by So Mei Po. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 105-111). / Abstracts in English and Chinese. / Title Page --- p.i / Table of Contents --- p.ii / List of Tables --- p.v / List of Figures --- p.vii / Abbreviations --- p.xi / Acknowledgements --- p.xii / Abstract --- p.xiii / Chapter CHAPTER ONE --- INTRODUCTION / Chapter 1.1 --- Chiral Recognition Detected by Mass Spectrometry --- p.1 / Chapter 1.2 --- Fast Atom Bombardment Mass Spectrometry --- p.7 / Chapter 1.2.1 --- Desorption/Ionization in FAB --- p.7 / Chapter 1.2.1.1 --- Matrix --- p.8 / Chapter 1.2.1.2 --- Atom/Ion Guns --- p.9 / Chapter 1.3 --- Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry --- p.9 / Chapter 1.3.1 --- Development of Matrix-Assisted Laser Desorption/Ionization --- p.10 / Chapter 1.3.2 --- Matrix-Assisted Laser Desorption/Ionization --- p.11 / Chapter 1.3.2.1 --- The Matrix --- p.12 / Chapter 1.3.2.2 --- Mechanisms of Ion Formation --- p.12 / Chapter 1.3.2.2.1 --- Desorption --- p.13 / Chapter 1.3.2.2.2 --- Ionization --- p.13 / Chapter 1.4 --- Blackbody Infrared Radiative Dissociation (BIRD) --- p.14 / Chapter 1.4.1 --- Photodissociation --- p.15 / Chapter 1.4.2 --- Blackbody Infrared Radiative Dissociation --- p.15 / Chapter 1.5 --- Outline of the Present Work --- p.18 / Chapter CHAPTER TWO --- INSTRUMENTATION AND EXPERIMENTAL / Chapter 2.1 --- Time-of-flight Mass Spectrometry --- p.19 / Chapter 2.1.1 --- Delayed Extraction --- p.23 / Chapter 2.1.2 --- Instrumentation --- p.24 / Chapter 2.1.2.1 --- Laser System --- p.24 / Chapter 2.1.2.2 --- Ion Source --- p.26 / Chapter 2.1.2.3 --- Reflector --- p.27 / Chapter 2.1.2.4 --- Detector --- p.27 / Chapter 2.1.2.5 --- Data Acquisition and Computer Control --- p.27 / Chapter 2.2 --- Fourier Transform Ion cyclotron Resonance Mass Spectrometry --- p.28 / Chapter 2.2.1 --- Ion Source --- p.29 / Chapter 2.2.1.1 --- Fast Atom Bombardment Mass spectrometry (FABMS) --- p.29 / Chapter 2.2.2 --- Electrostatic Ion Focusing System --- p.31 / Chapter 2.2.3 --- ICR Analyzer Cell and Magnet --- p.34 / Chapter 2.2.4 --- Data Acquisition and Handling system --- p.38 / Chapter 2.3 --- Experimental --- p.38 / Chapter 2.3.1 --- Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry --- p.38 / Chapter 2.3.1.1 --- Sample Preparation --- p.38 / Chapter 2.3.1.2 --- Mass Spectrometric Analysis --- p.39 / Chapter 2.3.2 --- Fast Atom Bombardment Mass Spectrometry --- p.39 / Chapter 2.3.2.1 --- Sample preparation --- p.39 / Chapter 2.3.2.2 --- Blackbody Infrared Radiative Dissociation --- p.39 / Chapter CHAPTER THREE --- HOST-GUEST COMPLEXES DETECTED BY MATRIX- ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY / Chapter 3.1 --- Introduction --- p.42 / Chapter 3.2 --- Sample Preparation --- p.45 / Chapter 3.3 --- Results and Discussions --- p.49 / Chapter 3.3.1 --- Cyclodextrins - Cyclic Maltooligosaccharides --- p.49 / Chapter 3.3.2 --- Maltooligosaccharide --- p.55 / Chapter 3.4 --- Conclusions --- p.64 / Chapter CHAPTER FOUR --- DIFFERENTIATION OF ENANTIOMERS USING MALDI-TOF-MS / Chapter 4.1 --- Introduction --- p.65 / Chapter 4.2 --- Experimental --- p.67 / Chapter 4.2.1 --- MALDI-MS Studies --- p.67 / Chapter 4.2.2 --- Calculation --- p.68 / Chapter 4.3 --- Results and Discussions --- p.69 / Chapter 4.3.1 --- MALDI-MS Studies --- p.69 / Chapter 4.3.2 --- Calculations --- p.74 / Chapter 4.4 --- Conclusion --- p.81 / Chapter CHAPTER FIVE --- BLACKBODY INFRARED RADIATION DISSOCIATION (BIRD) OF DIASTEREOCOMPLEXES / Chapter 5.1 --- Introduction --- p.86 / Chapter 5.2 --- Experimental --- p.88 / Chapter 5.3 --- Result and Discussion --- p.89 / Chapter 5.3.1 --- BIRD of Amino-acid/Cyclodextrin complexes --- p.89 / Chapter 5.3.2 --- BIRD of Proton-bound Amino Acid Dimers and Amino Acid/dipeptide Dimers --- p.91 / Chapter 5.4 --- Conclusion --- p.102 / Chapter CHAPTER SIX --- CONCLUSIONS AND FURTHER WORKS / Chapter 6.1 --- Conclusions --- p.103 / Chapter 6.2 --- Further Works --- p.104 / REFERENCES --- p.105

