No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

There is an urgency to make agriculture more environmentally sustainable and resilient to the changing climate that is exacerbating food insecurity and biodiversity loss. One approach to address this problem is improving crops through biotechnological genome modification, e.g., with CRISPR/Cas9. However, avoiding the regulation associated with genetically modified organism (GMO) labels is necessary for rapid, economical crop development. An alternate approach to transgenic methods of gene editing is the use of protoplasts (cells whose cell wall has been removed) for transient expression and subsequent regeneration of non-GMO, edited plants. However, efficient regeneration of plants from protoplasts is a bottleneck in the implementation of this technique. To create a universal method for protoplast regeneration, there first needs to be a baseline level of regeneration efficiency established in a model organism that is not only easy to work with but can also help us uncover the basic principles governing regeneration. To accomplish this, we are working with Arabidopsis which will allow us to demonstrate enhanced efficiency through culture conditions or ectopic gene expression (e.g., morphogenic transcription factors). Morphogenic transcription factors (MTFs) are a category of genes that coordinate the expression of multiple other genes, guiding the step-by-step formation of organs and embryos. We identified several MTFs that enhance root explant regeneration efficiency through a two-step root-to-shoot regeneration assay, and additionally distinguished the optimal timing of inducing expression of each MTF, either induced early during the callus induction step, late during the shoot induction step, or constantly induced during both steps. Characterizing the optimal induction timing for each MTF that enhances regeneration is crucial for their effective application. For example, when using transient expression in protoplasts for enhanced regeneration together with genetic modification, employing an MTF that boosts regeneration during early induction is likely to be advantageous, given that the MTF is only temporarily present alongside gene editing tools. We additionally investigated the links between these MTFs and their directly and indirectly regulated genetic targets to better understand the mechanistic control each of the MTFs have on regeneration. During these studies, we developed a baseline Arabidopsis protoplast regeneration method. Additionally, we identified five MTFs that enhance root-to-shoot regeneration and analyzed the target genes of the MTF that gave the highest regeneration efficiency. The future aim is to enhance protoplast regeneration using these MTFs. The overall goal of this research is to enhance plant regeneration to make biotechnology for crop trait improvement more broadly applicable. / Doctor of Philosophy / There is an urgency to make agriculture more environmentally sustainable and resilient to the changing climate that is exacerbating food insecurity and biodiversity loss. One approach to address this problem is improving crops through changing the genome in very specific ways. However, avoiding the regulation associated with genetically modified organism (GMO) labels is necessary for rapid, economical crop development. GMO labeling is required for plants that contain genetic characteristics that are not naturally present. To avoid integration of foreign genes while attaining a naturally occurring, beneficial trait, we can use gene editing tools that are temporarily present in a cell, which modify the genome before being degraded. This temporary expression can easily be accomplished using protoplasts, which are individual plant cells that have their cell wall removed. A protoplast with an edited genome must then be regenerated into a non-GMO, edited plant. However, efficient regeneration of plants from protoplasts is a bottleneck in the implementation of this technique. To create a universal method for protoplast regeneration, there first needs to be a baseline level of regeneration efficiency established in an organism that is not only easy to work with but can also help us uncover the basic principles governing regeneration. We accomplished this using Arabidopsis, which allowed us to demonstrate enhanced regeneration efficiency through optimizing protoplast culture conditions. Another approach for enhancing the regeneration efficiency of protoplasts is to alter which genes are present and govern the role of the cell. Overabundance of a gene responsible for plant growth and development could steer the protoplasts towards division and regeneration, when they are naturally unwilling to do so. Morphogenic transcription factors (MTFs) are a category of genes that orchestrate the levels of many other genes, guiding the step-by-step formation of organs and embryos. We identified several MTFs that enhance regeneration efficiency through a two-step root-to-shoot regeneration method, and additionally distinguished the optimal timing of inducing expression of each MTF, either induced early during the first step, late during the second step, or constantly induced during both steps. The induction timing is significant for the application of these MTFs; for instance, to enhance protoplast regeneration when the gene is only temporarily expressed alongside gene editing tools, using an MTF that enhances regeneration during early induction would be advantageous. We additionally investigated the links between these MTFs and their genetic targets that they directly or indirectly regulate to better understand the mechanistic control each of the MTFs have on regeneration. During these studies, we developed a baseline Arabidopsis protoplast regeneration method. Additionally, we identified five MTFs that enhance root-to-shoot regeneration and analyzed the target genes of the MTF that gave the highest regeneration efficiency. The future aim is to enhance protoplast regeneration using these MTFs. The overall goal of this research is to enhance plant regeneration to make biotechnology for crop trait improvement more broadly applicable.

