Phosphorous (P) is an essential nutrient, playing a central role in the life of a bacterial cell. It is involved in cellular metabolic pathways, cell signaling and is a component of many of the cell’s macromolecules. Since a majority of the biosphere’s microorganisms have not yet been cultured, much more can be learned about the biochemical and genetic mechanisms that govern bacterial P metabolism. The function-driven approach to metagenomics was applied to study P metabolism in the bacterial communities present in pulp and municipal wastewater treatment plant activated sludge and soil, leading to the isolation and identification of three new phosphatases, genes involved in P transport, regulation of P related functions and additional genes which may be important for the bacterial cell’s adaptation to the above communities. The identification of two new nonspecific acid phosphatases (NSAPs) phoNACX6.13 and phoNBCX4.10 and an alkaline phosphatase, phoAACX6.71, belonging to the nucleotide pyrophosphatase phosphodiesterase (NPP) family is reported here. The genes for the three phosphatases were cloned, sequenced, and analysed for upstream regulatory sequences in addition to biochemical characterization of their protein products. PhoB-binding sites were found upstream to phoAACX6.71 and NSAP phoNACX6.13, suggesting these genes are governed by the mechanisms of the previously described “pho” regulon. The two NSAPs have pH optima in the acidic neutral range while the alkaline phosphatase has an optimal pH at 9.5. The three phosphatases appear to be distantly related to known bacterial phosphatase enzymes. Phylogenetic analysis shows the newly identified NSAPs appear on a separate clade from known bacterial NSAPs. Key amino acid residues involved in the catalytic site of these NSAPs were identified in PhoNACX6.13 and PhoNBCX4.10.In PhoAACX6.71, key amino acid residues involved in catalysis and metal cofactor coordination were identified. The roles of these residues were confirmed based on the predicted molecular structure of these proteins. The structures indicate the three proteins are globular with folding patterns suitable for catalytic residues to bind and cleave the P substrate. This is the first report of functional characterization of phosphatases from uncultured bacteria. In addition to exploring the hydrolysis of phosphate esters, the transport and metabolism of other P compounds was also investigated. By phenotypic complementation of phosphonate growth deficient mutants of the legume symbiont, Sinorhizobium meliloti and large scale sequencing of selected metagenomic clones, 92 ORFs were isolated. As expected, about 25% of these ORFs are P transport proteins and P related regulators. Genes involved in other regulatory functions made up about 12% of the total while genes related to Nitrogen metabolism and assimilation account for about 8% of the newly identified ORFs. About 30% of the ORFs encoded general cellular functions or hypothetical proteins of unknown function. The results of this investigation demonstrate the effectiveness of functional metagenomics in studying genetic diversity of bacteria inhabiting complex microbial communities and in identifying new proteins of interest.

Phosphorous (P) is an essential nutrient, playing a central role in the life of a bacterial cell. It is involved in cellular metabolic pathways, cell signaling and is a component of many of the cell’s macromolecules. Since a majority of the biosphere’s microorganisms have not yet been cultured, much more can be learned about the biochemical and genetic mechanisms that govern bacterial P metabolism. The function-driven approach to metagenomics was applied to study P metabolism in the bacterial communities present in pulp and municipal wastewater treatment plant activated sludge and soil, leading to the isolation and identification of three new phosphatases, genes involved in P transport, regulation of P related functions and additional genes which may be important for the bacterial cell’s adaptation to the above communities. The identification of two new nonspecific acid phosphatases (NSAPs) phoNACX6.13 and phoNBCX4.10 and an alkaline phosphatase, phoAACX6.71, belonging to the nucleotide pyrophosphatase phosphodiesterase (NPP) family is reported here. The genes for the three phosphatases were cloned, sequenced, and analysed for upstream regulatory sequences in addition to biochemical characterization of their protein products. PhoB-binding sites were found upstream to phoAACX6.71 and NSAP phoNACX6.13, suggesting these genes