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
Defining New Building Blocks for the Construction of Artificial Genetic Circuits. By characterising the components of a natural genetic switch, we will make available a set of well defined genetic building blocks for construction of rationally designed biological circuits. The ability to build such circuits would have significant economic benefit in areas such as metabolic engineering, to improve the efficiency of production of natural compounds from micro-organisms, and in biomedicine, for the ....Defining New Building Blocks for the Construction of Artificial Genetic Circuits. By characterising the components of a natural genetic switch, we will make available a set of well defined genetic building blocks for construction of rationally designed biological circuits. The ability to build such circuits would have significant economic benefit in areas such as metabolic engineering, to improve the efficiency of production of natural compounds from micro-organisms, and in biomedicine, for the controlled release of therapeutic compounds. The involvement of Honours and Ph.D students in this project will expose the next generation of Australian scientists to this emerging discipline. International collaboration leading to publications in high impact scientific journals will enhance Australia's scientific reputation.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
IMPROVING NITROGEN USE EFFICIENCY IN CROP PLANTS: ROLE OF THE AMMONIUM TRANSPORT FAMILY AMT. Improving nitrogen use efficiency in crop plants will reduce the use of environmentally damaging nitrogen fertilisers that threaten through leaching the sustainability of Australia's agricultural sector and local water ecosystems. Plants contain genes that encode transport proteins required for the uptake of nitrogen (ammonium and nitrate) from the soil. We will identify the in planta activity of the A ....IMPROVING NITROGEN USE EFFICIENCY IN CROP PLANTS: ROLE OF THE AMMONIUM TRANSPORT FAMILY AMT. Improving nitrogen use efficiency in crop plants will reduce the use of environmentally damaging nitrogen fertilisers that threaten through leaching the sustainability of Australia's agricultural sector and local water ecosystems. Plants contain genes that encode transport proteins required for the uptake of nitrogen (ammonium and nitrate) from the soil. We will identify the in planta activity of the AMT family of ammonium transporters and associated signalling pathways which control the uptake and assimilation of ammonium in plants. This project will confirm the mechanisms involved in ammonium uptake from the soil and lead to the development of ammonium-nitrogen efficient crop plants.Read moreRead less
Biosynthesis of nonribosomal peptide toxins in cyanobacteria: A functional characterisation of microcystin synthetase. Microcystins are potent toxins and tumour promoters produced by cyanobacteria associated with blue-green algal blooms. This non-ribosomal peptide is produced by microcystin synthetase, a unique enzyme complex comprised of peptide synthetases, polyketide synthases, and integrated accessory enzymes. We have identified and characterised the extensive gene cluster encoding this enzy ....Biosynthesis of nonribosomal peptide toxins in cyanobacteria: A functional characterisation of microcystin synthetase. Microcystins are potent toxins and tumour promoters produced by cyanobacteria associated with blue-green algal blooms. This non-ribosomal peptide is produced by microcystin synthetase, a unique enzyme complex comprised of peptide synthetases, polyketide synthases, and integrated accessory enzymes. We have identified and characterised the extensive gene cluster encoding this enzyme. This project describes the biochemical characterisation of specific enzyme activities within microcystin synthetase and how they determine the final structure and toxicity of the many forms of microcystin. Interactions between this enzyme complex and its substrate amino acids will provide information for the genetic engineering of this and similar natural products.Read moreRead less
Regulation of Plant Development by Small RNAs. Understanding the roles of small RNAs and their pathways is a new field of research that is giving, and will continue to give profound insights into how multicellular organisms regulate gene expression at a genomic level. Research in this area has already led to RNA interference technology, by which almost any gene can be switched off, and there is considerable potential for other gene silencing and trait modification technologies to emerge. The pro ....Regulation of Plant Development by Small RNAs. Understanding the roles of small RNAs and their pathways is a new field of research that is giving, and will continue to give profound insights into how multicellular organisms regulate gene expression at a genomic level. Research in this area has already led to RNA interference technology, by which almost any gene can be switched off, and there is considerable potential for other gene silencing and trait modification technologies to emerge. The project will yield insights into fundamental biological processes which are expected to engender applications in agriculture and biotechnology. It will maintain and enhance Australia's position in this area.Read moreRead less
