Copper oxide nanoparticles (NPs) are used in an expanding range of industries including a potential for agricultural applications as a fungicide. Accidental spills or misapplication of CuO NPs may lead to soil contamination. Plant roots exude a wide range of organic chemicals for bioprotection and to enhance bioavailability of nutrients. Many of these chemicals are metal chelators that may increase the solubility of CuO NPs, thus enhancing the impact of these NPs on plants. This work was directed towards understanding which plant exudates force increased solubility of CuO NPs and to determine if the level of NP in the growth matrix drives a feedback effect, regarding composition and quantity of exudates. Wheat seedlings (Triticum aestivum cv Deloris) were grown in a sand matrix for 10 days after 3 days of germination. The sand was amended with sublethal doses of CuO NPs from 0 to 300 mg Cu/kg dry sand. Sand was selected as the solid growth matrix as a proxy for soil in terms of plant root morphology, mechanical impedance and water stress, while providing a low background of dissolved organic carbon for the isolation of root exudates. After plant growth, the pore water was collected from the sand by vacuum filtration and analyzed. By coupling analytic techniques including Triple Quad Mass Spectroscopy and ion chromatography with geochemical modeling, we have identified citrate and the phytosiderophore, deoxymugineic acid (DMA) as chelators that drove the majority of dissolution of CuO NPs, especially DMA at higher CuO NP doses. Altered biogeochemistry within the rhizosphere was correlated with increased plant uptake of Cu and bio-response via exudate type, quantity and metal uptake. Exposure of wheat to CuO NPs lead to dose-dependent reduction in Fe, Ca, Mg, Mn and K in roots and shoots. This work is relevant to growth of commercially important crop wheat in the presence of CuO NPs as a fertilizer, fungicide or a pollutant.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21150号 / 農博第2276号 / 新制||農||1059(附属図書館) / 学位論文||H30||N5124(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 北山 兼弘, 教授 小杉 緑子, 教授 本田 与一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Monospecific stands of invasive plant species are found in nearly all known ecosystems and can cause permanent lasting ecosystem damage via deleterious effects in soils. These deleterious soil effects are a proposed mechanism which drives invasions by plants and are known to be influenced by kin recognition in plants. Uncovering whether invasive species utilize kin recognition to facilitate their own ecological persistence via soil conditioning will allow us to better understand the drivers of plant invasions and help combat them. In my master’s thesis, I examined the role of kin recognition and kin selection on soil effects. I grew groups of Potentilla recta in groups of maternal half-sibs or strangers to condition the soil. I then grew a second generation of plants in that conditioned soil to determine the impacts of soil conditioning effects on plant performance. I found soil conditioning by groups of plants affected the performance of a second generation of plants based on the relatedness of the conditioning plants. Further, these soil effects of conditioning selectively benefit future individuals of a subsequent generation based on their relatedness. Moreover, these soil effects only existed in soil that has not been sterilized, indicating these soil effects depended on soil microbes. / Thesis / Master of Biological Science (MBioSci) / Invasive plants form dense stands of same-species individuals that can cause lasting deleterious effects to the soil. These deleterious soil effects have been proposed as a mechanism driving plant invasions. In my master’s thesis, I examined the role of kin recognition and kin selection on soil effects. I first grew groups of Potentilla recta in groups of maternal half-sibs or strangers to condition the soil, and then grew a second generation of plants in that conditioned soil to determine the impacts on plant performance. I found that soil influenced by groups of related plants affect increased the performance of a second generation of plants, particularly if the second generation was related to the first. Moreover, these soil effects only existed in soil that has not been sterilized, indicating these soil effects depended on soil microbes. I found that these soil effects of conditioning selectively benefited future individuals of a subsequent generation based on their relatedness.

No description available.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第23946号 / 農博第2495号 / 新制||農||1090(附属図書館) / 学位論文||R4||N5381(農学部図書室) / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 舘野 隆之輔, 教授 北島 薫, 教授 德地 直子 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

No description available.

No description available.