本論文報道了 (a) 基於1,4-二取代 1,2,3-三唑的短肽類似物的合成及表徵，和 (b)這些類肽化合物在溶液相中的自組裝及凝膠化特性研究。 / 本論文第一章簡單地介紹及槪括基於三唑的寡聚物的構象和超分子的屬性。 / 本論文第二章報告1,4-二取代 1,2,3-三唑在類肽化合物中作為聯繫單元和作為構象控制的多功能性。 / 本論文第三章敍述了一類新的包含1,2,3-三唑在分子骨幹中的類肽化合物的合成及表徵。以炔丙胺/炔丁胺和 α-疊氮酸作為雙官能團前體，不同氨基酸成分和不同C-端基的系列類肽化合物由反覆的合成過程製備而來。用炔丙醇代替炔丙胺, 相應的酯類似物也被製備用作比較研究。 / 本論文第四章敍述了這些類肽化合物的自組裝及凝膠化特性。根據一維¹H 核磁共振，二維核磁共振 (2D)，氫/氘交換核磁共振 (H/D)， 蒸汽壓力均分子量 (VPO), 圓二色譜 (CD) 和紅外光譜分析研究，基於三唑類的短肽化合物Boc-aa¹aa²***aa[superscript n]-X 被發現以頭接尾的方式自我二聚 (K[subscript dsubscript isubscript m] ~10-680 M⁻¹)。二聚常數 (K[subscript dsubscript isubscript m])隨著氨基酸單位數目的增加而增大。在相同的寡聚系列中，K[subscript dsubscript isubscript m]值受到C-端基的大小的強烈影響。三肽類似物Boc-aa¹aa²aa³-X 還是許多芳烴類溶劑的優秀有機凝膠因子。掃描電子顯微技術(SEM)形態研究顯示三維網路形成於凝膠過程中。另一方面，結果顯示，類肽化合物的連結器長度在二級結構的形成和自組裝特性上發揮重要作用。 / 爲了進一步發展頭尾二聚的概念，本論文第五章敍述頭接尾的β-髮夾類似結構可通過適當的連結器偶聯兩個基於三唑的三肽類似物來獲得，如4-羥基脯氨酸的衍生物。一維¹H 核磁共振，二維核磁共振 (2D)，氫/氘交換核磁共振 (H/D)和紅外光譜等分析方法被用來研究其自組裝特性。 / 這篇論文展示了用三唑類體系結構設計類肽分子的可行性。產品結構表徵及性質探索的結果為這些新的類肽化合物的進一步調查和應用奠定了基礎。 / This thesis reported (a) the synthesis and characterization of 1,4-disubstituted 1,2,3-triazole-based oligopeptides, and (b) the study on self assembling and gelation properties of the peptidomimetic compounds. / Chapter one gave a brief introduction and review on the click triazole-based oligomers, including their conformational and supramolecular properties. / Chapter two reviewed the versatility of 1,4-disubstituted 1,2,3-triazole unit as a linker and as a conformational controlling unit in peptidomimetics. / Chapter three disclosed the synthesis and characterization of a new class of linear peptidomimetics incorporating 1,2,3-triazoles in the backbone. Several series of click peptidomimetics, containing up to four amino acid residues and of different amino acid compositions and different C-terminal groups, were prepared by an iterative synthetic procedure, in which propargyl amine/homopropargyl amine and α-azido acids were used as bifunctional precursors. Using propargyl alcohol instead of propargyl amine, the corresponding ester analogs were also prepared for comparison studies. / In chapter four, the self-assembly and gelation properties of these peptidomimetics were illustrated. Click triazole-based oligopeptides Boc-aa¹aa²***aa[superscript n]-X (n = 2, 3 or 4) were found to self-dimerize (K[subscript dsubscript isubscript m] ~ 10-1020 M⁻¹) in a head-to-tail fashion according to ¹H NMR, two-dimensional NMR (2D), hydrogen/deuterium (H/D) exchange NMR, vapor pressure osmometry (VPO), circular dichroism (CD) and FT-IR studies. The dimerization constant (K[subscript dsubscript isubscript m]) was found to increase with increasing number of the amino acid units. Within the same oligomeric series, the K[subscript dsubscript isubscript m] value was strongly affected by the size of the C-terminal end group. The tripeptides Boc-aa¹aa²aa³-X were also excellent organogelators of many aromatic solvents. Morphological study indicated thata three-dimensional network was formed during the gelation process. On the other hand, the corresponding triester analog 98 and elongated analogs l-Boc-aa¹aa²aa³-Prg did not exhibit any self assembling properties. This revealed that the linker length and the amide units inside the click peptidomimetics played an important role in both the formation of secondary structures and the self-assembly properties. / To further develop the idea of head-to-tail dimerization, chapter five described the head-to-tail β-hairpin like