A indústria sucroenérgetica gera grande quantidade de resíduos, sendo a torta de filtro e as cinzas os principais resíduos sólidos. Uma das tecnologias desenvolvidas para o manejo destes resíduos é a compostagem. A aplicação do composto tem mostrado efeitos positivos na cultura da cana-de-açúcar no que diz respeito à fertilização fosfatada. Os objetivos do presente trabalho foram: I. Observar o comportamento das comunidades bacterianas durante a compostagem e o efeito da inoculação de estirpes bacterianas mobilizadoras de fósforo sobre a disponibilidade de fósforo no composto final; II. Avaliar o efeito da aplicação de diferentes fontes de P e de bactérias mobilizadoras de fósforo no desenvolvimento de plantas de cana-de-açúcar e o efeito sobre as comunidades bacterianas do solo. Nesse sentido, pilhas de compostagem foram instaladas na Usina São José da Estiva em Novo Horizonte, SP. Os tratamentos consistiram de pilhas com e sem rocha fosfática; e pilhas com e sem a inoculação das estirpes Pseudomonas aeruginosa PSBR12 e Bacillus sp. BACBR1. Amostragens foram realizadas quinzenalmente durante 60 dias. Adicionalmente determinou-se a atividade enzimática, e parâmetros químicos do composto. A comunidade bacteriana foi acessada por meio da técnica independente de cultivo T-RFLP (restriction fragment length polymorphism) e sequenciado por meio da plataforma de nova geração MiSeqTM System (Illumina). Com o objetivo de avaliar o efeito do composto e da inoculação de bactérias mobilizadoras de P no desenvolvimento da cana-de-açúcar foi instalado um experimento em casa de vegetação com plantas de cana de açúcar, utilizando-se composto, rocha fosfática e super fosfato triplo como fontes de P, além da inoculação dos seguintes: Inoculante 1: Pseudomonas sp. PSBR10, Azotobacter sp. AZTBR19, Rhizobium sp. RIZBR01; e o Inoculante 2: Bacillus simplex BACBR04, Bacillus sp. BACBR06, Rhizobium sp. RIZBR01. O experimento foi conduzido durante 75 dias. Ao fim do experimento foram analisados os seguintes parâmetros: biomassa seca, acúmulo de P, N, e K na parte aérea, e fosfatases no solo. A estrutura das comunidades bacterianas no solo foram avaliadas por meio do sequenciamento na plataforma Illumina. A aplicação de bactérias mobilizadoras de P durante a compostagem diminuiu o P ligado ao Ca. A mudança nas comunidades bacterianas durante a compostagem foi temporal, no início dominaram membros da ordem Lactobacillales, após 15 dias as ordens Bacillales e Clostridiales passaram a dominar o processo. As comunidades bacterianas são influenciadas principalmente pelos parâmetros pH, temperatura e umidade. Quanto ao experimento em casa de vegetação, o uso dos inoculantes (principalmente o inoculante 2) aumentou o acúmulo de P, N e K na parte aérea nos tratamentos que receberam composto e super fosfato triplo como fonte de P. A aplicação dos inoculantes e a adição do composto modificou a estrutura das comunidades bacterianas do solo; essa alteração quando os inoculantes são aplicados pode estar relacionada com o incremento no acúmulo de nutrientes. O uso de bactérias mobilizadoras de P é uma tecnologia potencial para o uso na agricultura, tanto na compostagem de resíduos da indústria sucroenergética com rocha fosfática, como no aumento da eficiência da fertilização fosfatada na cana-de-açúcar. / Sugarcane industry generates large amounts of waste, filter cake and ashes being the main solid wastes. One of the technologies developed for the management of this waste is composting. The application of compost has shown positive effects on the sugarcane culture with regard to phosphorus fertilization. The objectives of this study are: I. To study the diversity of bacterial communities during composting and the effect of inoculation of phosphorus mobilizing bacterial strains on the phosphorus availability in the final compost; II. To evaluate and compare the effects of the application of different sources of phosphorus and P mobilizing bacteria on the development of sugarcane and the effect on soil bacterial communities. Therefore, compost piles were installed at Usina São José da Estiva in Novo Horizonte, Brazil. Treatments consisted of piles with and without rock phosphate and with and without inoculation of Pseudomonas aeruginosa PSBR12 and Bacillus sp. BACBR1 strains. Samples were taken every two weeks for 60 days. In addition, the enzymatic and chemical composition of the compost was determined. The bacterial community was assessed through T-RFLP (restriction fragment length polymorphism) and was sequenced through the new generation platform MiSeqTM System (Illumina). The abundance of bacteria was evaluated by qPCR. In order to evaluate the effect of compost and of inoculating P mobilizing bacteria on sugarcane development, a greenhouse experiment was installed with sugarcane using compost, rock phosphate and triple superphosphate as P sources, besides inoculations, as follows: Inoculant 1: Pseudomonas sp. (PSBR10) Azotobacter sp. (AZTBR19), Rhizobium sp. (RIZBR01); and Inoculant 2: Bacillus simplex (BACBR04), Bacillus sp. (BACBR06), Rhizobium sp. (RIZBR01). The experiment was conducted during 75 days. At the end of the experiment the following parameters were analyzed: dry plant biomass, accumulation of P, N, and K in the shoot, and phosphatases in soil. Bacterial soil communities were sequenced through the new generation Illumina. The application of P mobilizing bacteria during composting decreased the Ca-linked P. Changes of the bacterial communities during composting were temporal. In the beginning, members of the order Lactobacillales were dominant and after 15 days a succession of bacterial communities occurred, when Bacillales and Clostridiales began to dominate. Bacterial communities are mostly influenced by the parameters pH, temperature and humidity. Moreover, in the greenhouse experiment, the use of inoculants (mainly inoculant 2) increased the accumulation of P, N and K in shoots in the treatments that received compost and triple superphosphate as P source. Inoculant application and compost addition modified soil bacterial community structures. Changes in the soil microbiome when inoculant was applied may be related to the increase in nutrients accumulation. The use of P mobilizing bacteria is a potential technology for use in agriculture, when composting waste from the sugarcane industry with rock phosphate or when increasing P fertilization efficiency in sugarcane in the field.