A citricultura brasileira apresenta números bastante significativos e expressivos, refletindo a grande importância social e econômica que essa atividade agrícola e industrial tem para a economia do país. O Brasil se destaca como o maior produtor de laranja do mundo. As plantas cítricas podem ser produzidas e multiplicadas de várias formas e a enxertia é a forma de propagação vegetativa mais utilizada comercialmente no Brasil. Dentre os porta-enxertos mais empregados, sobressaem-se o citrumeleiro Swingle e a tangerineira Sunki. Apesar das vantagens presentes nesses dois genótipos, a produção deles está sendo limitada por doenças causadas por fungos e estraminipilas. Em citros, as diversas espécies de Phytophthora são responsáveis pelas doenças gomose e podridões, principalmente de radicelas. P. nicotianae é a espécie que mais afeta as plantas cítricas no Brasil. Não obstante a grande importância de P. nicotianae para os porta-enxertos, alguns mecanismos de resistência ou susceptibilidade ainda requerem mais investigações cientificas. O presente trabalho visa a elucidação de alguns mecanismos de resistência dos citros a P. nicotianae, por meio de estudos fisiológicos e bioquímicos dos porta-enxertos, além da ação de meios de cultura e da qualidade da luz no estudo da fisiologia desse estraminipila. Para isso realizou-se a detecção de alguns equivalentes de compostos fenólicos através da técnica HPLC e o comportamento do genótipo resistente frente à possível inibição da síntese de compostos fenólicos através do tratamento das raízes do porta-enxerto Swingle com Pro-Ca; avaliou-se a atração de zoósporos de P. nicotianae por exsudatos radiculares provenientes dos dois porta-enxertos com o uso de uma armadilha adaptada; verificou-se o comportamento do zoósporo, a motilidade e a zoosporogênese frente à ação de vários compostos fenólicos e testou-se a ação de diferentes meios de culturas e da qualidade da luz no crescimento micelial e na esporulação de P. nicotianae. Os resultados revelaram que a tangerineira Sunki possui maiores quantidades de equivalentes em apigenina que o citrumeleiro Swingle nos dois períodos de avaliação, para o HPLC. O porta-enxerto resistente apresentou mais equivalentes de ácido clorogênico que o genótipo susceptível. Quanto ao Pro-Ca, os equivalentes de compostos fenólicos em raízes de plântulas do citrumeleiro Swingle não diferiram daquelas plantas tratadas com água. O Pro-Ca não inibiu e não desativou a síntese de compostos fenólicos. O uso do anticorpo contra a elicitina \"α-plurivorina\" teve resultados intermediários no consumo de água por plântulas de tangerineira Sunki e a atividade zoosporicida dos compostos fenólicos apresentou resultados variáveis no comportamento da motilidade de zoósporos. Os compostos fenólicos escopoletina e tricetinpentametoxi conseguiram paralisar a motilidade e proporcionaram as menores porcentagens de zoosporogênese. O meio de cultura AA permitiu a maior TCMD, seguido de CA e V8-CaCO3-Ágar. Os maiores valores de esporulação foram encontrados nesses dois últimos meios, respectivamente. Todas as faixas de luzes (e a ausência de luz) estudadas no presente trabalho podem ser avaliadas para o crescimento micelial, porém o tratamento claro foi aquele que mais induziu a esporulação de zoósporos de P. nicotianae. / The Brazilian citrus industry has very significant and expressive numbers, reflecting the great social and economic importance of this industrial and agricultural activity has for the economy. Brazil stands out as the world\'s largest orange producer. Citrus plants can be produced and multiplied in various ways and the bud is the form of vegetative propagation more commercially used in Brazil. Among the most commonly used rootstocks, stand up the Swingle citrumelo and Sunki mandarin. Despite the advantages these two genotypes present, their production is being limited by diseases caused by fungi and estraminipilas. In citrus, all species of Phytophthora are responsible for diseases gummosis and fibrous root rot, especially. P. nicotianae is the kind that affects citrus plants in Brazil. Regardless of the great importance of P. nicotianae for rootstocks, some mechanisms of resistance or susceptibility still require further scientific investigation. This study aims to elucidate some mechanisms of resistance of citrus to P. nicotianae, through physiological and biochemical studies of rootstocks, beyond of action culture media and quality of light in the physiological study of this estraminipila. To this was carried out to detect certain equivalent of phenolic compounds by HPLC and genotype resistant behavior against the possible inhibition of the synthesis of phenolic compounds by treatment of the roots of Swingle rootstock with Pro-Ca; evaluated the zoospores attraction P. nicotianae by exudates from the two rootstocks using an adapted trap; it was the zoospore behavior, motility and zoosporogenesis to the action of various phenolic compounds and tested the action of different culture media and quality of light on mycelial growth and sporulation of P. nicotianae. The results for HPLC revealed that Sunki mandarin has larger amounts of apigenin equivalents Swingle citrumelo in that the two periods. The sturdy rootstock had more chlorogenic acid equivalents of the susceptible genotype. As for the Pro-Ca equivalent of phenolic compounds in Swingle seedling roots not differ from those plants treated with water. The Pro-Ca not inhibited and not disabled the synthesis of phenolic compounds. The use of the antibody against elicitin \"α-plurivorin\" had intermediate results in water consumption by Sunki mandarin seedlings and zoosporicide activity of phenolic compounds showed variable results in the behavior of zoospore motility. The scopoletin and tricetinpentametoxi phenolic compounds managed to paralyze the motility and provided the smallest percentages of zoosporogenesis. The culture medium AA allowed greater DMGR, followed by CA and V8-CaCO3-Agar. The highest sporulation values were found in the last two media, respectively. All lights tracks (and the absence of light) studied in this work can be evaluated for mycelial growth, but the treatment light was that more induced sporulation of zoospores of P. nicotianae.

