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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.
131

Avaliação fisiológica e agronômica de soja geneticamente modificada para maior tolerância à seca / Physiologic and agronomic evaluation of genetically modified soybean to improve drought tolerance

Salinet, Luana Held 11 February 2009 (has links)
A soja é uma das culturas com maior importância sócio-econômica no mundo, visto o complexo agro-industrial que movimenta. A ocorrência de períodos de seca durante a estação de desenvolvimento das lavouras de soja é muito freqüente, provocando reduções drásticas na produtividade. Sendo a seca um fator limitante de produção fora do controle direto do homem, e a necessidade de suprir a demanda mundial crescente de alimentos, fazem com que a estabilidade da produtividade seja a chave para este entrave. O objetivo deste trabalho foi avaliar as respostas fisiológicas e agronômicas de dois genótipos de soja, um geneticamente modificado contendo a construção rd29A:DREB1A, visando maior tolerância à seca, e sua isolínea convencional, comparando-as frente a diferentes condições de disponibilidade hídrica no solo. Para tal, plantas de soja foram transformadas com o cassete rd29A:DREB1A, ambos elementos de Arabidopsis thaliana, introduzido por biobalística. O efeito da super expressão do gene AtDREB sobre parâmetros fisiológicos e agronômicos foi avaliado em casa de vegetação em três cultivos. Os experimentos foram instalados em blocos casualizados em arranjo fatorial (2x2), com quatros blocos e três amostras por bloco, e os resultados submetidos à análise de variância (ANOVA) e ao teste de Tukey (p 0,05) para comparações múltiplas das médias. Foram utilizadas sementes da cultivar BR16 transformada com a construção rd29A:DREB1A, nomeadas P58, e sementes BR16 não transformadas. As plantas foram submetidas à duas condições de disponibilidade hídrica: 15% de umidade gravimétrica do solo (UG) durante todo o ciclo (controle) e 2,5% de UG (tratamento sob estresse) a partir de R1/R2 (florescimento). Foram avaliadas as taxas fotossintética e transpiratória, condutância estomática e diferença de temperatura entre o ar e a folha com o medidor de trocas gasosas LI-6400 (Li-Cor ®), além da eficiência fotossintética e parâmetros agronômicos. Para condutância estomática, diferença de temperatura, taxas fotossintética e transpiratória, as maiores médias foram verificadas nas plantas sob 15% de UG e, dentro desta umidade, das plantas P58 em relação às BR16 geralmente. No tratamento sob estresse (2,5% de UG), as plantas transgênicas mantiveram valores superiores em praticamente todas as avaliações e, quando não, apresentaram valores que não diferiam estatisticamente das BR16. A eficiência fotossintética foi maior nas plantas P58 apenas nas avaliações finais e para as mesmas UG, e iguais estatisticamente nas demais avaliações. Para as avaliações agronômicas, as plantas BR16 apresentaram as maiores alturas em ambas as umidades, embora o mesmo número de nós que as P58. Para peso da parte aérea, número de sementes e número de legumes com semente e peso de semente, os maiores valores foram das plantas a 15% de UG e, dentro destas, das BR16. Os resultados indicam que a expressão da construção com o gene DREB1A confere maior tolerância à seca das plantas transgênicas, baseado em respostas fisiológicas, embora o desempenho agronômico deva ainda ser comprovado a campo. / Soybean is one of the major socio-economic important crops in the world due to the agro-industrial complex involved. The occurrence of drought during the period of development of soybean fields is very frequent, resulting in drastic yield decrease. As the drought being one limiting factor in the yield without human direct control, and the necessity of supplying the growing world food demand, keeping the stability of the yield seems to be the key for this problem. The objective of this study was to evaluate the physiologic and agronomic response of two soybean genotypes; one genetically modified containing the construction rd29A:DREB1A, aiming drought tolerance, and its conventional isoline, comparing them in different conditions of soil water availability. Soybean plants were transformed with the cassette rd29A:DREB1A, both elements of Arabidopsis thaliana, introduced by biobalistic method. The overexpression effect of AtDREB on physiologic and agronomic parameters was evaluated in greenhouse conditions during three cultivations. The experiment design used was the RBD (Randomized Blocks Design) in factorial scheme (2x2), with four blocks and three samples for block, and the results were submitted to the Analyze of Variance (ANOVA) and to the Tukey test (p 0,05) of multiples means comparisons. Transformed BR16 cultivar seeds were used with the construction rd29A:DREB1A, named P58, and seeds of no-transformed BR16 cultivars. The plants were submitted to two conditions of water availability: 15% of soil gravimetric humidity (GH) during all the experiment time (control) and 2,5% of GH (stress treatment) starting from R1/R2 (flowering stage). Photosynthetic and transpiration rates, stomatal conductance and temperature difference between the air and the leaf were measured with a portable open gas exchange system (LI-6400; Li- Cor ®), besides the photosynthetic efficiency and agronomic parameters, between nine and eleven-thirty in the morning. For stomatal conductance, temperature difference, photosynthetic and transpiration rates, the higher values were verified in the plants under 15% of GH and, within this humidity, these higher values were usually verified in plants P58 in relation to the BR16 plants. In the treatment under stress (2,5% of GH), the transgenic plants maintained higher values in almost all measurements and, when it did not occur, they showed values that did not differ statistically of the BR16 plants. The photosynthetic efficiency was higher in the P58 plants only in the final measures; and for the same GH, and statistically equal in the others measures. For the agronomic evaluations, the BR16 plants showed the highest heights in both humidities, even though they had the same number of nodes as the P58. For the aerial part weight, the number of seeds and the number of legumes with seed and seed weight, the highest values were of the plants under 15% of GH and, within these, of the BR16 plants in general. The results indicate that the expression of the construction with the gene DREB1A leads to a higher drought tolerance of the transgenic plants, based on physiologic response, although they still need tests on the field.
132

Análise da comunidade fúngica associada à cana-de-açúcar e estudo da interação Trichoderma virens - planta hospedeira / Analysis of sugarcane-associated fungal community and study of the interaction Trichoderma virens host plant

