No description available.

Chow Hoi Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 127-153). / Abstracts in English and Chinese. / Abstract --- p.iii / Acknowledgments --- p.vi / Abbreviations --- p.vii / Table of contents --- p.viii / List of Figures --- p.xi / List of Tables --- p.xiv / Chapter Chapter One --- Literature Review / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- The life cycle of rice --- p.3 / Chapter 1.3 --- Physiological and molecular studies on rice leaf development --- p.6 / Chapter 1.3.1 --- Physiological study of rice leaf development --- p.6 / Chapter 1.3.1.1 --- Leaf primordium formation and SAM --- p.6 / Chapter 1.3.1.2 --- Leaf expansion and water status --- p.7 / Chapter 1.3.1.3 --- Leaf senescence and phytohormone --- p.8 / Chapter 1.3.1.4 --- Rice leaf and temperature --- p.9 / Chapter 1.3.2 --- Molecular study of rice leaf development / Chapter 1.3.2.1 --- Leaf primordium formation and SAM --- p.10 / Chapter 1.3.2.2 --- Leaf elongation and related genes --- p.13 / Chapter 1.3.2.3 --- Leaf senescence and related genes --- p.13 / Chapter 1.3.2.4 --- Photoreceptor genes --- p.14 / Chapter 1.3.2.5 --- Temperature-related genes --- p.17 / Chapter 1.4 --- Prospectus --- p.18 / Chapter Chapter Two --- Isolation of Genes Differentially Expressed During the Development of Rice by RAP-PCR / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials and Methods --- p.23 / Chapter 2.2.1 --- Strains and culture conditions --- p.23 / Chapter 2.2.2 --- Isolation of total RNAs --- p.23 / Chapter 2.2.3 --- cDNA Library construction --- p.24 / Chapter 2.2.3.1 --- First strand synthesis --- p.24 / Chapter 2.2.3.2 --- cDNA amplification by LD PCR --- p.25 / Chapter 2.2.3.3 --- Proteinase K digestion --- p.25 / Chapter 2.2.3.4 --- Sfi digestion --- p.26 / Chapter 2.2.3.5 --- cDNA size fractionation by CHROMA-SPIN´ёØ-400 --- p.26 / Chapter 2.2.3.6 --- Ligation of cDNA to λTripEx2vector --- p.26 / Chapter 2.2.3.7 --- Titering the unamplified library --- p.27 / Chapter 2.2.3.8 --- Determining the percentage of recombinant clones --- p.27 / Chapter 2.2.3.9 --- Library amplification --- p.28 / Chapter 2.2.3.10 --- Titering the amplified library --- p.28 / Chapter 2.2.3.11 --- Converting λ TripEx2 recombinant clones to pTripEx2 recombinant plasmids --- p.28 / Chapter 2.2.4 --- RNA fingerprinting by RAP-PCR --- p.29 / Chapter 2.2.5 --- Reverse dot-blot analysis --- p.30 / Chapter 2.2.5.1 --- Membrane preparation --- p.30 / Chapter 2.2.5.2 --- Probe preparation --- p.30 / Chapter 2.2.5.3 --- Hybridization --- p.31 / Chapter 2.2.5.4 --- Stringency washes and chemiluminescent detection --- p.31 / Chapter 2.2.6 --- Sequencing of differentially expressed genes --- p.32 / Chapter 2.2.6.1 --- Extraction of plasmid DNA --- p.32 / Chapter 2.2.6.2 --- DNA cycle sequencing --- p.33 / Chapter 2.3 --- Results --- p.34 / Chapter 2.3.1 --- Total RNA isolation --- p.34 / Chapter 2.3.2 --- cDNA library --- p.37 / Chapter 2.3.3 --- RNA fingerprinting --- p.40 / Chapter 2.3.4 --- Reverse dot-blot analysis --- p.45 / Chapter 2.3.5 --- Sequence analyses --- p.48 / Chapter 2.4 --- Discussion --- p.68 / Chapter Chapter Three --- cDNA Microarray Analysis and expression Pattern Analysis by Northern Blot Hybridization / Chapter 3.1 --- Introduction --- p.71 / Chapter 3.2 --- Materials and Methods --- p.76 / Chapter 3.2.1 --- RNA extraction by RNeasy® Mini Kit for cDNA microarray --- p.76 / Chapter 3.2.2 --- Microarray analysis --- p.76 / Chapter 3.2.2.1 --- Array preparation --- p.76 / Chapter 3.2.2.2 --- Probe preparation --- p.78 / Chapter 3.2.2.3 --- Hybridization --- p.79 / Chapter 3.2.2.4 --- Stringency washes and TSA Detection --- p.79 / Chapter 3.2.2.5 --- Microarray Analyses --- p.80 / Chapter 3.2.3 --- RNA extraction by Tri-reagent for Northern Blot hybridization --- p.81 / Chapter 3.2.4 --- RNA fragmentation by formaldehyde gel electrophoresis --- p.81 / Chapter 3.2.5 --- Northern blotting --- p.82 / Chapter 3.2.6 --- Preparation of probe --- p.83 / Chapter 3.2.7 --- Hybridization and stringency washes --- p.84 / Chapter 3.2.8 --- Stripping and reprobing of Northern Blot --- p.85 / Chapter 3.3 --- Results --- p.86 / Chapter 3.3.1 --- Total RNA isolation --- p.86 / Chapter 3.3.2 --- Microarray analysis --- p.86 / Chapter 3.3.3 --- Normalization of microarray data --- p.91 / Chapter 3.3.4 --- Detection of probe labeling efficiency --- p.92 / Chapter 3.3.5 --- Northern blot analysis --- p.100 / Chapter 3.3.5.1 --- Genes expressed highly in primordia stage --- p.100 / Chapter 3.3.5.2 --- Genes with low expression in primordia stage --- p.101 / Chapter 3.3.5.3 --- Genes with high expression in half expanded stage --- p.101 / Chapter 3.3.5.4 --- Genes steadily increased in expression throughout the development --- p.103 / Chapter 3.3.5.5 --- Genes with low expression in fully expanded stage --- p.104 / Chapter 3.4 --- Discussion --- p.114 / Chapter Chapter four --- General Discussion --- p.122 / References --- p.127