In dieser Arbeit wurden zunächst die Kolonisationen von drei verschiedenen Pflanzengattungen durch den GFP-markierten Bacillus amyloliquefaciens FZB42 mittels confocaler Lasermikroskopie und Elektronmikroskopie verfolgt. Hier konnte gezeigt werden, dass FZB42 alle ausgewählten Pflanzen besiedeln konnte. Bei Arabidopsis- und Maiskeimlingen wurden die Wurzelhaare und Verbindungen, an denen laterale Wurzeln entstehen, durch FZB42 bevorzugt besiedelt. Weiterhin wurden bei Arabidopsis die Spitzen der Primärwurzeln, und bei Mais die Wurzelkerben bevorzugt besiedelt. Bei Lemna wurden FZB42 Zellansammlungen entlang der Furchen, die zwischen den Epidermiszellen der Wurzel liegen, sowie den intrazellulären Hohlräumen an der Blattunterfläche gefunden. Anschließend wurden die Transkriptome von FZB42, der mit Maiswurzelexudat angezogen wurde, mittels Microarray analysiert. Insgesamt wurden 302 Gene, die 8,2 % des Transkriptoms ausmachen, signifikant durch das Wurzelexudat beeinflusst, wobei die Mehrzahl (260 Gene) hochreguliert wurde. Die induzierten Gene, dessen Funktion bereits bekannt ist, sind hauptsächlich an dem Nährstoffwechsel, Chemotaxis und Beweglichkeit, sowie an der Produktion von Antibiotika beteiligt. Auch wurden die Trankriptome von sieben FZB42-Muatnten durch Microarray analysiert. Diese hatten jeweils eine Deletionen in fünf Sigmafaktor-Genen (sigB, sigD, sigM, sigV,and sigX) und zwei globalen Transkriptionsregulator-Genen (degU und abrB). Die Expression vieler Genen wird durch diese Genprodukte beeinflusst. Mögliche Mechanismen, wie diese Faktoren die bakterielle Reaktion auf Wurzelexsudaten beeinflüssen, wurden vorgeschlagen. Schließlich wurden Northernblott-Untersuchungen an möglichen sRNA-Kandidaten durchgeführt, dessen Expression signifikant durch Wurzelexudate beeinflusst wurde. Dabei konnten 6 von 20 vermeintlichen sRNA-Kandidaten betätigt werden. Dies weist auf eine noch unbekannte Rolle der sRNAs bei der Pflanzen-Mikroben-Wechselwirkung. / In this work colonization of three different plants genera, maize, Arabidopsis, and Lemna, by GFP-labeled Bacillus amyloliquefaciens FZB42 in a gnotobiotic system was firtly studied using confocal laser scanning microscopy and electron microscopy. It was shown that FZB42 is able to colonize all these three plants with a specific pattern. Root hairs and the junctions where lateral roots occurred were a preferred area of FZB42 on both maize and Arabidopsis seedlings. On Arabidopsis, tips of primary roots were another favored site of FZB42; while, on maize, the concavities in root surfaces were preferred. FZB42 cells were also able to colonize Lemna, preferably accumulating along the grooves between epidermis cells on roots and the concaved intercellular space on fronds. Secondly, microarray experiments were performed concerning the transcriptomic response of FZB42 to maize root exudates. A total of 302 genes representing 8.2% of FZB42 transcriptome were significantly altered in transcription by the presence of root exudates, the majority of them (260) were up-regulated in expression. The induced genes with known function were mainly involved in nutrition utilization, chemotaxis and motility, and antibiotic production. The transcriptome of seven FZB42 mutants, defective in five sigma factor genes (sigB, sigD, sigM, sigV, and sigX) and two global transcriptional regulator genes (degU and abrB), were also investigated through microarray experiments. A vast number of genes were indentified to be controlled by the protein factors respectively. Possible mechanisms were proposed of how these protein factors are involved in the response to root exudates. Finally, by northern blot existence of six out of 20 small RNA (sRNA) candidates was identified, which were significantly altered in expression by root exudates. This suggests that sRNA may play a hitherto unrecognized role in plant-microbe interaction.