are governed by the mechanisms of the previously described “pho” regulon. The two NSAPs have pH optima in the acidic neutral range while the alkaline phosphatase has an optimal pH at 9.5. The three phosphatases appear to be distantly related to known bacterial phosphatase enzymes. Phylogenetic analysis shows the newly identified NSAPs appear on a separate clade from known bacterial NSAPs. Key amino acid residues involved in the catalytic site of these NSAPs were identified in PhoNACX6.13 and PhoNBCX4.10.In PhoAACX6.71, key amino acid residues involved in catalysis and metal cofactor coordination were identified. The roles of these residues were confirmed based on the predicted molecular structure of these proteins. The structures indicate the three proteins are globular with folding patterns suitable for catalytic residues to bind and cleave the P substrate. This is the first report of functional characterization of phosphatases from uncultured bacteria. In addition to exploring the hydrolysis of phosphate esters, the transport and metabolism of other P compounds was also investigated. By phenotypic complementation of phosphonate growth deficient mutants of the legume symbiont, Sinorhizobium meliloti and large scale sequencing of selected metagenomic clones, 92 ORFs were isolated. As expected, about 25% of these ORFs are P transport proteins and P related regulators. Genes involved in other regulatory functions made up about 12% of the total while genes related to Nitrogen metabolism and assimilation account for about 8% of the newly identified ORFs. About 30% of the ORFs encoded general cellular functions or hypothetical proteins of unknown function. The results of this investigation demonstrate the effectiveness of functional metagenomics in studying genetic diversity of bacteria inhabiting complex microbial communities and in identifying new proteins of interest.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 22, 2010). Thesis advisor: Dr. Reid J. Smeda. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 84-87). Also available on the World Wide Web.

Orientador: Marcelo de Almeida Silva / Banca: Caio Antonio Carbonari / Banca: Carlos Gilberto Raetano / Banca: Pedro Jacob Christoffoleti / Banca: Henrique Coutinho Junqueira Franco / Resumo: A cana-de-açúcar é uma cultura de grande importância econômica no Brasil, tanto pela produção de açúcar e etanol quanto pela produção de diversos subprodutos. Nas diferentes fases fenológicas da cultura, a fase de maturação é de alta importância em variedades de maturação precoce no início da safra, onde a cultura depende das condições climáticas, podendo, em condições desfavoráveis, proporcionar baixo teor de açúcar, acarretando em prejuízos quantitativos e qualitativos da matéria-prima. Deste modo, o uso de maturadores torna-se estratégia fundamental de manejo para atingir rendimentos satisfatórios. No presente estudo, objetivou-se avaliar a eficácia de maturadores na qualidade tecnológica, bioenergética, enzimática e fisiológica, além dos efeitos residuais na planta e soqueira. O estudo foi realizado com a variedade RB966928 (precoce), em cana-planta (2014/2015) e cana-soca (2015/2016), em Igaraçu do Tietê-SP. Os tratamentos foram os seguintes: glifosato, nas doses de 0,35; 0,45; 0,50 e 1,00 L ha-1 de produto comercial (PC) (0,126; 0,162; 0,240 e 0,480 kg de equivalente ácido (ea), respectivamente); trinexapaque-etílico, nas doses de 0,60; 0,80; 1,00 e 1,20 L ha-1 de PC, equivalente a 0,150; 0,200; 0,250 e 0,300 L i.a., respectivamente; sulfometurom-metílico, na dose de 0,02 kg ha-1 de PC ou 0,015 kg de i.a.; e testemunha sem aplicação de maturadores. Os tratamentos foram aplicados 60, 45, 30 e 15 dias antes da colheita (DAC), no período de março a maio (safra 2014/2015). ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Sugarcane is a crop of great economic importance in Brazil, both for the production of sugar and ethanol and for the production of various by-products. In the different phenological stages of the crop, the maturation stage is of high importance in early maturing varieties at the beginning of the harvest, where the crop depends on the climatic conditions, and can under favorable conditions, provide low sugar content, leading to quantitative losses and quality of the raw material. In this way, the use of ripeners becomes a fundamental management strategy to achieve satisfactory yields. In the present study, the objective of this study was to evaluate the efficacy of ripeners in the technological, bioenergetic, enzymatic and physiological