Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein a ....Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein assembles without difficulty. This project will devise strategies for controlling this variability that will facilitate attempts to exploit plastid transformation for transplanting better versions of the photosynthetic CO2-fixing enzyme, Rubisco, into plants to improve their growth efficiency in terms of water, fertiliser and light use.Read moreRead less
Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or ....Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or light. The most efficient Rubiscos are more complex, with two different types of subunits which, in plants, are encoded in different subcellular compartments (nucleus and plastid). This proposal addresses the challenges associated with complementary engineering both genomes to substitute foreign Rubiscos into higher-plant chloroplasts.Read moreRead less
Stomatal function in transgenic plants with altered guard cell metabolism. Guard cells on the surface of leaves control the rate of water loss and CO2 uptake by changing stomatal aperture in response to environmental signals such light, CO2, humidity and water status. Guard cells therefore play a major role in determining plant productivity and water use efficiency. This project aims to examine the contribution of guard cell energy and carbon metabolism in mediating stomatal responses to the env ....Stomatal function in transgenic plants with altered guard cell metabolism. Guard cells on the surface of leaves control the rate of water loss and CO2 uptake by changing stomatal aperture in response to environmental signals such light, CO2, humidity and water status. Guard cells therefore play a major role in determining plant productivity and water use efficiency. This project aims to examine the contribution of guard cell energy and carbon metabolism in mediating stomatal responses to the environment in intact plants through the generation and analysis of transgenic plants with altered guard cell function. This will aid in the development of strategies for direct manipulation of stomatal function.Read moreRead less
New models for the role of chromatin in controlling inducible gene expression. This proposal aims to test novel models of how packaging of DNA in the nucleus plays a fundamental role in gene expression. Understanding these concepts is important in the context of successful gene therapy where major hurdles need to be overcome. This work also has implications for somatic cell therapy since it is important to understand how genes are expressed in order to successfully reprogram cells. Both of these ....New models for the role of chromatin in controlling inducible gene expression. This proposal aims to test novel models of how packaging of DNA in the nucleus plays a fundamental role in gene expression. Understanding these concepts is important in the context of successful gene therapy where major hurdles need to be overcome. This work also has implications for somatic cell therapy since it is important to understand how genes are expressed in order to successfully reprogram cells. Both of these areas are important to the Biotechnology industry. Answering questions about higher order chromatin structure in gene transcription will provide cutting edge, innovative knowledge that will have international significance. Read moreRead less
Organophosphate pesticide degradation: evolved enzymes and biomimetics for bioremediation and medicine. Organophosphate (OP) pesticides are an indispensable part of modern agriculture - their use results in dramatically increased crop yields. However, they are toxic and can damage the environment and cause significant health problems. Enzymes are currently being used to treat runoff water that is contaminated with OPs. The same enzymes also have the potential to aid in the treatment of OP poison ....Organophosphate pesticide degradation: evolved enzymes and biomimetics for bioremediation and medicine. Organophosphate (OP) pesticides are an indispensable part of modern agriculture - their use results in dramatically increased crop yields. However, they are toxic and can damage the environment and cause significant health problems. Enzymes are currently being used to treat runoff water that is contaminated with OPs. The same enzymes also have the potential to aid in the treatment of OP poisoning. However, OP degrading enzymes could be improved in many ways - we will evolve these enzymes to enhance their catalytic properties - to enable them to act more efficiently on an increased number of OPs. Read moreRead less
Identifying potential barriers to transplanting modified forms of the CO2-fixing enzyme, Rubisco, into plants. Improving the ability of crops to use water, light and fertiliser more efficiently would have economic benefits and ease the environmental impacts associated with agricultural practices. It is thought that such improvements can be made by enhancing the efficiency of the photosynthetic protein, Rubisco, which fixes most of the CO2 in the biosphere. The research proposed here uses unique ....Identifying potential barriers to transplanting modified forms of the CO2-fixing enzyme, Rubisco, into plants. Improving the ability of crops to use water, light and fertiliser more efficiently would have economic benefits and ease the environmental impacts associated with agricultural practices. It is thought that such improvements can be made by enhancing the efficiency of the photosynthetic protein, Rubisco, which fixes most of the CO2 in the biosphere. The research proposed here uses unique Rubisco transplantation capabilities that I have developed to improve our fundamental understanding of how Rubisco is processed and its activity regulated in plants. This will pave the way for our ongoing efforts to engineer and transplant more efficient Rubisco into crops.Read moreRead less