by Lau Wing Chung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1985 / Bibliography: leaves 209-236

by To Siu-wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 182-195). / ACKNOWLEDGEMENTS --- p.VI / ABSTRACT --- p.VII / LIST OF TABLES --- p.IX / LIST OF FIGURES --- p.XI / ABBREVIATIONS --- p.XVII / Chapter PART I --- GENERAL ASPECTS / Chapter CHAPTER 1 --- GENERAL INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- LITERATURE REVIEW / Chapter 2.1. --- History of fungal protoplast fusion / Chapter 2.1.1. --- Fungal protoplast preparation technique --- p.4 / Chapter 2.1.2. --- Application of fungal protoplasts --- p.5 / Chapter 2.2. --- Protoplast fusion by polyethene glycol (PEG) --- p.9 / Chapter 2.3. --- Incompatibility system in fungi --- p.10 / Chapter 2.4. --- Characterization of fusion products by genetic markers --- p.12 / Chapter PART II --- OPTIMIZATION OF PROTOPLAST RELEASE AND PROTOPLAST FUSION STUDIES / Chapter CHAPTER 3 --- PROTOPLAST ISOLATION OF Pleurotus florida AND Schizophyllum commune / Chapter 3.1. --- Introduction --- p.14 / Chapter 3.2. --- Materials and methods / Chapter 3.2.1. --- Strains and culture media --- p.14 / Chapter 3.2.2. --- Protoplast isolation in different types and concentrations of lytic enzyme --- p.15 / Chapter 3.2.3. --- Protoplast isolation using mycelium with different culture ages --- p.17 / Chapter 3.2.4. --- Protoplast isolation in different types and concentrations of osmotic stabilizers --- p.17 / Chapter 3.2.5. --- Collection of protoplast by centrifugation --- p.18 / Chapter 3.3. --- Results / Chapter 3.3.1. --- Effect of type and concentration of lytic enzyme --- p.19 / Chapter 3.3.2. --- Efficiency of protoplast isolation from mycelia with different culture ages --- p.25 / Chapter 3.3.3. --- Effect of types and concentrations of osmotic stabilizers --- p.28 / Chapter 3.3.4. --- Collecting efficiency of protoplast by centrifugation --- p.31 / Chapter 3.4. --- Discussion / Chapter 3.4.1. --- Choice of lytic enzyme system and time for enzyme digestion --- p.33 / Chapter 3.4.2. --- Culture age for maximum protoplast yield --- p.34 / Chapter 3.4.3. --- Choice of concentration and type of osmotic stabilizers --- p.35 / Chapter CHAPTER 4 --- PROTOPLAST FUSION OF Pleurotus florida AND Schizophyllum commune / Chapter 4.1. --- Introduction --- p.38 / Chapter 4.2. --- Materials and methods / Chapter 4.2.1. --- Protoplast formation and size of protoplasts --- p.39 / Chapter 4.2.2. --- Fluorescent staining of protoplasts' nuclei --- p.39 / Chapter 4.2.3. --- Stability of the genetics markers / Chapter 4.2.3.1. --- Preparation of media for checking the presence of genetics markers --- p.40 / Chapter 4.2.3.2. --- Determining the presence of auxotrophic as well as drug resistance markers --- p.42 / Chapter 4.2.4. --- Regeneration of mycelium from protoplast --- p.42 / Chapter 4.2.5. --- Protoplast fusion and screening of fusion products --- p.45 / Chapter 4.3. --- Results / Chapter 4.3.1. --- Size of protoplasts ofPf67 and Scl7 --- p.48 / Chapter 4.3.2. --- Proportion of protoplasts bearing nucleus --- p.48 / Chapter 4.3.3. --- Protoplast regeneration in regeneration medium / Chapter 4.3.3.1. --- Protoplasts regeneration morphologies --- p.52 / Chapter 4.3.3.2. --- Regeneration frequencies and back mutation frequencies of Pf67 and Scl7 protoplasts --- p.58 / Chapter 4.3.4. --- Effect of PEG fusion treatment on