Made available in DSpace on 2014-06-11T19:26:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-06Bitstream added on 2014-06-13T20:54:13Z : No. of bitstreams: 1 ferreira_cb_me_jabo.pdf: 3799793 bytes, checksum: f1b3670130a5947eeee6d1e3151f9b69 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Fundecitrus / Dentro da comercialização de frutas, a citricultura é a mais importante. Representa para muitos países, dentre eles, os EUA e o Brasil, uma importante atividade econômica. Porém, esta atividade, vem sofrendo com inúmeras doenças e/ou pragas como a doença do Cancro Cítrico Asiático causada pela bactéria Xanthomonas citri subsp. citri (X. citri). Deste modo, com o objetivo do estudo do genoma funcional da X. citri, um banco de mutantes deste microorganismo foi obtido por meio de inserção aleatória do transposon Tn5, nas quais foram selecionados 53 mutantes que apresentaram, de forma superficial, alterações fenotípica em relação à X. citri selvagem. Para uma avaliação mais precisa, eles passaram por uma nova confirmação de suas alterações fenotípicas, onde foram inoculados em folhas de Citrus sinensis (Laranjeira pêra-Rio) e Citrus limonia (limoeiro cravo) e monitorados durante 16 dias, e aqueles que apresentaram as maiores alterações em relação à selvagem, tiveram confeccionadas para si curvas de crescimento in vivo. Conseguiu-se, desta forma, avaliar quantitativamente o processo patogênico, relacionar seus sintomas com dados numéricos e ainda descobrir detalhes até então não conhecidos. O mapeamento, dos respectivos loci mutados, foi realizado por seqüenciamento de DNA a partir do transposon, demonstrando que a metodologia empregada para a obtenção dos mutantes foi eficiente, conseguiu também revelar diversas proteína ainda hipotéticas, e outras, até então, não considerados como implicados no processo patogênico, como, uma Integrase, Fe-S oxidoredutase, Helicase IV, Receptor Dependente de Ton-B, entre outros / Concerning the commercialization of fruits, the citrus production is the most important. It represents for many countries, amongst them, U.S.A. and Brazil, an important economic activity. However, this activity has been suffering with many illnesses and/or plagues as the illness from the Asiatic citrus canker caused by the Xanthomonas citri subsp. citri bacterium (X. citri). In this way, from a bank of mutants of X. citri, gotten by means of random insertion of commercial one derived from transposon Tn5, had been selected 53 mutants that had presented, of superficial form, some type of phenotype alteration in relation to the wild X. citri. To a more necessary evaluation, each one of them passed for a new confirmation of its phenotype alterations, where they had been inoculated in leafs of Citrus sinensis ('Pera' sweet orange) and Citrus limonia ('Rangpur' lime) and monitored during 16 days, and those that had presented the biggest alterations in relation to the savage, had confectioned for itself in planta growth curves. We obtain, in such a way, to evaluate quantitatively the pathogenic process, to relate its symptoms with numerical data and still to discover not known details until then. The mapping of respective locus mutated was carried through by sequencing of DNA from transposon, demonstrating that the methodology used for the attainment of the mutants was efficient and still to disclose diverse genes still hypothetical, and others, until then, not considered as implied in the pathogenic process, as, Integrase, Fe-S oxidoredutase, Helicase IV, TonB-dependent receptor, among others

