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
Integrated genetic regulation of photomorphogenesis in Pisum. This project will use a molecular genetic approach in garden pea to investigate the roles of photoreceptors that mediate developmental responses to light. It will define gene families encoding phytochrome, cryptochrome and phototropin photoreceptors, characterise photoreceptor gene expression, and identify mutants with impaired response to light. The mutants will be used in molecular, physiological and biochemical studies to examine h ....Integrated genetic regulation of photomorphogenesis in Pisum. This project will use a molecular genetic approach in garden pea to investigate the roles of photoreceptors that mediate developmental responses to light. It will define gene families encoding phytochrome, cryptochrome and phototropin photoreceptors, characterise photoreceptor gene expression, and identify mutants with impaired response to light. The mutants will be used in molecular, physiological and biochemical studies to examine how photoreceptors control and co-ordinate development throughout the plant via effects on plant hormone synthesis and response. Results from the project will be of practical importance in manipulating key aspects of plant growth to better suit particular environmental and agronomic objectives.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
Systemic control of nodule proliferation. We aim to clone and characterize the functions of the supernodulation (NTS-1) locus of soybean using positional cloning and functional genomics approaches. Supernodulation fascinatingly results from a mutant Nts-1 gene functioning in the shoot, although the phenotype is expressed as excessive nodule proliferation in the root. The cloned gene will be used to monitor expression changes after inoculation with Bradyrhizobium, treatment with nitrate, nod-fac ....Systemic control of nodule proliferation. We aim to clone and characterize the functions of the supernodulation (NTS-1) locus of soybean using positional cloning and functional genomics approaches. Supernodulation fascinatingly results from a mutant Nts-1 gene functioning in the shoot, although the phenotype is expressed as excessive nodule proliferation in the root. The cloned gene will be used to monitor expression changes after inoculation with Bradyrhizobium, treatment with nitrate, nod-factor, xylem exudates and phytohormones. We will use RT-PCR, in situ hybridisation and reporter gene expression in transgenic plants. Microarray analysis of soybean ESTs (4200 arrayed) will analyse concurrent gene expression changes in both root and shoot.Read moreRead less
Genetic and molecular analysis of long-distance gene silencing in Arabidopsis. Gene silencing is a surveillance mechanism in plants and animals to ensure that all genes are switched on or off at the right time. It is also a defence mechanism against viruses. Perturbation of gene silencing can be a cause of genetic diseases, and conversely, gene silencing has immense potential as a therapeutic tool for correcting genetic diseases and curing viral diseases. When silencing is triggered against a ge ....Genetic and molecular analysis of long-distance gene silencing in Arabidopsis. Gene silencing is a surveillance mechanism in plants and animals to ensure that all genes are switched on or off at the right time. It is also a defence mechanism against viruses. Perturbation of gene silencing can be a cause of genetic diseases, and conversely, gene silencing has immense potential as a therapeutic tool for correcting genetic diseases and curing viral diseases. When silencing is triggered against a gene or virus in plants, genetic signals are transmitted throughout the organism to systemically switch off the specific gene or virus. Expected long-term national/community benefits from understanding gene silencing are wide-ranging, from improved crops through to drugs and gene therapy.Read moreRead less
CENTRE for INTEGRATIVE LEGUME RESEARCH. Legumes are essential for environmental sustainability and are important for maintaining human health. The Centre combines innovative genomic approaches to investigate the causal phenotypic links required for regulation of legume growth. The unique coexistence of multiple pluripotent meristems in shoots, roots, flowers and nodules permits the discovery of new paradigms governing legume architecture, reproductive differentiation and root-nodule developmen ....CENTRE for INTEGRATIVE LEGUME RESEARCH. Legumes are essential for environmental sustainability and are important for maintaining human health. The Centre combines innovative genomic approaches to investigate the causal phenotypic links required for regulation of legume growth. The unique coexistence of multiple pluripotent meristems in shoots, roots, flowers and nodules permits the discovery of new paradigms governing legume architecture, reproductive differentiation and root-nodule development. New knowledge of the plant growth processes through mechanistic analysis of organ induction provides the tools to optimise the legume's productivity, quality, and environment adaptation.Read moreRead less
Eco-Turf: Water and nutrient use efficient turfgrasses from Australian biodiversity. Domestic water consumption in Australia is approximately 30% higher than the OECD average. Approximately one third of domestic water consumption is applied to the garden, including turfgrass lawns. Turfgrasses are significant users of fertilisers, which can lead to problems with runoff and infiltration into the water table. We will use the unique diversity of Australian couch grasses to identify new turfs for ....Eco-Turf: Water and nutrient use efficient turfgrasses from Australian biodiversity. Domestic water consumption in Australia is approximately 30% higher than the OECD average. Approximately one third of domestic water consumption is applied to the garden, including turfgrass lawns. Turfgrasses are significant users of fertilisers, which can lead to problems with runoff and infiltration into the water table. We will use the unique diversity of Australian couch grasses to identify new turfs for domestic, sportsground and amenity lawns. This project will develop tools to select turfgrasses that maintain quality with reduced inputs of water and nutrients, leading to an overall reduction in resource use and downstream ecological effects. Benefits of this project extend to urban and rural communities Australia-wide.Read moreRead less
MicroRNA control of gene expression and development in plants. Controlling a gene's activity is fundamental in biotechnology, from dissecting a gene's function to introducing desired traits in crop plants. Recently a new class of genes have been identified that are 'master-regulators' able to control the activity of many genes, and through this, they can ultimately control how an organism develops and functions. By understanding how these genes operate and the extent of their influence, not only ....MicroRNA control of gene expression and development in plants. Controlling a gene's activity is fundamental in biotechnology, from dissecting a gene's function to introducing desired traits in crop plants. Recently a new class of genes have been identified that are 'master-regulators' able to control the activity of many genes, and through this, they can ultimately control how an organism develops and functions. By understanding how these genes operate and the extent of their influence, not only will we gain greater insights into the gene regulatory networks required for multicellular life, but how we may develop methods of controlling gene activity that will have tremendous biotechnological applications.Read moreRead less