structures could be obtained by conjugating two click triazole-based tripeptides through an appropriate linker such as derivatives of 4-hydroxyproline. Analytical methods, such as ¹H NMR, two-dimensional NMR, H/D exchange NMR spectroscopy, and FT-IR studies, were used to determine their self assembling properties. / This thesis has demonstrated the feasibility of designing peptidomimetic molecules with the triazole architecture. The results of the product characterization and property exploration have laid down the groundwork for further investigation and application of this new of peptidomimetic compounds. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Ke, Zhihai. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 156-162). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Table of Contents --- p.i / Acknowledgements --- p.iv / Abbreviations --- p.v / Abstract --- p.vi / Publications related to this thesis --- p.x / Chapter Chapter One --- Click ChemistryA Powerful Tool to Create Supramolecular Chimeras / Chapter 1.1 --- Introduction to Click Chemistry --- p.1 / Chapter 1.2 --- General Synthetic Strategies of Acyclic Oligotriazoles --- p.6 / Chapter 1.3 --- Conformational Properties --- p.9 / Chapter 1.3.1 --- Helical Structures from Oligotriazoles --- p.9 / Chapter 1.3.2 --- Double Helical Structure from Oligotriazoles --- p.12 / Chapter 1.3.3 --- β-Strands and β-sheets derived from Oligotriazoles --- p.13 / Chapter 1.4 --- Supramolecular Properties --- p.14 / Chapter 1.4.1 --- Host-guest Binding --- p.14 / Chapter 1.4.2 --- Self Assembling Properties --- p.17 / Chapter 1.4.3 --- Chemosensing Properties --- p.19 / Chapter Chapter Two --- Click PeptidomimeticsTricks with Clicks / Chapter 2.1 --- Click ChemistryA New Ligation Tool for Peptidomimetics Synthesis --- p.20 / Chapter 2.2 --- Click Peptidomimetics --- p.22 / Chapter 2.2.1 --- Peptidepeptide --- p.23 / Chapter 2.2.2 --- Polymerpeptide --- p.25 / Chapter 2.2.3 --- Dendrimerpeptide --- p.26 / Chapter 2.2.4 --- Small moleculepeptide --- p.27 / Chapter 2.3 --- The triazole linkage as conformational control --- p.29 / Chapter 2.3.1 --- Triazole-based β-turn mimetics --- p.29 / Chapter 2.3.2 --- Cyclic turn mimetics --- p.31 / Chapter 2.3.3 --- Cis/trans-prolyl mimic --- p.33 / Chapter 2.3.4 --- Triazoles in helix bundles --- p.34 / Chapter 2.4 --- Oligotriazole peptides --- p.35 / Chapter 2.5 --- Summary and Aim of the Project --- p.36 / Chapter Chapter Three --- Design, Synthesis and Characterization of Oligotriazole-based Peptidomimetics / Chapter 3.1 --- Synthetic Design --- p.38 / Chapter 3.2 --- Choice of Reaction Conditions --- p.40 / Chapter 3.3 --- Synthesis of Linear Click Triazole-based Peptidomimetics --- p.41 / Chapter 3.3.1 --- Preparation of Click Triazole-based Peptidomimetics with Shorter Linkers --- p.42 / Chapter 3.3.2 --- Preparation of Click Triazole-based Peptidomimetics l-Boc-aa¹aa²**aa[superscript n]-X with a Longer Spacer --- p.47 / Chapter 3.3.3 --- Preparation of ester analogs and other model compounds --- p.49 / Chapter 3.4 --- Characterization of Linear Click Triazole-based Peptidomimetics --- p.51 / Chapter 3.4.1 --- Nuclear Magnetic Resonance (NMR) Spectroscopy --- p.52 / Chapter 3.4.1.1 --- ¹H NMR Spectroscopy --- p.52 / Chapter 3.4.1.2 --- ¹³C NMR Spectroscopy --- p.57 / Chapter 3.4.2 --- Mass Spectrometry Analysis --- p.59 / Chapter 3.4.3 --- High-performance Liquid Chromatography Analysis --- p.61 / Chapter 3.5 --- Conclusions --- p.62 / Chapter Chapter Four --- Self-Assembling Properties of Click Triazole-based Peptidomimetics / Chapter 4.1 --- Introduction --- p.63 / Chapter 4.2 --- Results and Discussion --- p.65 / Chapter 4.2.1 --- Nuclear Magnetic