Among abiotic stresses, salinity is considered the main limiting stress that negatively affects plant growth and reduces productivity worldwide. To overcome this challenge, a sustainable solution such as plant growth-promoting bacteria (PGPB) can be used to meet the increasing demand for food. The desert microbe Enterobacter sp SA187, an endophytic PGPB, induces salt tolerance in both model plant and crops. The interaction between SA187 and the host plant triggers the sulfur pathway in the bacteria which then provides multiple sulfur-containing compounds to its host plant. However, the molecular sensor of these compounds in the host plant is not known. Here, we show that SA187 activates the plant target of rapamycin (TOR) pathway. The beneficial effect of SA187 was lost in TOR mutants like raptor, and by the application of TOR inhibitor AZD8055. Next, we show that SA187 modulates the one- carbon (1C) metabolism of the host plant consisting of methionine and folate cycles. The beneficial effect of SA187 was compromised by using chemical inhibitors of folate cycle like Methotrexate (MTX) and Sulfadiazine (SDZ). The intermediates of the 1C metabolism like Homocysteine and S-adenosyl methionine (SAM) showed similar beneficial effects as SA187 colonized plants. Finally, we showed that SA187 enhances 1C metabolism activity by increasing methylation index (SAM/SAH ratio) in the plants. Taken together, we could show that host TOR-1C axis is essential for plant salt tolerance by SA187.

Resumo: Dentro da comercialização de frutas, a citricultura é a mais importante. Representa para muitos países, dentre eles, os EUA e o Brasil, uma importante atividade econômica. Porém, esta atividade, vem sofrendo com inúmeras doenças e/ou pragas como a doença do Cancro Cítrico Asiático causada pela bactéria Xanthomonas citri subsp. citri (X. citri). Deste modo, com o objetivo do estudo do genoma funcional da X. citri, um banco de mutantes deste microorganismo foi obtido por meio de inserção aleatória do transposon Tn5, nas quais foram selecionados 53 mutantes que apresentaram, de forma superficial, alterações fenotípica em relação à X. citri selvagem. Para uma avaliação mais precisa, eles passaram por uma nova confirmação de suas alterações fenotípicas, onde foram inoculados em folhas de Citrus sinensis (Laranjeira pêra-Rio) e Citrus limonia (limoeiro cravo) e monitorados durante 16 dias, e aqueles que apresentaram as maiores alterações em relação à selvagem, tiveram confeccionadas para si curvas de crescimento in vivo. Conseguiu-se, desta forma, avaliar quantitativamente o processo patogênico, relacionar seus sintomas com dados numéricos e ainda descobrir detalhes até então não conhecidos. O mapeamento, dos respectivos loci mutados, foi realizado por seqüenciamento de DNA a partir do transposon, demonstrando que a metodologia empregada para a obtenção dos mutantes foi eficiente, conseguiu também revelar diversas proteína ainda hipotéticas, e outras, até então, não considerados como implicados no processo patogênico, como, uma Integrase, Fe-S oxidoredutase, Helicase IV, Receptor Dependente de Ton-B, entre outros / Abstract: Concerning the commercialization of fruits, the citrus production is the most important. It represents for many countries, amongst them, U.S.A. and Brazil, an important economic activity. However, this activity has been suffering with many illnesses and/or plagues as the illness from the Asiatic citrus canker caused by the Xanthomonas citri subsp. citri bacterium (X. citri). In this way, from a bank of mutants of X. citri, gotten by means of random insertion of commercial one derived from transposon Tn5, had been selected 53 mutants that had presented, of superficial form, some type of phenotype alteration in relation to the wild X. citri. To a more necessary evaluation, each one of them passed for a new confirmation of its phenotype alterations, where they had been inoculated in leafs of Citrus sinensis ('Pera' sweet orange) and Citrus limonia ('Rangpur' lime) and monitored during 16 days, and those that had presented the biggest alterations in relation to the savage, had confectioned for itself in planta growth curves. We obtain, in such a way, to evaluate quantitatively the pathogenic process, to relate its symptoms with numerical data and still to discover not known details until then. The mapping of respective locus mutated was carried through by sequencing of DNA from transposon, demonstrating that the methodology used for the attainment of the mutants was efficient and still to disclose diverse genes still hypothetical, and others, until then, not considered as implied in the pathogenic process, as, Integrase, Fe-S oxidoredutase, Helicase IV, TonB-dependent receptor, among others / Orientador: Maria Inês Tiraboschi Ferro / Coorientador: Julio Cezar Franco de Oliveira / Banca: Manoel Victor Franco Lemos / Banca: Mariana Carina Frigieri / Mestre

