Wong Lee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 152-169). / Abstracts in English and Chinese. / Thesis Committee --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Acknowledgements --- p.v / Abbreviations --- p.vi / List of Figures --- p.vii / List of Tables --- p.ix / Table of Contents --- p.xi / Chapter 1 --- Literature Review --- p.1 / Chapter 1.1 --- GS-GOGAT cycle in plants and bacteria --- p.2 / Chapter 1.2 --- Roles of PII in regulation of glutamine synthetase in E. coli --- p.4 / Chapter 1.2.1 --- Regulation of GS in E. col --- p.4 / Chapter 1.2.2 --- Transcriptional regulation --- p.5 / Chapter 1.2.2.1 --- The glnALG operon / Chapter 1.2.2.2 --- Intracellular signal through PII and Utase-UR / Chapter 1.2.2.3 --- NRI/NRII as two-component system / Chapter 1.2.3 --- Post-translational regulation by adenylylation and deadenylylation --- p.11 / Chapter 1.2.3.1 --- Role of PII in adenylylation/deadenylylation / Chapter 1.2.4 --- Cumulative Feedback Inhibition --- p.15 / Chapter 1.3 --- PII in other bacteria --- p.15 / Chapter 1.4 --- PII in other higher organisms --- p.20 / Chapter 1.5 --- "PII protein is conserved in enteric bacteria, cyanobacteria, archaea, algae and higher plants" --- p.23 / Chapter 1.6 --- Nitrogen assimilation in higher plants --- p.25 / Chapter 1.6.1 --- Nitrogen uptake --- p.25 / Chapter 1.6.2 --- Primary nitrogen assimilation --- p.28 / Chapter 1.6.3 --- Nitrogen transport and interconversions --- p.28 / Chapter 1.6.4 --- Nitrogen flow --- p.29 / Chapter 1.6.5 --- Molecular regulation of nitrogen assimilation and possible roles of PII in plants --- p.30 / Chapter 1.7 --- Hypothesis of this study --- p.33 / Chapter 2. --- Materials and Methods --- p.35 / Chapter 2.1 --- Materials --- p.35 / Chapter 2.1.1 --- Plant materials --- p.35 / Chapter 2.1.2 --- Equipment and facilities used --- p.35 / Chapter 2.1.3 --- Growth media --- p.37 / Chapter 2.1.4 --- Buffers and solutions used in RNA extraction --- p.38 / Chapter 2.1.5 --- Buffers and solutions used in Northern blot analysis --- p.41 / Chapter 2.1.6 --- Molecular reagents and synthetic oligonucleotides used in the preparation of DIG-labeled probes --- p.45 / Chapter 2.1.7 --- Chemicals used in BioRad Protein Assay --- p.48 / Chapter 2.1.8 --- Chemicals and apparatus used in chlorophylls extraction and quantitation --- p.49 / Chapter 2.1.9 --- Buffers and solutions used in the glutamine synthetase enzyme extraction and assay --- p.49 / Chapter 2.2 --- Methods --- p.50 / Chapter 2.2.1 --- Plant growth --- p.50 / Chapter 2.2.2 --- RNA extraction --- p.52 / Chapter 2.2.3 --- Northern blot analysis --- p.54 / Chapter 2.2.4 --- Chlorophyll extraction and quantitation --- p.61 / Chapter 2.2.5 --- Root length measurement --- p.61 / Chapter 2.2.6 --- Total glutamine synthetase enzyme assay --- p.61 / Chapter 2.2.7 --- Measurement of total nitrogen in seeds --- p.64 / Chapter 2.2.8 --- Recording growth and development --- p.64 / Chapter 3. --- Results --- p.65 / Chapter 3.1 --- Overexpression ofPII and truncated PII mRNA in transgenic plants --- p.65 / Chapter 3.2 --- General growth characteristics of PII transgenic plants when grown on soil --- p.70 / Chapter 3.3 --- Physiological changes in the PII and truncated PII transgenic lines --- p.72 / Chapter 3.3.1 --- Fresh weight of the young seedlings --- p.73 / Chapter 3.3.2 --- Chlorophyll contents of shoots --- p.75 / Chapter 3.3.3 --- Root lengths --- p.88 / Chapter 3.3.4 --- Carbon and nitrogen status of seeds --- p.94 / Chapter 3.4 --- Expression of nitrogen assimilatory genes in PII and truncated PII transgenic lines --- p.96 / Chapter 3.4.1 --- Nitrate reductases --- p.96 / Chapter 3.4.2 --- Glutamine synthetases --- p.99 / Chapter 3.4.3 --- Asparagine synthetases --- p.107 / Chapter 3.5 --- Total glutamine synthetase enzyme activity --- p.117 / Chapter 4. --- Discussion --- p.126 / Chapter 4.1 --- Overexpressing PII and truncated PII in the transgenic plants --- p.126 / Chapter 4.2 --- The overall growth and development --- p.135 / Chapter 4.3 --- Chlorophyll --- p.135 / Chapter 4.4 --- Root length --- p.137 / Chapter 4.5 --- Expression of nitrogen assimilatory genes --- p.138 / Chapter 4.5.1 --- Genes encoding nitrate reductase --- p.138 / Chapter 4.5.2 --- Genes encoding glutamine synthetase --- p.140 / Chapter 4.5.3 --- Genes encoding asparagine synthetase --- p.141 / Chapter 4.6 --- Overall GS enzyme levels in the rosette leaves --- p.144 / Chapter 4.7 --- N/C ratio of the seed storage --- p.146 / Chapter 4.8 --- Proposed model for the roles of PII --- p.147 / Chapter 4.9 --- Conclusions --- p.149 / Chapter 4.10 --- Further studies --- p.150 / References --- p.152