Romão, Aline Silva 21 June 2010 (has links)
Fungos associados às plantas desempenham diversas funções biológicas importantes e constituem imensos reservatórios de novos compostos químicos, atividades biológicas e processos biotecnológicos ainda subexplorados. A diversidade estimada para esses microrganismos é enorme, porém menos de 7 % das espécies é conhecida. Em cana-de-açúcar, uma das principais culturas agrícolas do Brasil, estudos de interação e diversidade são recentes e ainda incipientes, principalmente com relação à comunidade fúngica e sua interação com plantas transgênicas. Uma das espécies presentes na comunidade fúngica associada à cana-de-açúcar é o fungo Trichoderma virens, o qual apresenta grande potencial de exploração como agente de controle biológico, promotor de crescimento vegetal e produtor de enzimas e metabólitos secundários. Nesse sentido, o presente trabalho buscou primeiramente determinar a estrutura e diversidade da comunidade de fungos (endófitos de raiz e rizosfera) associados a duas variedades de cana-de-açúcar, uma convencional (SP80-1842) e outra transgênica (IMI-1, expressando resistência ao herbicida imazapir), e avaliar possíveis efeitos da transgênese, do estágio de crescimento e do manejo agrícola. Além disso, uma linhagem de T. virens, isolada como endófito de raiz dessa planta, foi selecionada para estudos de interação fungo-planta e determinação dos mecanismos envolvidos na sua atividade de controle biológico. Na primeira etapa do trabalho, que compreendeu isolamento, caracterização e avaliação de alterações na comunidade fúngica, os resultados obtidos mostraram que a comunidade fúngica associada à cana-de-açúcar é formada por pelo menos 35 gêneros diferentes, a maioria do filo Ascomicota, sendo que a sua estrutura incluiu um grande número de gêneros pouco frequentes e um pequeno número de gêneros altamente frequentes (Penicillium, Fusarium, Aspergillus, Trichoderma e Epicoccum), dos quais alguns apresentam especificidade ao local de isolamento (raiz ou rizosfera). A avaliação de possíveis efeitos sobre a comunidade fúngica mostrou que a idade da planta foi o único fator que influenciou de forma significativa as características dessa comunidade, sendo que os efeitos da transgênese, se existentes, devem ser secundários quando comparados às fontes naturais de variação. Na segunda etapa, a linhagem de T. virens T.v.223 foi transformada pelo sistema Agrobacterium tumefaciens e o transformante gerado (expressando resistência à higromicina B e a proteína GFP) foi utilizado em ensaios de interação via reisolamento e microscopia. Os resultados revelaram que esse fungo não promoveu alterações fenotípicas visíveis na planta hospedeira, colonizou predominantemente as raízes, onde formou camadas densas de micélio ao seu redor, antes de penetrar o espaço intercelular das primeiras camadas de célula da epiderme do tecido radicular. Por último, mutantes de T. virens deficientes para produção de quitinases foram gerados por deleção gênica e silenciamento gênico via RNAi e avaliados quanto à capacidade de controle biológico de diferentes fitopatógenos em ensaios em casa de vegetação. Curiosamente, os resultados mostraram que as enzimas quitinolíticas podem ser essenciais à atividade de controle biológico efetuada por T. virens, mas que a importância e a participação dessas enzimas no processo dependem do tipo de planta e de patógeno envolvidos na interação, já que mais de um mecanismo deve contribuir para o controle biológico por T. virens, como por exemplo, a indução de resistência da planta. / Plant-associated fungi perform several important biological functions and are considered a vast source of novel chemical compounds, biological activities and biotechnological processes, whose potential is underexplored. The estimated diversity for these microorganisms is massive, but less than 7% of the species are already known. Sugarcane, one of the most important crops in Brazil, has only recently been studied regarding interactions and diversity, but these studies are still incipient, mainly concerning fungal community and its interaction with transgenic plants. One of the species found on sugarcane fungal community is the fungus Trichoderma virens, whose potential on biological control, growth promotion, and enzymes and secondary metabolites production is huge. Taking this into consideration, the current work aimed to determine the structure and diversity of the fungal community (root endophytes and rhizosphere) associated to two varieties of sugarcane, the conventional (SP80-1842) and the transgenic counterpart (IMI-1, expressing imazapyr herbicide resistance), and assess possible effects from transgenese, growth stage and management. In addition, a strain of T. virens, isolated as a sugarcane endophyte, was selected to perform the fungal-plant interaction assays and to determine its biological control mechanisms. The results of the first part of this work, including the isolation, characterization and evaluation of fungal community changes, showed that the sugarcane fungal community is made up by at least 35 different genera, most of them belonging to Ascomycota phylum, and its structure included many genera observed in very low frequencies, and a few genera highly frequent (Penicillium, Fusarium, Aspergillus, Trichoderma and Epicoccum), from which some have specificity to the place of isolation (root or rhizosphere). Assessing possible effects upon the fungal community showed that the growth stage was the only factor significantly influencing the communitys features, besides, if transgenese effects are present, they may be minor compared to other natural sources of variation. The second part of this work included the Agrobacterium tumefaciens-mediated transformation of T. virens strain T.v.223 and utilization of the generated transformant (hygromycin B resistant and GFPexpressing) to perform interaction studies by re-isolation and microscopy. The results revealed that this fungus did not promote any phenotypic change in the host plant, it was found mostly in roots, formed a dense mycelia cover over the roots and was able to penetrate intercellular spaces of root epidermis first layers. Finally, T. virens chitinase-deficient mutants were generated by gene deletion and RNAi gene silencing, and tested for biological control activity against different phytopathogens in greenhouse assays. Curiously, the results showed that chitinolytic activity may be essential to the biocontrol activity of T. virens, but its significance and the input of each chitinase depends on the plant and pathogen playing the interaction, since more than one mechanism may account for T. virens biological control, for instance, the induction of plant resistance.
133

Expression and characterization of a human lysosomal enzyme α-iduronidase in tobacco BY-2 cells. / Expression & characterization of a human lysosomal enzyme α-iduronidase in tobacco BY-2 cells / Expression and characterization of a human lysosomal enzyme alpha-iduronidase in tobacco BY-2 cells