Resonance (NMR) Spectroscopy --- p.65 / Chapter 4.2.1.1 --- Variable Concentration ¹H NMR --- p.65 / Chapter 4.2.1.2 --- Two-dimensional ¹H NMR --- p.71 / Chapter 4.2.1.3 --- Hydrogen/deuterium (H/D) exchange --- p.74 / Chapter 4.2.2 --- Vapor Pressure Osmometry (VPO) --- p.77 / Chapter 4.2.3 --- Infra-red (IR) Spectroscopy --- p.78 / Chapter 4.2.4 --- Theoretical Calculation --- p.80 / Chapter 4.2.5 --- Circular Dichroism (CD) --- p.81 / Chapter 4.2.6 --- Gelation Behaviors --- p.83 / Chapter 4.2.6.1 --- General Gelation Properties --- p.83 / Chapter 4.2.6.2 --- Morphology Studies --- p.87 / Chapter 4.3 --- Conclusions --- p.90 / Chapter Chapter Five --- β-Hairpin Structure from Click Triazole-based Peptidomimetics / Chapter 5.1 --- Introduction and Design of β-hairpin --- p.91 / Chapter 5.2 --- β-Hairpin Like Click Triazole-based Peptidomimetics Based on a Bifunctional Aromatic Linker 105 --- p.92 / Chapter 5.3 --- β-Hairpin Like Click Peptidomimetics Based on a Proline Linker 113 --- p.97 / Chapter 5.4 --- Conclusions --- p.107 / Chapter Chapter Six --- Conclusion and Outlook --- p.109 / Chapter Chapter Seven --- Experimental Procedures / Chapter 7.1 --- General Information --- p.112 / Chapter 7.2 --- Experimental Procedures --- p.113 / Chapter 7.3 --- Other Experimental --- p.152 / References --- p.156 / Chapter Appendix 1 --- (Nuclear Magnetic Resonance Spectra) --- p.A1 / Appendix 2 --- p.A111

Master of Science / Department of Animal Sciences and Industry / Evan C. Titgemeyer / Two experiments were conducted to determine effects of postruminal amino acid (AA) supplementation on protein deposition and signaling of the mammalian target of rapamycin (mTOR) pathway. For both experiments, 7 ruminally cannulated Holstein steers (172.7 ± 3.7 and 201.7 ± 3.8 kg initial BW in Exp. 1 and 2, respectively) were utilized in 6  6 Latin square designs with 7 d periods. A basal AA solution containing all essential AA, with the exception of lysine, were provided to all steers in each study in order to meet growth requirements, while making lysine the only limiting AA. Steers were fed 2.8 kg/d of a pelleted soyhull diet designed to be low in ruminally undegradable protein. Glucose was infused abomasally and volatile fatty acids were infused ruminally to prevent energy from being limiting. Steers were housed in metabolism crates to obtain total collection of both urine and feces. Blood and muscle biopsies of the longissimus lumborum were collected on the last day of each period. In experiment 1, treatments consisted of 2 levels of lysine (0 or 6 g/d) and 3 levels of leucine (0, 15, or 30 g/d) infused abomasally. Nitrogen retention increased with supplemental lysine. Leucine linearly decreased plasma concentrations of total AA. Plasma urea N (PUN) decreased with supplemental lysine. Total, phosphorylated, and the percent phosphorylated Akt were unaffected by treatments. The percentage of 4E-BP1 phosphorylated decreased linearly when leucine was supplemented. A tendency for a lysine x quadratic leucine effect was observed for the ratio of phosphorylated RPS6²⁴⁰/²⁴⁴ in which the intermediate level of leucine led to a decrease in the percent of RPS6²⁴⁰/²⁴⁴ phosphorylated when no lysine was supplied but increased when 6 g lysine/d was supplied. No differences were observed in the abundance of total, phosphorylated, or percent phosphorylated mTOR or in total abundance of E3 ubiquitin ligase proteins, MuRF1 or MAFbx. Experiment 2 was conducted similarly as experiment 1. Treatments consisted of 2 levels of lysine (0 or 6 g/d) and 3 mixtures of supplemental essential AA [none (control), 103 g/d essential AA (EAA), or EAA plus 30 g/d leucine (EL)] abomasally infused. Supplementation