Carbon uptake and water use by plants: is there pre-stomatal control? Society relies on mathematical descriptions of climate change, weather forecasting, crop performance, and other processes in which the control of carbon uptake and water loss by plants forms a basic element. Scientists also use the same element in ascribing sources and sinks of carbon dioxide (CO2), describing vegetation, hydrological and ecological processes. A key physiological assumption in this element is now in doubt and ....Carbon uptake and water use by plants: is there pre-stomatal control? Society relies on mathematical descriptions of climate change, weather forecasting, crop performance, and other processes in which the control of carbon uptake and water loss by plants forms a basic element. Scientists also use the same element in ascribing sources and sinks of carbon dioxide (CO2), describing vegetation, hydrological and ecological processes. A key physiological assumption in this element is now in doubt and we will test it rigorously and if necessary provide a robust alternative. We will do this by developing a novel 'window' on intact leaf functioning that will reveal the concentration of water vapour and other gases inside leaves.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
Active bicarbonate transporters from cyanobacteria: physiological properties, genetic regulation, and introduction into plants for crop improvement. An intriguing set of membrane transport proteins that accumulate bicarbonate into marine cyanobacterial cells will be investigated. These proteins support the crucial process of photosynthetic carbon dioxide fixation in marine cyanobacteria (blue-green algae), which are major contributors to global carbon dioxide sequestration and form one of the f ....Active bicarbonate transporters from cyanobacteria: physiological properties, genetic regulation, and introduction into plants for crop improvement. An intriguing set of membrane transport proteins that accumulate bicarbonate into marine cyanobacterial cells will be investigated. These proteins support the crucial process of photosynthetic carbon dioxide fixation in marine cyanobacteria (blue-green algae), which are major contributors to global carbon dioxide sequestration and form one of the foundations of the marine food web. These bicarbonate "transporters" will also be transferred into a model plant system to test whether the efficiency of photosynthesis can be improved, with corresponding gains in the water-use efficiency of these plants. If successful this technology will have profound global implications for improving crop production in semi-arid areas.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
Proteome Analysis of Plant Response Pathways to Microbial Signals in the Model Legume, Medicago truncatula. This project will investigate plant responses to soil microbes in the model legume, Medicago truncatula, to provide fundamental information needed to design crops with improved abilities to interact beneficially with soil microbes. Plant development and performance are significantly influenced by soil microbes, but it is largely unknown how the information contained in microbial signalling ....Proteome Analysis of Plant Response Pathways to Microbial Signals in the Model Legume, Medicago truncatula. This project will investigate plant responses to soil microbes in the model legume, Medicago truncatula, to provide fundamental information needed to design crops with improved abilities to interact beneficially with soil microbes. Plant development and performance are significantly influenced by soil microbes, but it is largely unknown how the information contained in microbial signalling molecules is relayed to plants. Proteome analysis and immunocytochemistry will be combined to identify and localise differentially expressed proteins in roots treated with specific microbial signal molecules. Annotated Proteome databases will be generated to strengthen and complement an international project on M. truncatula genome analysis.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
Photosynthetically active bicarbonate transporters from cyanobacteria & their rational redesign for application in engineered crops that use less water. Marine blue-green algae are critical components of global primary productivity and fisheries productivity but CO2 acquisition processes in these organisms are poorly understood. Our aim is to determine the protein structure and regulatory controls present in two classes of cyanobacterial bicarbonate transporters that are required for efficient p ....Photosynthetically active bicarbonate transporters from cyanobacteria & their rational redesign for application in engineered crops that use less water. Marine blue-green algae are critical components of global primary productivity and fisheries productivity but CO2 acquisition processes in these organisms are poorly understood. Our aim is to determine the protein structure and regulatory controls present in two classes of cyanobacterial bicarbonate transporters that are required for efficient photosynthesis. This information is now critical to the our goal of redesigning these bicarbonate transporters so they will be functional in plants, thereby contributing to the applied objective of engineering crop plants that could produce good grain yields with reduced water requirements.Read moreRead less
Physiological and molecular controls of plant transpiration efficiency: investigating the role of the ERECTA gene. Water is the single most limiting factor in agriculture and the world's supply of fresh water is diminishing, the greatest fraction of total water use being by agriculture. Progress in water-use efficiency will have social value, and this program should help us to achieve it. Our progress in this area is already one of the most successful of 'bottom-up' approaches - in the sense of ....Physiological and molecular controls of plant transpiration efficiency: investigating the role of the ERECTA gene. Water is the single most limiting factor in agriculture and the world's supply of fresh water is diminishing, the greatest fraction of total water use being by agriculture. Progress in water-use efficiency will have social value, and this program should help us to achieve it. Our progress in this area is already one of the most successful of 'bottom-up' approaches - in the sense of transferring knowledge from biochemistry and biophysics to breeding and agronomy, as CSIRO now has a successful wheat breeding program based on this earlier work of ours. Now that we have discovered a gene that controls water-use efficiency at the leaf level, we wish to see how the gene works, and how it affects mineral nutrition of leaves.Read moreRead less