Les bactéries promotrices de la croissance des plantes (PGPR) peuvent améliorer la performance et la tolérance des plantes lors de stress environnementaux. Arabidopsis thaliana est un modèle de choix pour étudier les mécanismes impliqués dans les interactions plante-bactéries. Nous avons analysé de multiples traits associés à la dynamique de croissance, au développement et la physiologie des végétaux afin d'évaluer les effets de l'inoculation par Phyllobacterium brassicacearum STM196, une PGPR isolée de la rhizosphère du colza, sur les réponses d'A. thaliana à des stress hydriques de différentes intensités. Grâce à des outils performants de phénotypage, nous avons développé une nouvelle approche d'analyse à haut-débit pour examiner l'implication de STM196 dans les stratégies de résistance des plantes au stress hydrique. Nos résultats montrent pour la première fois que les PGPR peuvent interférer dans les stratégies d'échappement des plantes grâce à des modifications de la croissance et du temps de floraison. De plus, STM196 induit une meilleure résistance au déficit hydrique modéré et une meilleure tolérance à la déshydratation sous une contrainte hydrique sévère. L'inoculation par STM196 peut ainsi représenter une valeur ajoutée aux stratégies de résistance intrinsèques aux plantes, ce qui est illustrée par sa remarquable capacité à promouvoir la survie et la production de biomasse végétale dans des environnements contrastés. Nos résultats soulignent l'importance des interactions plantes-bactéries dans les réponses des plantes à la sécheresse et offrent de nouvelles voies de recherches pour l'amélioration de la résistance à la sécheresse dans les cultures. / Plant growth promoting rhizobacteria (PGPR) can enhance plant performance and plant tolerance to environmental stresses. Arabidopsis thaliana is a useful organism to study the mechanisms involved in plant-PGPR interactions. We analyzed multiple plant traits related to growth dynamics, development and physiology in order to assess the effects of Phyllobacterium brassicacearum STM196 strain, isolated from the rhizosphere of oilseed rape, on Arabidopsis responses to well-defined soil water availability. Using powerful tools for phenotyping, we developed a new high-throughput analysis to examine the implication of STM196 on plant strategies to cope with water stress. Our results show for the first time that PGPR can interfere in escape strategies of plants through modifications in plant growth and flowering time. Moreover, STM196 induced a better resistance to moderate water deficit and a better tolerance to dehydration under a severe stress. Inoculation by STM196 can represent an added value to plant resistance strategies, as illustrated by its remarkable ability to promote plant survival and biomass production under contrasted environments. Our results highlight the importance of plant-bacteria interactions in plant responses to drought and provide a new avenue of investigations to improve drought resistance in crops.

A indústria sucroenérgetica gera grande quantidade de resíduos, sendo a torta de filtro e as cinzas os principais resíduos sólidos. Uma das tecnologias desenvolvidas para o manejo destes resíduos é a compostagem. A aplicação do composto tem mostrado efeitos positivos na cultura da cana-de-açúcar no que diz respeito à fertilização fosfatada. Os objetivos do presente trabalho foram: I. Observar o comportamento das comunidades bacterianas durante a compostagem e o efeito da inoculação de estirpes bacterianas mobilizadoras de fósforo sobre a disponibilidade de fósforo no composto final; II. Avaliar o efeito da aplicação de diferentes fontes de P e de bactérias mobilizadoras de fósforo no desenvolvimento de plantas de cana-de-açúcar e o efeito sobre as comunidades bacterianas do solo. Nesse sentido, pilhas de compostagem foram instaladas na Usina São José da Estiva em Novo Horizonte, SP. Os tratamentos consistiram de pilhas com e sem rocha fosfática; e pilhas com e sem a inoculação das estirpes Pseudomonas aeruginosa PSBR12 e Bacillus sp. BACBR1. Amostragens foram realizadas quinzenalmente durante 60 dias. Adicionalmente determinou-se a atividade enzimática, e parâmetros químicos do composto. A comunidade bacteriana foi acessada por meio da técnica independente de cultivo T-RFLP (restriction fragment length polymorphism) e sequenciado por meio da plataforma de nova geração MiSeqTM System (Illumina). Com o objetivo de avaliar o efeito do composto e da inoculação de bactérias mobilizadoras de P no desenvolvimento da cana-de-açúcar foi instalado um experimento em casa de vegetação com plantas de cana de açúcar, utilizando-se composto, rocha fosfática e super fosfato triplo como fontes de P, além da inoculação