with essential AA, with or without leucine, increased the percentage of RPS6 phosphorylated, with a greater increase when leucine was included as part of the supplement. A lysine x (control vs. EAA+EL) interaction was observed for N retention in which the EAA and EL treatments did not improve N retention when no lysine was supplemented, but they increased it when 6 g lysine/d was provided. PUN increased above control when EAA or EL was provided, but PUN decreased when lysine was supplied. Supplementation of EAA or EL increased plasma total AA concentrations, but EL led to lower total plasma AA than EAA; however, concentrations were greater for EL than for control. In summary, leucine supplementation alone did not yield effects on whole-body protein deposition or on regulatory factors known to affect muscle protein synthesis, whereas a mixture of excess essential AA improved both lysine utilization and phosphorylation of RPS6²⁴⁰/²⁴⁴. These studies demonstrate the effects of essential AA, both limiting and nonlimiting, on protein deposition in growing cattle.

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Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Biology. / Vita. / Bibliography: leaves 187-195. / Ph.D.

Protein-protein interactions (PPIs) dominate all cellular functions across every domain of life. If PPIs become aberrant, they may result in many human diseases, such as cancer or Alzheimer’s. Despite their clinical significance, modulating aberrant PPIs is a daunting task. Most PPI surfaces are long, hydrophilic and structurally complex. Thus, finding molecules that moderate specific aberrant PPIs is an important goal in drug discovery research. For example, PPIs have been modulated by peptidomimetics, synthetic peptides that assume three-dimensional structures similar to proteins, but unlike natural peptides, they are proteolytically stable. However, building libraries of peptidomimetics is challenging as current methods rely on solid phase peptide synthesis, which limits the size and diversity of peptidomimetic libraries. As such, using the translation machinery to synthesize peptidomimetics is an attractive approach. In Chapter 1, we begin by discussing bacterial protein synthesis. Then, we delve into a detailed discussion of the application of the bacterial translation machinery for the in vitro translation of synthetic peptides. In this discussion, we review the different technologies, their advantages and limitations with respect to the incorporation of amino acids with unnatural backbones. After reviewing the methods used to incorporate backbone analogs, and their compatibility with the bacterial translation machinery, we describe a novel approach for the ribosomal incorporation of -amino acids analogs containing an -substituent, -hydroxy--amino acids (Chapter 2). We demonstrate that the ribosome incorporates this new class of substrates through the formation of an intermediate ester bond that rapidly rearranges to form a native peptide bond. Using this approach, we show that -hydroxy--amino acid single incorporation efficiencies are comparable the incorporation efficiencies obtained with natural amino acids. In Chapter 3, we apply this approach to the synthesis of peptides containing multiple -hydroxy--amino acids. This chapter describes the results obtained with the in vitro synthesis of peptides containing two consecutive -hydroxy--amino acids, three consecutive -hydroxy--amino acids, and alternating -hydroxy--amino acids and -amino acids. Based on these results, we propose experiments to improve these incorporation yields for the application of this technology for the in vitro synthesis of diverse peptidomimetic libraries.