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

Chum Wing Yan Winnie. / "August 2006." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 190-223). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

A method for Agrobacterium-mediated transformation of hybrid poplar (Populus alba x P. grandidentata) suspension cultures and regeneration of transformed plants is described. The best protocol was one in which suspension cultures were inoculated with Agrobacterium tumefaciens to a density of 10⁷ cfu's/ml, cocultivated for 48 hours, plated to cellulose acetate filters at a density of 14 colonies/mm², and cultured on medium containing 1 mg/1 2,4-D. Although cefotaxime inhibited callus growth, it was used in the plating medium to suppress proliferation of Agrobacterium. Selection appeared to be more reliable using hygromycin as compared to kanamycin or geneticin (G418). Transgenic plants were regenerated by culturing the calli on media containing thidiazuron, but no shoots could be regenerated using BA. / Graduation date: 1992

Thesis (Ph.D.)--Ohio University, March, 2007. / Title from PDF t.p. Includes bibliographical references.

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 80-103). Also available on the World Wide Web.

Thesis (MSc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: Grapevine is worldwide an agronomically important crop. Traditionally selective breeding has been used to improve existing cultivars. In the last ten years, however, the advent of biotechnology has shortened these breeding programmes by producing transgenic grapevine. Because this new technology is aimed at the possible genetic manipulation of the ripening process in grape berries, it is important to elucidate all the mechanisms that may be involved in ripening. The aim of the present study was the identification of genes that play an important role during the ripening process in grape berries. This was achieved by investigation of putative differentially expressed genes in ripening Chardonnay berries isolated through subtractive hybridisation. Two subtraction libraries, representing early and late ripening stages were constructed. Four of the ten genes analysed exhibited expression during berry ripening. One of the four genes was expressed in a tissue and stage specific manner. Further characterisation of eight of the DNA and protein sequences revealed that the putative translation products of these clones had homologues that are involved in amongst others cell wall structure in other species. These included UDP-glucose dehydrogenase, which is involved in the synthesis of hemicellulose precursors. The remaining seven clones encoded putative stress response proteins. These included two heat shock proteins, a vacuolar pyrophosphatase and a protein involved in cell division. It is suggested that specific grape mRNAs accumulate in response to stresses such as the storage of high concentrations of sugars and rapid cell expansion. These processes occur rapidly during the ripening of berries. Accumulation of specific mRNAs can be attributed to part of the normal ripening developmental programme. / AFRIKAANSE OPSOMMING: Druiwe is wêreldwyd 'n belangrike landbougewas en kultivars word tradisioneel deur middel van tydsame selektiewe teling verbeter. Die tyd wat hieraan bestee word, kan verkort word deur die implementering van biotegnologie en die produksie van transgeniese duiwe. Omdat hierdie nuwe tegnologie op die moontlike genetiese manipulering van die rypwordingsproses in druiwe gemik is, is dit belangrik dat alle meganismes betrokke by rypwording ondersoek en verstaan word. Die doel van hierdie studie was om gene wat moontlik tydens die rypwordingsproses in druiwe 'n rol kan speel, te identifiseer. Hierdie doel is bereik deurdat differensieel uitgedrukte gene uit die kultivar Chardonnay geïsoleer is met behulp van verrykingsbiblioteke vanuit jong en volwasse druiwekorrels. Vier van die tien gene wat geanaliseer is, word uitgedruk tydens die rypwordingsproses. Verder het een van die vier gene weefsel- en rypwordingstadium- spesifisiteit getoon. Volledige karakterisering van agt van die DNA- en proteïenvolgordes het aangedui dat die proteïenprodukte van hierdie gene homoloog is aan volgordes wat onder andere by selwandstruktuur betrokke is. Dit sluit UDP-glukose dehidrogenase in, wat betrokke is by die sintese van hemi-sellulose boustene. Die ander sewe gene kodeer vir moontlike spanningsproteïene. Twee hitteskokproteïene, 'n vakuolêre pirofosfatase en 'n proteïen wat betrokke is by selverdeling is geïdentifiseer. Daar word voorgestel dat druiwe mRNA versamel in reaksie op spanningsituasies soos die berging van hoë konsentrasies suikers en selvergroting. Hierdie prosesse vind baie vinnig plaas tydens rypwording. Versameling van spesifieke mRNAs kan toegeskryf word as 'n normale deel van die rypwordingsproses.

Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: For the expression of transgenes in plant cells, appropriate promoter sequences have to be introduced upstream of the gene to ensure efficient transcription. While to date the maize ubiquitin (Ubi1) promoter has been the most effective transgene promoter for sugarcane, there is a high demand for tissue and stage specific promoters for localised transgene expression in the mature culm. The present study sought to characterise genes preferentially expressed in the core and peripheral tissues of the mature culm, which can further be used as research tools for specific promoter isolation. cDNA expression arrays containing 3840 clones from a late stage cDNA library representative of the core and peripheral tissues of the mature culm were prepared. The cDNA expression arrays were then differentially screened in independent hybridisation experiments with radioactively-labeled cDNA representations of core and peripheral tissues of internode 7, and peripheral tissues of internode 10. Comparison of the expression profiles of the arrayed cDNA targets in the three probes led to the identification of 60 tissue-specific, 17 stage-specific and 50 selectively expressed cDNAs within the mature sugarcane culm. ~ESTs of 33 chosen selectively expressed cDNAs with a relatively stronger pattern of expression in the core than in the peripheral tissues revealed sequence homology to a diverse collection of genes in the mature culm. These included genes associated with general cellular metabolism such as protein synthesis, protein modification and structural protein. Also identified were stress-responsive genes. The putative translational products of some of these clones had homologs that are involved in cell-wall structure in other species. These included the [acalin homolog, a lectin, hydroxyproline rich glycoprotein and structured polyprotein C. Many of the cDNAs thought to be involved in cell wall structure or stress related responses also accumulate in a developmental manner in other plants. These may indicate that specific mature culm mRNAs accumulate in response to stresses such as rapid cell expansion or as part of the late developmental program. An unexpected observation was that only one gene associated with sucrose metabolism was identified, namely sucrose synthase. These results confirmed that culm maturation was not controlled by sucrose metabolism despite its distinct physiological characteristic of storing high levels of sugars. ESTs analysis further revealed that sequence homology was not obtained for all the cDNAs exhibiting stage and tissue specific expression in the core and peripheral tissues of the mature culm. These could represent novel genes not only from sugarcane but all plants. Northern analysis demonstrated that 9 putatively identified selectively expressed genes tested so far accumulated specifically in the core and peripheral tissues of the mature culm. No expression was detected in root, leaf, leafroll and internode 3. However, their selective expression in a single internode as observed on the arrays (i.e hybridisation signal intensity being higher in the core than in the peripheral tissue) was not detected on the northern blots. These showed that cDNA expression arrays were not a highcapacity gene expression assay since they were prone to false expression analysis. The validity of results obtained through array screening should always be verified in an independent manner, preferably by the northern hybridisation analysis. Hence, the present study shows that the combination of differential screening, northern blot and DNA sequence analysis permits the rapid characterisation of differentially expressed genes in the core and peripheral tissues of the mature sugarcane culm. These can further be used as research tools for mature culm - specific promoter isolation in the sugarcane. / AFRIKAANSE OPSOMMING: Die doeltreffende uitdrukking van transgene in plantselle is afhanklik van 'n gepaste promotorvolgorde wat stroomop van die geen ingevoeg word. Die Ubi1-promotor van mielies was tot dusver die doeltreffendste transgeenpromotor in suikerriet, maar daar is 'n groot behoefte aan promotors wat weefsel- en ontwikkelingstadium-spesifieke geenuitdrukking kan beheer. Hierdie studie het op die isolering en karakterisering van gene wat selektief in die kern- of periferale stingelweefsel van suikerriet uitgedruk word, gefokus. Hierdie gene sal verder benut kan word om promotors te isoleer. eDNA uitdrukkingsreekse ("expression arrays") van 'n volwasse stingel eDNA biblioteek is voorberei. Hierdie reekse, wat 3840 klone bevat het, is in onafhanklike hibridiseringseksperimente met radioaktiefgemerkte eDNA van onderskeidelik kern- en periferale stingelweefsel van lit 7 en periferale stingelweefsel van lit 10 afgetas. 