dos seguintes: Inoculante 1: Pseudomonas sp. PSBR10, Azotobacter sp. AZTBR19, Rhizobium sp. RIZBR01; e o Inoculante 2: Bacillus simplex BACBR04, Bacillus sp. BACBR06, Rhizobium sp. RIZBR01. O experimento foi conduzido durante 75 dias. Ao fim do experimento foram analisados os seguintes parâmetros: biomassa seca, acúmulo de P, N, e K na parte aérea, e fosfatases no solo. A estrutura das comunidades bacterianas no solo foram avaliadas por meio do sequenciamento na plataforma Illumina. A aplicação de bactérias mobilizadoras de P durante a compostagem diminuiu o P ligado ao Ca. A mudança nas comunidades bacterianas durante a compostagem foi temporal, no início dominaram membros da ordem Lactobacillales, após 15 dias as ordens Bacillales e Clostridiales passaram a dominar o processo. As comunidades bacterianas são influenciadas principalmente pelos parâmetros pH, temperatura e umidade. Quanto ao experimento em casa de vegetação, o uso dos inoculantes (principalmente o inoculante 2) aumentou o acúmulo de P, N e K na parte aérea nos tratamentos que receberam composto e super fosfato triplo como fonte de P. A aplicação dos inoculantes e a adição do composto modificou a estrutura das comunidades bacterianas do solo; essa alteração quando os inoculantes são aplicados pode estar relacionada com o incremento no acúmulo de nutrientes. O uso de bactérias mobilizadoras de P é uma tecnologia potencial para o uso na agricultura, tanto na compostagem de resíduos da indústria sucroenergética com rocha fosfática, como no aumento da eficiência da fertilização fosfatada na cana-de-açúcar. / Sugarcane industry generates large amounts of waste, filter cake and ashes being the main solid wastes. One of the technologies developed for the management of this waste is composting. The application of compost has shown positive effects on the sugarcane culture with regard to phosphorus fertilization. The objectives of this study are: I. To study the diversity of bacterial communities during composting and the effect of inoculation of phosphorus mobilizing bacterial strains on the phosphorus availability in the final compost; II. To evaluate and compare the effects of the application of different sources of phosphorus and P mobilizing bacteria on the development of sugarcane and the effect on soil bacterial communities. Therefore, compost piles were installed at Usina São José da Estiva in Novo Horizonte, Brazil. Treatments consisted of piles with and without rock phosphate and with and without inoculation of Pseudomonas aeruginosa PSBR12 and Bacillus sp. BACBR1 strains. Samples were taken every two weeks for 60 days. In addition, the enzymatic and chemical composition of the compost was determined. The bacterial community was assessed through T-RFLP (restriction fragment length polymorphism) and was sequenced through the new generation platform MiSeqTM System (Illumina). The abundance of bacteria was evaluated by qPCR. In order to evaluate the effect of compost and of inoculating P mobilizing bacteria on sugarcane development, a greenhouse experiment was installed with sugarcane using compost, rock phosphate and triple superphosphate as P sources, besides inoculations, as follows: Inoculant 1: Pseudomonas sp. (PSBR10) Azotobacter sp. (AZTBR19), Rhizobium sp. (RIZBR01); and Inoculant 2: Bacillus simplex (BACBR04), Bacillus sp. (BACBR06), Rhizobium sp. (RIZBR01). The experiment was conducted during 75 days. At the end of the experiment the following parameters were analyzed: dry plant biomass, accumulation of P, N, and K in the shoot, and phosphatases in soil. Bacterial soil communities were sequenced through the new generation Illumina. The application of P mobilizing bacteria during composting decreased the Ca-linked P. Changes of the bacterial communities during composting were temporal. In the beginning, members of the order Lactobacillales were dominant and after 15 days a succession of bacterial communities occurred, when Bacillales and Clostridiales began to dominate. Bacterial communities are mostly influenced by the parameters pH, temperature and humidity. Moreover, in the greenhouse experiment, the use of inoculants (mainly inoculant 2) increased the accumulation of P, N and K in shoots in the treatments that received compost and triple superphosphate as P source. Inoculant application and compost addition modified soil bacterial community structures. Changes in the soil microbiome when inoculant was applied may be related to the increase in nutrients accumulation. The use of P mobilizing bacteria is a potential technology for use in agriculture, when composting waste from the sugarcane industry with rock phosphate or when increasing P fertilization efficiency in sugarcane in the field.

