Leach. Os extratos foram preparados por maceração em metanol 10% (p/v) por sete dias, à temperatura ambiente. A atividade antioxidante dos extratos foi determinada pela metodologia que utiliza o radical estável DPPH. A toxicidade dos extratos foi avaliada frente ao microcrustáceo A. salina. Os extratos de O. frutescens e B. australis apresentaram as seguintes classes de metabólitos secundários: Alcalóides, Antraquinonas, Cumarinas, Polifenóis (Taninos), Saponinas. Nos extratos de T. oblongifolia, além dos metabólitos citados anteriormente, foi detectada a presença de Flavonóides. A atividade antioxidante, observada em 30 minutos na concentração de 24 µg/mL de extrato, foi de: O. frutescens - 38,3%, T. oblongifolia - 32,3%, e B. australis - 32,1%. A Concentração Letal, CL50, dos extratos em A. salina foi de: O. frutescens - 149,75 ± 1,02 µg/mL, T. oblongifolia - 148,8 ± 1,74 µg/mL, e B. australis - 684 ± 9,04 µg/mL. Neste contexto, destacamos as espécies, nativas da Floresta Atlântica, O. frutescens e T. oblongifolia de grande potencial na bioprospecção de moléculas biologicamente ativas.Item Avaliação fitoquímica e atividade antioxidan e, antimutagênica e toxicológica do extrato aquoso das folhas de Ocimum gratissimum L.(Revista Brasileira de Plantas Medicinais, 2014-05-20) Gontijo, D.C.; Fietto, L.C.; Leite, J.P.V.A espécie Ocimum gratissimum L., popularmente conhecida como alfavaca, é uma planta muito usada na medicina tradicional brasileira, à qual são atribuídas diversas atividades terapêuticas quando usada na forma de infuso de suas folhas. Neste estudo foi realizada a caracterização fitoquímica, a avaliação da ação antioxidante e a investigação dos efeitos antimutagênico e antigenotóxico, além do efeito mutagênico e genotóxico potencial do extrato aquoso liofilizado a parir das folhas de O. gratissimum (EAOG). O conteúdo de polifenóis totais no extrato foi determinado pelo método Folin-Ciocalteu, sendo encontrado 11,3 µg EAG/mg de EAOG. A atividade antioxidante foi avaliada pelo teste do 1,1-difenil-2-picril hidrazil (DPPH•), apresentando IC50 de 83,0 µg/mL. A antimutagenicidade e mutagenicidade foram avaliadas em cepas de Salmonella typhimurium (TA98 e TA100) utilizando o teste Salmonella/microssoma (Salmonella typhimurium/microssomas) em diferentes concentrações. EAOG induziu a atividade antimutagênica para a cepa TA98. A mutagenicidade não foi observada para o extrato em ambas as linhagens. Adicionalmente, a ação antigenotoxica avaliada pelo teste de clivagem do DNA-plasmidial também foi observada para EAOG. Os resultados também demonstraram que o extrato não foi capaz de induzir a genotoxicidade pelo teste empregado. Este estudo relata, pela primeira vez, as propriedades antimutagênica e antigenotóxica do extrato aquoso de O. gratissimum.Item Gerenciamento do resíduo sólido no ambiente de trabalho: uma visão socioambiental(ELO Diálogo em Extensão, 2014-12) Fortes, Nayara de Paula; Vieira, Geisla Teles; Silva, Carlos Henrique daO trabalho surgiu da iniciativa de uma aluna do curso de Engenharia Ambiental da UEMG, campus João Monlevade, cuja experiência profissional técnica em contabilidade a motivou a buscar formas de promover o comprometimento das empresas com a prática de responsabilidade ambiental. O objetivo foi reduzir o acúmulo de papel reciclável no local de trabalho, doando-o à associação de catadores (Atlimarjom), uma vez que o município não possui coleta seletiva operacional. Para execução deste estudo, procederam-se 35 visitas em escritórios de contabilidade e empresas afins - acumuladores de papel branco - para explanação do projeto e convites para a participação nele. Após o aceite de 14 empresas/escritórios (40%), uma logística com dias e horários foi definida para a coleta do papel. Como resultado, obteve-se a redução no acúmulo de papel no ambiente de trabalho e o aumento significativo das doações de papel branco feitas para a Atlimarjom, retratando uma prática eficiente e replicável para outros setores.
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