January 2006 (has links)
Fu Lai Hong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 106-110). / Abstracts in English and Chinese. / Thesis/Assessment Committee --- p.ii / Statement --- p.iii / Acknowledgements --- p.iv / Abstract --- p.v / 摘要 --- p.vi / Lists of Figures --- p.x / Lists of Tables --- p.xiii / List of Abbreviations --- p.xiv / Amino acid abbreviation --- p.xvi / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter 1.1 --- Human α-L-iduronidase (hIDUA) --- p.2 / Chapter 1.1.1 --- Lysosomal storage disease --- p.2 / Chapter 1.1.2 --- Treatments of MPS 1 --- p.4 / Chapter 1.2 --- Plant cells as bioreactors --- p.5 / Chapter 1.3 --- The Plant secretary pathway --- p.7 / Chapter 1.3.1 --- Transport of soluble proteins --- p.9 / Chapter 1.3.2 --- Transport of integral membrane proteins --- p.10 / Chapter 1.4 --- Differences between plant and human proteins --- p.11 / Chapter 1.5 --- Reducing the differences between plant and human proteins --- p.12 / Chapter 1.6 --- Previous study: Expression of IDUA in transgenic tobacco plant --- p.13 / Chapter 1.7 --- Project objectives --- p.14 / Chapter 1.8 --- Long term significance --- p.14 / Chapter Chapter 2 --- Materials and Methods --- p.15 / Chapter 2.1 --- Introduction --- p.16 / Chapter 2.2 --- Materials --- p.18 / Chapter 2.2.1 --- Chemical --- p.18 / Chapter 2.2.2 --- Plant materials --- p.18 / Chapter 2.2.3 --- Plasmid vectors and bacterial strains --- p.18 / Chapter 2.2.4 --- Human a-iduronidase (hIDUA) cDNA --- p.19 / Chapter 2.2.5 --- Primers --- p.20 / Chapter 2.3 --- Methods --- p.22 / Chapter 2.3.1 --- Generation of IDUA antibodies --- p.22 / Chapter 2.3.1.1 --- Synthetic peptide raised IDUA antibodies --- p.23 / Chapter 2.3.1.1.1 --- Design of synthetic peptides --- p.23 / Chapter 2.3.1.1.2 --- Immunization of rabbits --- p.25 / Chapter 2.3.1.2 --- E. coli-derived rhIDUA protein --- p.25 / Chapter 2.3.1.2.1 --- Cloning and expression of rhIDUA --- p.25 / Chapter 2.3.1.2.2 --- Western analysis of E. coli-derived rhIDUA --- p.29 / Chapter 2.3.1.2.3 --- MS/MS analysis of rhIDUA protein --- p.29 / Chapter 2.3.1.2.4 --- Immunization of rabbits --- p.31 / Chapter 2.3.2 --- Affinity-purified antibodies --- p.33 / Chapter 2.3.3 --- Characterization of affinity-purified IDUA antibodies --- p.33 / Chapter 2.3.4 --- Construction of chimeric gene constructs --- p.34 / Chapter 2.3.5 --- Expression of IDUA in tobacco BY-2 cells --- p.39 / Chapter 2.3.5.1 --- Electropoartion of Agrobacteria --- p.39 / Chapter 2.3.5.2 --- Agrobacterium-mediated transformation --- p.39 / Chapter 2.3.5.3 --- Screening of positive trans formants --- p.40 / Chapter 2.3.6 --- Characterization of transgenic BY-2 cell expressing IDUA fusion --- p.40 / Chapter 2.3.6.1 --- Genomic DNA polymerase chain reaction (Genomic DNA PCR) --- p.40 / Chapter 2.3.6.1.1 --- Genomic DNA extraction from BY-2 callus --- p.40 / Chapter 2.3.6.1.2 --- Genomic DNA PCR of tobacco BY-2 callus --- p.41 / Chapter 2.3.6.2 --- Reverse transcription-PCR (RT-PCR) --- p.42 / Chapter 2.3.6.2.1 --- Total RNA extraction from BY-2 cell --- p.42 / Chapter 2.3.6.2.2 --- RT-PCR of BY-2 cell --- p.42 / Chapter 2.3.6.3 --- Western blot analysis of BY-2 cell and medium --- p.43 / Chapter 2.3.6.3.1 --- Protein extraction from tobacco BY-2 cells and culture medium --- p.43 / Chapter 2.3.6.3.2 --- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) --- p.44 / Chapter 2.3.6.3.3 --- Immunodetection and Coomassie blue stain --- p.44 / Chapter 2.3.7 --- Purification of IDUA from culture media --- p.46 / Chapter Chapter 3 --- Results --- p.47 / Chapter 3.1 --- Generation of IDUA antibodies --- p.48 / Chapter 3.1.1 --- Cloning and expression of rhIDUA in E. coli --- p.48 / Chapter 3.1.2 --- Characterization of IDUA antibodies --- p.51 / Chapter 3.1.2.1 --- Specificity of IDUA antibodies towards hIDUA protein. --- p.51 / Chapter 3.1.2.2 --- Cross-reactivity of IDUA antibodies with wild type tobacco BY-2 cell --- p.55 / Chapter 3.2 --- Chimeric gene constructs construction and confirmation --- p.58 / Chapter 3.3 --- Screening of transformed tobacco BY-2 callus with kanamycin-resistance --- p.66 / Chapter 3.4 --- Genomic DNA PCR screening of transformed tobacco BY-2 callus . --- p.67 / Chapter 3.5 --- RT-PCR screening of transformed BY-2 cells --- p.70 / Chapter 3.6 --- Western blot analysis of transformed tobacco BY-2 cells and culture media --- p.72 / Chapter 3.6.1 --- Tobacco BY-2 cells --- p.72 / Chapter 3.6.2 --- Tobacco BY-2 cell culture media --- p.76 / Chapter 3.7 --- Purification of IDUA protein in culture media --- p.81 / Chapter Chapter 4 --- Discussion --- p.82 / Chapter Chapter 5 --- Summary and Future Perspectives --- p.89 / Chapter 5.1 --- Summary --- p.90 / Chapter 5.2 --- Future perspectives --- p.92 / Appendix Identification and Characterization of an Unknown Protein by 1B Antibody --- p.93 / Chapter 6.1 --- Introduction --- p.94 / Chapter 6.2 --- Objectives --- p.94 / Chapter 6.3 --- Materials and Methods --- p.95 / Chapter 6.3.1 --- Western blot analysis of different plant species --- p.95 / Chapter 6.3.2 --- Subcellular localization of the unknown protein --- p.95 / Chapter 6.3.3 --- Affinity-purification of the unknown protein --- p.95 / Chapter 6.4 --- Results --- p.97 / Chapter 6.4.1 --- Western blot analysis of different plant species --- p.97 / Chapter 6.4.2 --- Subcellular localization of an unknown protein --- p.98 / Chapter 6.4.3 --- Affinity-purification of 1B protein --- p.104 / Chapter 6.5 --- Summary and Future Perspectives --- p.105 / Chapter 6.5.1 --- Summary --- p.105 / Chapter 6.5.2 --- Future Perspectives --- p.105 / References --- p.106
134

Membrane anchor for vacuolar targeting: expression of a human lysosomal enzyme iduronidase (hIDUA) in transgenic tobacco plants.