Some plant-beneficial bacteria with biopesticide potential produce antimicrobial compounds that are tightly involved in multitrophic interactions occurring in the phytosphere among which antagonism toward a diverse range of phytopathogens. However, there is a crucial need for an accurate assessment of antibiotic production rate in this environment colonized by these bacteria. In this context, we conducted the present thesis work with the scope to better understand how two different Bacillus genus strains produce lipopeptides in the rhizosphere of plants. In the first part, one of the strains (B. amyloliquefaciens S499) was selected out of other isolates for its technological traits and in vitro inhibition growth activity of plant pathogenic fungi. We further demonstrated its biocontrol potential in tomato open-field experiments where plantings have been devastated by a local fungus preliminary identified as Fusarium semitectum. In a second part, we combined two mass spectrometry-based approaches (electrospray ionization and imaging) to analyze the pattern of surfactin, iturin and fengycin lipopeptide families produced in planta by strain S499. Our results show that rhizosphere conditions are conducive for surfactin synthesis but not for other types of lipopeptides and that the lipopeptide pattern can be markedly influenced by nutritional factors, biofilm formation and oxygen availability. In a last part, surfactin gene expression (srfA) level was evaluated in situ on tomato root using the reporter gene (LacZ) inserted in B. subtilis strain BGS3. Results showed effective expression of srfA and production of surfactin in biologically important level quantities upon establishment of bacterial population on roots. Our results also demonstrate that BGS3 developing in colonies, efficiently utilizes the main substrates from plant exudates to produce surfactins. The production may also be favored in bacteria growing slowly in the rhizosphere. Globally, this work contributes to better appreciate the impact of some environmental factors on the in situ biosynthesis of lipopeptides by strains of Bacillus which is probably an essential step for improving the level and reliability of their efficacy as biological agents for the control of plant diseases.

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No. of bitstreams: 2 Dissertação - Alan Carlos Alves de Souza - 2014.pdf: 1318444 bytes, checksum: 0ecebb757edfdc4bb5ddcc76cbb631df (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-24 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Rice is considered a cereal that has the potential to eradicate hunger and malnutrition. However, during its cultivation, is submitted to biotic and abiotic stresses, which lowers productivity in key growing regions, followed by the rising cost of inputs such as fertilizers and pesticides. The aim of this work was to study the effect of silicon, alone and in combination with bioagents on growth promotion and leaf blast suppression of on upland rice. Two experiments, E1 and E2 were conducted in a factorial design in the greenhouse conditions. E1: aimed to select the best treatments for plant growth promotion and rice blast (Magnaporthe oryzae) suppression. It was composed by 5 plots (control; 1 ton SiCaMg.ha-1; 2 ton SiCaMg.ha-1; 4 ton SiCaMg.ha-1; 8 ton SiCaMg.ha-1), 5 subplot (control; Burkholderia pyrrocinia; Pseudomonas fluorescens, Trichoderma asperellum; mixture of all these three bioagents) and 8 replication. E2: aimed to investigate the defense mechanisms of the best treatment selected in E1. It was composed of 2 plots (control; 2 ton SiCaMg.ha-1) and subplot 3 (control; Trichoderma asperellum; mixture of all these three bioagents) and 4 replication. Silicon fertilization and bioagents interaction proved to be promising. In E1, T. asperellum combined with 2 ton.ha-1 of SiCaMg plant fertilization increased 45.63% of plant growth and, the combination of all three bioagents with 2 ton ha of SiCaMg plants fertilization was the best treatment reducing 96% of leaf blast. In E2, the two best treatments in E1 statistically increased QUI, GLU, POX and FAL activity as well AS content in the absence of Magnaporthe oryzae. However, 24 and 48 hours after challenger inoculation with M. oryzae, only QUI and GLU activity and AS content statistically increased in the treatment that combined all three bioagents and 2 ton.ha-1 of SiCaMg plants fertilization. Leaf blast reduction through the activation of defense mechanisms elected the combination silicon fertilization and bioagents as important strategies for sustainable rice disease management. / O arroz é considerado o cereal que possui potencial para a erradicação da fome e da má nutrição. Porém, durante seu cultivo, é submetido a estresses bióticos e abióticos, o que diminui a produtividade nas principais regiões de cultivo, acompanhado do aumento dos custos com insumos, como fertilizantes e agrotóxicos. O objetivo deste trabalho foi estudar o efeito do silício, isoladamente e em combinação com bioagentes, na supressão de brusone foliar em plantas de arroz de terras altas. Foram realizados dois experimentos, em delineamento fatorial, em casa de vegetação (E1 e E2). E1: composto de 5 tratamentos (controle; 1 ton SiCaMg.ha-1; 2 ton SiCaMg.ha-1;4 ton SiCaMg.ha-1; 8 ton SiCaMg.ha-1), 5 subtratamentos (controle; Burkholderia pyrrocinia; Pseudomonas fluorescens; Trichoderma asperellum; mistura dos três bioagentes) e 8 repetições, com o objetivo de selecionar os melhores tratamentos, através da severidade de brusone (Magnaporthe oryzae) nas folhas. E2: composto por 2 tratamentos (controle; 2 ton SiCaMg.ha-1), 3 subtratamentos (controle; Trichoderma asperellum; mistura dos três bioagentes) e 4 repetições, com o objetivo de investigar o efeito dos melhores tratamentos, para a promoção de crescimento das plantas e supressão de brusone foliar e na ativação dos mecanismos de defesa da planta. A interação entre a adubação silicatada e os bioagentes mostrou-se promissora. Em E1, o melhor tratamento para a redução de brusone foliar foi a combinação entre os três bioagentes e plantas adubadas com 2 ton SiCaMg.ha-1, suprimindo a doença em 96%. Em E2, as combinações entre T. asperellum e plantas adubadas com 2 ton SiCaMg.ha-1 e, a mistura dos bioagentes em plantas adubadas com 2 ton SiCaMg.ha-1 aumentaram significativamente a atividade das enzimas quitinase, β-1,3 glucanase, peroxidase, fenilalanina amônia-liase, e o teor de ácido salicílico na ausência de Magnaporthe oryzae. A mistura dos três bioagentes, em plantas adubadas com 2 ton SiCaMg.ha-1 proporcionou o aumento expressivo das enzimas quitinase, β-1,3 glucanase e o teor de ácido salicílico às 24 e 48 horas após a inoculação com M. oryzae. A redução da brusone foliar acompanhada da participação ativa dos mecanismos de defesa elegem a adubação silicatada e os bioagentes como estratégias importantes para o manejo sustentável.