Role of a novel zinc-binding motif in the structure-function of deubiquitinating enzymes. The ubiquitin pathway destroys many proteins that control cell function and growth, by attaching ubiquitin to them and marking them for degradation. Deubiquitinating enzymes (DUBs) regulate protein destruction by controlling the amount of ubiquitin attached. DUBs and the ubiquitin pathway can also be manipulated in biotechnology applications. However, very little is known about the structure/function of DUB ....Role of a novel zinc-binding motif in the structure-function of deubiquitinating enzymes. The ubiquitin pathway destroys many proteins that control cell function and growth, by attaching ubiquitin to them and marking them for degradation. Deubiquitinating enzymes (DUBs) regulate protein destruction by controlling the amount of ubiquitin attached. DUBs and the ubiquitin pathway can also be manipulated in biotechnology applications. However, very little is known about the structure/function of DUBs. We have identified a new zinc-binding motif in DUBs, and we will explore how this contributes to their structure, and interactions with other proteins. This will significantly enhance our knowledge of how DUBs function in both biotechnology and in controlling cell function.Read moreRead less
Epigenetic silencing in vertebrates: evolution and function from the bottom-up. The primary benefits are contribution to Australia's knowledge base and raising the profile of functional genomics in Australia, with the research priority of Frontier Technologies for Building and Transforming Australian Industries and priority goals in Breakthrough Science and Frontier Technologies. This project focuses on important biological questions surrounding gene regulation and sex chromosome evolution. Inte ....Epigenetic silencing in vertebrates: evolution and function from the bottom-up. The primary benefits are contribution to Australia's knowledge base and raising the profile of functional genomics in Australia, with the research priority of Frontier Technologies for Building and Transforming Australian Industries and priority goals in Breakthrough Science and Frontier Technologies. This project focuses on important biological questions surrounding gene regulation and sex chromosome evolution. International attention has already resulted in genome characterization of Australian icons (wallaby, Tasmanian devil and platypus), more research on these, and other Australian animals, will further highlight the importance of Australian fauna and impact positively on our scientific profile.Read moreRead less
Origin and evolution of genes on the human X chromosome. Two groups of functionally related genes are found on the human X chromosome in disproportionately high numbers. I will test whether an uneven distribution of genes is common in mammalian genomes, or whether the human X is special. I will test hypotheses of how the gene groups arose on the human X by comparing their location and expression patterns in other mammals, and other vertebrates. It will then be clear whether the ancestral autosom ....Origin and evolution of genes on the human X chromosome. Two groups of functionally related genes are found on the human X chromosome in disproportionately high numbers. I will test whether an uneven distribution of genes is common in mammalian genomes, or whether the human X is special. I will test hypotheses of how the gene groups arose on the human X by comparing their location and expression patterns in other mammals, and other vertebrates. It will then be clear whether the ancestral autosome was ?chosen?, whether it ?selfishly? accumulated these genes, or whether the function of genes changed in response to selective pressures.Read moreRead less
Small is beautiful: Did gene-rich regions of mammal chromosomes evolve from microchromosomes? Most birds and reptile genomes feature many tiny microchromosomes. These are not junk, as previously thought, but contain most of the genes. Mammals lack microchromosomes, but contain gene-rich regions with similar attributes. We suggest that microchromosomes originated by genome duplication, and evolved into the gene-rich regions of mammalian chromosomes. We will test this hypothesis by comparing seque ....Small is beautiful: Did gene-rich regions of mammal chromosomes evolve from microchromosomes? Most birds and reptile genomes feature many tiny microchromosomes. These are not junk, as previously thought, but contain most of the genes. Mammals lack microchromosomes, but contain gene-rich regions with similar attributes. We suggest that microchromosomes originated by genome duplication, and evolved into the gene-rich regions of mammalian chromosomes. We will test this hypothesis by comparing sequences and genes in microchromosomes of birds, reptiles and monotremes. This will clarify the origin and evolution of the ?microgenome?, establish its suitability as a model for vertebrate genome organisation, and demonstrate whether microchromosomes are the ancestors of the gene-rich regions of mammalian chromosomes.Read moreRead less