Host colonization is mediated through the secretion of effector proteins in order to neutralize host immune responses. However, the mechanism of the effector delivery during biotrophic invasion is not well defined in M. oryzae. In this thesis, I define the role of the exocyst complex, an evolutionarily conserved octameric protein complex involved in vesicle docking to the plasma membrane (composed of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70 and Exo84), during infection-related development in M. oryzae. Like other filamentous fungi, M. oryzae, exocyst components localize to the vegetative hyphal tip distinct from the Spitzenkörper. However, at the initial stage of infection-related development all the exocyst components localise as a ring at the cortex of the appressorium and re-assembles around the appressorium pore in an actin-dependent manner in mature appressoria. I report that the septin network is required for the transition of exocyst ring from periphery to the appressorium pore. Deletion of Exo70 and Sec5 showed significant reduction in protein secretion and plant infection. I show that Sec6 is required for the exocyst assembly around the appressorium pore and effector secretion from the appressorium. I report that, during biotrophic invasion, effectors are secreted through a distinct pathway. Apoplastic effectors, Bas4 and Slp1 are secreted via a Golgi-dependent pathway while secretion of cytoplasmic effectors, Pwl2 and Bas1 meditates through a Golgi-independent pathway in which exocyst components Exo70 and Sec5 are involved.

The related A genome species of the Oryza genus are the effective gene pool for rice. Here, we report draft genomes for two Australian wild A genome taxa: O. rufipogon-like population, referred to as Taxon A, and O. meridionalis-like population, referred to as Taxon B. These two taxa were sequenced and assembled by integration of short- and long-read next-generation sequencing (NGS) data to create a genomic platform for a wider rice gene pool. Here, we report that, despite the distinct chloroplast genome, the nuclear genome of the Australian Taxon A has a sequence that is much closer to that of domesticated rice (O. sativa) than to the other Australian wild populations. Analysis of 4643 genes in the A genome clade showed that the Australian annual, O. meridionalis, and related perennial taxa have the most divergent (around 3 million years) genome sequences relative to domesticated rice. A test for admixture showed possible introgression into the Australian Taxon A ( diverged around 1.6 million years ago) especially from the wild indica/O. nivara clade in Asia. These results demonstrate that northern Australia may be the centre of diversity of the A genome Oryza and suggest the possibility that this might also be the centre of origin of this group and represent an important resource for rice improvement.

Le cas de l'interaction modèle entre le riz et le champignon pathogène Magnaporthe oryzae a été étudié afin de mieux comprendre les effets d'une pratique culturale, la fertilisation azotée, sur la résistance. Ce travail a permis de mettre au point un système simplifié permettant d'étudier au laboratoire l'augmentation de la sensibilité induite par l'apport azoté, un phénomène dénommé NIS (Nitrogen-Induced Susceptibility), d'analyser les effets de l'azote sur la croissance de M. oryzae et son pouvoir pathogène, d'explorer les effets de l'azote au travers de la diversité du riz et des différents types de résistance (complètes et partielles), et d'identifier par cartographie des zones du génome du riz importantes pour la NIS. L'expression des gènes de défenses ne semble pas altérée en cas de régime riche en azote. Au contraire, le suivi cytologique de l'infection par M. oryzae a mis évidence que la pénétration du champignon n'était pas modifiée par la présence d'azote alors que sa croissance dans la plante est accrue. Le niveau de maladie a pu être augmenté par apport d'acides aminés 24h après le début de l'infection, suggérant qu'une relation trophique est probablement à la base de la NIS. Une analyse de l'effet de l'azote sur la sensibilité à la pyriculariose à travers la diversité du riz nous a permis de mieux caractériser la diversité du phénomène de NIS. La NIS est très polymorphe mais n'est pas corrélée à la différence liée aux sous-groupes indica et japonica du riz. Par ailleurs, un fort apport en azote a réduit la résistance déclenchée par le gène de résistance Pi1, suggérant que la robustesse de ces gènes peut être affectée par la NIS Enfin, un locus qui contrôle la sensibilité du riz à la pyriculariose sous un régime riche en azote a été identifié sur le chromosome 1. Plusieurs éléments suggèrent un lien possible entre l'efficacité de l'utilisation de l'azote (NUE) et la NIS. / Nitrogen-Induced Susceptibility (NIS) to plant diseases is a widespread phenomenon. In this work, we set an experimental system in which nitrogen supply strongly affects rice blast susceptibility whereas it is only slightly perturbing plant growth. We show that fungal growth is affected before and after penetration in the plant but that the final penetration rate is not affected; thus a change in penetration is not responsible for increased susceptibility. Differences in total nitrogen amount and defense gene expression before infection are unlikely to be responsible for the observed increase in penetration. After penetration, small changes in plant growth, but not modifications of the transcriptional regulation of defense genes, could be responsible for nitrogen-induced susceptibility. On the other hand, the fungus seems to perceive small differences in nitrogen amount after penetration and this may explain enhanced growth under high nitrogen regime. Indeed, exogenous treatment with some free amino acids after inoculation mimicked Nitrogen-Induced Susceptibility, further arguing that this phenomenon is mostly due to a trophic relation between the plant and the fungus. We also used our experimental system that does not strongly affect plant development to address the question of NIS polymorphism across rice diversity. We show that the capacity of rice to display NIS is highly polymorphic and does not correlate with difference related to indica/japonica sub-groups. We also tested the robustness of three different major resistance genes under high nitrogen. Nitrogen partially breaks down resistance triggered by the Pi1 gene. Cytological examination indicates that penetration rate is not affected by high nitrogen whereas growth of the fungus is increased inside the plant. Using the CSSL mapping population between Nipponbare and Kasalath, we identified a Kasalath locus on chromosome 1, called NIS1, which dominantly increases susceptibility under high nitrogen. We discuss the possible relationships between Nitrogen Use Efficiency (NUE), disease resistance regulation and NIS. This work provides evidences that robust forms of partial resistance exist across diversity and can be genetically mapped. This work also suggests that under certain environmental circumstances, complete resistance may breakdown, irrelevantly of the capacity of the fungus to mutate. These aspects should be considered while breeding for robust forms of resistance to blast disease.