Made available in DSpace on 2014-08-20T13:44:46Z (GMT). No. of bitstreams: 1 dissertacao_vanessa_nogueira_soares.pdf: 1259107 bytes, checksum: 8e6ace87f8297ed0ea1e307687b21567 (MD5) Previous issue date: 2011-03-14 / The development of new technologies to increase productivity in various crops involves constant research on the effectiveness and implementation of these new techniques for seed treatment. The objective was to evaluate the physiological increase in rice seeds treated with PGPR promote plant growth (DFs185 (Pseudomonas synxantha) DFs223, (P. fluorescens), DFs306 (unidentified), DFs416 (Bacillus sp.) and two levels of thiamethoxam (100mL / L and 200 mL / L of thiamethoxam product per 100kg seed) under ideal conditions for development and stress conditions by low temperatures. Were used six lots of BRS Querência with differences in physiological quality. Two experiments were conducted, in the first the variables were: germination, first count germination, cold test, length of coleoptiles, length of roots, total length, dry weight of roots, coleoptiles dry weight, speed index emergency and emergency for 14 days. In the second experiment were used seeds treated with thiamethoxam, DFs185 (P. synxantha) and without treatment, the variables were: germination, first count germination, germination rate, rate of emergence, emergence to 14 days length of coleoptiles and roots and electrophoretic patterns of isoenzymes α-amylase, esterase and peroxidase, all tests were performed at temperatures of 25, 20 and 15 ° C. Seed treatment with thiamethoxam and rhizobacterial stimulates the physiological quality of seeds of low quality rice. The most influenced by seed treatment with thiamethoxam and the bacterial isolates DFs185 (P. synxantha) DFs223, (P. fluorescens), DFs306 (unidentified), DFs416 (Bacillus sp.) were germination and emergence. The treatments thiamethoxam and P. synxantha (DFs185) did not alter the expression and intensity of expression of esterase and peroxidase isoenzymes. The bacterium P. synxantha (DFs185) is promising for treatment of rice seeds to stimulate germination and emergence. Treatments thiamethoxam and P. synxantha (DFs185) showed not beneficial effect on quality of rice seeds subjected to low temperature stress. / O desenvolvimento de novas tecnologias visando ao aumento de produtividade em diferentes cultivos implica em investigações constantes sobre a eficiência e aplicação dessas novas técnicas no tratamento de sementes. O objetivo deste trabalho foi avaliar o potencial fisiológico de sementes de arroz tratadas com rizobactérias promotoras de crescimento de plantas (DFs185 (Pseudomonas synxantha), DFs223, (P. fluorescens), DFs306 (não identificado), DFs416 (Bacillus sp.) e duas doses de tiametoxam (100mL/L e 200mL/L do produto tiametoxam por 100kg de sementes) em condições ideais de desenvolvimento e condição de estresse por baixas temperaturas. Foram realizados dois experimentos, no primeiro as variáveis avaliadas foram: germinação, primeira contagem da germinação, teste de frio, comprimento da parte aérea, comprimento da parte radicular, comprimento total, fitomassa seca de raízes, fitomassa seca da parte aérea, índice de velocidade de emergência e emergência aos 14 dias. No segundo experimento utilizaram-se sementes tratadas com tiametoxam, DFs185 (P. synxantha) e sem tratamento, as variáveis avaliadas foram: germinação, primeira contagem da germinação, velocidade de germinação, índice de velocidade de emergência, emergência aos 14 dias comprimento da parte aérea e radicular e padrões eletroforéticos de isoenzimas α-amilase, esterase e peroxidase, todos os testes foram realizados nas temperaturas de 25, 20 e 15°C. O tratamento das sementes com rizobactérias e com tiametoxam estimula a qualidade fisiológica de sementes de arroz de baixa qualidade. As variáveis mais influenciadas pelo tratamento de sementes com tiametoxam e os isolados bacterianos DFs185 (P. synxantha), DFs223, (P. fluorescens), DFs306 (não identificado), DFs416 (Bacillus sp.) foram germinação e emergência. Os tratamentos tiametoxam e P. synxantha (DFs185) não alteraram a expressão e intensidade de expressão das isoenzimas esterase e peroxidase. A bactéria P. synxantha (DFs 185) é promissora para o tratamento de sementes de arroz por estimular a germinação e a emergência. Os tratamentos tiametoxam e P. synxantha (DFs185), não apresentam efeito benéfico na qualidade de sementes de arroz submetidas a estresse por baixas temperaturas.