quality, as well as the residual effects on plant and ratoon. The study was carried out with the variety RB966928 (early), in sugarcane cane-plant (2014/2015) and sugarcane ratoon-cane (2015/2016), in Igaraçu do Tietê-SP. Treatments were as follows: glyphosate at the doses of 0.35; 0.45; 0.50 and 1.00 L ha-1 of commercial product (PC) (0.126, 0.162, 0.240 and 0.480 kg of acid equivalent (ea), respectively); trinexapac-ethyl, at doses of 0.60; 0.80; 1.00 and 1.20 L ha-1 of PC, equivalent to 0.150; 0.200; 0.250 and 0.300 L i.a., respectively; sulfometurom-methyl, at a dose of 0.02 kg ha-1 PC or 0.015 kg a.i. and control without application of maturators. The treatments were applied at 60, 45, 30 and 15 days before harvest (DBH), from March to May (harvest 2014/2015). The pre-harvest results allowed us to conclude that, regardless of the ripener and the dose, all of them altered the quality of the raw material, where the higher DBH provided greater accumulation of sucrose. Glyphosate increased the sucrose content as the dose increased, impairing stem yield (TCH), pol (TPH) and sugar per ha (TAH) in sugarcane. Glyphosate at 0.35 L ha-1 did not impair TCH by DBH, and increased TPH and TAH at 45 DBH. However, ... / Doutor

Reproductive endpoints are generally not considered in regulatory risk assessments used to inform registration decisions for pesticides, and relatively few studies have examined effects of herbicides on reproduction in non-target plants. In two sets of greenhouse experiments using three wild species (Rudbeckia hirta L., Centaurea cyanus L. and Trifolium pratense L), effects on flowering phenology and inflorescence characteristics were investigated following low, drift-equivalent glyphosate exposure at an early bud stage. Weekly post-spray observations included the number of inflorescences, aborted buds and malformed inflorescences. In the experiment focusing on inflorescence characteristics (C. cyanus and T. pratense only), inflorescences and pollen were collected at five weeks post-spray to measure inflorescence dry weight, count the number of reproductive florets, estimate the amount of pollen per floret, and assess pollen germination in vitro. Flower production was adversely affected in all three species, including delays in flowering, significant increases in the number of aborted buds and malformed inflorescences, an overall reduction in the number of inflorescences produced, as well as a reduction in the duration of individual inflorescence bloom time (R. hirta and T. pratense assessed only). Inflorescence dry weight and in vitro pollen germination were significantly reduced for C. cyanus exposed to glyphosate, but not for T. pratense. However, both species experienced a significant reduction in the number of reproductive florets produced per inflorescence in response to glyphosate exposure. Neither species was observed to have significant reductions in the amount of pollen produced per reproductive floret. These results have important implications for risk assessment, demonstrating that current glyphosate use in Canada and elsewhere could be adversely affecting non-target flowering plants in field margins, as well as other taxa that rely on them, particularly pollinators. Les effets sur la reproduction des plantes ne sont généralement pas pris en ligne de compte dans les évaluations réglementaires sur les risques des pesticides lors de leur homologation. De plus, relativement peu d'études ont examiné les effets des herbicides sur la reproduction des plantes non ciblées. Dans deux séries d'expériences en serres avec trois espèces sauvages (Rudbeckia hirta L., Centaurea cyanus L. et Trifolium pratense L), les effets sur la phénologie florale et les caractéristiques des inflorescences ont été étudiés après une faible exposition au glyphosate équivalente à la dérive durant la pulvérisation lorsque les plantes sont au début des boutons floraux. Des observations hebdomadaires post-pulvérisation ont été effectuées sur le nombre d'inflorescences, de bourgeons avortés et d’inflorescences malformées. Dans l'expérience portant sur les caractéristiques des inflorescences (C. cyanus et T. pratense seulement), les inflorescences et le pollen ont été recueillis cinq semaines après la pulvérisation pour mesurer le poids sec des inflorescences, compter le nombre de fleurons reproducteurs, estimer la quantité de pollen par fleur et évaluer la germination du pollen in vitro. La production de fleurs a été affectée chez les trois espèces, y compris des retards de floraison, des augmentations significatives du