Rice consumption is responsible for the largest dietary contribution of inorganic arsenic. In addition to the direct human health impact of arsenic, arsenic toxicity impacts on rice yield. Thus two issues must be addressed: rice sensitivity to arsenic and the contribution of rice towards dietary arsenic. The grass Holcus lanatus achieves arsenate tolerance through the constitutive down regulation of phosphate transporters, which facilitate arsenate uptake. To gain a better understanding of mechanisms underlying arsenic sensitivity in rice and determine if phosphate uptake was responsible for differential arsenic sensitivity between two rice cultivars (Azucena and Bala) an experiment was undertaken examining the role of phosphate in rice arsenic sensitivity. Although high phosphate treatments were found to provide protection against both arsenate and arsenite toxicity and the two cultivars were found to respond differently to phosphate induced protection, the mechanism underlying reduced arsenic sensitivity did not appear to be controlled through a reduced phosphate uptake system. Attempts to link lab-based arsenic sensitivity of various rice cultivars to published biomass and tissue arsenic concentrations of rice grown in the field is presented. No consistent trend was identified across field sites although two negative correlations at two different sites were found (grain arsenic concentrations and shoot dry weight plotted against arsenate sensitivity). These data demonstrated the importance environment influence on traits examined. These correlations suggest that breeding for more arsenic resistant rice strains may increase plant yield but inadvertently lead to an increase in grain arsenic. Finally, QTL mapping and genome-wide association mapping were used to identify genomic regions and candidates genes responsible for variations in shoot arsenic concentrations in rice. The purpose of which was to offer a better understanding of the mechanisms responsible for this variation. Unfortunately the QTLs revealed were not reproduced in the association mapping study. A list of potential positional candidate genes are summarised and functional candidates identified and discussed.

Thesis (M.B.A.)--Chinese University of Hong Kong. / Bibliogaraphy; leaves 118-119.

Chan Man Ling. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 102-114). / Abstracts in English and Chinese. / Table of Contents / ACKNOWLEDGEMENTS --- p.iii / ABSTRACT --- p.iv / TABLE OF CONTENTS --- p.vii / LIST OF FIGURES --- p.xi / LIST OF TABLES --- p.xiii / LIST OF ABBREVIATIONS --- p.xiv / Chapter CHAPTER 1. --- GENERAL INTRODUCTION --- p.1 / Chapter CHAPTER 2. --- LITERATURE REVIEW --- p.4 / Chapter 2.1 --- The importance of rice --- p.4 / Chapter 2.2 --- The prevalence of hunger and malnutrition --- p.4 / Chapter 2.3 --- Limitation of essential amino acids in crop plants --- p.5 / Chapter 2.4 --- Lysine biosynthesis and catabolism --- p.7 / Chapter 2.5 --- Lysine biosynthetic pathway --- p.7 / Chapter 2.5.1 --- The biosynthesis of aspartate --- p.7 / Chapter 2.5.2 --- The aspartate family pathway --- p.9 / Chapter 2.5.2.1 --- Aspartate kinase (AK) --- p.11 / Chapter 2.5.2.2 --- Dihydrodipicolinate synthase (DHPS) --- p.13 / Chapter 2.5.2.3 --- Threonine Synthase (TS) and other enzymes --- p.15 / Chapter 2.6 --- The lysine catabolic pathway --- p.16 / Chapter 2.6.1 --- "LKR-SDHproteins, mRNAs and genes" --- p.18 / Chapter 2.6.2 --- Regulation of lysine catabolic pathway --- p.21 / Chapter 2.6.2.1 --- Regulation at biochemical level --- p.21 / Chapter 2.6.2.2 --- Regulation through linkage between LKR and SDH --- p.22 / Chapter 2.6.2.3 --- Regulation through LKR/SDH gene expression --- p.24 / Chapter 2.6.2.4 --- Implication of regulatory mechanism of saccharopine pathway --- p.26 / Chapter 2.7 --- Overall regulation of lysine content in plants --- p.27 / Chapter 2.8 --- Increasing lysine content in plants --- p.28 / Chapter 2.8.1 --- "Breeding, selection and naturally occurring mutants" --- p.28 / Chapter 2.8.2 --- Induced biochemical mutants --- p.29 / Chapter 2.8.3 --- Transgenic plants --- p.31 / Chapter 2.8.4 --- Insight into the way of lysine accumulation --- p.35 / Chapter 2.9 --- Gene silencing in plant --- p.36 / Chapter 2.9.1 --- Mechanism of antisense RNA and RNAi --- p.36 / Chapter 2.9.2 --- Application of antisense technology to produce transgenic plants --- p.39 / Chapter 2.10 --- Hypothesis --- p.41 / Chapter CHAPTER 3. --- MATERIALS AND METHODS --- p.43 / Chapter 3.1 --- Chemicals --- p.43 / Chapter 3.2 --- Bacterial strains --- p.43 / Chapter 3.3 --- Chimeric gene construction for rice transformation --- p.43 / Chapter 3.3.1 --- Plasmids and genetic materials --- p.43 / Chapter 3.3.2 --- Construction of chimeric genes with seed-specific promoters --- p.46 / Chapter 3.3.3 --- Construction of chimeric gene with 35S promoter --- p.51 / Chapter 3.3.4 --- Construction of antisense and RNAi constructs --- p.53 / Chapter 3.3.5 --- "Construction of chimeric genes expressing AK, DHPS and RNAi synchronously" --- p.58 / Chapter 3.3.6 --- Confirmation of sequence fidelity of chimeric genes --- p.59 / Chapter 3.4 --- Rice transformation --- p.59 / Chapter 3.4.1 --- Plant materials --- p.59 / Chapter 3.4.2 --- Preparation of Agrobacterium --- p.59 / Chapter 3.4.3 --- Agrobacterium-mediated rice transformation --- p.60 / Chapter 3.4.3.1 --- Callus induction from mature seed embryos --- p.60 / Chapter 3.4.3.2 --- Callus induction from immature seed embryos --- p.60 / Chapter 3.4.3.3 --- "Co-cultivation, selection and regeneration of transgenic rice" --- p.60 / Chapter 3.5 --- Analysis of transgenic expression --- p.62 / Chapter 3.5.1 --- Genomic DNA extraction --- p.62 / Chapter 3.5.2 --- Total RNA extraction --- p.62 / Chapter 3.5.3 --- Synthesis of DIG-labeled DNA probe / Chapter 3.5.4 --- Southern blot analysis --- p.65 / Chapter 3.5.5 --- Northern blot analysis --- p.65 / Chapter 3.5.6 --- Extraction of immature seed protein --- p.65 / Chapter 3.5.7 --- Tricine SDS-PAGE --- p.66 / Chapter 3.5.8 --- Western blot analysis --- p.66 / Chapter 3.6 --- Free amino acid analysis --- p.67 / Chapter CHAPTER 4. --- RESULTS --- p.68 / Chapter 4.1 --- Construction of chimeric genes --- p.68 / Chapter 4.2 --- Rice transformation --- p.70 / Chapter 4.3 --- Detection of target genes in transgenic rice lines --- p.72 / Chapter 4.3.1 --- PCR of Genomic DNA --- p.72 / Chapter 4.3.2 --- Southern blot analysis --- p.75 / Chapter 4.4 --- Northern blot analysis --- p.77 / Chapter 4.5 --- "Western blot analysis ofAK, DHPS and LKR protein" --- p.80 / Chapter 4.6 --- Free amino acid analysis --- p.82 / Chapter 4.6.1 --- Free lysine content --- p.82 / Chapter 4.6.2 --- Changes of other amino acids --- p.84 / Chapter CHAPTER 5. --- DISCUSSION --- p.93 / Chapter 5.1 --- Rice transformation and transgene expression --- p.93 / Chapter 5.2 --- Co-expression of E. coli feedback-insensitive AK and DHPS --- p.94 / Chapter 5.3 --- Enhancing free Lys through down-regulation of LKR --- p.95 / Chapter 5.4 --- Co-expression of AK and DHPS together with down-regulation of LKR --- p.96 / Chapter 5.5 --- Free amino acid changes in different genotypes --- p.97 / Chapter 5.6 --- Future perspectives --- p.98 / Chapter CHAPTER 6. --- CONCLUSION --- p.100 / REFERENCES --- p.102