January 2005 (has links)
Seto Tai Chi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 122-138). / Abstracts in English and Chinese. / Thesis Committee --- p.ii / Statement --- p.iii / Acknowledgements --- p.iv / Abstract (in English) --- p.v / Abstract (in Chinese) --- p.vii / Table of Contents --- p.ix / List of Tables --- p.xvi / List of Figures --- p.xv / Chapter Chapter 1 --- General Introduction and Literature Review --- p.1 / Chapter 1.1 --- Introduction --- p.2 / Chapter 1.2 --- Tobacco seed as bioreactor --- p.4 / Chapter 1.2.1 --- Advantages of using tobacco seed to produce bioactive human lysosomal enzyme --- p.4 / Chapter 1.2.2 --- Disadvantages and potential problems of using tobacco seed to produce bioactive human lysosomal enzyme --- p.5 / Chapter 1.2.2.1 --- Difference of asparagine-linked N-glycosylation between plant and human protein --- p.8 / Chapter 1.2.2.2 --- Immunogenicity of recombinant protein with plant-derived N-glycan to human --- p.10 / Chapter 1.2.2.3 --- "Strategy to ""humanize"" plant-derived recombinant human lysosomal enzyme" --- p.10 / Chapter 1.2.2.4 --- Lack of specific glycan structure一mannose-6-phosphate (M6P) tag addition --- p.11 / Chapter 1.2.2.5 --- Strategy for M6P tag addition on plant-derived human lysosomal enzyme --- p.12 / Chapter 1.3 --- The plant secretory pathway --- p.13 / Chapter 1.3.1 --- Plant vacuole in tobacco seed --- p.16 / Chapter 1.3.2 --- Soluble protein trafficking in plant cell --- p.17 / Chapter 1.3.3 --- Integral membrane protein trafficking in plant cell --- p.17 / Chapter 1.3.4 --- Components involved in integral membrane protein trafficking to PSV crystalloid --- p.19 / Chapter 1.3.4.1 --- BP-80 (80-kDa binding protein) --- p.19 / Chapter 1.3.4.2 --- α-TIP (α-tonoplast intrinsic protein) --- p.20 / Chapter 1.3.5 --- Using specific integral membrane protein trafficking system to target recombinant human lysosomal enzyme to tobacco seed PSV --- p.21 / Chapter 1.4 --- Homo sapiens α-L-iduronidase (hIDUA) --- p.21 / Chapter 1.4.1 --- Global situation of lysosomal storage disease一hIDUA deficiency --- p.21 / Chapter 1.4.2 --- Physiological role --- p.22 / Chapter 1.4.3 --- Molecular property --- p.24 / Chapter 1.4.3.1 --- Mutation and polymorphism --- p.24 / Chapter 1.4.4 --- Lysosomal secretory pathway --- p.24 / Chapter 1.4.5 --- Biochemical property --- p.25 / Chapter 1.4.6 --- Clinical application --- p.27 / Chapter 1.4.6.1 --- Enzyme replacement therapy (ERT) --- p.27 / Chapter 1.4.6.2 --- Clinical trial --- p.28 / Chapter 1.4.6.3 --- Economic value --- p.29 / Chapter 1.4.7 --- Expression system --- p.29 / Chapter 1.4.7.1 --- Production (overexpression) of rhIDUA in CHO cell system --- p.30 / Chapter 1.4.7.2 --- Production of rhIDUA in tobacco plant leaf --- p.30 / Chapter 1.5 --- Project objective and long-term significance --- p.30 / Chapter 1.5.1 --- Project objective --- p.30 / Chapter 1.5.2 --- Long-term significance --- p.31 / Chapter Chapter 2 --- Generation and Characterization of Anti-IDUA Antibodies --- p.32 / Chapter 2.1 --- Introduction --- p.33 / Chapter 2.2 --- Materials --- p.33 / Chapter 2.2.1 --- Chemical --- p.33 / Chapter 2.3 --- Methods --- p.35 / Chapter 2.3.1 --- Generation of polyclonal anti-IDUA antibody --- p.35 / Chapter 2.3.1.1 --- Design of synthetic peptide --- p.35 / Chapter 2.3.1.2 --- Conjugation of synthetic peptide to carrier protein --- p.39 / Chapter 2.3.1.3 --- Immunization of rabbit --- p.39 / Chapter 2.3.2 --- Characterization of polyclonal anti-IDUA antibody in rabbit serum --- p.40 / Chapter 2.3.2.1 --- Dot-blot analysis --- p.40 / Chapter 2.3.3 --- Purification of polyclonal anti-IDUA antibody --- p.42 / Chapter 2.3.3.1 --- Construction of anti-IDUA antibody affinity column --- p.42 / Chapter 2.3.3.2 --- Affinity-purification of anti-IDUA antibody --- p.42 / Chapter 2.3.4 --- Western blot detection of denatured rhIDUA --- p.42 / Chapter 2.4 --- Results --- p.43 / Chapter 2.4.1 --- Characterization of polyclonal anti-IDUA antibody --- p.43 / Chapter 2.5 --- Discussion --- p.51 / Chapter 2.6 --- Conclusion --- p.51 / Chapter Chapter 3 --- Generation and Characterization of Transgenic Tobacco Plants Expressing rhIDUA Fusions --- p.52 / Chapter 3.1 --- Introduction --- p.53 / Chapter 3.1.1 --- Signal peptide of hIDUA (hIDUA SP) --- p.54 / Chapter 3.1.2 --- Signal peptide of proaleurain (Pro. SP) --- p.54 / Chapter 3.1.3 --- Hypothesis to be tested in this study --- p.54 / Chapter 3.2 --- Materials --- p.55 / Chapter 3.2.1 --- Chemical --- p.55 / Chapter 3.2.2 --- Primers --- p.55 / Chapter 3.2.3 --- Bacterial strain --- p.58 / Chapter 3.2.4 --- The insert-Homo sapiens α-L-iduronidase (hIDUA) cDNA used in this study --- p.58 / Chapter 3.2.5 --- The vector-pLJ526 used in this study --- p.59 / Chapter 3.3 --- Methods --- p.61 / Chapter 3.3.1 --- Construction of chimeric gene construct --- p.61 / Chapter 3.3.1.1 --- Restriction endonuclease´ؤPfIMIl --- p.61 / Chapter 3.3.1.2 --- Recombinant DNA and molecular cloning techniques used in this study --- p.61 / Chapter 3.3.1.3 --- Cloning of pSPIDUA-FLAG --- p.62 / Chapter 3.3.1.4 --- Cloning of pSPIDUA-control --- p.62 / Chapter 3.3.1.5 --- Cloning of a universal construct (pUniversal) --- p.62 / Chapter 3.3.1.6 --- Cloning of pSP-IDUA-T7 --- p.66 / Chapter 3.3.1.7 --- Cloning of pSP-IDUA-control --- p.66 / Chapter 3.3.1.8 --- Cloning of chimeric gene construct into Agrobacterium binary vector --- p.66 / Chapter 3.3.2 --- Expression of chimeric gene construct in tobacco plant --- p.73 / Chapter 3.3.2.1 --- Tobacco plant --- p.73 / Chapter 3.3.2.2 --- Electroporation of Agrobacterium --- p.73 / Chapter 3.3.2.3 --- Agrobacterium-mediated transformation of tobacco plant --- p.74 / Chapter 3.3.2.4 --- Selection and regeneration of tobacco transformant --- p.75 / Chapter 3.3.3 --- Characterization of transgenic tobacco plant expressing rhIDUA fusion --- p.75 / Chapter 3.3.3.1 --- Genomic DNA polymerase chain reaction (PCR) --- p.75 / Chapter 3.3.3.2 --- Southern blot analysis --- p.76 / Chapter 3.3.3.3 --- Total RNA reverse transcription-PCR (RT-PCR) --- p.77 / Chapter 3.3.3.4 --- Northern blot analysis of tobacco leaf --- p.78 / Chapter 3.3.3.5 --- Western blot analysis --- p.79 / Chapter 3.3.4 --- Purification of plant-derived rhIDUA fusion --- p.81 / Chapter 3.3.4.1 --- Construction of affinity column with anti-IDUA antibody --- p.81 / Chapter 3.3.4.2 --- Affinity-purification of rhIDUA fusion from tobacco mature seed --- p.81 / Chapter 3.3.5 --- Confocal immunoflorescence study --- p.82 / Chapter 3.3.5.1 --- Preparation of paraffin section --- p.82 / Chapter 3.3.5.2 --- Single immunocytochemical labeling --- p.82 / Chapter 3.3.5.3 --- Double labeling with one monoclonal and one polyclonal antibodies --- p.83 / Chapter 3.3.5.4 --- Double labeling with two polyclonal antibodies --- p.83 / Chapter 3.3.5.5 --- Image collection --- p.84 / Chapter 3.4 --- Results --- p.85 / Chapter 3.4.1 --- Chimeric gene construction and confirmation --- p.85 / Chapter 3.4.2 --- Selection and regeneration of tobacco transformant with kanamycin- resistance --- p.86 / Chapter 3.4.3 --- Genomic DNA PCR screening of tobacco transformant --- p.88 / Chapter 3.4.4 --- Southern blot analysis of tobacco transformant --- p.91 / Chapter 3.4.5 --- Total RNA RT-PCR screening of tobacco transformant --- p.93 / Chapter 3.4.6 --- Northern blot analysis of tobacco transformant --- p.93 / Chapter 3.4.7 --- Western blot analysis --- p.96 / Chapter 3.4.7.1 --- Western blot analysis of pSP-IDUA-T7-121 transformant leaf --- p.96 / Chapter 3.4.7.2 --- Western blot analysis of pSP-IDUA-T7-121 transformant mature seed --- p.98 / Chapter 3.4.8 --- Affinity-purification of rhIDUA fusion --- p.98 / Chapter 3.4.9 --- Expression level of rhIDUA fusion --- p.102 / Chapter 3.4.10 --- Subcellular localization of rhIDUA fusion --- p.102 / Chapter 3.5 --- Discussion --- p.111 / Chapter Chapter 4 --- Summary and Future Perspectives --- p.117 / References --- p.122 / Appendix 1 --- p.139 / Appendix II (List of Abbreviations) --- p.141
135