nombre de bourgeons avortés et d’inflorescences malformées, une réduction globale du nombre d'inflorescences produites et une diminution de la durée de floraison par inflorescence. (R. hirta et T. pratense évalués seulement). Le poids sec des inflorescences et la germination in vitro du pollen ont été significativement réduits chez C. cyanus exposé au glyphosate, mais pas chez T. pratense. Cependant, les deux espèces ont subi une réduction significative du nombre de fleurons reproducteurs produits par inflorescence en réponse à l'exposition au glyphosate. Aucune des deux espèces n'a montré de réduction significative de la quantité de pollen produit par fleuron. Ces résultats ont des implications importantes pour l'évaluation de risques, démontrant que le glyphosate, tel qu’utilisé présentement au Canada et ailleurs, pourrait nuire aux plantes à fleurs non ciblées retrouvées en bordure de champs, ainsi qu'à d'autres taxons qui en dépendent, particulièrement les pollinisateurs.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-17T18:45:01Z No. of bitstreams: 2 lilian_reis.pdf: 1391156 bytes, checksum: cc8dfb4a72b4024971a5879aeb9bc7aa (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-17T18:46:59Z (GMT) No. of bitstreams: 2 lilian_reis.pdf: 1391156 bytes, checksum: cc8dfb4a72b4024971a5879aeb9bc7aa (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-17T18:47:39Z (GMT) No. of bitstreams: 2 lilian_reis.pdf: 1391156 bytes, checksum: cc8dfb4a72b4024971a5879aeb9bc7aa (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2014-12-17T18:47:39Z (GMT). No. of bitstreams: 2 lilian_reis.pdf: 1391156 bytes, checksum: cc8dfb4a72b4024971a5879aeb9bc7aa (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2013 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O manejo das plantas daninhas possui grande import?ncia para a manuten??o dos n?veis produtivos da cultura do caf?. O herbicida mais utilizado mundialmente na cultura do caf? ? o glyphosate, por possuir alta efici?ncia e ser mais barato. Ele atua inibindo a enzima 5-enolpiruvilshiquimato, respons?vel pela produ??o de tr?s amino?cidos tirosina, fenilalanina, tryptofano. Influenciando assim a produ??o de metabolitos secund?rios, inclusive os relacionados a forma??o das estruturas anat?micas, metabolitos de defesa e fotoss?ntese. Objetivou-se no presente trabalho avaliar os efeitos da deriva simulada de glyphosate sobre a anatomia e fisiologia de cultivares de caf? arabica. Para isso, fez-se tr?s avalia??es diferenciadas visando avaliar modifica??es primeiramente morfoanat?micas, depois concentra??es de fen?is totais, flavon?ides, cafe?na e por ultimo, floresc?ncia, concentra??es de clorofilas e quantifica??es de est?matos. O experimento foi instalado em esquema fatorial (3 x 5), com tr?s cultivares de caf? MGS Travessia, Oeiras MG 6851 e Catua? IAC 144, e cinco doses de glyphosate (0,0; 57,6; 115,2; 230,4 e 460,8 g ha-1), em delineamento de blocos casualizados, com quatro repeti??es. Trinta dias ap?s a aplica??o, foram coletadas doze folhas rec?m-expandidas do ?ltimo ramo plagiotr?pico do cafeeiro, quatro folhas para as analises anat?micas, quatro para as analises de concentra??es de fen?is, flavonoides, cafe?na e as quatro ultimas para a quantifica??o estom?tica. Nas analises morfoanat?micas observou-se os seguintes resultados: ocorreram sintomas de intoxica??o como estreitamento foliar e clorose nas folhas mais jovens das plantas. Com o aumento da dose de glyphosate, a cultivar Catua? sofreu redu??o na espessura foliar total, enquanto, que para as demais ocorreu incremento nesta caracter?stica. Para as vari?veis epiderme adaxial, epiderme abaxial e par?nquima lacunoso, ocorreu decr?scimo de espessura, contudo ocorreu aumento da espessura do par?nquima lacunoso com aumento das doses de glyphosate. Pode-se concluir que as tr?s cultivares quando submetidas ? deriva de glyphosate sofrem modifica??es morfoanat?micas. Com a redu??o do par?nquima pali??dico ocorre redu??o da taxa fotossint?tica e consequente redu??o do crescimento e produ??o do caf?. Para as analises de concentra??es de fen?is, flavon?ides e cafe?na, observou-se os seguintes resultados: com aumento das doses de glyphosate houve aumento na concentra??o de fen?is totais foliares at? a dose de 115,2 g ha-1 de glyphosate, para as tr?s cultivares, acima dessa dose as concentra??es de fen?is foram reduzidas. No entanto, com aumento das doses de glyphosate a concentra??o de flavon?ides diminuiu at? a dose de 115,2 g ha-1 de glyphosate, para as cultivares Travessia e Oeiras, acima dessa dose a concentra??o