Les plantes interagissent en permanence avec une grande diversité de microorganismes qu'elles sélectionnent entre autre au niveau de leurs racines. Certaines bactéries, qualifiées de PGPR (Plant Growth-Promoting Rhizobacteria), sont capables de stimuler la croissance et la santé de la plante, grâce à l'expression d'une large panoplie de propriétés phytobénéfiques. L'hypothèse actuelle serait que les PGPR possédant un nombre maximal de ces fonctions auraient un plus fort impact bénéfique sur le végétal. Toutefois, l'occurrence de ces PGPR multifonctions dans la rhizosphère n'est pas connue. De plus, les possibles interactions entre propriétés co-occurrentes au sein d'une même PGPR et la résultante de ces interactions sur la plante sont relativement peu documentées. Dans ce contexte, ce projet de thèse a eu comme objectif général de mieux comprendre la distribution des propriétés phytobénéfiques chez un groupe bactérien possédant un large éventail de ses propriétés, celui des Pseudomonas fluorescents et d'évaluer chez une PGPR modèle multifonction, Pseudomonas fluorescens F113, si des interactions fonctionnelles existent entre ces propriétés et déterminer leurs contributions respectives à l'effet phytostimulateur. L'étude d'environ 700 isolats de Pseudomonas provenant de la rhizosphère de deux cultivars de maïs et de sol nonrhizosphérique, a mis en évidence que ces cultivars sélectionnent majoritairement des Pseudomonas fluorescents (i) arborant un nombre réduit de propriétés phytobénéfiques (1 à 5 propriétés) et (ii) appartenant à des sous-groupes taxonomiques particuliers. Par ailleurs, l'étude de génomique comparative que nous avons menée au sein du groupe des Pseudomonas fluorescents souligne le lien entre phylogénie et les profils de propriétés phytobénéfiques possédées par les Pseudomonas. Enfin, chez P. fluorescens F113, les propriétés co-occurrentes ne contribuent pas de façon égale à l'effet observé sur la plante. L existence d'interactions entre ces propriétés co-occurrentes a également été mise en évidence. De ce réseau d'interactions, résultera un effet bénéfique observé sur la plante particulier. Ces résultats sont importants pour mieux comprendre la place et le rôle de ces PGPR multifonctions dans la rhizosphère. Ils permettent d'approfondir nos connaissances à propos du fonctionnement écologique des Pseudomonas fluorescents au sein du rhizomicrobiote / Plants are constantly interacting with a huge diversity of microorganisms, especially in the rhizosphere, where plant roots (through rhizodeposition) will select particular bacterial populations. Some bacteria, called PGPR (Plant Growth-Promoting Rhizobacteria), are able, in turn, to improve plant growth and health, through the expression of a wide range of plantbeneficial properties. The current hypothesis is that PGPR harboring a maximum number of these plant-beneficial properties would provide a better effect on plant. However, the occurrence of these multi-trait PGPR in the rhizosphere is unknown. In addition, the interaction between co-occurring plant-beneficial properties within the same PGPR and their resulting effects on plant are poorly documented. In this context, the aims of this thesis were to (i) determine the distribution of plant-beneficial properties in the fluorescent Pseudomonas bacterial group, known to harbor a wide range of these properties, and (ii) to evaluate in the PGPR model strain Pseudomonas fluorescens F113, if a crosstalk between plant-beneficial properties occurs and to determine the relative contribution of each co-occurring plantbeneficial properties. The study of 700 Pseudomonas isolates from the rhizosphere of two maize cultivars and from non-rhizosphere soils shows that cultivars mostly select fluorescent Pseudomonas (i) displaying few plant-beneficial properties (up to 5 properties) and (ii) belonging to particular taxonomic subgroups. Furthermore, the comparative genomic study we conducted within the fluorescent Pseudomonas group emphasizes the link between phylogeny and plant-beneficial profiles owned by Pseudomonas. Finally, in P. fluorescens F113, co-occurring plant-beneficial properties do not contribute equally to the observed effects on plant. The existence of crosstalks between these co-occurring plant-beneficial properties was also highlighted. This network of functional interactions may lead to specific effects on plant. These results are important for understanding the place and role of multi-trait PGPR in the rhizosphere. They help to deepen our understanding of the ecological functioning of fluorescent Pseudomonas among the rhizomicrobiote

Cyclodipeptides (CDPs) are the smallest, most stable cyclic peptides that are synthesized as secondary metabolites by bacteria. The aim of this study was to investigate the effect of the Pseudomonas argentinensis (SA190) and four (CDPs), named as cis-cyclo-(Pro-Phe) (Cyclo2), cis-cyclo-(Pro-Leu) (Cyclo3), cis-cyclo-(Pro-Tyr) (Cyclo4) and cis-cyclo-(Pro-Val) (Cyclo5), with three concentrations (1µM, 100nM, and 10nM), on the growth of Arabidopsis thaliana under normal plant growth conditions [1/2MS media], salt conditions [125 mM NaCl] and drought conditions [25% PEG]. Moreover, we determined the most effective CDPs with optimal concentration. It was found that cis-cyclo-(Pro-Tyr) (Cyclo4) at a concentration of 100nM had an effect on the plant growth and can mimic the effect of SA190 under normal [1/2MS media] conditions. Also, cis-cyclo-(Pro-Tyr) (Cyclo4) at a concentration of 1µM can mimic the effect of SA190 under salt conditions [125mM NaCl]. Finally, cis-cyclo-(Pro-Val) (Cyclo5) at a concentration of 1µM can mimic the effect of SA190 under drought conditions [25% PEG].