Call number: LD2668 .T4 1959 P43

Call number: LD2668 .T4 1959 S67

Merging from the Distance offers a place to display the poems I have created during my tenure as a graduate student. The four sections found within represent different personal aesthetics. My thesis is also representational of a personal chronology, for it was my intention to demonstrate my efforts of contemporary poetry. Many of the poems seek to engage symbiosis by combining different languages, forms, and levels of diction. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

O presente trabalho teve como proposta a preparação de amidos termoplásticos (TPS) e compósitos a partir de amido de arroz e subprodutos do processo de beneficiamento do arroz, no qual resulta em 20% de palha e 14% de grãos quebrados. Estudou-se o amido de arroz como nova fonte para preparação de termoplásticos, avaliou-se o efeito da incorporação de palha de arroz aos TPS a fim de superar as limitações apresentadas por estes tais como baixo desempenho mecânico e alta absorção de umidade, avaliou-se a possibilidade de preparação de termoplásticos diretamente dos grãos de arroz e quirera e investigou-se a influência das condições de processamento (tempo e temperatura) na preparação dos termoplásticos. O amido de arroz foi plasticizado com glicerol em proporções que variaram de 20 a 40%. Para os compósitos, o teor de reforço (palha) variou de 1 a 5% e o teor de glicerol foi fixado em 30%. Tanto os materiais de partida quanto os termoplásticos e compósitos obtidos foram caracterizados por MEV e difração de raios-X; quanto às propriedades térmicas por TG, DSC e DMTA; quanto às propriedades mecânicas por ensaio mecânico de tração. O comportamento frente à absorção de água também foi investigado. O estudo das condições de processamento foi feito com base nos resultados obtidos a partir da reometria de torque, difração de raios-X e MEV e demonstrou que a utilização de apenas uma das técnicas é insuficiente para determinação das condições de processamento que melhor contribuem para desestruturação do grânulo, mistura e homogeneização do TPS. Os TPS preparados a partir de amido de arroz e glicerol seguiram a mesma tendência de variação de suas propriedades em função do teor de plasticizante que os TPS preparados a partir de outras fontes de amido. Levando em consideração TPS preparados a partir de amido de mandioca, milho e batata, observa-se que os TPS preparados a partir de amido de arroz apresentaram a menor absorção de água. Em relação aos compósitos, a palha contribuiu para melhorar o desempenho mecânico, no entanto favoreceu o aumento da absorção de água. Foi possível obter termoplásticos preparados diretamente dos grãos de arroz (polido e integral) e da quirera. Em comparação com o TPS amido/glicerol, os TPS obtidos a partir dos grãos apresentaram maior cristalinidade, rigidez e temperatura de transição vítrea. No entanto, apresentaram menor estabilidade térmica, menor ductilidade e maior absorção de água. / This work aimed at preparation of thermoplastic starch (TPS) and composites from rice starch and byproducts of the beneficiation process of rice, which results in 20% of husk and 14% of broken grains. The rice starch was studied as a new source for preparing thermoplastics. The effect of incorporation of rice husk to the TPS was evaluated aiming to overcome the limitations presented by pure TPS such as poor mechanical properties and high moisture absorption. The preparation of thermoplastic directly from grain and broken rice was also studied. The rice starch was plasticized with glycerol in proportions ranging from 20 to 40%. For composites, the amount of husk ranged from 1 to 5% and glycerol content was 30%. The effect of processing conditions (time and temperature) in the preparation of thermoplastics were investigated. Starting materials, thermoplastics and composites were characterized by SEM and X-ray diffraction; the thermal properties by TG, DSC and DMTA; and mechanical properties by mechanical tests. The behavior in the water uptake was also investigated. The processing conditions study was based on the results obtained from the torque rheometry, X-ray diffraction and scanning electron microscopy and demonstrated that the use of only one technique is inadequate to determine the best processing conditions. The TPS prepared from rice starch and glycerol followed the same trend of variation of its properties as a function of plasticizer content when compared to TPS prepared from other starch sources. Considering TPS prepared from cassava starch, corn and potato, it was observed that the TPS prepared from rice starch presented a lower water uptake. For composites, husk has improved mechanical performance, but favors the increase in water uptake. It was possible to obtain thermoplastic prepared directly from grain rice (polished and integral) and broken grain. Compared to the starch/glycerol TPS, TPS obtained from the grains had higher crystallinity, and stiffness and glass transition temperature. However, had lower thermal stability, lower ductility and increased absorption of water.

