The ability to accumulate uranium was tested on 20 different cultivars and GMOs of Nicotiana spp. grown in Hoagland's hydroponic medium indoors. Apart from the accumulation and translocation of uranium in plants, the effects of genetic modifications and adaptations of hydroponic medium on the ability of plants to accumulate uranium were tested. N. glauca, N. tabacum cv. M 51 and GMO M 51 Pro seemed to be the best plants for accumulation of uranium. Concentrations of uranium in these plants grown in medium with 0,5 mM of uranium were as high as 31.28 mg/g dry weight in roots and 0.21 mg/g in upper parts. N. tabacum cv. La Burley 21 and GMOs TRI2 - T1 and TRI2 - T2 were tested for accumulation and translocation of uranium. Highest concentration was 72.49 mg/g in roots, 4 mg/g in stems and 1.1 mg/g in highest leaves for plants cultivated in medium with 1 mM of uranium. Absence of phosphate in the hydroponic medium resulted in increased accumulation of uranium.

Unlike most other fruits that accumulate oil in seed tissues, avocado stores large amounts of oil in the form of triacylglycerol (TAG) in its mesocarp tissue. The regulation of TAG biosynthetic pathways in such nonseed tissues is poorly understood. RNA-Seq was used to identify the transcriptional networks underlying TAG biosynthesis in developing mesocarp of avocado. Deep transcriptional profiling studies revealed that several transcripts were differentially represented between the early and late developmental stages of mesocarp. The temporal expression pattern of transcripts associated with fatty acid biosynthesis in plastid coincided with increasing oil content. Furthermore, except for the transcripts that likely encode enzymes involved in the terminal step in TAG synthesis, others involved in TAG assembly in the endoplasmic reticulum were poorly expressed. This pattern of higher expression for genes involved in fatty acid synthesis but not TAG assembly was similar to previously observed pattern in other seed and nonseed tissues. Comparative analysis of transcript levels for about 1500 transcription factors, across different species and oil-storing tissues, also revealed that WRINKLED1 may be highly conserved across species but transcriptional regulation of oil biosynthesis, includes distinct tissue-specific features. In conclusion, while the biochemical pathways for oil biosynthesis in nonseed tissue are highly similar to that of seed tissues, certain distinctive modes of regulation of fatty acid biosynthesis and TAG assembly likely occur in oil-rich nonseed tissues.

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Philosophiae Doctor - PhD / This thesis investigates socio-spatial trajectories of class formation and processes of accumulation from below and above on redistributed farmland, the ‘New Qwaqwa Farms’ in the Eastern Free State province of South Africa, from the mid-1980s to 2016. Class formation trajectories of the studied land beneficiaries are traced across localised historical geographies and political contexts, from apartheid to the current democratic dispensation, that is, from the land beneficiaries’ recent ancestral history as labour tenants on white-owned farmland, and subsequent systematic expulsions from farmland, to their Bantustan labour reserve resuscitations as mainly nonagricultural petty commodity producers, and later targeting for land reform, as one measure of redistribution.

In response to DNA damage, mammalian cells activate various DNA repair pathways to remove DNA lesions and, meanwhile, halt cell cycle progressions to allow sufficient time for repair. The nucleotide excision repair (NER) and the ATR-dependent cell cycle checkpoint activation are two major cellular responses to DNA damage induced by UV irradiation. However, how these two processes are coordinated in the response is poorly understood. Here we showed that the essential NER factor XPA (xeroderma pigmentosum group A) underwent nuclear accumulation upon UV irradiation, and strikingly, such an event occurred in an ATR (Ataxia-Telangiectasia mutated and RAD3-related)-dependent manner. Either treatment of cells with ATR kinase inhibitors or transfection of cells with small interfering RNA targeting ATR compromised the UV-induced XPA nuclear translocation. Consistently, the ATR-deficient cells displayed no substantial XPA nuclear translocation while the translocation remained intact in ATM (Ataxia-Telangiectasia mutated)-deficient cells in response to UV irradiation. Moreover, we found that ATR is required for the UV-induced nuclear focus formation of XPA. Taken together, our results suggested that the ATR checkpoint pathway may modulate NER activity through the regulation of XPA redistribution in human cells upon UV irradiation.

Acid sulfate soils covers an area area about 600 km-2 along the coast line of Northern Sweden. These soils originate from land uplift and oxidized sulfide soils. The oxidation process releases sulfur and Fe(III) and will lower the pH-value and mobilize metals that will cause toxic environments for water living organisms. Concerns of how higher occurrence of extreme weather conditions will affect the mobilization of metals has occurred. Understanding of the mobilizations of metals in different catchment conditions is therefore important knowledge for preparation of risk analyzes to protect ecosystems from toxic effects. The aim of this study is to compare accumulation of metals in sediments from marine and limnic environments to investigate how lakes effects the mobilization of metals in catchments consisting of acid sulfate soil. Answering the questions of accumulation differences between the catchments and how organic matter affects the mobilization and accumulation of metals. Sediment cores were collected in two different catchment areas, known to be affected by acid sulfate soils, in Västerbotten county. 22 different elements were analyzed by x-ray fluorescence spectroscopy and Loss-on-ignition (LOI) was used as a proxy for organic matter. The results indicate that draining of land areas, often due to agriculture and deforestation, increases mobilization and accumulation of metals correlated with both organic and lithogenic fractions to a large extent. However, elements such as S, Ni, Zn, Fe, Cu, Na, Mg, Al, Rb, Sr and Zr are derived from mobilization from acid sulfate soils where elements with high correlation with organic matter accumulates in limnic environment conditions.

To study the effect of NaCl stress on gene expression in alfalfa (Medicago sativa L.), greenhouse and laboratory experiments were conducted with 22 cultivars during germination and post-germination growth. The ability of alfalfa cultivars to germinate at the different NaCl concentrations was not related to their postgermination performance (salt tolerance) under those conditions. Genetic effects were evident for Na and Cl ion uptake and accumulation in alfalfa shoots and roots. The strategies of alfalfa cultivars to cope with NaCl stress includes exclusion of Na from shoots and Cl from roots or from the whole plant depending on cultivar and NaCl level. The reduction in shoot dry weight was not related to water stress or reduction in Ca, Mg, or chlorophyll concentrations. Results of this study indicated that the reduction in K ion uptake and more directly the toxic effects of high Na and Cl in plant tissues contributed to the reduction in shoot dry weight . The possible subpartitioning of Na and Cl ions between different tissues, cell types, cell components, and/or the different changes in protein structure and enzyme activity at the high Na and Cl concentrations, independent of total concentration of ions, might also contribute to differences in salt tolerance (shoot dry weight) among cultivars. The factors determining shoot dry weight in alfalfa grown under the different NaCl treatments of this study were not the same for all cultivars. Sodium chloride stress induced qualitative and quantitative changes in shoot and root proteins of alfalfa. These changes were dependent on cultivar and salt concentration, as well as length of exposure to salt stress.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20007号 / 農博第2191号 / 新制||農||1045(附属図書館) / 学位論文||H28||N5016(農学部図書室) / 33103 / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 本田 与一, 教授 髙部 圭司, 准教授 坂本 正弘 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20956号 / 理博第4408号 / 新制||理||1633(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)准教授 渡辺 勝敏, 教授 曽田 貞滋, 教授 中川 尚史 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM