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
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
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
How do nano-molecular carboxysome protein structures function in alpha and beta-cyanobacteria and can we use them for novel reaction compartmentalisation? In blue-green algae, protein nano-structures, known as carboxysomes, act as tiny compartments where carbon dioxide (CO2) can be fixed into simple sugars at high efficiency. This important photosynthetic process forms the basis of global primary productivity on this planet, but most land-based CO2 fixation lacks the efficiency seen in blue-gree ....How do nano-molecular carboxysome protein structures function in alpha and beta-cyanobacteria and can we use them for novel reaction compartmentalisation? In blue-green algae, protein nano-structures, known as carboxysomes, act as tiny compartments where carbon dioxide (CO2) can be fixed into simple sugars at high efficiency. This important photosynthetic process forms the basis of global primary productivity on this planet, but most land-based CO2 fixation lacks the efficiency seen in blue-greens. This research aims to determine how the proteins that make up carboxysomes are 3-dimensionally arranged and how these structures function to enhance rates of CO2 fixation. A more thorough understanding of the carboxysome is likely to have potential applications in industrial nano-technology and improve our understanding of oceanic primary productivity.Read moreRead less
Functional characterisation of the necrotrophic effector proteins Tox1 and Tox3 from the wheat pathogen Stagonospora nodorum. Fungal pathogens cost the Australian agricultural industry over one billion dollars per year. This project will build upon recent key advances to provide a fundamental basis on how fungal pathogens cause disease. The results from this study will promote future advances in disease management with the aim of securing Australian wheat supplies.
Isolation and functional characterisation of a pathogen meta effector able to inhibit detection of multiple disease effectors by resistant plants. The rust fungi are a major economic threat to crop production in Australia. This project will investigate the molecular mechanism used by a rust fungus to prevent detection of multiple disease-inducing proteins by resistant plants and generate knowledge that will lead to the development of new and more effective disease control strategies.
The identification of Mycosphaerella graminicola effectors that promote pathogenicity on wheat. Fungal diseases are one of the greatest challenges to sustainable wheat production in the 21st century. Septoria tritici blotch is one such disease as it inflicts millions of tonnes in yield losses per annum. This project will identify the molecular basis of Septoria tritici blotch and assess its potential as an Australian biosecurity threat.
Control of sucrose source/sink status by the plant immune system. This project aims to investigate the roles of plant malectin receptor kinases in pathogen recognition and response. The project will utilise molecular and cell biological tools to detect complex formation and changes in sugar import into cells. Expected outcomes of this project include a better understanding of how pathogens manipulate plant cells to their benefit, and greater knowledge of which host molecules participate in this ....Control of sucrose source/sink status by the plant immune system. This project aims to investigate the roles of plant malectin receptor kinases in pathogen recognition and response. The project will utilise molecular and cell biological tools to detect complex formation and changes in sugar import into cells. Expected outcomes of this project include a better understanding of how pathogens manipulate plant cells to their benefit, and greater knowledge of which host molecules participate in this process. This should provide significant benefits such as a new theoretical basis to engineer crop plants for resistance against devastating diseases.Read moreRead less