Plants absorb CO2 through pores in their leaves called stomata, which are known to open and close in response to myriad environmental and physiological triggers. We demonstrate that blue light inhibits stomatal aperture oscillations in both the guard cells and surrounding tissue layers, whereas these oscillations continue under the influence of red light. This observation of blue light behavior agrees with recent research and suggests another physiological pathway for oscillations.

This project investigated the physiological responses of grapevine to deficit irrigation strategies including partial rootzone drying (PRD) and regulated deficit irrigation (RDI). The principle objectives of the project were to (1) establish if the response to partial rootzone drying (PRD) is as a consequence of irrigation amount or a unique vine physiological response to PRD; (2) to investigate the effect of limiting environmental conditions on vine responses to PRD and deficit irrigation; (3) to investigate the effect of PRD and deficit irrigation on berry metabolism and maturation; and (4) effect of PRD and deficit irrigation on vine water-use. The experiment used field-grown Shiraz grapevines in a commercial vineyard in the Strathbogie Ranges in north-eastern Victoria. The experiment ran from season 2001/2002 through to 2003/2004 in a medium vigour, warm climate vineyard, with soils of low water holding capacity. (For complete abstract open document)

Thesis (Ph.D.)--University of Melbourne, Agriculture and Food Systems,Faculty of Land and Food Resources, 2006. / Typescript. Includes bibliographical references.

Thesis--Catholic University of America. / Bibliography: p. 30-32.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (Ph. D.)--Ohio State University, 2007. / Full text release at OhioLINK's ETD Center delayed at author's request

Células estomáticas e reações metabólicas de plantas foram modelados por meio da teoria dos grafos neste trabalho; a distância entre estômatos vizinhos na folha foi adotada como parâmetro utilizado para a conectividade em redes onde os estômatos foram definidos como nodos. A direção da formação de produtos e substratos em reações metabólicas determinou a conectividade nas redes metabólicas, onde cada metabólito foi definido como um nodo. As redes de estômatos foram capazes de gerar uma grande quantidade de informação geométrica associada à distância entre os estômatos. Estas medidas se mostraram uma poderosa ferramenta para avaliar a plasticidade fenotípica em folhas de plantas. A adaptação de plantas a condições ambientais extremas, como altas taxas de umidade e grandes variações no tempo de exposição à luz, puderam ser quantificadas por parâmetros de redes. Parâmetros topológicos globais das redes metabólicas mostraram que elas possuem propriedades estatísticas e topológicas de redes livre escala, como nos seres vivos em geral. Entretanto, alguns parâmetros topológicos locais das redes como a medida hub-score, geram vetores de características que, se comparados entre plantas, geram informação filogenética. Além disso, nós comprovamos que é possível construir modelos que sugerem uma organização geral para o metabolismo, por meio de algorítmos de conectividade hierárquica. O algorítmo de k-cores foi usado para gerar camadas de conectividade nas redes metabólicas. A atribuição química dos metabólitos ao longo das camadas k-core, mostra que a hierarquia de conexões está associada a especialização do metabolismo. Isto sugere que o algorítimo também gera informação sobre a evolução da maquinaria metabólica. Portanto, o modelo para conectar elementos de uma rede metabólica adotado neste trabalho, traz informações naturais sobre as plantas, o que sugere que exista parâmetros físicos das reações metabólicas representados pelo modelo. / Stomatic cells and metabolic reactions were modeled by graph theory in this work. The distance between stomata was adopted as connectivity parameter in the networks where stomata were defined as nodes. The direction of formation from products and substrates in the metabolic reactions, determined the connectivity from the metabolic networks, where each metabolite was defined as a node. The networks of stomata were able to generate a large amount of geometric information based at distance between the stomata. These measures represented a powerful tool to evaluate the phenotypic plasticity in leaves of plants. Global topological parameters from plant the metabolic networks revealed that plant metabolic networks has the topology of free scale networks, as in living beings in general. However, some local topological parameters of the networks such as the hub-score, can be organized as characteristic vectors with differential phylogenetic information. In addition, we have shown that it is possible to construct models that suggest a general organization for the metabolism through algorithms with iterative percolation from network connectivity. The k-cores algorithm was used to generate layers of connectivity in the metabolic networks. The chemical assignment of the metabolites along the k-core layers shows that the hierarchy of connections is associated with specialization of metabolism. This suggests that the algorithm also generates information about the evolution of the metabolic machinery. Therefore, the model used to connect elements of the metabolic networks adopted in this work, brings natural information about the plants, which suggests that there are physical parameters of the metabolic reactions represented by the model.

The services that urban trees provide to human society and the natural environment are widely recognized, but urban trees are in jeopardy due to climate change and urban stressors. With drought as a major threat in many areas, it is important for the future of urban forestry to select species composition based upon performance under water stress. Certain leaf functional traits can help horticulturalists more accurately predict water usage of urban trees. Comprehension through rigorous experimentation is lacking, partly due to the thousands of mostly exotic species. Previous studies suggest that species whose leaves have a denser arrangement of smaller stomata and a higher leaf mass per area (LMA) are better adapted to low water availability. We sampled 70 urban tree species California and analyzed their stomatal length, stomatal density, and LMA. We compared the traits with water use data from the Water Use Classification of Landscape Species to assess possible correlations. All pairwise trait comparisons show significant correlation (P < 0.05), and LMA is significantly higher in low water use species compared to medium water use species (P= 0.0045). After using independent contrasts to incorporate phylogenetic relationships, significance was lost, implying that basal divergences are responsible for observed trends. Other potential explanations for differences in species water usage are foliar longevity (deciduous vs. evergreen) and stomatal distribution (amphistomatous vs. hypostomatous). Low water use species are more likely to be evergreen and amphistomatous compared to medium water use species. Consideration of all these traits in combination with good management practices can help ensure future success of urban forests.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20213号 / 理博第4298号 / 新制||理||1617(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)講師 嶋田 知生, 教授 長谷 あきら, 教授 鹿内 利治 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

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