Some microorganisms are known to form mutualistic symbiosis with plant roots and by their impact they can improve some plant parameters. These symbiotic microorganisms, which are able to improve some plant parameters, include especially mycorrhizal fungi, plant growth promoting bacteria and some saprotrophic mycoparasitical fungi. Mechanisms of changes of these parameters, as influenced by symbiotic microorganisms, are known only in part and nowadays are being actively researched. Aims of this work were to find out if selected microbial treatments influence selected growth, physiological and yield parameters of plants and contents of selected substances in fruits. Within this work were made three pot greenhouse experiments (experiments 1, 2 and 3) and three pilot greenhouse experiments (experiments 4, 5 and 6), performed on tomato (Solanum lycopersicum) and cucumber (Cucumis sativus) plants. Plants were grown in hydroponics using a carrier of rockwool and they were watered by nutrient solution. As microbial treatments for plants in experiments have been used a mixture of arbuscular mycorrhizal fungi (AM), mixture of plant growth promoting bacteria (PGPB), saprotrophic mycoparasitical fungus Trichoderma harzianum (Th) and various mutual combinations of these treatments. There have been observed...

The inoculation with Azospirillum brasilense is one of the main strategies to supplement the inorganic inputs of nitrogen (N) and to increase the root development in maize. However, the beneficial inoculation effects are not always reached, which, in part, is due to genotypic variation in the plant host, resulting in different degrees of outcome. In this context, we aimed to study the genetic control and genomic prediction of maize traits related to the responsiveness to A. brasilense inoculation. For this, 118 maize hybrids were conducted under N stress and N stress plus A. brasilense treatments in controlled conditions over 2016 and 2017 seasons. We evaluated root and shoot traits and performed diallel analyses, association mapping, and genomic prediction methods considering 59,215 Single-Nucleotide Polymorphism (SNP) markers. Our results revealed a quantitative inheritance of the partnership-related maize traits, with both additive and non-additive genetic effects involved in the genetic control. Furthermore, several candidate genes were identified for the maize-A. brasilense association, especially with heterozygous (dis)advantage effects. In general, the prediction accuracies were higher mostly for the inoculated treatment compared to the non-inoculated. Finally, our findings enable a deeper understanding towards the genetic basis of the maize responsiveness to A. brasilense and may support plant breeders to establish selection strategies aiming the development of superior genotypes for this association. / A inoculação com Azospirillum brasilense é uma das principais estratégias para suplementar os insumos inorgânicos de nitrogênio (N) e aumentar o desenvolvimento radicular do milho. No entanto, os efeitos benéficos da inoculação nem sempre são alcançados, o que, em parte, é devido à variação genotípica da planta hospedeira, que ocasiona diferentes graus de resultados. Neste contexto, nosso objetivo foi estudar o controle genético e a predição genômica de caracteres de milho relacionados à responsividade para a inoculação com A brasilense. Para isso, 118 híbridos de milho foram conduzidos sob estresse de N e estresse de N mais A brasilense em condições controladas nos anos de 2016 e 2017. Nós avaliamos características de raiz e parte aérea e realizamos análises dialélicas, mapeamento associativo e métodos de predição genômica considerando 59.215 marcadores Single-Nucleotide Polymorphism (SNP). Nossos resultados revelaram uma herança quantitativa das características do milho relacionadas à essa parceria, com efeitos genéticos aditivos e não-aditivos envolvidos no controle genético. Além disso, vários genes candidatos foram encontrados para a associação milho-A brasilense, especialmente com efeitos de (des)vantagens de heterozigotos. Em geral, as acurácias de predição foram mais maiores principalmente para o tratamento inoculado em comparação ao não inoculado. Finalmente, nossos resultados possibilitam uma compreensão mais aprofundada das bases genéticas da responsividade do milho à A. brasilense e podem auxiliar os melhoristas de plantas a estabelecerem estratégias de seleção visando o desenvolvimento de genótipos superiores para essa associação.

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