This thesis describes a series of experiments concerned with the production of aromatised rice. The end product showed no visible difference from untreated rice, and the cooked product had a perceivable aroma. The aromatisation process used liquid carbon dioxide as a vehicle to deliver the aroma, and eugenol, isoeugenol, methyl eugenol, cinnamyl alcohol and cinnamaldehyde were used as the principle model aroma components. The aromas penetrated the cores of the rice grains, providing a longer period for the aroma compounds to migrate toward the surface and be lost to the open air. The stability of the injected compounds in aromatised rice was investigated, showing that aroma loss was a first-order process, although some model compounds showed evidence of two binding models, with two distinct phases of aroma loss. The strength of aroma binding to rice was further assessed by means of gas-chromatography columns, and the model aroma compounds interacted best with the rice-flour column. Shelf-life studies demonstrated that eugenol and cinnamaldehyde in aromatised rice showed no significant changes after being stored for 6 months in sealed vacuum aroma-barrier plastic bags, and the aromas could be detected by the human olfactory system after the rice had been cooked by boiling and steaming / Doctor of Philosophy (PhD)

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 91-101).

Thesis (M. Agr. Sc.)--University of Queensland, 2001. / Includes bibliographical references.

A high-resolution computer-based survey for transposable elements performed on 910 Kb of rice genomic DNA sequences revealed the presence of both class I and class II transposable elements. Elements from most major families of plant transposable elements were identified, and new groups were reported for these families. Miniature inverted-repeat transposable elements (MITES) are clearly the predominant type of transposable element in the rice sequences examined. Phylogenetic analysis of the putative transposases of several transposable elements indicated that Tourist-like miniature inverted-repeat transposable elements (MITES) are closely related to the bacterial insertion sequence 5 (IS5) family of transposable elements, while Emigrant-like and Stowaway-like MITES are both related to members of the IS630/TcI/mariner superfamily of elements. Finally, the nucleotide sequences of MITES, Ac-like, Mutator-like elements (MULE), short interspersed nuclear elements (SINEs) and other unclassified elements, as well as their insertion polymorphism data have been used to reconstruct the relationships between rice species in the AA genome. The use of a combination of transposable element data sets generated the most reliable cladograms.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 279-302). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 279-302). Also available on the Internet.

Thesis (Ph. D.)--University of Minnesota, 1926. / Biography. "Literature cited": p. 41-43.