auxotrophic and drug resistance markers of Pf67 and Scl7 --- p.60 / Chapter 4.3.5. --- Fusion products obtained from screening process --- p.61 / Chapter 4.4. --- Discussion / Chapter 4.4.1. --- Effect of protoplast isolation and PEG treatment on the two fusion parents --- p.63 / Chapter 4.4.2. --- Structural heterogeneity of protoplasts --- p.64 / Chapter 4.4.3. --- Polymorphic nature of protoplast regeneration --- p.67 / Chapter 4.4.4. --- Protoplast fusion frequence --- p.67 / Chapter PART III --- ANALYSIS OF FUSION PARENTS AND FUSION PRODUCTS / Chapter CHAPTER 5 --- MORPHOLOGICAL AND CYTOLOGICAL STUDIES / Chapter 5.1. --- Introduction --- p.69 / Chapter 5.2. --- Materials and methods / Chapter 5.2.1. --- Strains --- p.69 / Chapter 5.2.2. --- Study on colonial and mycelial morphology --- p.70 / Chapter 5.2.3. --- Fluorescent staining of mycelial nuclei with DAPI --- p.70 / Chapter 5.2.4. --- Study on fruit body and basidial morphology / Chapter 5.2.4.1. --- Fruiting on agar plate --- p.71 / Chapter 5.2.4.2. --- Scanning electron microscopic examination --- p.73 / Chapter 5.3. --- Results / Chapter 5.3.1. --- Variation of colonial morphology --- p.74 / Chapter 5.3.2. --- Morphologies and the number of nuclei in the mycelial cells of fusion parents and fusion products --- p.76 / Chapter 5.3.3. --- Fruit body morphology --- p.82 / Chapter 5.3.4. --- Basidial morphology --- p.84 / Chapter 5.4. --- Discussion --- p.87 / Chapter CHAPTER 6 --- PHYSIOLOGICAL STUDIES OF FUSION PARENTS AS WELL AS FUSION PRODUCTS BY INVESTIGATING THE GROWTH RESPONSES TO DRUGS / Chapter 6.1. --- Introduction --- p.90 / Chapter 6.2. --- Materials and methods / Chapter 6.2.1. --- Strains and media --- p.96 / Chapter 6.2.2. --- Growth responses of the strains to different concentrations of drugs --- p.97 / Chapter 6.3. --- Results / Chapter 6.3.1. --- Comparison of growth pattern as well as growth rate between fusion parents and fusion regenerants --- p.98 / Chapter 6.3.2. --- Growth responses of fusion parents and fusion products on complete medium --- p.105 / Chapter 6.3.3. --- Growth responses of fusion parents and fusion regenerants on complete medium with acriflavin --- p.108 / Chapter 6.3.4. --- Growth responses of fusion parents and fusion products on complete medium with guaiacol --- p.111 / Chapter 6.4. --- Discussion / Chapter 6.4.1. --- General considerations on experimental design --- p.115 / Chapter 6.4.2. --- Growth responses of protoplast regenerants of either fusion parents --- p.116 / Chapter 6.4.3. --- Growth responses on complete medium without fungitoxic drug --- p.117 / Chapter 6.4.4. --- Growth responses on the acriflavin agar medium --- p.118 / Chapter 6.4.5. --- Growth responses on guaiacol agar medium --- p.119 / Chapter 6.4.6. --- Summary --- p.120 / Chapter CHAPTER 7 --- GENETICAL STUDIES / Chapter 7.1. --- Introduction --- p.121 / Chapter 7.2. --- Materials and methods / Chapter 7.2.1. --- Segregation tests of auxotrophic and drug resistance markers in progeny of dikaryotic fusion product --- p.127 / Chapter 7.2.2. --- Complementation test of fusion products as well as the spore germinants of dikaryotic fusion product PS1 --- p.129 / Chapter 7.2.3. --- Recovery of the individual nuclear type of dikaryotic fusion product PS1 --- p.130 / Chapter 7.2.4. --- Genomic fingerprinting / Chapter 7.2.4.1. --- Strains and culture medium --- p.133 / Chapter 7.2.4.2. --- Genomic DNA