Suscetibilidade à proteína Cry1Ac e estrutura genética em populações de Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) no Brasil / Susceptibility to Cry1Ac protein and genetic structure in populations of Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) in Brazil

Karina Cordeiro Albernaz 26 April 2011 (has links)
Heliothis virescens (Fabricius) é uma das pragas-alvo do algodão geneticamente modificado que expressa a proteína Cry1Ac de Bacillus thuringiensis Berliner (Bt). Estudos sobre a suscetibilidade de H. virescens à proteína Cry1Ac e sobre a estrutura genética e padrões de fluxo gênico nas escalas locais e regionais desse inseto são fundamentais para a implementação de programas de Manejo da Resistência de Insetos (MRI) no Brasil. Dessa forma, os principais objetivos do trabalho foram: (a) avaliar a suscetibilidade à proteína Cry1Ac em populações de H. virescens coletadas nas principais regiões produtoras de algodão no Brasil (Bahia, Goiás, Mato Grosso e Mato Grosso do Sul) durante as safras agrícolas 2007/08 e 2008/09; e (b) avaliar a variabilidade genética e fluxo gênico de populações de H. virescens provenientes das culturas de algodão (safras 2007/08, 2008/09 e 2009/10) e de soja (safra 2009/10) utilizando sequências de DNA mitocondrial (DNAmit). As linhas-básica de suscetibilidade à proteína Cry1Ac foram estabelecidas mediante o uso de lagartas neonatas, por meio de bioensaios de incorporação das diferentes concentrações da proteína em dieta artificial. Para avaliar a variabilidade genética e o fluxo gênico entre populações de H. virescens utilizou-se sequências de DNAmit das subunidades I e II da citocromo oxidase COI e COII e a subunidade 6 da desidrogenase dinucleotídica da adenina nicotinamida nad6. As CLs50 estimadas variaram de 0,18 a 0,66 µg de Cry1Ac/mL de dieta para as populações coletadas na safra 2007/08 (variação de 3,7 vezes). Da mesma forma, as concentrações efetivas médias para a inibição do desenvolvimento larval (CE50) variaram de 0,0053 a 0,0161 µg de Cry1Ac/mL dieta (variação de 3,0 vezes). A partir da análise conjunta dos dados de concentração-mortalidade de todas as populações avaliadas, foram definidas e validadas as concentrações diagnósticas de 3,1 e 5,6 µg de Cry1Ac/mL de dieta para programas de monitoramento da resistência de H. virescens à proteína Cry1Ac no Brasil. Baseadas em análises de agrupamento (Neighbor-Joining e Análise de Componentes Principais) e Bayesiana (Structure) foram verificadas uma baixa estruturação entre as populações de H. virescens de diferentes regiões, bem como para aquelas coletadas em plantas hospedeiras diferentes. As análises de AMOVA também indicaram baixa estruturação genética entre as populações de H. virescens estudadas independente da cultura (Fst= 0,019) ou escala geográfica (Fst= 0,012), sugerindo um nível significativo de fluxo gênico. Em média, a distância genética entre as amostras foi de 0,1%. Uma rede de haplótipos obtida com os dados combinados resultou em 35 haplótipos, com quatro haplótipos únicos presentes somente nas amostras coletadas em soja. A principal característica dessa rede é a forma de estrela na distribuição dos haplótipos, bem como a ocorrência de muitos alelos em baixa frequência. Esse tipo de rede é característico de populações que passaram por uma recente expansão populacional e, de fato, a história demográfica de H. virescens, baseada no teste de distribuição da diferença genética par-a-par entre haplótipos (distribuição de Mismatch) e nos resultados negativos nos testes de neutralidade seletiva indicam também um episódio de expansão populacional recente. As informações obtidas no presente trabalho serão fundamentais para o acompanhamento da efetividade das estratégias de manejo da resistência de H. virescens à proteína Cry1Ac no Brasil. / The tobacco budworm, Heliothis virescens (Fabricius), is one of target pests of genetically modified cotton expressing Cry1Ac insecticidal protein derived from Bacillus thuringiensis Berliner. Studies on susceptibility of H. virescens to Cry1Ac and the genetic structure and gene flow patterns at local and regional levels are crucial for establishing an Insect Resistance Management (IRM) program for Bt cotton in Brazil. Thus, the objectives of this study were (a) to evaluate the susceptibility of field-collected populations of H. virescens to Cry1Ac from major cotton-growing regions in Brazil (Bahia, Goiás, Mato Grosso and Mato Grosso do Sul) in the cropping seasons of 2007/08 and 2008/09; and (b) to evaluate the genetic variability and gene flow among H. virescens populations from cotton (2007/08, 2008/09 and 2009/10 cropping seasons) and soybean (2009/10 cropping season) with mitochondrial DNA markers. Baseline susceptibility data to Cry1Ac protein were estimated with neonate larvae thereby using diet incorporation bioassays. Genetic variation and gene flow among H. virescens populations were evaluated by using mitDNA sequences of cytochrome oxidase subunities I and II COI e COII and the subunity 6 of dinucleotide dehydrogenase of adenine nicotinamide nad6. The estimated LC50 values varied from 0.18 to 0.66 µg of Cry1Ac/mL of diet among the 2007/08 populations (3.7 fold variation). Similarly, the EC50 values based on growth inhibition ranged from 0.0053 to 0.0161 µg of Cry1Ac/mL of diet for the 2007/08 populations (3.0 fold variation). A joint analysis of the mortality data across all tested populations was used to develop candidate diagnostic concentrations for future monitoring programs. The proposed diagnostic concentrations of 3.1 and 5.6 µg of Cry1Ac/mL of diet were validated against field-collected populations from 2008/09 and will form the basis for future resistance monitoring programs with H. virescens. Based on cluster analysis (Neighbor-Joining and Principal Coordinate Analysis) and Bayesian analysis (Structure), a low structure was detected among H. virescens populations either by regions or host plants. AMOVA analysis also indicated low genetic structure among H. virescens populations across crops (Fst= 0.019) or geographic scale (Fst= 0.012), suggesting a significant gene flow. The mean genetic distance among samples was 0.1%. The haplotype network obtained with joint data resulted in 35 haplotypes, with four unique haplotypes present only in samples collected from soybean crop. The major characteristics of the haplotype network were the star-like pattern and the occurrence of many alleles at low frequencies. This type of network is typical for populations that passed through a recent population expansion and, in fact, the demographic history of H. virescens, based on distribution test of pair-wise genetic difference among haplotypes (Mismatch distribution) and negative results from tests of selective neutrality also indicate an episode of a recent population expansion.
136