A produtividade de uma lavoura de soja representa apenas, aproximadamente, 20% do potencial genético. Dessa forma, a exploração das características genéticas tem sido alvo dos pesquisadores para incrementar a produtividade da cultura. Dentro disso, a potencialização fisiológica pela aplicação de estimulantes biológicos, desde a germinação das sementes até a fase reprodutiva da cultura, tem sido uma das principais estratégias adotadas. Visando um aporte à pesquisa nas respostas fisiológicas da cultura, objetivou-se avaliar os efeitos fisiológicos do tratamento de sementes e aplicações foliares de micronutrientes, hormônios e aminoácidos e o quanto estes representam na produção em sistemas de alta produtividade. Foram realizados dois experimentos, sendo um em casa de vegetação (condições parcialmente controladas) (Experimento I) e outro a campo (Experimento II) no Centro Universitário de Patos de Minas (UNIPAM), Patos de Minas-MG, durante o período de janeiro a maio de 2013. Foram realizadas avaliações bioquímicas (atividade das enzimas nitrato redutase, urease, catalase, peroxidase e superóxido dismutase, peroxidação de lipídios e teor de prolina), fisiológicas (fotossíntese liquida) e fenométricas (emergência, índice de velocidade emergência, valor SPAD, taxa de crescimento de raiz, caule e folha, massa de matéria seca total e área foliar), além do número de vagens e da produtividade. Para o primeiro experimento, foram utilizados quatro tratamentos de sementes (controle; micronutrientes - Zn, Mn, B, Mo, Ni e Co; hormônios - ácido indol butírico, ácido giberélico e cinetina; e aminoácidos - ácido glutâmico, arginina, glicina, metionina e cisteína) com seis repetições em delineamento inteiramente casualizado. No segundo experimento, foram utilizados seis tratamentos de semente (controle; micronutrientes; hormônios; aminoácidos; micronutrientes e hormônios; e micronutrientes e aminoácidos) em dois sistemas de manejo: sistema convencional e sistema para produtividade potencial, com utilização de redutor de crescimento e aplicações periódicas de organominerais via foliar (doze tratamentos com quatro repetições em delineamento em blocos ao acaso). Com base nos resultados obtidos, conclui-se que: (i) o tratamento de sementes com micronutrientes potencializa a assimilação de nitrogênio e a fotossíntese líquida, e incrementa o teor de clorofila (valor Spad) e taxa de crescimento de plantas de soja; (ii) a utilização de aminoácidos ou hormônios reduz o nível de estresse das plantas durante o período inicial de crescimento e aumenta a produção de massa de matéria seca; (iii) o tratamento de sementes com micronutrientes, hormônios ou aminoácidos incrementa o teor de clorofila (valor Spad), (iv) o sistema para produtividade potencial potencializa a atividade fisiológica das plantas e, consequentemente, aumenta o número de vagens por planta e a produtividade em relação ao sistema convencional; (v) em sistema para produtividade potencial, o tratamento de sementes com micronutrientes é o mais responsivo (aumento de produtividade em 18,5%), e (vi) no sistema convencional, o tratamento com micronutrientes e aminoácidos aumenta a produtividade em 80%. / The actual soybean productivity represents about 20% of genetic potential. Thus, the exploitation of genetic characteristics has been targeted by researchers to increase crop yield. In addition, the physiological potentiation by applying biological stimulants, from seed germination to the reproductive stage of the crop, has been one of the main strategies adopted. Seeking a contribution to research on the physiological responses of soybean crop, aimed to evaluate the physiological effects of seed treatment and foliar applications of micronutrients, amino acids and hormones and how they represent in the production of the high productivity systems. Two experiments were carried out, one in the greenhouse (partially controlled conditions) (Experiment I) and other in the field (Experiment II) at the University Center of \"Patos de Minas\" (UNIPAM), \"Patos de Minas\", \"Minas Gerais\" State, Brazil, during the period of January to May 2013. Biochemical assessments (nitrate reductase, urease, catalase, peroxidase and superoxide dismutase activities, lipid peroxidation and proline content), physiological (net photosynthesis) and fenometric evaluations (emergency, emergency speed index, Spad value, leaf area, growth rate of root, stem, leaf, total dry matter and leaf area), beyond of the number of pods per plant and productivity. For the first experiment, four seed treatments (control; micronutrients - Zn, Mn, B, Mo, Ni and Co; hormones - indol butyric acid, gibberellic acid and kinetin; and amino acids - glutamic acid, arginine, glycine, methionine and cysteine) with six replications were carried out in a completely randomized design. For the second experiment, six seed treatments (control; micronutrients; hormones; amino acids; micronutrients and hormones; and micronutrients and amino acids) were used in two management systems: conventional system and system for potential productivity, using growth reducer and periodic leaf applications of biological stimulants (twelve treatments with four replications in a randomized blocks design). Based on obtained results, it is concluded that: (i) the seed treatment with micronutrients potentiates the nitrogen assimilation and net photosynthesis, and increases the chlorophyll content (Spad value) and soybean plant growth rate; (ii) the use of amino acids or hormones reduces plant stress level during the initial period of plant growth and increase the dry matter production; (iii) the seed treatment with micronutrients, hormones or amino acids increases chlorophyll content (Spad value); (iv) the system for potential productivity potentiates the physiological activity of plants and, consequently, increases the number of pods per plant and productivity when compared to conventional system; (v) under system for potential productivity, the seed treatment with micronutrients is the most responsive (increases productivity in 18.5%); and (vi) under conventional system, the treatment with micronutrients and amino acids increases the productivity in 80%.