preparation by cesium chloride (CsCl) method --- p.135 / Chapter 7.2.4.3. --- Genomic DNA preparation by chloroform :TE saturated phenol method --- p.136 / Chapter 7.2.4.4. --- Qualitative analysis of genomic DNA --- p.137 / Chapter 7.2.4.5. --- Quantitative analysis of genomic DNA --- p.137 / Chapter 7.2.4.6. --- DNA amplification by arbitrarily primed -polymerase chain reaction --- p.138 / Chapter 7.3. --- Results / Chapter 7.3.1. --- Progeny analysis and determination of auxotrophic as well as drug resistance markers --- p.140 / Chapter 7.3.2. --- Complementation tests of the fusion products as well as the spore germinants of dikaryotic fusion product PS1 --- p.143 / Chapter 7.3.3. --- Monokaryotic protoplast regenerants of dikaryotic fusion product PS1 --- p.147 / Chapter 7.3.4. --- Studies on extraction of undigested genomic DNA --- p.148 / Chapter 7.3.5. --- Genomic fingerprinting by AP-PCR --- p.155 / Chapter 7.4. --- Discussion / Chapter 7.4.1. --- Genomic DNA extraction --- p.161 / Chapter 7.4.2. --- Recovery of the individual nuclear type of dikaryotic fusion product PS1 --- p.165 / Chapter 7.4.3. --- Genomic changes in fusion products --- p.167 / Chapter 7.4.4. --- Progeny analysis and determination of auxotrophic as well as drug resistance markers --- p.171 / Chapter PART IV --- SUMMING-UP / Chapter CHAPTER 8 --- GENERAL SUMMARY AND CONCLUSION REMARKS / Chapter 8.1. --- General summary --- p.176 / Chapter 8.2. --- Conclusion remarks and future studies --- p.179 / REFERENCES --- p.182 / APPENDIX A SOLUTIONS

by Jiong Zhao. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 197-217). / Acknowledgments --- p.III / Abstract --- p.IX / Abbreviations --- p.XI / Chapter Chapter 1. --- General Introduction --- p.1 / Chapter 1.1 --- What is a mushroom? --- p.1 / Chapter 1.2 --- Mushroom Genetics: its development and prospective --- p.1 / Chapter 1.2.1 --- Genome karyotype by pulsed field gel electrophoresis analysis --- p.2 / Chapter 1.2.2 --- Mitochondrial Genetics --- p.4 / Chapter 1.2.3 --- Mating type genes --- p.5 / Chapter 1.2.4 --- Transformation --- p.7 / Chapter 1.2.5 --- Parasexual processes --- p.8 / Chapter 1.2.6 --- Mushroom breeding --- p.11 / Chapter Chapter 2. --- Literature review: Protoplast fusion in fungi --- p.14 / Chapter 2.1 --- Introduction --- p.14 / Chapter 2.2 --- Protoplast fusion in yeasts --- p.14 / Chapter 2.2.1 --- Intraspecific fusion --- p.14 / Chapter 2.2.2 --- Interspecific fusion --- p.15 / Chapter 2.2.3 --- Intergeneric fusion --- p.16 / Chapter 2.3 --- Protoplast fusion in some Filamentous fungi --- p.17 / Chapter 2.3.1 --- Aspergillus --- p.17 / Chapter 2.3.2 --- Fusarium --- p.18 / Chapter 2.3.3 --- Tricoderma --- p.19 / Chapter 2.4 --- Protoplast fusion in strains --- p.21 / Chapter 2.4.1 --- Protoplast isolation and regeneration --- p.21 / Chapter 2.4.2 --- Intraspecific fusion in mushroom species --- p.24 / Chapter 2.4.3 --- Interspecific fusion in mushroom species --- p.24 / Chapter 2.4.4 --- Intergeneric fusion in mushroom species --- p.26 / Chapter 2.4.5 --- Transfer of nuclei in mushroom species --- p.27 / Chapter 2.5 --- General conclusions about literatures --- p.27 / Chapter 2.5.1 --- Brief points about fungal protoplast fusion --- p.27 / Chapter 2.5.2 --- Some arguements about fusion works in mushrooms strains --- p.31 / Chapter 2.5.2.1 --- Classification of parental strains --- p.31 / Chapter 2.5.2.2 --- Control