Genetic and Hormonal Regulation of Plant Growth. Leguminous plants make a substantial contribution to the Australian economy. To ensure future growth, we need to know more about how legume development is regulated. Genetic mutants, typically affecting the growth-promoting gibberellin plant hormones, played a key role in the green revolution, which transformed agriculture world-wide. Recent results show that gibberellin acts in concert with another hormone, auxin. We will generate new auxin-relat ....Genetic and Hormonal Regulation of Plant Growth. Leguminous plants make a substantial contribution to the Australian economy. To ensure future growth, we need to know more about how legume development is regulated. Genetic mutants, typically affecting the growth-promoting gibberellin plant hormones, played a key role in the green revolution, which transformed agriculture world-wide. Recent results show that gibberellin acts in concert with another hormone, auxin. We will generate new auxin-related mutants that will help us to understand how auxin and auxin-mediated interactions affect crop architecture and performance. Further benefit will accrue from training of students in state-of-the-art techniques, and the generation of new germplasm for use by other researchers and plant breeders. 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
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
Microgenomics - a tool to dissect effects of salinity on gene expression in specific cell types of Arabidopsis and rice. This project will provide novel, fundamental understanding of the cell type-specific processes involved in salinity tolerance in higher plants. As such, it will impact on our understanding of a range of processes relevant to salinity tolerance, an area of great importance to Australian agriculture and environmental sustainability. The increased understanding arising from this ....Microgenomics - a tool to dissect effects of salinity on gene expression in specific cell types of Arabidopsis and rice. This project will provide novel, fundamental understanding of the cell type-specific processes involved in salinity tolerance in higher plants. As such, it will impact on our understanding of a range of processes relevant to salinity tolerance, an area of great importance to Australian agriculture and environmental sustainability. The increased understanding arising from this project will underpin future work to increase agricultural productivity and the quality of life for all in the Australian and international communities.Read moreRead less
Elucidating the interactions between drought tolerance and photoprotection in plants. The 2002-03 drought cost Australia in the order of $10Billion and 70,000 jobs. Associated with reduced rainfall is increased sunlight irradiance, which exacerbates the reduction in crop yield due to the combined damage of a water deficit and oxidative damage caused by the excess light. Plants have networks of responses to minimise damage due to drought and excess light. We have identified a novel class of genes ....Elucidating the interactions between drought tolerance and photoprotection in plants. The 2002-03 drought cost Australia in the order of $10Billion and 70,000 jobs. Associated with reduced rainfall is increased sunlight irradiance, which exacerbates the reduction in crop yield due to the combined damage of a water deficit and oxidative damage caused by the excess light. Plants have networks of responses to minimise damage due to drought and excess light. We have identified a novel class of genes that optimise or alter different aspects of these networks and we wish to define the nature of that optimisation to determine how it could be transfered to crop plants.Read moreRead less
Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will cap ....Molecular analysis of photosynthetically-linked, active CO2 uptake and CO2 signal transduction by cyanobacteria (blue-green algae). Cyanobacteria (blue-green algae) have evolved a very efficient means of capturing and concentrating CO2 for photosynthetic fixation into sugars, the basic building blocks for cell growth. This process is dependent on the operation of several unique, active uptake systems for CO2 and HCO3-, with their genetic expression regulated by CO2 supply. This proposal will capitalize on our progress in describing the functional genetics of this process and aims to elucidate the mechanism of active CO2 uptake and the way that cells sense the ambient CO2 concentration. The information gained is likely to be useful for designing improved crops.Read moreRead less
Chloroplast pigments as developmental signals. This project will define roles of chloroplast pigments in cellular signaling, plant growth and development. Effective communication between the chloroplast and the nucleus is essential for maintaining viability and productivity of the cell. Similarly, long-distance signaling is required for coordinated growth and development and we hypothesise that pigments also have importance in this role. Our proposal brings together the multidisciplinary skills ....Chloroplast pigments as developmental signals. This project will define roles of chloroplast pigments in cellular signaling, plant growth and development. Effective communication between the chloroplast and the nucleus is essential for maintaining viability and productivity of the cell. Similarly, long-distance signaling is required for coordinated growth and development and we hypothesise that pigments also have importance in this role. Our proposal brings together the multidisciplinary skills and resources of six investigators to define how certain carotenoids and chlorophyll precursors regulate gene expression and to determine the identity of what is most likely a carotenoid derivative with hormonal properties that controls lateral branch growth.Read moreRead less
Long noncoding RNAs and their regulatory roles in epigenetic control of gene expression in plants. Epigenetic control of gene expression plays a critical role in development, environmental adaptation, stress response and disease resistance in plants, but its molecular basis remains largely unknown. The proposed study should contribute to the emerging field of epigenetics by discovering new regulatory noncoding RNAs involved in epigenetic mechanisms in plants. These new discoveries could potentia ....Long noncoding RNAs and their regulatory roles in epigenetic control of gene expression in plants. Epigenetic control of gene expression plays a critical role in development, environmental adaptation, stress response and disease resistance in plants, but its molecular basis remains largely unknown. The proposed study should contribute to the emerging field of epigenetics by discovering new regulatory noncoding RNAs involved in epigenetic mechanisms in plants. These new discoveries could potentially provide new opportunities and platforms for improving the performance, yield and quality of crop plants. The proposed study is therefore consistent with the national research priority goals such as breakthrough science, frontier technologies and promoting an innovation culture.Read moreRead less
Calcium compartmentation in leaves: testing an integrated model of water and calcium transport with cell specific functional genomics. Calcium is a vital nutrient to animals and humans and its storage in vegetation is important for its accessibility. We believe this storage is linked to water flow in the leaf by a novel mechanism. This project will provide fundamental understanding of the cell type-specific processes involved in calcium storage and water flow in plants. High calibre PhD and Hono ....Calcium compartmentation in leaves: testing an integrated model of water and calcium transport with cell specific functional genomics. Calcium is a vital nutrient to animals and humans and its storage in vegetation is important for its accessibility. We believe this storage is linked to water flow in the leaf by a novel mechanism. This project will provide fundamental understanding of the cell type-specific processes involved in calcium storage and water flow in plants. High calibre PhD and Honours students will be educated to maintain the momentum of international excellence within Australia in the field of plant nutrient relations. The increase in understanding will allow future work to improve calcium availability and water use by plants to the benefit of agricultural productivity and quality of life.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