No description available.

Ma Junhao. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 111-123). / Abstracts in English and Chinese. / Thesis Committee --- p.i / Statement --- p.ii / Abstract --- p.iii / Acknowledgements --- p.vii / General Abbreviations --- p.ix / Abbreviations of Chemicals --- p.xi / Table of Contents --- p.xii / List of Figures --- p.xvi / List of Tables --- p.xix / Chapter 1. --- Literature review --- p.1 / Chapter 1.1 --- Importance of amino acid metabolism --- p.1 / Chapter 1.1.1 --- Rice as the important source of essential amino acids --- p.1 / Chapter 1.1.2 --- Rice seeds are nutritionally incomplete --- p.2 / Chapter 1.1.3 --- The nitrogen source for aspartate family amino acid synthesis --- p.3 / Chapter 1.1.4 --- Synthesis of aspartate family amino acids in plants --- p.4 / Chapter 1.1.5 --- Regulation of the aspartate pathway at free amino acid level --- p.12 / Chapter 1.2 --- Regulation of amino acid metabolism during seed development --- p.14 / Chapter 1.3 --- Signalling system for nitrogen metabolism --- p.17 / Chapter 1.3.1 --- Nitrogen signalling in plants --- p.18 / Chapter 1.3.2 --- GCN signalling: another nitrogen signalling pathway --- p.21 / Chapter 1.3.2.1 --- Mechanism of GCN signalling pathway in yeast --- p.21 / Chapter 1.3.2.2 --- GCN in mammalian --- p.24 / Chapter 1.3.2.3 --- GCN in higher plant --- p.24 / Chapter 1.3.3 --- Relationship between carbon and nitrogen metabolic signaling in plants --- p.26 / Chapter 1.3.4 --- Paradigm for elucidating new signal transduction pathways --- p.29 / Chapter 1.4 --- Hypothesis of this thesis work --- p.30 / Chapter 2. --- Materials and Methods --- p.32 / Chapter 2.1. --- Materials --- p.32 / Chapter 2.1.1 --- Plants --- p.32 / Chapter 2.1.2 --- Bacterial strains and vectors --- p.32 / Chapter 2.1.3 --- Chemicals and reagents --- p.33 / Chapter 2.1.4 --- Buffer，solution and gel --- p.33 / Chapter 2.1.5 --- Commercial kits --- p.33 / Chapter 2.1.6 --- Equipments and facilities used --- p.33 / Chapter 2.1.6 --- Growth medium --- p.34 / Chapter 2.2 --- Methods --- p.34 / Chapter 2.2.1 --- Profiling genes expression pattern in developing rice seeds --- p.34 / Chapter 2.2.1.1 --- Growth conditions of rice --- p.34 / Chapter 2.2.1.2 --- Collection of developing rice seeds --- p.35 / Chapter 2.2.1.3 --- Total RNA extraction from rice seeds --- p.37 / Chapter 2.2.1.4 --- Total RNA extraction from plant leaf --- p.37 / Chapter 2.2.1.5 --- Gel electrophoresis --- p.38 / Chapter 2.2.1.6 --- First strand cDNA synthesis from rice total RNA --- p.39 / Chapter 2.2.1.7 --- Search for the coding sequence of rice genes related to amino acid metabolism --- p.39 / Chapter 2.2.1.8 --- Alignment of homologous coding sequence between family member genes --- p.42 / Chapter 2.2.1.9 --- Primer design --- p.42 / Chapter 2.2.1.10 --- Quantitation of total RNA and determination of internal control --- p.45 / Chapter 2.2.1.11 --- PCR to amplify the DNA fragments --- p.45 / Chapter 2.2.1.12 --- DNA Sequencing --- p.46 / Chapter 2.2.1.13 --- Generation and testing of single-stranded DIG-labelled DNA probes --- p.46 / Chapter 2.2.1.14 --- Northern blot --- p.47 / Chapter 2.2.1.15 --- RT-PCR (Reverse-transcription polymerase chain reaction) --- p.48 / Chapter 2.2.2 --- Expression assay of selected genes in herbicide