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Manipulation of nitrogen sink-source relationship in plants.

Chiao Ying Ann. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 127-140). / Abstracts in English and Chinese. / Thesis Committee --- p.I / Statement --- p.II / Abstract --- p.III / 摘要 --- p.V / Acknowledgements --- p.VII / Abbreviations --- p.IX / Abbreviation of chemicals --- p.XI / Table of Contents --- p.XII / List of figures and tables --- p.XVIII / Chapter Chapter 1. --- Literature review / Chapter 1.1 --- Significances of manipulation of nitrogen sink-source relationship --- p.1 / Chapter 1.2 --- Nitrogen sink-source relationship in plants --- p.2 / Chapter 1.3 --- Aspartate family amino acid metabolism --- p.5 / Chapter 1.3.1 --- Asparagine metabolism --- p.9 / Chapter 1.3.1.1 --- "Asparagine synthetase (AS, EC 6.3.5.4)" --- p.9 / Chapter 1.3.1.2 --- "Asparaginase (ANS, EC 3.5.1.1)" --- p.10 / Chapter 1.3.2 --- Metabolism of aspartate-derived essential amino acids --- p.10 / Chapter 1.3.2.1 --- "Aspartate kinase (AK, EC 2.7.2.4)" --- p.10 / Chapter 1.3.2.2 --- "Homoserine dehydrogenase (HSD, EC 1.1.1.3)" --- p.12 / Chapter 1.3.2.3 --- "Dihydrodipicolinate synthase (DHPS, EC 4.2.1.52)" --- p.13 / Chapter 1.3.2.4 --- "Lysine a-ketoglutarate reductase (LKR, EC 1.5.1.7)" --- p.14 / Chapter 1.3.2.5 --- "Threonine synthase (TS, EC 4.2.3.1)" --- p.15 / Chapter 1.3.2.6 --- Cystathionine γ-synthase (CGS,EC 2.5.1.48) --- p.16 / Chapter 1.3.2.7 --- Threonine deaminase (TD,EC 4.3.1.19) --- p.17 / Chapter 1.4 --- Previous attempts to manipulate seed protein quantity and quality --- p.18 / Chapter 1.4.1 --- Enhancement of amino acids transported from source to sink --- p.18 / Chapter 1.4.2 --- Redirection of metabolic pathways to increase target amino acids --- p.19 / Chapter 1.4.2.1 --- Production of aspartate by Aspartate Aminotransferase (AAT) --- p.24 / Chapter 1.4.2.2 --- Deregulation of AK to increase the common substrate for all essential aspartate family amino acids --- p.25 / Chapter 1.4.2.3 --- Inhibition of TS and enhancement of CGS to increase Met biosynthesis --- p.25 / Chapter 1.4.2.3.1 --- Inhibition of TS --- p.26 / Chapter 1.4.2.3.2 --- Enhancement of CGS --- p.26 / Chapter 1.4.2.4 --- Deregulation of DHPS and reduction of lysine catabolism to increase lysine content --- p.27 / Chapter 1.4.2.4.1 --- Deregulation of DHPS --- p.28 / Chapter 1.4.2.4.2 --- Reduction of Lys catabolism --- p.29 / Chapter 1.4.2.3.3 --- Deregulation of DHPS and reduction of LKR --- p.29 / Chapter 1.4.3 --- Expression of seed storage proteins to entrap the free amino acids --- p.30 / Chapter 1.5 --- Expression of multiple transgenes in plants --- p.34 / Chapter 1.5.1 --- Significance of multiple genes manipulation in seed quality improvement --- p.34 / Chapter 1.5.2 --- Difficulties in introduction of multiple genes into plant genomes --- p.34 / Chapter 1.5.3 --- Recent advances in introduction of multiple genes into plant genome --- p.35 / Chapter 1.6 --- Global nitrogen regulators in plants --- p.36 / Chapter 1.6.1 --- Global regulation of nitrogen metabolism --- p.36 / Chapter 1.6.2 --- General amino acid control by GCN system --- p.38 / Chapter 1.6.3 --- General amino acid control in plants --- p.39 / Chapter 1.6.4 --- GCN system in plants --- p.41 / Chapter 1.7 --- Hypothesis and specific objectives of this study --- p.42 / Chapter Chapter 2 --- Materials