Bacillus amyloliquenaciense FZB42 ist ein bekanntes Pflanzenwachstum-stimulierendes Rhizobakterium. Es produziert neben einer Vielzahl an Sekundärmetaboliten mit antibakterieller und antifungaler Wirkung, auch das Pflanzenhormon IAA. Obwohl viele dieser Mechanismen diskutiert werden, ist wenig darüber bekannt, auf welche Weise die Bakterien das Pflanzenwachstum fördern. In dieser Arbeit wurde eine Transposonmutagenese mithilfe des ‘mariner-transposons’ durchgeführt, und so eine Transposonbibliothek erstellt. Diese wurde dann auf geeignete Phänotypen untersucht, um die Gene zu finden, welche bestimmte Phänotypen verursachen. So konnten drei Mutanten erzeugt werden, die auf Grund der gestörten Biofilmbildung und der Fähigkeit zu schwärmen die Pflanzenwurzeln nicht mehr kolonialisieren konnten. Eine solche degU-Mutante, welche in der Biofilmbildung und ‚Swarming’ defizitär war und zwei Mutanten (yusV und pabB), die eine Beeinträchtigung in der Biofilmbildung aufwiesen, konnten durch Komplementation und Retransformation bestätigt werden. Mithilfe des Lemna-Biosystems und anderer Analysen mit A. thaliana konnten drei Gene bei B. amyloliqufaciens FZB42 gefunden werden, die wichtig für die Förderung des Pflanzenwachstums sind. Koloniesierungsexperimente der Wurzeln von A. thaliana mit diesen Mutanten zeigten deutlich verändertes Wachstum, verglichen mit dem Wildtypstamm. Ein weiteres Ziel dieser Arbeit war es neue Antibiotika in Mutanten, die in ihren nicht-ribosomalen Synthesen blockiert sind, zu finden. So konnten durch die Untersuchungen der Transposonbibliothek der Mutanten zwei neue Antibiotika entdeckt werden. Genauere Analysen dieser Antibiotika bestätigten, dass es sich um ein neues Bacteriocin (Amylocyclicin A) und ein neues Thiazol/Oxazole-modifiziertes Microcin (Plantazolicin) handelt. Die abschließenden Arbeiten beschäftigten sich dann mit Untersuchungen von Genen, welche für die Produktion von Substanzen gegen Nematoden verantwortlich sind. Hierbei konnten vier Mutanten gefunden werden, die durch eine Transposoninsertion eine schlechtere. / Bacillus amyloliqufaciens FZB42 has been known as PGPR which has an impressive effect to improve plant growth. It produces not only vast array of secondary metabolites with antibacterial and antifungal activities, but also produces the plant hormone IAA. Although many mechanisms have been elucidated, our knowledge about basic molecular mechanisms responsible for its beneficial action is far from complete. In this study, transposon mutagenesis based on mariner tranposon was applied to generate tranposon library which then was screened to identify the genes involved in plant growth-promoting activity. Three mutants that were impaired in their ability to colonize plant surface due to defects in biofilm formation and swarming motility were found. One mutant (degU mutant) showed defect in biofilm formation and swarming motility, as well, two mutants (yusV mutant and pabB mutant) impaired in biofilm formation were confirmed by complementation and retransformation. Screening by the Lemna biosystem and further assays with A. thaliana revealed three genes responsible for reduction in plant growth promoting activity of B. amyloliqufaciens FZB42. Colonization studies of these mutants in A. thaliana roots revealed patterns different to the wild type. A further issue pursued in this study was to discover new antibiotics using a mutant which has been blocked in its nonribosomally pathway. Screening of tranposon librabries from this mutant led to the finding of two novel ribosomally synthesized antibiotics. Further characterization revealed that these new antibiotics belonged to a novel bacteriocin (Amylocyclicin A) and a novel thiazole/oxazole-modified microcin (Plantazolicin). Last work in this study was looking for genes responsible for nematocidal production. Four mutants which showed reduction in nematocidal activity due to transposon insertion were found.