treated plants --- p.49 / Chapter 2.2.2.1 --- Growing conditions and herbicide treatments --- p.49 / Chapter 2.2.2.2 --- GCN2 homologue in Arabidopsis and rice --- p.51 / Chapter 2.2.2.3 --- RT-PCR to analyze the change in expression level of selected genes in herbicide treated plants --- p.53 / Chapter 2.2.3 --- Generation of transgenic Arabidopsis --- p.56 / Chapter 2.2.3.1 --- Preparation of T-vector for T-ligation --- p.56 / Chapter 2.2.3.2 --- Cloning of Arabidopsis GCN2 gene --- p.56 / Chapter 2.2.3.3 --- Transformation of the plasmid into DH5a competent cell --- p.57 / Chapter 2.2.3.4 --- Screening of right recombinants --- p.58 / Chapter 2.2.3.5 --- Construction of chimeric AtGCN2 genes --- p.59 / Chapter 2.2.3.6 --- Transformation of electro-competent Agrobacterium cell --- p.60 / Chapter 2.2.3.7 --- Transformation of Arabidopsis by vacuum infiltration --- p.61 / Chapter 2.2.3.8 --- Selection of hemizygous and homozygous transgenic plants --- p.61 / Chapter 2.2.3.9 --- Screening of the T3 transformants --- p.63 / Chapter 2.2.3.10 --- Expression analysis of homozygous AtGCN2 transgenic Arabidopsis --- p.63 / Chapter 3. --- Results --- p.63 / Chapter 3.1 --- Profiling genes expression pattern in developing rice seeds --- p.63 / Chapter 3.1.1 --- Quantification of total RNA from seeds at different developing stages --- p.63 / Chapter 3.1.2 --- DNA sequence analysis --- p.66 / Chapter 3.1.3 --- Profiling the gene expression in developing rice seeds --- p.67 / Chapter 3.1.3.1 --- Expression profiles of nitrogen assimilation related genes --- p.67 / Chapter 3.1.3.2 --- Expression profiles of aspartate pathway genes --- p.72 / Chapter 3.1.3.3 --- Expression profiles of branched-chain amino acid synthesis pathway genes --- p.78 / Chapter 3.2 --- Relationship between GCN2 and amino acid metabolism in plants --- p.82 / Chapter 3.2.1 --- GCN2 homologue in A. thaliana and rice --- p.82 / Chapter 3.2.2 --- GCN2 and amino acid starvation --- p.85 / Chapter 3.2.3 --- Effects of amino acid starvation on GCN2 expression --- p.90 / Chapter 3.2.3 --- Changes in the expression level AK and BCAT genes in herbicide treated rice and A. thaliana --- p.93 / Chapter 3.3 --- Characterization of GCN2 transgenic A. thaliana --- p.96 / Chapter 3.3.1 --- Construct of pBI121-AtGCN2 --- p.96 / Chapter 3.3.2 --- Construction of GCN2 transgenic A. thaliana --- p.96 / Chapter 3.3.3 --- Expression of GCN2 in transgenic A. thaliana --- p.97 / Chapter 3.3.4 --- Expression level changes of AK and BCAT in transgenic A. thaliana --- p.99 / Chapter 4. --- Discussions --- p.101 / Chapter 4.1 --- Expression pattern of selected metabolic genes in developing plant seeds --- p.101 / Chapter 4.1.1 --- Most genes studied displayed a similar pattern --- p.101 / Chapter 4.1.2 --- Regulation of gene expression in developing rice seeds --- p.105 / Chapter 4.2 --- GCN2 and its role in higher plants --- p.106 / Chapter 4.2.1 --- The existence of the GCN2 gene in rice --- p.106 / Chapter 4.2.2 --- GCN2 responses solely to amino acid starvation --- p.106 / Chapter 5. --- Conclusion and Prospective --- p.109 / Reference --- p.111 / Appendix I: Chemicals and reagents --- p.124 / "Appendix II: Buffer, solution and gel" --- p.126 / Appendix III: Commercial kits --- p.128 / Appendix IV: Equipments and facilities used --- p.128