Sobrevivência e desenvolvimento de Spodoptera frugiperda e Pseudoplusia includens (Lepidoptera: Noctuidae) em algodão Cry1Ac/Cry2Ab2 e Cry1Ac/Cry1F: Implicações para o Manejo da Resistência de Insetos / Survival and development of Spodoptera frugiperda and Pseudoplusia includens (Lepidoptera: Noctuidae) in cotton Cry1Ac/Cry2Ab2 and Cry1Ac/Cry1F: Implications for Insect Resistance Management

Sorgatto, Rodrigo José 10 April 2013 (has links)
Spodoptera frugiperda (J. E. Smith) e Pseudoplusia includens (Walker) são importantes insetos-praga no algodoeiro (Gossypium hirsutum L.) devido às injúrias de desfolha e destruição de estruturas reprodutivas no caso de S. frugiperda. Os eventos de algodão Bt que expressam as proteínas Cry1Ac/Cry2Ab2 (Bollgard® II) e Cry1Ac/Cry1F (WideStrike(TM)) de Bacillus thuringiensis Berliner são ferramentas disponíveis para o controle dessas espécies-praga. A fim de subsidiar o Manejo da Resistência de Insetos (MRI) foram conduzidos estudos em laboratório para avaliar a sobrevivência e desenvolvimento de S. frugiperda e P. includens nos eventos de algodão Cry1Ac/Cry2Ab2 e Cry1Ac/Cry1F. Em bioensaios com discos de folhas, a eficácia de controle de neonatas nos dois eventos de algodão Bt foi superior a 80% para S. frugiperda e de 100% para P. includens. Em bioensaios com brácteas com neonatas de S. frugiperda, a eficácia de controle de ambos os eventos de algodão Bt também foi superior a 80%. As lagartas de S. frugiperda sobreviventes em algodão Bt apresentaram severa inibição de desenvolvimento larval em folhas (> 75%) e brácteas (> 44%). Em bioensaios com simulações de alimentação larval, as quais consistiam em grupos de lagartas alimentadas com o algodão Bt aos 0, 3, 6, 9, 12, 15 e 18 dias após a inoculação (DAI), S. frugiperda e P. includens demonstraram que a suscetibilidade dessas espécies diminuiu com o avançar do desenvolvimento larval. Para S. frugiperda, em todas as simulações de alimentação com o algodão Cry1Ac/Cry2Ab2 houve lagartas que atingiram as fases de pupa e adulto. Por outro lado, quando expostas ao algodão Cry1Ac/Cry1F, somente algumas das lagartas de 5º e 6º ínstares atingiram as fases de pupa e adulto. Para P. includens, somente lagartas no 6º ínstar atingiram as fases de pupa e adulto quando alimentadas com os dois eventos de algodão Bt. Os parâmetros biológicos de S. frugiperda sobreviventes em algodão Cry1Ac/Cry2Ab2 foram afetados negativamente com aumento da duração da fase larval (? 9 dias), baixa viabilidade larval (1,4%) e de insetos que completaram o ciclo biológico (0,9%), aumento no intervalo entre gerações (? 9 dias) e redução da taxa intrínseca de crescimento populacional (? 83%). Os eventos de algodão Cry1Ac/Cry2Ab2 e Cry1Ac/Cry1F são promissores no controle de S. frugiperda e P. includens. No entanto, a atividade inseticida dos dois eventos de algodão Bt em lagartas de S. frugiperda e P. includens diminui com o desenvolvimento larval e essa constatação deve ser considerada em programas de MRI, especialmente na disposição espacial do refúgio. / Spodoptera frugiperda (J. E. Smith) and Pseudoplusia includens (Walker) are important insect pests in cotton (Gossypium hirsutum L.) due to damage on leaves and reproductive structures in the case of S. frugiperda. The events of Bt cotton expressing proteins Cry1Ac/Cry2Ab2 (Bollgard® II) and Cry1Ac/Cry1F (WideStrike(TM)) from Bacillus thuringiensis Berliner are tools available to control these pest species. To develop an Insect Resistance Management (IRM), we performed laboratory studies to evaluate the survival and development of S. frugiperda and P. includens. In fresh leaf discs bioassays, the control efficacy of neonates in both Bt cotton events was greater than 80% mortality for S. frugiperda and 100% for P. includens. In fresh bracts bioassays to neonates of S. frugiperda, the control efficacy of both Bt cotton events was over 80%. The surviving larvae of S. frugiperda in Bt cotton showed severe growth inhibition (weight and instar) in leaves (> 75%) and bracts (> 44%). In simulations feed bioassays with larvae, which consisted of groups of larvae fed on Bt cotton at 0, 3, 6, 9, 12, 15 and 18 days after inoculation (DAI), S. frugiperda and P. includens showed that the susceptibility of species decreases with advancing larval development. For S. frugiperda, in all feed simulations with cotton Cry1Ac/Cry2Ab2 had caterpillars that reached pupae and adult stages. Moreover, when exposed to cotton Cry1Ac/Cry1F, only some caterpillars of 5th and 6th instars reached pupae and adult stages. For P. includens, only some caterpillars of 6th instar reached pupae and adult stages when fed with two events of Bt cotton. The biological parameters of S. frugiperda fed on cotton Cry1Ac/Cry2Ab2 were negatively affected with increasing duration of the larval stage (? 9 days), reduced larval viability (1,4%) and insects that completed the life cycle (0,9%), increased the generation time (? 9 days) and decreased the intrinsic rate of increase (? 83%). The events of cotton Cry1Ac/Cry2Ab2 and Cry1Ac/Cry1F are promising for the control of S. frugiperda and P. includens. However, the insecticidal activity of both events of Bt cotton in larvae of S. frugiperda and P. includens decreases through larval development and this finding should be considered in programs of MRI, especially in the spatial arrangement of the refuge.
137