de flavon?ides para essas duas cultivares aumentaram. Ocorreu aumento da concentra??o de flavon?ides para a cultivar Catua? quando aplicado a dose de 115,2 g ha-1 de glyphosate, para doses mais altas ocorreu diminui??o da concentra??o de flavon?ides totais. Com aumento das doses de glyphosate, as concentra??es de cafe?na apresentaram comportamento similar entre as cultivares Oeiras e Catua?, ocorrendo diminui??o da concentra??o de cafe?na at? a dose de 115,2 g ha-1 de glyphosate e aumento a concentra??o de cafe?na para doses superiores. Observou-se que houve aumento na concentra??o de cafe?na para cultivar Travessia a partir de 115,2 g ha-1 de glyphosate. De acordo com o teste histoqu?mico todas as tr?s cultivares estudadas apresentaram maiores concentra??o de fen?is no par?nquima pali??dico ap?s a aplica??o da deriva de glyphosate. Conclui-se que, quando submetidas a subdoses de glyphosate, as cultivares analisadas apresentaram modifica??es bioqu?micas para as concentra??es de fen?is totais, flavon?ides totais e cafe?na. Com baixas doses 57,6 e 115,2 g/ ha?? de glyphosate, ocorreu aumento da concentra??o de fen?is totais aumentando assim a capacidade de defesa das cultivares, entretanto com o aumento das doses de glyphosate ocorreu redu??o da concentra??o de fen?is totais. A produ??o de flavon?ides e cafe?na possuem efeitos variados para as doses de glyphosate podendo aumentar e diminuir a concentra??o de forma independente, pois os metabolitos s?o supridos por outras rotas. Nas analises fisiol?gicas, observou-se os seguintes resultados: os valores da vari?vel fluoresc?ncia m?xima (Fm) decresceram de acordo com o aumento das doses de glyphosate, a cultivar Travessia apresentou maior decr?scimo que as demais cultivares. Para efici?ncia fotoqu?mica m?xima (Fv/Fm) ocorreu com o aumento do estresse de acordoo com o aumento das doses aplicadas do glyphosate. As concentra??es de clorofila a, b e total sofreram decr?scimo de acordo com o aumento das doses aplicadas de glyphosate. Para as vari?veis, ?ndice estom?tico e densidade estom?tica ocorreram um decr?scimo de valores de acordo com o aumento da dose aplicada de glyphosate. A cultivar Travessia apresentou maior queda de valor para o ?ndice estom?tico e densidade estom?tica. Conclui-se que as subdoses de glyphosate provocaram danos na fotoss?ntese de forma direta, pois, ocorreu diminui??o das concentra??es das clorofilas e da intensidade da fluoresc?ncia m?xima, promovendo, assim, maior estresse nas cultivares de caf?. A diminui??o do n?mero de est?matos ? mais uma das prov?veis explica??es para a influ?ncia na fotoss?ntese promovida pelo glyphosate / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / Abstract Weed management is greatly important to keep levels of coffee production. Glyphosate is the most used herbicide in the world for being of high efficiency and cheaper. Its action is on the enzyme 5enolpyruvylshikimate that is responsible for producing tyrosin, phenylalanine and tryptophan. It inhibits their production, consequently influencing the production of secondary metabolites, mainly the ones related to anatomical structures, metabolites of defense and photosynthesis. This study was carried out in order to evaluate effects of drift simulation of glyphosate on anatomy and physiology of Arabica coffee cultivars. There were three different stages of evaluations: first morphoanatomical modifications, then concentrations of total phenol, flavonoids and cafeine, and finally fluorescence, chlorophyll concentrations and stomata quantification. The experiment was arranged in a factorial scheme (3 x 5), with three coffee cultivars (MGS Travessia, Oeiras MG 6851 and Catua? IAC 144), at five glyphosate rates (0.0; 57.6; 115.2; 230.4 and 460.8 g ha-1), in a randomized block design, with four replicates. Thirty days after application, twelve recently expanded leaves from the last plagiotropic branches were collected: four for anatomical analysis, four for analysis of concentrations of total phenol, flavonoids and cafeine and four to quantify stomata. Morphoanatomical analysis showed intoxication symptoms such as foliar narrowing and chlorosis on the younger leaves were observed. Increasing glyphosate rate, the cultivar Catua? reduced its total foliar tickness, while to the others it was increased. Adaxial and abaxial epiderms and spongy parenchyma had their thickness decreased, however spongy parenchyma increased at higher rates of glyphosate. It could be concluded that the three cultivars under glyphosate drift shows morphoanatomical modifications. When