Establishing plant communities is essential for the restoration of contaminated land. As potential cover materials, fly ash and sewage sludge can prevent formation of acid mine drainage from sulfidic mine waste. The aim of the thesis was to i) screen for plants that can be established in, and prevent leakage of metals and nutrients from sludge on top of ash and tailings, and ii) investigate root growth into sealing layers of ash and sludge. Analyses were performed under laboratory, greenhouse and field conditions using selected plant species to examine the release of Cd, Cu, Zn, N, and P from the materials. Plant physiological responses and interactions with fly ash were also investigated. The data show that plants can decrease metal and nutrient leakage from the materials, and lower the elemental levels in the leachate, but with varying efficiencies among plant species. Plants capable of taking up both nitrate and ammonium were more efficient in preventing N leakage compared with those taking up primarily ammonium. Fast growing plants could raise the pH in acidic sludge leachate, but the initial pH decrease and N leakage was not counteracted by plants. Germination in fresh sludge was problematic, but enhanced by aeration of the sludge. In general, the accumulation of metals in plant shoots was low, especially if ash was located below the sludge. Fresh ash was phytotoxic (e.g., high alkalinity, salinity and metal levels) and induced the activity of stress-related enzymes in shoots. In sealing layers of aged and cured ash, roots could grow if the penetration resistance was low, or into the surface of stronger layers if the surface had become pulverized. The roots caused dissolution of calcium-rich minerals, possibly by exudation of saccharides. Addition of sludge to an ash layer increased root growth, likely due to decreased bulk density and pH, and nutrient addition. In conclusion, with selected plant species and a properly constructed cover, metal and nutrient leaching from the materials and root growth into the sealing layer can be restricted.

A citricultura brasileira apresenta números bastante significativos e expressivos, refletindo a grande importância social e econômica que essa atividade agrícola e industrial tem para a economia do país. O Brasil se destaca como o maior produtor de laranja do mundo. As plantas cítricas podem ser produzidas e multiplicadas de várias formas e a enxertia é a forma de propagação vegetativa mais utilizada comercialmente no Brasil. Dentre os porta-enxertos mais empregados, sobressaem-se o citrumeleiro Swingle e a tangerineira Sunki. Apesar das vantagens presentes nesses dois genótipos, a produção deles está sendo limitada por doenças causadas por fungos e estraminipilas. Em citros, as diversas espécies de Phytophthora são responsáveis pelas doenças gomose e podridões, principalmente de radicelas. P. nicotianae é a espécie que mais afeta as plantas cítricas no Brasil. Não obstante a grande importância de P. nicotianae para os porta-enxertos, alguns mecanismos de resistência ou susceptibilidade ainda requerem mais investigações cientificas. O presente trabalho visa a elucidação de alguns mecanismos de resistência dos citros a P. nicotianae, por meio de estudos fisiológicos e bioquímicos dos porta-enxertos, além da ação de meios de cultura e da qualidade da luz no estudo da fisiologia desse estraminipila. Para isso realizou-se a detecção de alguns equivalentes de compostos fenólicos através da técnica HPLC e o comportamento do genótipo resistente frente à possível inibição da síntese de compostos fenólicos através do tratamento das raízes do porta-enxerto Swingle com Pro-Ca; avaliou-se a atração de zoósporos de P. nicotianae por exsudatos radiculares provenientes dos dois porta-enxertos com o uso de uma armadilha adaptada; verificou-se o comportamento do zoósporo, a motilidade e a zoosporogênese frente à ação de vários compostos fenólicos e testou-se a ação de diferentes meios de culturas e da qualidade da luz no crescimento micelial e na esporulação de P. nicotianae. Os resultados revelaram que a tangerineira Sunki possui maiores quantidades de equivalentes em apigenina