Suscetibilidade à proteína Cry1Ac e estrutura genética em populações de Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) no Brasil / Susceptibility to Cry1Ac protein and genetic structure in populations of Heliothis virescens (Fabricius) (Lepidoptera: Noctuidae) in Brazil

Albernaz, Karina Cordeiro 26 April 2011 (has links)
Heliothis virescens (Fabricius) é uma das pragas-alvo do algodão geneticamente modificado que expressa a proteína Cry1Ac de Bacillus thuringiensis Berliner (Bt). Estudos sobre a suscetibilidade de H. virescens à proteína Cry1Ac e sobre a estrutura genética e padrões de fluxo gênico nas escalas locais e regionais desse inseto são fundamentais para a implementação de programas de Manejo da Resistência de Insetos (MRI) no Brasil. Dessa forma, os principais objetivos do trabalho foram: (a) avaliar a suscetibilidade à proteína Cry1Ac em populações de H. virescens coletadas nas principais regiões produtoras de algodão no Brasil (Bahia, Goiás, Mato Grosso e Mato Grosso do Sul) durante as safras agrícolas 2007/08 e 2008/09; e (b) avaliar a variabilidade genética e fluxo gênico de populações de H. virescens provenientes das culturas de algodão (safras 2007/08, 2008/09 e 2009/10) e de soja (safra 2009/10) utilizando sequências de DNA mitocondrial (DNAmit). As linhas-básica de suscetibilidade à proteína Cry1Ac foram estabelecidas mediante o uso de lagartas neonatas, por meio de bioensaios de incorporação das diferentes concentrações da proteína em dieta artificial. Para avaliar a variabilidade genética e o fluxo gênico entre populações de H. virescens utilizou-se sequências de DNAmit das subunidades I e II da citocromo oxidase COI e COII e a subunidade 6 da desidrogenase dinucleotídica da adenina nicotinamida nad6. As CLs50 estimadas variaram de 0,18 a 0,66 µg de Cry1Ac/mL de dieta para as populações coletadas na safra 2007/08 (variação de 3,7 vezes). Da mesma forma, as concentrações efetivas médias para a inibição do desenvolvimento larval (CE50) variaram de 0,0053 a 0,0161 µg de Cry1Ac/mL dieta (variação de 3,0 vezes). A partir da análise conjunta dos dados de concentração-mortalidade de todas as populações avaliadas, foram definidas e validadas as concentrações diagnósticas de 3,1 e 5,6 µg de Cry1Ac/mL de dieta para programas de monitoramento da resistência de H. virescens à proteína Cry1Ac no Brasil. Baseadas em análises de agrupamento (Neighbor-Joining e Análise de Componentes Principais) e Bayesiana (Structure) foram verificadas uma baixa estruturação entre as populações de H. virescens de diferentes regiões, bem como para aquelas coletadas em plantas hospedeiras diferentes. As análises de AMOVA também indicaram baixa estruturação genética entre as populações de H. virescens estudadas independente da cultura (Fst= 0,019) ou escala geográfica (Fst= 0,012), sugerindo um nível significativo de fluxo gênico. Em média, a distância genética entre as amostras foi de 0,1%. Uma rede de haplótipos obtida com os dados combinados resultou em 35 haplótipos, com quatro haplótipos únicos presentes somente nas amostras coletadas em soja. A principal característica dessa rede é a forma de estrela na distribuição dos haplótipos, bem como a ocorrência de muitos alelos em baixa frequência. Esse tipo de rede é característico de populações que passaram por uma recente expansão populacional e, de fato, a história demográfica de H. virescens, baseada no teste de distribuição da diferença genética par-a-par entre haplótipos (distribuição de Mismatch) e nos resultados negativos nos testes de neutralidade seletiva indicam também um episódio de expansão populacional recente. As informações obtidas no presente trabalho serão fundamentais para o acompanhamento da efetividade das estratégias de manejo da resistência de H. virescens à proteína Cry1Ac no Brasil. / The tobacco budworm, Heliothis virescens (Fabricius), is one of target pests of genetically modified cotton expressing Cry1Ac insecticidal protein derived from Bacillus thuringiensis Berliner. Studies on susceptibility of H. virescens to Cry1Ac and the genetic structure and gene flow patterns at local and regional levels are crucial for establishing an Insect Resistance Management (IRM) program for Bt cotton in Brazil. Thus, the objectives of this study were (a) to evaluate the susceptibility of field-collected populations of H. virescens to Cry1Ac from major cotton-growing regions in Brazil (Bahia, Goiás, Mato Grosso and Mato Grosso do Sul) in the cropping seasons of 2007/08 and 2008/09; and (b) to evaluate the genetic variability and gene flow among H. virescens populations from cotton (2007/08, 2008/09 and 2009/10 cropping seasons) and soybean (2009/10 cropping season) with mitochondrial DNA markers. Baseline susceptibility data to Cry1Ac protein were estimated with neonate larvae thereby using diet incorporation bioassays. Genetic variation and gene flow among H. virescens populations were evaluated by using mitDNA sequences of cytochrome oxidase subunities I and II COI e COII and the subunity 6 of dinucleotide dehydrogenase of adenine nicotinamide nad6. The estimated LC50 values varied from 0.18 to 0.66 µg of Cry1Ac/mL of diet among the 2007/08 populations (3.7 fold variation). Similarly, the EC50 values based on growth inhibition ranged from 0.0053 to 0.0161 µg of Cry1Ac/mL of diet for the 2007/08 populations (3.0 fold variation). A joint analysis of the mortality data across all tested populations was used to develop candidate diagnostic concentrations for future monitoring programs. The proposed diagnostic concentrations of 3.1 and 5.6 µg of Cry1Ac/mL of diet were validated against field-collected populations from 2008/09 and will form the basis for future resistance monitoring programs with H. virescens. Based on cluster analysis (Neighbor-Joining and Principal Coordinate Analysis) and Bayesian analysis (Structure), a low structure was detected among H. virescens populations either by regions or host plants. AMOVA analysis also indicated low genetic structure among H. virescens populations across crops (Fst= 0.019) or geographic scale (Fst= 0.012), suggesting a significant gene flow. The mean genetic distance among samples was 0.1%. The haplotype network obtained with joint data resulted in 35 haplotypes, with four unique haplotypes present only in samples collected from soybean crop. The major characteristics of the haplotype network were the star-like pattern and the occurrence of many alleles at low frequencies. This type of network is typical for populations that passed through a recent population expansion and, in fact, the demographic history of H. virescens, based on distribution test of pair-wise genetic difference among haplotypes (Mismatch distribution) and negative results from tests of selective neutrality also indicate an episode of a recent population expansion.
138

