by Wong Fuk Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 100-115). / Abstracts in English and Chinese. / Thesis committee --- p.i / Statement --- p.ii / Abstract --- p.iii / Chinese abstract --- p.v / Acknowledgements --- p.vii / Abbreviations --- p.ix / Table of contents --- p.xii / List of figures --- p.xvi / List of tables --- p.xvii / Chapter 1. --- Literature review / Chapter 1.1 --- Soybeans / Chapter 1.1.1 --- Economical importance of soybean --- p.1 / Chapter 1.1.2 --- History and origin of soybean --- p.4 / Chapter 1.1.3 --- Qualitative traits of cultivated and wild soybeans --- p.5 / Chapter 1.1.4 --- Soybean resource in China --- p.6 / Chapter 1.1.5 --- Salt tolerant soybeans in China --- p.6 / Chapter 1.2 --- Salinization as a global problem --- p.7 / Chapter 1.3 --- Toxicity of salt in plants --- p.8 / Chapter 1.4 --- Salt stress signal transduction in plants --- p.10 / Chapter 1.4.1 --- Ionic and osmotic stress signaling / Chapter 1.4.1.1 --- Ca2+ signaling --- p.11 / Chapter 1.4.1.2 --- The SOS pathway --- p.12 / Chapter 1.4.1.3 --- Protein kinase pathways --- p.13 / Chapter 1.4.1.4 --- Phospholipid signaling --- p.14 / Chapter 1.4.1.5 --- ABA signaling --- p.17 / Chapter 1.4.2 --- Detoxification signaling --- p.17 / Chapter 1.4.3 --- signaling to coordinate cell division ana expansion --- p.18 / Chapter 1.5 --- Plant adaptations in plants --- p.18 / Chapter 1.5.1 --- Ion homeostasis --- p.18 / Chapter 1.5.1.1 --- Reduction of Na+ influx into the cells --- p.19 / Chapter 1.5.1.2 --- Extrusion of Na+ out of the cell --- p.19 / Chapter 1.5.1.3 --- Vacuolar compartmentation of Na+ --- p.20 / Chapter 1.5.2 --- Osmotic adjustment --- p.20 / Chapter 1.5.3 --- Antioxidant protection --- p.21 / Chapter 1.5.4 --- Morphological and structural modification --- p.21 / Chapter 1.6 --- The relationship of salt stress and phosphorus deficiency --- p.22 / Chapter 1.7 --- The importance of phosphorus in plants --- p.25 / Chapter 1.8 --- The role of purple acid phosphatase (PAP) in plants --- p.25 / Chapter 1.9 --- PAPs in soybean --- p.27 / Chapter 1.10 --- Hypothesis and significance of this project --- p.27 / Chapter 2. --- Materials and methods / Chapter 2.1 --- Materials / Chapter 2.1.1 --- Plant materials --- p.29 / Chapter 2.1.2 --- The clones used in this work --- p.30 / Chapter 2.1.3 --- Growth media for soybeans --- p.31 / Chapter 2.1.4 --- Equipment and facilities --- p.31 / Chapter 2.1.5 --- Primers --- p.31 / Chapter 2.1.6 --- Chemicals and reagents --- p.31 / Chapter 2.1.7 --- Solutions --- p.32 / Chapter 2.1.8 --- Commercial kits --- p.32 / Chapter 2.1.9 --- Software --- p.32 / Chapter 2.2. --- Methods / Chapter 2.2.1 --- Growth and salt treatment condition / Chapter 2.2.1.1 --- Establishment a collection of typical salt tolerant and sensitive soybean varieties --- p.33 / Chapter 2.2.1.2 --- Samples for northern analysis of salt inducible genes --- p.33 / Chapter 2.2.1.3 --- Samples for characteristics of GmPAP3 gene --- p.35 / Chapter 2.2.1.4 --- Samples for oxidative stress test --- p.36 / Chapter 2.2.2 --- Total RNA extraction --- p.36 / Chapter 2.2.3 --- Denaturing gel electrophoresis of RNA --- p.38 / Chapter 2.2.4 --- Expression pattern analysis / Chapter 2.2.4.1 --- Preparation of single-stranded DIG-labeled PCR probes --- p.39 / Chapter 2.2.4.2 --- Testing the concentration of DIG-labeled probes --- p.40 / Chapter 2.2.4.3 --- Northern blot --- p.41 / Chapter 2.2.5 --- Soluble ions analysis --- p.42 / Chapter 2.2.6 --- Acid phosphatase activity assays --- p.42 / Chapter 2.2.7 --- Phylogenetic analysis and subcellular localization prediction of GmPAP3 --- p.43 / Chapter 3. --- Results / Chapter 3.1 --- Establishing a collection of typical salt tolerant and sensitive soybean varieties --- p.44 / Chapter 3.2 --- Characterization of salt inducible genes --- p.48 / Chapter 3.3 --- Characterization of GMPAP3 gene --- p.63 / Chapter 3.3.1 --- Phylogenetic studies of the GmPAP3 --- p.64 / Chapter 3.3.2 --- The salt-inducible GmPAP3 gene in soybean encodes a putative mitochondria-located PAP --- p.64 / Chapter 3.3.3 --- Expression of GmPAP3 was induced by NaCl stress but not P deficiency --- p.71 / Chapter 3.3.4 --- Expression of GmPAP3 was induced by oxidative stress --- p.80 / Chapter 4. --- Discussion --- p.82 / Chapter 4.1 --- A collection of typical salt tolerant and sensitive soybean varieties --- p.83 / Chapter 4.2 --- Inducibility of identified salt-inducible gene in different varieties --- p.85 / Chapter 4.2.1 --- The possible roles of identified salt-inducible genes --- p.85 / Chapter 4.2.2 --- Expression profiles of identified salt-inducible genes --- p.89 / Chapter 4.3 --- The novel gene GmPAP3 --- p.92 / Chapter 5. --- Conclusion and perspectives --- p.98 / References --- p.100 / Appendix I: Expression profiles of the salt inducible genes in root tissue of selected varieties --- p.116 / Appendix II: Major equipment and facilities used in this research --- p.124 / Appendix III: Major chemicals and reagents used in this research --- p.125 / Appendix IV: Major common solutions used in this research --- p.127