Abstract not available

Graduation date: 1995

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Title from PDF of title page (University of Missouri--Columbia, viewed on March 8, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Nicholas Kalaitzandonakes. Vita. Includes bibliographical references.

published_or_final_version / abstract / toc / Botany / Doctoral / Doctor of Philosophy

published_or_final_version / Botany / Master / Master of Philosophy

In this work we studied various aspects of DNA repair in plants, focusing mainly on point mutation repair and its interconnection with double-strand break repair. We were using transgenic point mutation and recombination substrates as a primary tool in our experiments. We have compared two transgenic homologous recombination assays (B-glucuronidase- and luciferase-based), analyzed the sensitivity of DNA repair machinery to ultraviolet radiation and assessed the involvement of AtKu80, Atm and AtXpd repair genes in point mutation repair. Ours study revealed the following: the luciferase-based recombination assay is more sensitive then B-glucuronidase-based; double-stand break repair machinery is sensitive to ultraviolet radiation, which results in increased pint mutation formation; chosen DNA repair genes might be impaired in point mutation repair, however further experimentations are needed to confirm this. / xi, 132 leaves : ill. ; 29 cm.

No description available.

Human protein C (HPC) is a vitamin-K dependent plasma glycoprotein which is one of the major components regulating anticoagulation. HPC injection is a promising therapy for several diseases but a heterologous production system would be preferred over purifying HPC from human plasma because of its low concentration (4-5 $ mu$g/ml). A cDNA clone coding for HPC was inserted downstream of the CaMV 35S promoter and of a dimer of the CaMV 35S promoter. Tobacco plants were transformed using Agrobacterium and a binary vector strategy. Kanamycin resistant plants were regenerated and enzyme linked immunosorbent assay determined that HPC, in crude plant extracts, accounted for up to 0.03% of plant soluble proteins. HPC was found to be expressed by R$ sb1$ seedlings suggesting successful integration of the T-DNA into plant genome. A partial protein purification system was developed in order to enrich the protein mixture for HPC. HPC was found to bind tightly at pH 6.0 to Fast Flow Q Sepharose resin.