and methods --- p.46 / Chapter 2.1 --- Materials --- p.46 / Chapter 2.1.1 --- "Vectors, bacterial strains and plants" --- p.46 / Chapter 2.1.2 --- Chemicals and reagents used --- p.49 / Chapter 2.1.3 --- "Buffer, solution, gel and medium" --- p.49 / Chapter 2.1.4 --- Commercial kits used --- p.49 / Chapter 2.1.5 --- Equipments and facilities used --- p.49 / Chapter 2.2 --- Methods --- p.50 / Chapter 2.2.1 --- Molecular techniques --- p.50 / Chapter 2.2.1.1 --- DNA gel electrophoresis --- p.59 / Chapter 2.2.1.2 --- PCR technique --- p.50 / Chapter 2.2.1.3 --- Restriction digestion --- p.50 / Chapter 2.2.1.4 --- Ligation (for sticky-end ligation) --- p.51 / Chapter 2.2.1.5 --- DNA purification --- p.51 / Chapter 2.2.1.6 --- DNA sequencing --- p.51 / Chapter 2.2.1.7 --- Transformation of competent E. coli cells --- p.52 / Chapter 2.2.1.8 --- Preparation of plasmid from bacterial cells --- p.53 / Chapter 2.2.1.9 --- Transformation of competent Agrobacterium tumefaciens cells --- p.53 / Chapter 2.2.1.10 --- DNA extraction from plant tissue (Small-scale) --- p.54 / Chapter 2.2.1.11 --- RNA extraction from plant tissue --- p.55 / Chapter 2.2.2 --- Growth conditions of A. thaliana --- p.55 / Chapter 2.2.2.1 --- Surface sterilization of A. thaliana seeds --- p.55 / Chapter 2.2.2.2 --- Growing A. thaliana --- p.55 / Chapter 2.2.3 --- Characterization of transgenic A. thaliana with altered sink-source relationship --- p.57 / Chapter 2.2.3.1. --- Determination of amino acid contents in seeds --- p.57 / Chapter 2.2.3.2. --- Expression study of developing siliques of transgenic lines --- p.58 / Chapter 2.2.3.2.1 --- Tagging siliques of different developmental stages --- p.58 / Chapter 2.2.3.2.2 --- Extraction of silique RNA --- p.58 / Chapter 2.2.3.2.3 --- cDNA synthesis --- p.58 / Chapter 2.2.3.2.4 --- Real-time PCR --- p.59 / Chapter 2.2.4 --- Characterization of transgenic A. thaliana overexpressing GCN2 --- p.60 / Chapter 2.2.4.1 --- Gene expression study of vegetative tissues by real-time PCR --- p.60 / Chapter 2.2.4.2 --- Gene expression study of developing siliques by real-time PCR --- p.61 / Chapter 2.2.5 --- Making transgenic A. thaliana --- p.61 / Chapter 2.2.5.1 --- Cloning of multigene construct --- p.61 / Chapter 2.2.5.1.1 --- Subcloning of target genes into donor vectors --- p.61 / Chapter 2.2.5.1.1.1 --- Cloning of LRP into donor vector VS --- p.61 / Chapter 2.2.5.1.1.2 --- Cloning of dapA into donor vector SV --- p.64 / Chapter 2.2.5.1.1.3 --- Cloning of ansB into donor vector VS --- p.67 / Chapter 2.2.5.1.1.4 --- Cloning of antisense LKR fragment into donor vector SV --- p.70 / Chapter 2.2.5.1.2 --- Preparation of phosphorylated linkers --- p.73 / Chapter 2.2.5.1.3 --- Introduction of target genes to acceptor vector --- p.73 / Chapter 2.2.5.2 --- Agrobacterium-mediated transformation of A. thaliana via Vacuum infiltration --- p.78 / Chapter 2.2.5.3 --- Screening of transformants --- p.79 / Chapter Chapter 3. --- Results --- p.80 / Chapter 3.1 --- Characterization of transgenic lines with altered sink-source relationship --- p.80 / Chapter 3.1.1 --- Amino acid analysis of mature seeds of transgenic lines --- p.80 / Chapter 3.1.1.1 --- Aspartate family amino acids levels remain steady in seeds of transgenic plants --- p.83 / Chapter 3.1.1.2 --- Increase in seed Met content in Met-rich protein expressing transgenic plants --- p.85 / Chapter 3.1.1.3 --- Increase in seed Lys content in phas-dapA/phas-LRP transgenic plants --- p.87 / Chapter 3.1.2 --- Gene expression study of transgenic line --- p.89 / Chapter 3.1.2.1 --- Down-regulation of akthr1 and akthr2 in transgenic plants with altered N sink-source relationship --- p.89 / Chapter 3.1.2.2 --- Down regulation of GCN2 in transgenic plants with altered N sink-source relationship --- p.90 / Chapter 3.1.2.4 --- Expression study of other genes in aspartate family pathway --- p.90 / Chapter 3.2 --- Characterization of GCN2 overexpressing line --- p.93 / Chapter 3.2.1 --- Gene expression study of seedlings of GCN2 overexpressing plants --- p.93 / Chapter 3.2.1.1 --- Increased GCN2 expression by azaserine treatment --- p.93 / Chapter 3.2.1.2 --- Increased akthrl and akthr2 expression in GCN2 overexpressing plants --- p.96 / Chapter 3.2.1.3 --- Expression study of other genes in aspartate family pathway --- p.96 / Chapter 3.2.2 --- Gene expression study of GCN2 overexpressing plants during seed development --- p.98 / Chapter 3.3 --- Construction of transgenic plants by multigene assembly system --- p.100 / Chapter 3.3.1 --- Successful construction of recombinant plasmid carrying four target genes --- p.100 / Chapter 3.3.2 --- Transformation of A. thaliana with multigene vector --- p.103 / Chapter Chapter 4 --- Discussion --- p.104 / Chapter 4.1 --- Characterization of transgenic plants with altered sink-source relationship of aspartate family amino acid metabolism --- p.104 / Chapter 4.1.1 --- Total content of aspartate family amino acids remains steady in transgenic lines --- p.105 / Chapter 4.1.2 --- Methionine content increases in phas-PN2S and phas-MetL transgenic plants --- p.106 / Chapter 4.1.3 --- Relative lysine content increases in phas-dapA/phas-LRP transgenic plants --- p.107 / Chapter 4.1.4 --- Coordinated regulation of gene expressions of akthrl and akthr2 with GCN2 expression in transgenic plants with altered sink-source relationship --- p.109 / Chapter 4.2 --- GCN system in plants --- p.110 / Chapter 4.2.1 --- Transcriptional regulation of GCN2 in A. thaliana --- p.110 / Chapter 4.2.2 --- Regulation of amino acid biosynthesis by GCN system --- p.111 / Chapter 4.2.2.1 --- Regulation of akthrl and akthr2 by GCN2 --- p.111 / Chapter 4.2.2.2 --- GCN4 homolog in plants? --- p.112 / Chapter 4.2.2.3 --- Regulation of amino acid metabolism by GCN system --- p.113 / Chapter 4.3 --- Generation of transgenic plants with a combination of altered sink- source relationship --- p.114 / Chapter Chapter 5. --- Conclusion and Future Prospective --- p.116 / Appendix I: The major chemicals and reagents used in this research --- p.118 / "Appendix II: Major buffers, solutions and mediums used in this research" --- p.120 / Appendix III: Commercial kits used in this research --- p.125 / Appendix IV: Major equipment and facilities used in this research --- p.126 / References --- p.127

Identiferoai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_325664
Date January 2006
ContributorsChiao, Ying Ann., Chinese University of Hong Kong Graduate School. Division of Molecular Biotechnology.
Source SetsThe Chinese University of Hong Kong
LanguageEnglish, Chinese
Detected LanguageEnglish
TypeText, bibliography
Formatprint, xix, 140 leaves : ill. ; 30 cm.
RightsUse of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

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