Reinforcing and broadening wheat resistance against Fusarium diseases by a barley deoxynivalenol detoxifying UDP‐glucosyltransferase and its pyramiding with ectopic glycosidase inhibitors / Renforcement et extension de la résistance du blé aux maladies causées par Fusarium par l'expression d'une UDP-glycosyltransférase d'orge capable de détoxifier le déoxynivalenol seule ou en conjonction avec l'expression d'inhibiteurs ectopiques de glycosidase

Mandala, Giulia 24 April 2018 (has links)
Les maladies du blé causées par Fusarium, comme la brulure de l’épi (FHB) et la pourriture de la tige (FCR), entrainent une réduction de production, de la qualité du blé et des problèmes de sécurité alimentaire liés à la présence de mycotoxines affectant la santé de l’Homme et des animaux: la plus représentée étant le déoxynivalénol (DON). Le DON est un inhibiteur de la synthèse protéique qui agit durant l’infection comme un facteur de virulence. La glycosylation du DON en D3G (DON-3-O-glicoside) catalysée par des UDP-glycosyltransférases (UGTs) est le principal mécanisme de protection des plantes contre sa toxicité. Dans ce travail, nous avons démontré que la détoxification du DON par l’UGT confère une résistance à large spectre contre les champignons produisant DON F.graminearum et F.culmorum. Nous avons produit des plants de blé dur exprimant de manière constitutive le gène HvUGT13248 (Ubi-UGT) et des plants de blé panifiables exprimant ce gène au niveau du tissu floral (Lem-UGT). Les plants Ubi-UGT ont montré une réduction significative des symptômes de FHB durant les stades précoces et médians de l’infection, et de FCR à tous les stades de l’infection. De plus, les plants Lem-UGT ont montré une corrélation entre les niveaux d’expression de l’UGT et de protection observée. Finalement, nous avons démontré que la pyramidation des gènes associés à des mécanismes de résistance différents peut renforcer la résistance de l’hôte à l’infection. Des plants de blé ont été générés exprimant à la fois l’enzyme HvUGT13248, et des inhibiteurs de glycosidases: AcPMEI ou PvPGIP2, impliqués dans la dégradation de la paroi cellulosique, et qui ont montré une résistance accrue à la FHB. / Fusarium diseases, including Fusarium head blight (FHB) and Fusarium crown rot (FCR) represent major agricultural problems worldwide, causing reduction of grain yield and quality and food safety. In particular, grain contamination by Fusarium mycotoxins, mainly deoxynivalenol (DON), is responsible for health problems in humans and animals. DON is a protein synthesis inhibitor, acting as a virulence factor during pathogenesis. The principal mechanism involved in enhancing plant tolerance to DON is glycosylation, forming DON-3-β-D-glucoside (D3G), performed by specific UDP-glucosyltransferases (UGTs). In this work, we demonstrated that DON-detoxification by UGT confers a broad-spectrum resistance against the DON-producing fungi F. graminearum and F. culmorum, characterized by different time of infection and target organs. We produced transgenic durum wheat plants (Ubi-UGT) constitutively expressing the barley HvUGT13248 and bread wheat plants (Lem-UGT) expressing HvUGT13248 in flower tissues. Ubi-UGT plants revealed significant reduction of FHB symptom, during early-mid stages of infection, and of FCR symptom, throughout the infection timing. The floral-specific expression highlighted a dose-dependent efficacy of the UGT detoxification mechanism. In addition, we demonstrated that pyramiding of genes controlling different resistance mechanisms can further reinforce the host response by stacking transgenes controlling the DON-to-D3G conversion and the inhibition of cell wall degrading enzymes by glycosidase inhibitors in the same wheat genotype. We obtained plants expressing HvUGT13248 and AcPMEI or HvUGT13248 and PvPGIP2, which exhibited increased FHB resistance.
139

Effects of yeast cell cycle gene expression in transgenic Nicotiana tabacum

Webb, Penelope,1967- January 2001 (has links)
Abstract not available
140

Downstream Processing of Recombinant Proteins from Transgenic Plant Systems: Phenolic Compounds Removal from Monoclonal Antibody Expressing Lemna minor and Purification of Recombinant Bovine Lysozyme from Sugarcane

Barros, Georgia 2012 May 1900 (has links)
Transgenic plant systems have been proposed as bioreactors in the production of pharmaceutical and industrial proteins. The economic benefits of inexpensive plant production systems could be erased if the downstream processing ends up being expensive. To avoid monoclonal antibody (mAb) modification or fouling of chromatography resins, removal of phenolics from plant extracts is desirable. Removal of major phenolics in Lemna extracts was evaluated by adsorption to PVPP, XAD-4, IRA-402 and Q-Sepharose resins. Analysis of phenolics adsorption to XAD-4, IRA-402 and Q-Sepharose showed superior dynamic binding capacities at pH 4.5 than at 7.5. The economic analysis using SuperPro Designer 7.0 indicated that addition of a phenolics adsorption step would increase mAb production cost only 20% by using IRA-402 compared to 35% for XAD-4 resin. The overall mAb processing cost can be reduced by implementing a phenolics removal step. To understand phenolics-resin interactions, adsorption isotherms of phenolic compounds (chlorogenic acid, ferulic acid, rutin, syringic acid and vitexin-2-O-rhamnoside) from different phenolic classes on three resins (IRA-402, PVPP, XAD-4) at pH 4.5 and 7.5 were determined. Differences in adsorption with the type of phenolics were observed, and PVPP was not efficient for phenolics removal. Screening of sugarcane lines for bovine lysozyme (BvLz) accumulation indicated that expression levels are still inadequate for commercial development. To maximize BvLz extraction, pH and ionic strength were evaluated; five conditions resulted in equivalent BvLz/TSP ratio. Membrane filtration process using BvLz extracts attained partial removal of native proteins by the 100 kDa membrane step, but also BvLz loss (21-29%). Regardless of the extraction condition, at least 47% of the starting BvLz was lost during the membrane processing. None of the evaluated extraction conditions caused a substantial recovery of BvLz in the concentrate. Alternative purification options for the IEX+HIC process, which achieved 95% BvLz purity, were tested. Direct loading of sugarcane extract concentrate on HIC and XAD-4 pretreatment of juice did not recovered BvLz as effectively as the IEX chromatography. Pure BvLz was obtained by the XAD+HIC process, but higher purification fold and HIC yield were achieved by the IEX+HIC process, due to the complete separation of BvLz and 18-kDa protein.

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