Is the extreme phosphate sensitivity found among Australian plants a consequence of their adaptation to a severely phosphate-limited environment? The phosphorus (P)-impoverished soils of south-western Australia have allowed the evolution of many plants that are amazingly efficient at retrieving P from dying tissues. This project will contribute to the understanding of the mechanism determining P efficiency and will contribute significantly to the development of crops that are less reliant on non ....Is the extreme phosphate sensitivity found among Australian plants a consequence of their adaptation to a severely phosphate-limited environment? The phosphorus (P)-impoverished soils of south-western Australia have allowed the evolution of many plants that are amazingly efficient at retrieving P from dying tissues. This project will contribute to the understanding of the mechanism determining P efficiency and will contribute significantly to the development of crops that are less reliant on non-renewable P fertilisers.Read moreRead less
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
Plant Transfer Cells - Discovering the Mechanisms of Wall Ingrowth Formation. This project seeks fundamental molecular understanding of how specialized plant cells that are designed for optimum transport of nutrients develop. So-called "transfer cells" are important for efficient nutrient transport and distribution in many crop species of significance to agriculture. Discovering the mechanisms that coordinate development of these specialized cells will maintain Australia's international reputat ....Plant Transfer Cells - Discovering the Mechanisms of Wall Ingrowth Formation. This project seeks fundamental molecular understanding of how specialized plant cells that are designed for optimum transport of nutrients develop. So-called "transfer cells" are important for efficient nutrient transport and distribution in many crop species of significance to agriculture. Discovering the mechanisms that coordinate development of these specialized cells will maintain Australia's international reputation in this field of research, as well as provide technological opportunities to enhance crop yields by manipulating the efficiency of nutrient distribution in crop species. Read moreRead less
Induction of Plant Transfer Cells - Discovering Regulatory Networks. This project seeks molecular understanding of regulatory mechanisms responsible for inducing formation of specialized plant cells that are of central importance in controlling nutrient transport. These so-called "transfer cells" play pivotal roles in determining crop nutrition and hence yield under normal and stressful environments such as soil nutrient deficiencies and salinity. Discovering regulatory mechanisms that control f ....Induction of Plant Transfer Cells - Discovering Regulatory Networks. This project seeks molecular understanding of regulatory mechanisms responsible for inducing formation of specialized plant cells that are of central importance in controlling nutrient transport. These so-called "transfer cells" play pivotal roles in determining crop nutrition and hence yield under normal and stressful environments such as soil nutrient deficiencies and salinity. Discovering regulatory mechanisms that control formation of these specialized cells will maintain Australia's international reputation in this field of research. In addition, the information platform generated may provide technological opportunities to optimise nutrient flows in healthy plants, combat certain environmental stresses and control pathogen attack.
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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.
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
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
The other half of the G-protein story: Functional analysis of the plant G-protein gamma subunits. It is now established that G-proteins are involved in the transduction of a number of important processes in plants (Cell division, stomata control, defence, light perception, etc). Nevertheless the data accumulated to date is based on the study of one of the two subunits (alpha) of the G-proteins. Almost nothing is known about the role of the second (and independent) subunit: beta-gamma. We will st ....The other half of the G-protein story: Functional analysis of the plant G-protein gamma subunits. It is now established that G-proteins are involved in the transduction of a number of important processes in plants (Cell division, stomata control, defence, light perception, etc). Nevertheless the data accumulated to date is based on the study of one of the two subunits (alpha) of the G-proteins. Almost nothing is known about the role of the second (and independent) subunit: beta-gamma. We will study for the first time the role of the beta-gamma subunit in plants. We will use a comprehensive approach combining biochemical, physiological, phenotypic, genomic and proteomic studies.Read moreRead less