experiments --- p.31 / Chapter 2.5.2.3 --- Indentification methods of hybrids --- p.32 / Chapter 2.6 --- General research ideas about experiments --- p.33 / Chapter Chapter 3 --- Protoplast isolation and regeneration in some mushroom species --- p.37 / Chapter 3.1 --- Introduction --- p.37 / Chapter 3.2 --- Materials and Methods --- p.38 / Chapter 3.2.1 --- Strains --- p.38 / Chapter 3.2.2 --- Media --- p.38 / Chapter 3.2.3 --- Protoplast release --- p.40 / Chapter 3.2.4 --- Protoplast regeneration --- p.41 / Chapter 3.3 --- Results and Discussion --- p.41 / Chapter 3.3.1 --- Effect of culture age --- p.41 / Chapter 3.3.2 --- Effect of lytic enzyme --- p.42 / Chapter 3.3.3 --- Effect of concentration of mycelium --- p.45 / Chapter 3.3.4 --- Effect of filter system --- p.46 / Chapter 3.3.5 --- Effect of different regeneration protocols --- p.48 / Chapter 3.3.6 --- Effect of soluable starch --- p.49 / Chapter 3.3.7 --- Effect of PEG on the regeneration frequency --- p.50 / Chapter 3.4 --- Conclusions --- p.53 / Chapter Chapter 4 --- Monokaryotization by protoplasting technique in some heterothallic mushroom species --- p.54 / Chapter 4.1 --- Introduction --- p.54 / Chapter 4.2 --- Materials and Methods --- p.55 / Chapter 4.2.1 --- Strains and media --- p.55 / Chapter 4.2.2 --- Production of neo-monokaryons by protoplast technique --- p.55 / Chapter 4.2.3 --- Identification of mating types in protoplasted monokaryons --- p.57 / Chapter 4.3 --- Results / Chapter 4.3.1 --- Formation of neo-monokaryons --- p.57 / Chapter 4.3.2 --- Monokaryotization in different strains --- p.60 / Chapter 4.3.3 --- Comparison of parental and protoplasted monokaryons --- p.60 / Chapter 4.3.4 --- Comparison of regeneration rate of parental monokaryons --- p.62 / Chapter 4.4 --- Discussion / Chapter 4.4.1 --- Differences of regeneration time in monokaryons and dikaryons --- p.64 / Chapter 4.4.2 --- Genetic differences between parental and neo-monokaryons --- p.64 / Chapter 4.4.3 --- Mechanism for the production of neo-monokaryons --- p.65 / Chapter 4.4.4 --- Advantages of protoplasting technique in mushroom breeding --- p.65 / Chapter 4.4.5 --- Protoplasting technique in the identification of fusion hybrids --- p.67 / Chapter 4.5 --- Couclusions --- p.68 / Chapter Chapter 5 --- Intraspecific hybridization in Coprinus cinereus and Schizophyllum commune by PEG-induced protoplast fusion and electrofusion --- p.69 / Chapter 5.1 --- Introduction --- p.69 / Chapter 5.2 --- Materials and Methods / Chapter 5.2.1 --- Strains and Media --- p.70 / Chapter 5.2.2 --- Fusogen --- p.70 / Chapter 5.2.3 --- Inactivation chemicals --- p.71 / Chapter 5.2.4 --- Inactivation of protoplasts --- p.71 / Chapter 5.2.5 --- PEG induced protoplast fusion --- p.72 / Chapter 5.2.6 --- Electrofusion --- p.72 / Chapter 5.2.7 --- Investigation of protoplast fusion yield and fusion frequency --- p.73 / Chapter 5.2.8 --- Comparison of mycelium growth rate --- p.73 / Chapter 5.2.9 --- Fruiting test --- p.74 / Chapter 5.3 --- Results / Chapter 5.3.1 --- Inactivation by IA and DP --- p.76 / Chapter 5.3.2 --- Effect of different fusogens on fusion frequency --- p.79 / Chapter 5.3.3 --- Effect of different fusion protocols on fusion frequency --- p.79 / Chapter 5.3.4 --- Optimization of electrofusion --- p.80 / Chapter 5.3.5 --- Fusion frequency resulted by PEG and electrofusion --- p.83 / Chapter 5.3.6 --- Comparison of colony