Orientador: Carlos Gilberto Raetano / Banca: Peter Baur / Banca: Evandro Pereira Prado / Banca: José Otávio Machado Menten / Banca: Marcelo da Costa Ferreira / Resumo: A incidência de doenças é um dos principais fatores que afeta a orizicultura brasileira e a baixa eficiência de controle tem causado perdas significativas na quantidade e na qualidade do arroz. Alguns fatores têm influenciado na baixa eficiência do controle das doenças, e entre estes, a aplicação dos fungicidas com volumes muito reduzidos e o não uso ou o uso inadequado de adjuvantes. Esta pesquisa tem como objetivo avaliar a interação da aplicação de adjuvantes e fungicidas na cultura do arroz irrigado, em diferentes volumes de calda, bem como mensurar seus efeitos na sanidade e na produção de grãos. A pesquisa foi desenvolvida em campo e laboratório. O experimento a campo foi conduzido em tabuleiros irrigados na Fazenda Santa Helena, município de Roseira, principal região orizícola do Estado de São Paulo - Brasil, sendo utilizado o cultivar Puitá Inta CL, importante material utilizado na região. O experimento constou de 13 tratamentos, distribuídos no esquema fatorial 4 x 3 (fungicida associado a 3 diferentes adjuvantes e fungicida isolado x 3 volumes de calda, e um tratamento controle). O delineamento experimental foi o de blocos ao acaso, composto por 52 parcelas (13 tratamentos e 4 repetições), tendo cada parcela área de 1.500 m². Os adjuvantes utilizados foram: Fighter (mistura de surfactantes não iônicos), Natur'l Óleo (óleo vegetal) e Aureo (éster metílico de óleo de soja). O fungicida Brio (epoxiconazole + cresoxim-metílico) foi pulverizado duas vezes, coincidentes c... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The incidence of diseases is one of the main factors affecting Brazilian rice production and the low efficiency of control has caused significant losses in rice quantity and quality. Some factors have influenced the low efficiency of disease control, including the application of fungicides at very low volumes and the non-use or inappropriate use of adjuvants. This research aims to evaluate the interaction of the application of adjuvants and fungicides in the irrigated rice crop, in different spray volumes, as well as to measure their effects on sanity and grain production. The research was developed in the field and laboratory. The field experiment was conducted on irrigated at Fazenda Santa Helena, in the municipality of Roseira, the main rice region of the São Paulo State - Brazil, using the cultivar Puitá Inta CL, an important material in cultivation in the region. The experiment consisted of 13 treatments, distributed in the factorial scheme 4 x 3 (fungicide associated with 3 different adjuvants and isolated fungicide x 3 spray volumes, and a control treatment). The experimental design was a randomized block design, consisting of 52 plots (13 treatments and 4 replications), each plot having an area of 1,500 m². The adjuvants used were: Fighter (mixture of nonionic surfactants), Natur'l Oil (vegetable oil) and Aureo (methyl ester of soybean oil). The fungicide Brio (epoxiconazole + kresoxim-methyl) was sprayed twice, coinciding with the booting and beginning of flowering of the plants (72 and 86 days of the culture cycle - BBCH 45 and 61), using tank volumes of 10 L ha-1 for aerial spraying and 100 and 200 L ha-1 for ground spraying. During the conduction of the experiment were carried out evaluations of the efficiency of the treatments in the control of the brown spot, through the evaluations of the incidence and severity in the rice leaves. Visual evaluations of phytotoxification were also ... / Doutor