'n Vergelyking van die uitdrukkingsprofiele van die eDNA teikens in dié drie peilergroepe het tot die identifisering van 60 weefsel-spesifieke-, 17 ontwikkelingstadium-spesifiekeen 50 selektief uitgedrukte eDNAs in die volwasse suikerrietstingel gelei. Uitdrukkingsvolgordemerkers ("ESTs") van 33 geselekteerde eDNAs wat in hoër vlakke in die kern uitgedruk is, se volgordes toon homologie aan 'n wye verskeidenheid gene in die volwasse stingel. Hierdie groep sluit gene in wat met algemene sellulêre ..metabolisme soos proteïensintese, proteïenmodifisering en strukturele proteïene geassosieer is. Spanningsverwante gene is ook hier geïdentifiseer. Die transleringsprodukte van sommige klone het homoloë wat by selwandstruktuur in ander spesies betrokke is, soos die jaealin-homoloog, 'n lektien, hidroksiprolien-ryke glikoproteïen en gestruktureerde poliproteïen C. 'n Wye verskeidenheid eDNAs wat by selwandstruktuur of spanningsverwante reaksies betrokke is, akkumuleer ook in 'n ontwikkelingsafhanklike wyse in ander plante. Dit mag 'n aanduiding wees dat spesifieke mRNAs in die volwasse stingel in reaksie op spanning wat met vinnige seluitsetting gepaardgaan, versamel. Slegs een geen wat met sukrose metabolisme geassosieer is, nl. sukrosesintase, is in hierdie studie geïdentifiseer. Hierdie onverwagte waarneming het bevestig dat, ondanks suikerriet se kenmerkende vermoë om hoë konsentrasies suiker te berg, stingelveroudering nie net met sukrose metabolisme geassosieer kan word nie. Nie al die eDNA-fragmente wat geïsoleer is, het homologie aan ander gene in die internasionale databasisse getoon nie, wat moontlik kan aandui dat nuwe gene suksesvol geïsoleer is. Nege ontwikkelingstadium-spesifieke gene wat slegs in die volwasse stingelweefsels uitgedruk word, is dmv noordelike oordraganalises geïdentifiseer. Geen transkripte van hierdie gene is in die wortels, blaarrol, blare of jong stingel waargeneem nie. Die weefselspesifisiteit wat met die uitdrukkingsreekse waargeneem is, kon nie mbv noordelike orrdraganalises bevestig word nie. Dit mag 'n aanduiding wees dat die uitdrukkingsreekse vals positiewe resultate kan oplewer en dit is raadsaam om voortaan altyd die verkrygde profiele met ander, meer sensitiewe tegnieke, te bevestig. Die studie het aangetoon dat 'n kombinasie van differensiële aftasting, noordelike oordraganalise en DNA-volgordebepaling gebruik kan word om gene wat differensieel uitgedruk word in die volwasse suikerrietstingel, te identifiseer. Hierdie geenfragmente kan nou vir promotorisoleringsdoeleindes aangewend word.

M.Sc. (Biochemistry) / During microbial invasion, a variety of defense responses are induced in host plants. In order for host plants to combat potential diseases induced by microbes, they must be equipped with pattern recognition receptors (PRRs) localized at the cell surface, since such receptors enable the perception of conserved microbial epitopes termed microbe/pathogen-associated molecular patterns (M/PAMPs), thereby resulting in the activation of plant innate immunity via M/PAMP-triggered immunity (P/MTI). Lipopolysaccharide (LPS) is the major component of the outer leaflet of the external membrane of Gram-negative bacteria. This thermo-stable lipoglycan is exposed towards the external environment and plays an important role in bacterial adaptation to external surroundings. LPS is recognized as a major M/PAMP in plants, and thus potentiates or elicits defense-related responses such as the production of antimicrobial compounds and the expression of immune response genes. One of the most widely investigated effects of LPS on plants is its ability to prevent and/or suppress the hypersensitive response (HR) induced by an array of bacteria. The HR is a programmed cell death response which ends in a local necrosis of plant tissue, thereby resulting in a reduced number of viable bacteria that can further promote disease progression in the host.