palisade parenchyma is reduced, consequently photosynthetic rate, growth and coffee production reduce. Analyzing concentrations of total phenol, flavonoids and caffeine, it was observed that phenol concentration increased when glyphosate rates were increased up to 115.2 g ha-1 in all three cultivars, showing reduction at higher rates. For Travessia and Oeiras cultivars, the flavonoid concentration decreased at higher glyphosate rates, starting its increase at rates higher than 115.2 g ha-1. For Catua?, flavonoid concentration increased at 115.2 g ha-1 being reduced with higher rates. Regarding caffeine concentration, it was similar to Oeiras and Catua?. This concentration decreased at 115.2 g ha-1 and got higher at superior rates. The cultivar Travessia showed higher caffeine concentration at rates higher than 115.2 g ha-1. According to the histochemical tests, all the three cultivars present higher phenol concentration on paladise parenchyma after application of glyphosate drift. It can be conclude that, when submitted to subrates of glyphosate, cultivars shows biochemical modifications to all concentrations evaluated. At 57.6 and 115.2 g ha-1 total phenol increased providing a better capacity of defense to cultivars, however, when increasing these rates, total phenol concentration decreased. Flavonoids and caffeine production have varied effects on glyphosate rates. They can increase or decrease independently because metabolites are fulfilled by other ways. Through physiological analysis, it could be observed that values of maximum fluorescence decreased with higher glyphosate rates, and Travessia cultivar presented highest decrease. Chlorophyll concentrations a, b and total decreased according to rates increase, being harder to chlorophyll a. Values of stomatal index and stomatal density decreased when increasing glyphosate rate, being harder to cultivar Travessia. It can be concluded that subrates of glyphosate cause damage on photosynthesis because of the reduction on chlorophyll concentration and fluorescence intensity. Reduction of stomata number is also one of the features that can explain the influence promoted by glyphosate on photosynthesis.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-19T12:31:00Z No. of bitstreams: 2 tereza_cristina_pmenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-19T12:31:33Z (GMT) No. of bitstreams: 2 tereza_cristina_pmenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-19T12:31:42Z (GMT) No. of bitstreams: 2 tereza_cristina_pmenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Rejected by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br), reason: rever nome do arquivo on 2014-12-19T12:35:15Z (GMT) / Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-19T12:36:30Z No. of bitstreams: 2 tereza_cristina_pimenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-19T12:37:00Z (GMT) No. of bitstreams: 2 tereza_cristina_pimenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-19T12:37:08Z (GMT) No. of bitstreams: 2 tereza_cristina_pimenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-19T12:37:43Z (GMT) No. of bitstreams: 2 tereza_cristina_pimenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-12-19T12:37:43Z (GMT). No. of bitstreams: 2 tereza_cristina_pimenta_goncalves_catrinck.pdf: 1238472 bytes, checksum: 651b04064f25bbcb2260de4d863373f2 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Com este trabalho, objetivou-se otimizar simultaneamente metodologias para derivatiza??o de glyphosate (GLY) e ?cido aminometilfosf?nico (AMPA) para an?lises por cromatografia gasosa acoplada a espectrometria de massas (CG-EM) e cromatografia l?quida de alta efici?ncia com detector ultravioleta (CLAE-UV). Al?m disso, foram otimizadas as condi??es cromatogr?ficas por CLAE-UV para a an?lise destes compostos. O GLY foi selecionado para o estudo por ser um herbicida amplamente utilizado para o controle de pragas que, junto ao seu principal metab?lito secund?rio (AMPA) apresenta potencial risco toxicol?gico para a sa?de humana e para o meio ambiente. Devido aos seus efeitos delet?rios, alguns m?todos anal?ticos t?m sido desenvolvidos a fim de monitorar seus res?duos no meio ambiente. M?todos cromatogr?ficos t?m sido preferencialmente usados, contudo as mol?culas em estudo apresentam baixa volatilidade e aus?ncia de grupos crom?foros, sendo necess?rio adicionar etapas de derivatiza??o. Neste trabalho foram avaliadas duas metodologias para derivatiza??o das mol?culas de GLY e AMPA: com piririna e N-O(bistrimetilsilil)trifluoroacetamida (BSTFA) para an?lises por