diameters and fruiting time --- p.84 / Chapter 5.4 --- Discussion / Chapter 5.4.1 --- Inactivation of protoplasts by biochemical inhibitors --- p.85 / Chapter 5.4.2 --- Optimization of PEG induced fusion --- p.86 / Chapter 5.4.3 --- Optimization of electrofusion --- p.86 / Chapter 5.4.4 --- Identification of fusion heterokaryons --- p.87 / Chapter 5.4.5 --- Comparison of PEG and electrofusion --- p.89 / Chapter 5.4.2 --- Effect of mitochondria --- p.90 / Chapter 5.5 --- Couclusions --- p.91 / Chapter Chapter 6 --- Interspecific hybridization between Volvariella volvacea and Volvariella bomhycina by protoplast fusion --- p.92 / Chapter 6.1 --- Introduction --- p.92 / Chapter 6.2 --- Materials and Methods / Chapter 6.2.1 --- Strains and Media --- p.93 / Chapter 6.2.2 --- Protoplast production and regeneration --- p.94 / Chapter 6.2.3 --- Inactivation of protoplasts --- p.94 / Chapter 6.2.4 --- Protoplast fusion --- p.94 / Chapter 6.2.5 --- Selection of fusion products --- p.95 / Chapter 6.2.6 --- Analyses of progeny --- p.95 / Chapter 6.2.7 --- Identification of fusants by protoplasting technique --- p.96 / Chapter 6.2.8 --- Nuclear DNA contents in parents and hybrids --- p.96 / Chapter 6.2.9 --- Genomic DNA amplification by arbitraly primers --- p.96 / Chapter 6.2.10 --- Amplification by nuclear and mitochondrial rDNA --- p.97 / Chapter 6.2.11 --- Fruiting test --- p.97 / Chapter 6.3 --- Results / Chapter 6.3.1 --- Inactivation of Vb10 protoplasts --- p.98 / Chapter 6.3.2 --- Low temperature effect on Vv34 --- p.100 / Chapter 6.3.3 --- Selection of fusants --- p.100 / Chapter 6.3.4 --- Analyses of progeny --- p.106 / Chapter 6.3.5 --- Identification by protoplasting technique --- p.108 / Chapter 6.3.6 --- Nuclear DNA contents in parents and hybrids --- p.110 / Chapter 6.3.7 --- Arbitraly primer amplified PCR fingerprinting --- p.113 / Chapter 6.3.8 --- rDNA PCR results --- p.119 / Chapter 6.3.9 --- Interspecific variations / Chapter 6.3.10 --- Genome analysis of hybrids by pulse field gel electrophoresis / Chapter 6.3.11 --- Fruiting test / Chapter 6.4 --- Discussion / Chapter 6.4.1 --- Strain choice --- p.125 / Chapter 6.4.2 --- Low temperature strains --- p.125 / Chapter 6.4.3 --- Nuclear DNA content --- p.125 / Chapter 6.4.4 --- AP-PCR and RAPDs markers --- p.126 / Chapter 6.4.5 --- Interspecific fusion in Volvariella --- p.126 / Chapter 6.5 --- Couclusions --- p.130 / Chapter Chapter 7 --- Intergeneric hybridization between Schizophyllum commune and Pleurotus florida by protoplast fusion --- p.131 / Chapter 7.1 --- Introduction --- p.131 / Chapter 7.2 --- Materials and Methods / Chapter 7.2.1 --- Strains and Media --- p.132 / Chapter 7.2.2 --- Protoplast fusion --- p.133 / Chapter 7.2.3 --- Analyses of progeny --- p.134 / Chapter 7.2.4 --- Phylogenetic analysis --- p.135 / Chapter 7.2.5 --- Fruiting test --- p.135 / Chapter 7.3 --- Results / Chapter 7.3.1 --- Selection of fusion products --- p.135 / Chapter 7.3.2 --- Analyses of fusion progeny --- p.139 / Chapter 7.3.3 --- Identification by protoplasting technique --- p.143 / Chapter 7.3.4 --- Determination of nuclear DNA contents --- p.145 / Chapter 7.3.5 --- rDNA PCR analysis in fusion --- p.148 / Chapter 7.3.6 --- Identification of hybrids by AP-PCR and RAPDs markers --- p.151 / Chapter 7.3.7 --- Phylogenetic analysis --- p.162 / Chapter 7.3.8 --- Fruiting test --- p.164 / Chapter 7.4 --- Discussion --- p.165 / Chapter 7.5 --- Couclusions --- p.169 / Chapter Chapter 8 --- Protoplast fusion in shiitake and other species --- p.171 / Chapter 8.1 --- Introduction --- p.172 / Chapter 8.2 --- Materials and Methods --- p.172 / Chapter 8.3 --- Results and Discussion --- p.173 / Chapter 8.4 --- Couclusion --- p.179 / Chapter Chapter 9. --- General discussion and conclusions --- p.180 / Appendix 1. Determination of ploidy in some mushrooms --- p.187 / Appendix 2. Genomic DNA Isolation --- p.188 / Appendix 3. Arbitrary primer polymerase chain reaction --- p.190 / Appendix 4. rDNA PCR Amplification conditions --- p.193 / Appendix 5. Pulsed Field Gel Electrophoresis --- p.195 / Appendix 6. Genetic distance analysis in hybrids and their parents --- p.196 / References --- p.197

No description available.

Programmed cell death (PCD) is pervasive in eukaryotes, playing a fundamental role in development. PCD in animals has been studied in detail, partly due to Caenorhabditis elegans, a worm whose anatomy allowed for the investigation of exactly 131 cells that die via PCD. Elucidating this complex pathway in this simple worm laid the foundation for further insights into mammalian PCD. Overall, less is known regarding PCD in plants, where cell death is broadly separated into developmentally regulated and environmentally induced. The lace plant (Aponogeton madagascariensis) undergoes developmentally regulated PCD to form perforations between longitudinal and transverse veins over its leaf surface. The optimization of protoplast isolation and induced cell death via heat shock (HS) in the lace plant is detailed here. Following HS, protoplasts displayed characteristics of PCD including: Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) positive nuclei, increases in vesicles as well as Brownian motion, and plasma membrane blebbing. Additionally, mitochondrial dynamics were investigated, and a role for the mitochondrial permeability transition pore (MPTP) was indirectly established via cyclosporine A (CsA) experimentation. The main focus of this dissertation was to elucidate cellular dynamics during developmentally regulated PCD in the lace plant, which is visibly discernable during the window stage of leaf development. A single areole within a window stage leaf was further divided into three areas based on the progression of PCD; non-PCD (NPCD) cells, early PCD (EPCD) cells, and late PCD (LPCD) cells. Using this gradient, mitochondria were delineated into four stages based on distribution, motility, and membrane potential. Additionally, it was determined that the MPTP also played a role in developmental lace plant PCD, as inhibition of the pore with CsA not only reduced caspase-like proteases (CLPs) but also stopped perforation formation. Furthermore, the actin cytoskeleton was also investigated, with evidence suggesting it as a possible target for CLPs. The novel use of lace plant leaves for long-term live cell imaging allowed for the establishment of a timeline of cellular events that occur during developmental PCD. Major conclusions of this dissertation reveal various similarities between environmental induced and developmentally regulated PCD in this one plant species.

vii, 252 leaves : ill., photos., tables ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1979)--University of Adelaide, Dept. of Agronomy, 1978

Thesis (Ph.D. 1979) -- University of Adelaide, Dept. of Agronomy, 1978.