A cinza da casca do arroz (CCA) é um resíduo rico em sílica amorfa. Um método simples e de baixo consumo energético para extração desta sílica foi pesquisado, obtendo-se um material com baixo teor de impurezas e alta reatividade, adequado para a síntese de zeólitas e wolastonita (CaSiO3). As zeólitas sintéticas, que não possuem estruturas similares na natureza, são cada vez mais valorizadas no mercado devido a pureza e eficiência em aplicações específicas nas áreas de troca iônica, peneira molecular e catálise. A wolastonita com elevado grau de pureza tem várias aplicações na indústria e agricultura. O mineral wolastonita pode ser formado de várias maneiras na natureza. Em geral é aceito que existem dois processos de formação; os quais envolvem o metamorfismo (calor e pressão) do calcário. Neste trabalho, foi desenvolvido um novo processo para a síntese das zeólitas e da wolastonita, ambas a partir da sílica coloidal da CCA; tendo como objetivo um processo de um menor custo energético, menor número de etapas e menor consumo de reagentes. Foram sintetizadas neste trabalho as zeólitas: A, usada em detergentes, e a ZSM-5, empregada na indústria petroquímica, devido a sua alta seletividade em reações catalíticas e grande estabilidade térmica e resistência aos ácidos. A primeira etapa na síntese da wolastonita foi estudada com o objetivo da formação do hidrossilicato de cálcio (CSH). Contudo, onze hidrossilicatos de cálcio diferentes ocorrem no sistema Ca(OH)2-SiO2-H2O que em uma segunda etapa passam por um tratamento térmico para dar formação a fase wolastonita. / Rice hull ash (RHA) is a industry scrap rich in amorphous silica. A simple and low-energy cost method for the extraction of this silica was researched. A low level of impurity and high reactivity material was produced, which is appropriate for the synthesis of zeolites and wolastonite (CaSiO3). The synthetic zeolites, has not similar structures in nature, and they have been more and more valued in the market due to their purity and efficiency in specific applications like ion exchange, molecular sieve and catalysis areas. High purity wolastonite has many applications in manufacturing and agriculture. The mineral wolastonite can be formed in nature in different ways; it is generally accepted two forming processes, both encompassing limestone metamorphism (heat and pressure). In this work, a new process for the synthesis of zeolites and wolastonite from RHA colloidal silica was developed. Moreover, the process is aimed at lower energy costs, fewer stages and fewer reactants consume. In this work, zeolite A used in detergent and zeolite ZSM-5, employed in the petrochemical industry due to its high selectivity in catalytic reactions and its high thermo and acid stability, were synthesized. The first step of the wolastonite synthesis was studied, with the purpose of obtaining calcium hydrosilicate. Eleven different hydrosilicates occur in the system Ca(OH)2-SiO2-H2O, in the second step, it was annealed to form the wolastonite phase.

Due to the stochasticity, diversity and variability of gene expression, transgenic crop study, is confronted with some uncertainties, such as what kinds of the influence from foreign gene on the transgenic crop, and how to fulfill the monitoring of transgenic crop growth real-/ near real-time efficiently. The influence of foreign gene could be treated as a special source of stress to vegetation. Therefore, it is promising to detect the difference between transgenic and contrast group and so as to monitor the growth of sample to assist to fulfill sample screening work, focusing on the plant biophysical traits or responses to stress by spectral techniques. Hyperspectral remote sensing technique is a kind of practical and field spectroscopy technique, which is simple, rapid, real-/ near real-time, user friendly and cheap. In this study, this technique was employed to indicate the differences between transgenic crop samples and their parents, and to monitor their growth. By the proposed approach, fine spectra of transgenic paddy rice were obtained, and the growth of samples were monitored the by their biophysical traits, finally the screening of cultivars were fulfilled in contrast controlled experiments. The biophysical traits or bio-process were concentrated on rather than on micro-structure or components of proteins. It will be implemented to monitor the growth of the samples real-/ near real-time, helping researchers know their samples clearly and screen samples efficiently. / In order to develop and validate this approach, 6 experiments in different fields were conducted, including three kinds of genomes and their transgenic samples. They were classified as the experiment-repeat experiments and the gene-repeat experiments. Moreover, a three-month experiment was also conducted for evaluating the capability of the approach to monitor the sample growth under the condition of an artificial stress (herbicide stress). Morphologic and parameterized features of foliar spectra of samples were applied to indicate the growth of the samples. / In the future, more factors should be considered. They are mainly: much more effective communication with biological researchers should be conducted; more research methods should be introduced, the study scope should be extended to the whole bands (350-2500nm) and more foliar chemicals should be involved as indicators of the growth status of the samples, etc. ii / The results proved this approach proposed was not a substitute to the popular methods for gene detection and crop assessment, but an important, helpful and efficient complement to make the crop breeding study under control and efficient as much as possible. By the approach, the researcher could know their samples clearly and real-/near real- time. / Li, Ru. / Advisers: Jinsong Chen; Hui Lin. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.