CG-EM e com cloroformiato de 9-fluorenilmetila (FMOC-Cl) para an?lises por CLAE-UV. A utiliza??o de piridina:BSTFA em propor??o 60:100, respectivamente, sem vibra??o ultrass?nica e ajuste de pH resultaram em condi??es ?timas de an?lises por CG-EM. J? para an?lises por CLAE-UV, tamp?o borato 200 mmol L-1, FMOC-Cl 500 mg L-1, homogeneiza??o por 5 minutos, an?lise imediatamente ap?s a rea??o e lavagem com ?ter diet?lico promoveram resultados satisfat?rios. Finalmente, as condi??es ?timas de an?lise por CLAE-UV foram estudas e determinou-se que a fase m?vel composta por acetonitrila/tamp?o fosfato, comprimento de onda 260 nm, gradiente com propor??o de 25:75 v/v (0-2,5 minutos), 65:35 v/v (4,5-10 minutos) e 25:75 v/v (11-12 minutos) apresentaram melhores resultados. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT This study aimed to optimize both methodologies for derivatization of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) for analysis by gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography with ultraviolet detector (HPLC-UV). Moreover, the chromatographic conditions were optimized by HPLC-UV for the analysis of these compounds. The GLY was selected for the study because it is a herbicide widely used for pest control that, with its main secondary metabolite (AMPA) has potential toxicological risk to human health and the environment. Due to the deleterious effects, some analytical methods have been developed to monitor their residues on the environment. Chromatographic methods have been used preferentially, however the molecules in study have low volatility and absence of chromophoric groups being necessary to add derivatization steps. In this work were evaluated two methodologies for derivatization of GLY and AMPA molecules: pyridine and N-O(bistrimethylsilyl)trifluoroacetamide (BSTFA) for analysis by GC-MS and 9-fluorenylmethyl chloroformate (FMOC-Cl) for analysis by HPLC-UV. The use of pyridine:BSTFA in ratio 60:100, respectively, without ultrasonic vibration and adjustment pH result in better analyses conditions by GC-MS. Already for analysis by HPLC-UV, borate buffer 200 mmol L-1, FMOC-Cl 500 mg L-1, homogenization for 5 minutes, analysis immediately after reaction and washing with diethyl ether promoted satisfactory results. Finally, the optimal conditions for analysis by HPLC-UV were studied and it was determined that the mobile phase consisting of acetonitrile / phosphate buffer, wavelength 260 nm, ratio gradient 25:75 v / v (0-2.5 minutes ), 65:35 v / v (4.5-10 minutes), 25:75 v / v (11-12 minutes) showed better results.

Field and greenhouse studies were conducted in 2007 and 2008 to evaluate the foliar efficacy of saflufenacil on horseweed (Conyza canadensis (L.) Cronq.). In the field, saflufenacil applied alone at the lowest rate (25 g/ha) resulted in less control than all other herbicide treatments that included saflufenacil. The addition of glyphosate to 25 g/ha of saflufenacil increased the level of control over either herbicide applied alone. However, the addition of glyphosate to 50 g/ha of saflufenacil or greater was not beneficial because saflufenacil alone provided at least 95% control. Overall, horseweed height at the time of herbicide application had very little effect on the efficacy of saflufenacil applied alone or in combination with glyphosate. Application variables can enhance the foliar activity of saflufenacil. In the greenhouse, saflufenacil combined with glyphosate provided greater control than saflufenacil applied alone on both glyphosate-susceptible and -resistant horseweed populations. Regardless of horseweed population or glyphosate, saflufenacil had greater activity when crop oil concentrate rather than nonionic surfactant was used as the adjuvant. Decreasing light level within 24 hours of herbicide application resulted in greater saflufenacil activity. Applying saflufenacil in a pH 5 spray solution resulted in greater activity than pH 7 or pH 9. Although effects from saflufenacil applied under different temperatures were evident in early timings, there were no lasting effects on the efficacy of saflufenacil. Saflufenacil had significant activity on both glyphosate-susceptible and -resistant horseweed. Under certain conditions when complete control of horseweed is not achieved, such as low application rates, large target weeds, and varying environmental conditions, application variables including glyphosate tank-mixtures, crop oil concentrate, low spray solution pH, and low light level may increase the level of horseweed control from saflufenacil.

