Adenosine triphosphate (ATP) is well recognized for its role as the primary cellular energy currency. However, studies dating back to 1929 have reshaped our understanding of ATP as not only an energy source, but also as a signaling agent. Among the most important of these discoveries are animal purinergic receptors (P2X and P2Y receptors) that perceive extracellular ATP (eATP), primarily in the nervous system. Though eATP is an established receptor agonist in animals and applied poorly hydrolyzable ATP analogs have numerous effects on growth in plants, eATP is not widely accepted as a signal in plants where no purinoceptor has been identified. Here, enriched outside-out plasma membrane vesicles were isolated and proteins labeled with a radioactive ATP analog (8N₃ATP[α²³P]) to identify a putative purinoceptor-like receptor. We used etiolated seedlings to capture proteins from plant tissue that was actively growing and used sodium carbonate washes to separate peripheral and integral membrane proteins. With this method, we have generated lists of plasma membrane ATP binding proteins, and therefore possible eATP receptors. Ectoapyrases are phosphohydrolases thought to regulate eATP in both animals and plants. Here, we also investigated the expression and role of the candidate ectoapyrases AtAPY1 and AtAPY2 in guard cells and stomatal responses. AtAPY1 and AtAPY2 transcript and protein expression was confirmed in guard cells. Early genetic studies using an apy2 knock out with induced RNAi-silencing of APY1 suggest a role for these apyrases in stomatal regulation. In response to treatment with five hours light, the apyrase-suppressed line features wider stomatal aperture when compared to WS wild-type. / text

Research was conducted to determine individual suitability of native and Canadian-bred selected plants in terms of growth and survivability for local extensive green roofs. The experiment was single-factor (species) with 12 levels (two Sedum spp. [controls]; 10 Canadian-bred or native plant species) in a randomized complete block design with three blocks. Variables measured were percent survival and cover, height, fresh and dry weights, stomatal conductance, transpiration, photosynthetic rate, soil temperature, soil moisture, and reflectance. Artemisia stelleriana contributed more to cooling through transpiration than Sedum floriferum, and maintained similar soil moisture to Sedum acre. Lotus corniculatus was similar to the controls in photosynthetic rate and had higher reflectance than Sedum acre in July. With high biomass and photosynthetic rates, Aster novi-belgii may contribute more to carbon sequestration and insulation than the controls. Artemisia stelleriana , Lotus corniculatus, and Aster novi-belgii are suitable species for extensive green roofs in northern Nova Scotia.

主催：JST/CREST，Vrije University, ALTERRA, IBPC

No description available.

Thesis (Ph. D.)--Miami University, Dept. of Botany, 2008. / Title from second page of PDF document. Includes bibliographical references (p. 115-131).

This thesis presents a new calibration of the Ginkgo stomatal index as a proxy for atmospheric CO2 concentrations using leaves from modern Ginkgo biloba herbarium specimens. Scanning electron images were obtained to count stomates and cells on leaves collected between 1829 and 2015. Average stomatal index (SI) was then calculated for each year. SI is defined as #stomates/(#stomates + # epidermal cells)*100. The relationship between stomatal index and atmospheric CO2 can be expressed in an equation following the form recommended by Wynn (2003), as the most likely representation of the physical laws governing CO2 diffusion across stomates. The new fitted equation for determining CO2 from Ginkgo SI is: CO2=205.7+13,630,000 x SI^(-5.224). This new equation is applied to suitably preserved Cenozoic fossil leaves of Ginkgo and results in a downward revision of estimated CO2 levels, while preserving the general shape of greenhouse spikes in the middle Miocene and Eocene. These spikes correlate to climatic warm and wet spikes derived from paleosol evidence during those times. / 10000-01-01

Stomatal conductance and mesophyll conductance for CO2 transport are two key components of diffusive limitations of photosynthesis, since they restrict CO2 flux from the leaf surface to the sub-stomatal cavity and from there to the sites of carboxylation. This thesis summarizes our findings in the field of nature of mesophyll conductance to CO2 transport and its regulation per se and in respect to stomatal conductance.

L'efficience intrinsèque d'utilisation de l'eau (Wi) définit comme le rapport de l'assimilation nette de CO2 (A) sur la conductance stomatique à la vapeur d'eau (gs) est un estimateur au niveau foliaire du compromis fait par la plante entre l'accumulation de biomasse et sa consommation en eau. De nombreuses études ont révélé une forte diversité inter et intra-spécifique de ce trait intégré dans le temps dont l'origine est encore mal connue. Les travaux réalisés sur les variations journalières de A et gs ont jusqu'à maintenant révélé un rôle plus important de la diversité de gs dans la diversité de Wi. Une approche de modélisation inversée a permis de décomposer les variations de gs, observées lors de cinétiques journalières, sous la forme de paramètres décrivant les réponses stomatiques aux différentes variables microclimatiques. Comparé aux modèles décrivant les variations de gs en régime permanent, le développement d'un nouveau modèle dynamique a permis d'ajouter une dimension temporelle essentielle décrivant la réponse temporelle des stomates aux variations microclimatiques. La diversité des réponses temporelles des stomates détectée ne semble pas dépendre de leur densité ou de leur taille. Elle présente toutefois une asymétrie entre l'ouverture et la fermeture des stomates qui participe à la diversité des variations journalières de gs et impacte le bilan hydrique journalier au niveau du plant entier. Ainsi, on peut distinguer deux composantes aux variations journalières de Wi liées à gs : une composante temporelle due à la lente réponse des stomates et une autre composante due aux différences de perception des variations du microclimat / Intrinsic water use efficiency (Wi), defined as the ratio between net CO2 assimilation rate (A) and stomatal conductance to water vapour (gs), is a leaf level estimator of the trade-off between biomass accumulation and water loss at the plant level. A number of studies have shown a strong inter and intra-specific diversity, usually using a time integrated estimator of this trait. However, the origin of this diversity is not yet well known. Up to now, research on the daily variations of Wi have shown a stronger influence of gs on the diversity of Wi as compared to A. An inverse modelling approach has allowed partitioning the variations of gs observed during daily time-courses into parameters, which describe the stomatal responses to different microclimatic variables. Compared to steady-state gs models, the development of a new dynamic model of gs has allowed adding a necessary temporal dimension, which describes the temporal response of stomata to environmental variations. The observed diversity of these temporal stomatal responses was not related to stomatal density or size. The temporal responses of stomata were shown to be asymmetric between opening and closing, which impacts the observed diversity of gs during daily time courses as well as whole plant water relations. Overall these results suggest two components that determine the variations of Wi related to gs during daily time courses: one component due to the temporal response of stomata in itself, and one component which is due to differences in the sensing of microclimate variations

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21805号 / 農博第2318号 / 新制||農||1065(附属図書館) / 学位論文||H31||N5177(農学部図書室) / 京都大学大学院農学研究科農学専攻 / (主査)教授 白岩 立彦, 教授 奥本 裕, 教授 稲村 達也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第13321号 / 論理博第1568号 / 新制||理||1663(附属図書館) / 名古屋大学大学院生命農学研究科 / (主査)教授 石田 厚, 教授 田村 実, 教授 永益 英敏 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DFAM