A genetic analysis of the role of an atypical hexokinase in gene regulation. This project addresses a question which is relevant to all living things-how do changes in the environment of a cell bring about a change in gene expression? The aim of this project is to investigate the role of hexokinases in gene regulation by studying the Aspergillus nidulans xprF gene, which encodes an an unusual hexokinase. Hexokinases are thought to be the glucose sensors in plants, animals and fungi, and play a ....A genetic analysis of the role of an atypical hexokinase in gene regulation. This project addresses a question which is relevant to all living things-how do changes in the environment of a cell bring about a change in gene expression? The aim of this project is to investigate the role of hexokinases in gene regulation by studying the Aspergillus nidulans xprF gene, which encodes an an unusual hexokinase. Hexokinases are thought to be the glucose sensors in plants, animals and fungi, and play a role in the development of diabetes in humans. In plants, sugars affect many processes including growth, flowering, photosynthesis, nitrogen metabolism, starch synthesis, pigmentation and response to pathogens.Read moreRead less
Targeted bioengineering and systems biology for solar powered hydrogen production in green algal cells. The development of clean fuels to combat climate change and protect against oil price shocks, is an urgent challenge facing our society. Fuels make up ~67% of the energy market, yet most low-CO2 emissions technologies (e.g. nuclear and clean-coal-technology) target the electricity market. In contrast the Solar Bio-H2 process uses algal photobioreactors to drive solar-powered H2 fuel production ....Targeted bioengineering and systems biology for solar powered hydrogen production in green algal cells. The development of clean fuels to combat climate change and protect against oil price shocks, is an urgent challenge facing our society. Fuels make up ~67% of the energy market, yet most low-CO2 emissions technologies (e.g. nuclear and clean-coal-technology) target the electricity market. In contrast the Solar Bio-H2 process uses algal photobioreactors to drive solar-powered H2 fuel production from water (ultimately sea water, facilitating desalination). This project aims to improve the efficiency of the process towards economical levels. The Solar Bio-H2 process reduces water requirements for biofuel production. Locating bioreactors on non-arable land also eliminates competition between biofuel and food production.Read moreRead less
Plant transformation: exploiting anti-apoptosis genes for very high efficiency transformation. Crop improvement through genetic modification depends on the ability to transform target species. The most desirable method is Agrobacterium mediated transformation. However, plant species and cultivars differ significantly in their ability to be efficiently transformed by Agrobacterium. This is particularly true for the economically important cereals. We have discovered that anti-apoptosis genes, whic ....Plant transformation: exploiting anti-apoptosis genes for very high efficiency transformation. Crop improvement through genetic modification depends on the ability to transform target species. The most desirable method is Agrobacterium mediated transformation. However, plant species and cultivars differ significantly in their ability to be efficiently transformed by Agrobacterium. This is particularly true for the economically important cereals. We have discovered that anti-apoptosis genes, which inhibit programmed cell death, dramatically increase the Agrobacterium transformation efficiency in bananas and sugarcane. We will utilise this information and develop the use of these genes to increase the efficiency of transformation in those crops and cultivars that are difficult to transform using Agrobacterium.Read moreRead less
Identification of transcription factor genes involved in the regulation of aspects of photosynthetic capacity in plants. There is increasing evidence to suggest that we may be reaching a yield plateau with many agricultural plants and that future avenues for yield increases may depend on increases in photosynthetic capacity per unit leaf area. Molecular genetic technology offers the promise of the direct manipulation of photosynthetic gene expression to increase photosynthetic capacity. This pro ....Identification of transcription factor genes involved in the regulation of aspects of photosynthetic capacity in plants. There is increasing evidence to suggest that we may be reaching a yield plateau with many agricultural plants and that future avenues for yield increases may depend on increases in photosynthetic capacity per unit leaf area. Molecular genetic technology offers the promise of the direct manipulation of photosynthetic gene expression to increase photosynthetic capacity. This project aims to understand one important part of genetic regulation, the transcription factors, that may determine aspects of photosynthetic capacity. Altered expression of these transcription factors in transgenic plants will be used to test the their ability to control photosynthesis and generate agricultural intellectual property.Read moreRead less