Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air insi ....Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air inside leaves based on stable isotope analysis of carbon dioxide and water vapour exchanged between leaves and air. The project is expected to provide fundamental knowledge about how stomata regulate photosynthesis and water use, with significant implications for modelling vegetation function and for improving the performance of crop plants.Read moreRead less
Guanylate cyclases - an expanding family critical in plant growth and development. The enzyme guanylate cyclase (GC) forms an important signalling molecule. We have identified unique GC molecules from higher plants. We shall use strategic basic research to determine the biological importance of these novel molecules in plant growth and development. We have formed an international team to achieve these goals and also to develop strong scientific links between Australia and other countries such as ....Guanylate cyclases - an expanding family critical in plant growth and development. The enzyme guanylate cyclase (GC) forms an important signalling molecule. We have identified unique GC molecules from higher plants. We shall use strategic basic research to determine the biological importance of these novel molecules in plant growth and development. We have formed an international team to achieve these goals and also to develop strong scientific links between Australia and other countries such as South Africa. The outcomes will provide new insight into the biological function of the novel GCs. Consequently, the new knowledge is critical to the development of novel biotechnological approaches to benefit sustainable agriculture in Australia.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
Tree-mediated methane fluxes: A new frontier in the global carbon cycle. Methane is an extremely potent greenhouse gas. Recent evidence suggests that tree-mediated fluxes may be a significant, but overlooked source of methane to the atmosphere. This project aims to quantify the magnitude and drivers of tree-mediated methane fluxes from Australia’s dominant forest types. Innovatively, we will be using a novel combination of empirical field based measurements, gas tracer experiments, microbial ana ....Tree-mediated methane fluxes: A new frontier in the global carbon cycle. Methane is an extremely potent greenhouse gas. Recent evidence suggests that tree-mediated fluxes may be a significant, but overlooked source of methane to the atmosphere. This project aims to quantify the magnitude and drivers of tree-mediated methane fluxes from Australia’s dominant forest types. Innovatively, we will be using a novel combination of empirical field based measurements, gas tracer experiments, microbial analysis and modelling methods. Expected outcomes are a mechanistic understanding of tree-mediated methane fluxes, helping to constrain regional, national and global methane budgets. The results of this study will help inform publicly funded greenhouse gas abatement strategies, ensuring a maximal return on investment.Read moreRead less
Will stomatal responses to humidity and carbon dioxide constrain tropical forest productivity as atmospheric carbon dioxide rises? This project will investigate two physiological processes that will partly determine growth responses of tropical forest trees to rising atmospheric carbon dioxide. The project will produce equations summarising physiological responses that can be incorporated into process-based models of tropical forest productivity.
Reading the isotopic archive: carbon and oxygen stable isotope ratios as recorders of plant physiological processes. This project will investigate how plant physiological processes are reflected in stable isotope ratios of carbon and oxygen in plant tissues. Results will contribute towards a mechanistic understanding of the processes that cause isotopic modifications, thereby enabling an improved interpretation of naturally occurring stable isotope signals.
Comparative eco-physiology of two contrasting arid-zone woodlands in Central Australia: hydrological niche separation and ecosystem resilience. This proposal addresses two fundamental questions: how do co-occurring species co-exist and why do Australian ecosystems have larger ecosystem water-use-efficiencies than those in the USA? This proposal will: determine the resilience of two contrasting arid-zone woodlands; compare variation in hydraulic-related plant traits across co-existing species; an ....Comparative eco-physiology of two contrasting arid-zone woodlands in Central Australia: hydrological niche separation and ecosystem resilience. This proposal addresses two fundamental questions: how do co-occurring species co-exist and why do Australian ecosystems have larger ecosystem water-use-efficiencies than those in the USA? This proposal will: determine the resilience of two contrasting arid-zone woodlands; compare variation in hydraulic-related plant traits across co-existing species; and, determine the relative contribution of changes in assimilation and stomatal conductance to variation (across species and time) in water-use-efficiency. Outcomes of this work include a mechanistic understanding of the behaviour of water-limited woodlands in current and future climates. This is significant because such biomes are globally important and are home to two billion people. Read moreRead less
Genome Approaches to Investigate Metabolic Coordination in Plant Cells. Metabolism of C and N in legume nodules requires interaction between the symbiotic bacteria and plant organelles, particularly metabolism in plastids and mitochondria. Fixed N is assimilated through the de novo synthesis of purines in both plastids and mitochondria. However, each of the nine pathway enzymes is encoded by a single gene, indicating each protein is targeted to both organelles. Purine metabolism will provide ....Genome Approaches to Investigate Metabolic Coordination in Plant Cells. Metabolism of C and N in legume nodules requires interaction between the symbiotic bacteria and plant organelles, particularly metabolism in plastids and mitochondria. Fixed N is assimilated through the de novo synthesis of purines in both plastids and mitochondria. However, each of the nine pathway enzymes is encoded by a single gene, indicating each protein is targeted to both organelles. Purine metabolism will provide a model to assess the more general occurrence of dual-targeted proteins in plants. The aim is to identify and eventually exploit the signalling mechanism(s) that mediate communication between plastids and mitochondria.Read moreRead less
Engineering plants via modified microtubule dynamics. The plant microtubule cytoskeleton is involved in many economically important functions such as controlling growth and development, cellulose deposition, and responses to pathogens and salinity. This project will increase our understanding of how the regulation of the microtubule cytoskeleton affects these processes and move us nearer to achieving economically important goals, such as the development of crop plants with improved traits. Thi ....Engineering plants via modified microtubule dynamics. The plant microtubule cytoskeleton is involved in many economically important functions such as controlling growth and development, cellulose deposition, and responses to pathogens and salinity. This project will increase our understanding of how the regulation of the microtubule cytoskeleton affects these processes and move us nearer to achieving economically important goals, such as the development of crop plants with improved traits. This project will also help maintain Australia's position at the forefront of plant cell and molecular biology.Read moreRead less
Impacts of groundwater extraction on ecophysiology of Australian trees. The aim of this project is to determine the response of trees to the extraction of shallow groundwater. Groundwater-dependent ecosystems rely on a supply of groundwater to maintain ecosystem health, structure and function, and excessive depletion of groundwater resources has a negative impact on these ecosystems. The project intends to combine a field-scale experimental depletion of groundwater resources simultaneously with ....Impacts of groundwater extraction on ecophysiology of Australian trees. The aim of this project is to determine the response of trees to the extraction of shallow groundwater. Groundwater-dependent ecosystems rely on a supply of groundwater to maintain ecosystem health, structure and function, and excessive depletion of groundwater resources has a negative impact on these ecosystems. The project intends to combine a field-scale experimental depletion of groundwater resources simultaneously with alterations in rainfall input and measurements of tree responses. The results of the project are intended to inform industry regulators and the water supply industry on how to improve management of both groundwater and vegetation resources.Read moreRead less