Made available in DSpace on 2014-06-11T19:33:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-25Bitstream added on 2014-06-13T19:44:37Z : No. of bitstreams: 1 nepomuceno_mp_dr_jabo.pdf: 1277830 bytes, checksum: e1f6fbc84f1437cd0f07462d57343d7e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A soja [Glycine max (L.) Merrill] é uma importante oleaginosa cultivada no Brasil e vem avançando em novas áreas, incluindo as de pastagens. Problemas quanto à queda de produção são relatados por sojicultores quando utilizam pastagens de Urochloa dessecada com o herbicida glyphosate e imediatamente semeiam a soja. Objetivou-se, por meio de um conjunto de experimentos, avaliar os efeitos de épocas de dessecação de U. ruziziensis (Germain & Evrard) Morr. & Zulaoga, da quantidade da cobertura morta formada e da incorporação ou deposição desta na superfície do solo, sobre a nodulação, desenvolvimento e características produtivas da soja transgênica ‘M-SOY 7908 RR’ no sistema de plantio direto, assim como a extração, isolamento e identificação de substâncias químicas majoritárias de U. ruziziensis com efeito alelopático e a sua possível relação com a precipitação pluvial. Inicialmente, foram conduzidos dois experimentos a campo. Em Colina (SP) foram testadas quatro épocas de dessecação da cobertura vegetal: 30, 20, 10 e 0 dias antes da semeadura (DAS) da soja, enquanto em Jaboticabal (SP) os tratamentos corresponderam a seis épocas de dessecação: 25, 20, 16, 12, 7 e 0 DAS. Nos dois anos agrícolas utilizou-se 1,44 kg e.a. ha-1 do herbicida glyphosate para a dessecação. A dessecação de U. ruziziensis no mesmo dia da semeadura da soja reduziu a altura das plantas, o número de vagens por planta e a produtividade de grãos. A época recomendada para o manejo químico de U. ruziziensis com glyphosate está entre 10 e 20 dias antes da semeadura da soja. Na sequência, foram conduzidos três experimentos sob condições semi controladas, na FCAV-UNESP. No primeiro experimento os tratamentos constituíram da incorporação ou deposição na superfície do solo de três quantidades... / Soybean (Glycine max) is an important oleaginous planted in Brazil that has been cropped in new areas, including pastures. Problems of reducing production have been reported by soybean growers when the crop is immediately sown after dissection of pastures of Urochloa spp. using glyphosate. Developing a set of experiments, the objectives were to evaluate the effects of the burndown timing of U. ruziziensis, the amont of mulch formed, and the incorporation and deposition of mulch onto soil surface on nodulation, development, and yield characteristics of transgenic soybean ‘M-SOY 7908 RR cropped in no-tillage system, as well as to extract, isolate, and identify majority chemical substances from U. ruziziensis with allelopatic effect and to evaluate the possible relation between the allelopatic effect and the rainfall. Initially, two field trials were carried out. In Colina (SP), four burndown timing were tested, being 30, 20, 10, and 0 days before soybean sowing (DBS) and, in Jaboticabal (SP), burndown timing of 25, 20, 16, 12, 7, and 0 DBS was tested. In both seasons, glyphosate was applied at 1.44 kg a.e. ha-1 for U. ruziziensis dissection. Dissection of U. ruziziensis with glyphosate at the same day of soybean sowing reduced plant height, number of pods per plant, and grain yield. Recommended time for U. ruziziensis dissection is between 10 and 20 DBS. In the sequence, three experiments in semicontrolled conditions were carried out at FCAV/UNESP. In the first one, treatments constituted of the incorporation into soil or deposition onto soil surface of three mulch amounts of U. ruziziensis dissected using glyphosate. Treatments, hereafter expressed by T1, T2, and T3, corresponded to 2.5, 5.0, and 10.0 t ha-1 of mulch deposited onto soil surface, respectively, while T4, T5, and T6 corresponded to the same amounts of mulch... (Complete abstract click electronic access below)