que o citrumeleiro Swingle nos dois períodos de avaliação, para o HPLC. O porta-enxerto resistente apresentou mais equivalentes de ácido clorogênico que o genótipo susceptível. Quanto ao Pro-Ca, os equivalentes de compostos fenólicos em raízes de plântulas do citrumeleiro Swingle não diferiram daquelas plantas tratadas com água. O Pro-Ca não inibiu e não desativou a síntese de compostos fenólicos. O uso do anticorpo contra a elicitina \"α-plurivorina\" teve resultados intermediários no consumo de água por plântulas de tangerineira Sunki e a atividade zoosporicida dos compostos fenólicos apresentou resultados variáveis no comportamento da motilidade de zoósporos. Os compostos fenólicos escopoletina e tricetinpentametoxi conseguiram paralisar a motilidade e proporcionaram as menores porcentagens de zoosporogênese. O meio de cultura AA permitiu a maior TCMD, seguido de CA e V8-CaCO3-Ágar. Os maiores valores de esporulação foram encontrados nesses dois últimos meios, respectivamente. Todas as faixas de luzes (e a ausência de luz) estudadas no presente trabalho podem ser avaliadas para o crescimento micelial, porém o tratamento claro foi aquele que mais induziu a esporulação de zoósporos de P. nicotianae. / The Brazilian citrus industry has very significant and expressive numbers, reflecting the great social and economic importance of this industrial and agricultural activity has for the economy. Brazil stands out as the world\'s largest orange producer. Citrus plants can be produced and multiplied in various ways and the bud is the form of vegetative propagation more commercially used in Brazil. Among the most commonly used rootstocks, stand up the Swingle citrumelo and Sunki mandarin. Despite the advantages these two genotypes present, their production is being limited by diseases caused by fungi and estraminipilas. In citrus, all species of Phytophthora are responsible for diseases gummosis and fibrous root rot, especially. P. nicotianae is the kind that affects citrus plants in Brazil. Regardless of the great importance of P. nicotianae for rootstocks, some mechanisms of resistance or susceptibility still require further scientific investigation. This study aims to elucidate some mechanisms of resistance of citrus to P. nicotianae, through physiological and biochemical studies of rootstocks, beyond of action culture media and quality of light in the physiological study of this estraminipila. To this was carried out to detect certain equivalent of phenolic compounds by HPLC and genotype resistant behavior against the possible inhibition of the synthesis of phenolic compounds by treatment of the roots of Swingle rootstock with Pro-Ca; evaluated the zoospores attraction P. nicotianae by exudates from the two rootstocks using an adapted trap; it was the zoospore behavior, motility and zoosporogenesis to the action of various phenolic compounds and tested the action of different culture media and quality of light on mycelial growth and sporulation of P. nicotianae. The results for HPLC revealed that Sunki mandarin has larger amounts of apigenin equivalents Swingle citrumelo in that the two periods. The sturdy rootstock had more chlorogenic acid equivalents of the susceptible genotype. As for the Pro-Ca equivalent of phenolic compounds in Swingle seedling roots not differ from those plants treated with water. The Pro-Ca not inhibited and not disabled the synthesis of phenolic compounds. The use of the antibody against elicitin \"α-plurivorin\" had intermediate results in water consumption by Sunki mandarin seedlings and zoosporicide activity of phenolic compounds showed variable results in the behavior of zoospore motility. The scopoletin and tricetinpentametoxi phenolic compounds managed to paralyze the motility and provided the smallest percentages of zoosporogenesis. The culture medium AA allowed greater DMGR, followed by CA and V8-CaCO3-Agar. The highest sporulation values were found in the last two media, respectively. All lights tracks (and the absence of light) studied in this work can be evaluated for mycelial growth, but the treatment light was that more induced sporulation of zoospores of P. nicotianae.