LATERAL GENE TRANSFER, GENOME EVOLUTION AND THE EMERGENCE OF NEW DISEASES CAUSED BY FUNGAL PATHOGENS IN THE PLEOSPORALES. Normal evolution involves the transfer of genes within species. The modest variation between progeny powers natural selection. Lateral gene transfer is the movement of genetic material between species. It allows for large evolutionary steps. Although common in bacteria, it has rarely been described convincingly in higher organisms such as fungi, plants or animals. We have evi ....LATERAL GENE TRANSFER, GENOME EVOLUTION AND THE EMERGENCE OF NEW DISEASES CAUSED BY FUNGAL PATHOGENS IN THE PLEOSPORALES. Normal evolution involves the transfer of genes within species. The modest variation between progeny powers natural selection. Lateral gene transfer is the movement of genetic material between species. It allows for large evolutionary steps. Although common in bacteria, it has rarely been described convincingly in higher organisms such as fungi, plants or animals. We have evidence that one group of fungal pathogens is particularly adept at acquiring new genes that enable them to cause new diseases. We will determine the mechanism and frequency of gene transfer in this group. The work had fundamental significance in evolutionary biology, in the emergence of new diseases and in the use of genetically-modified organisms.Read moreRead less
Molecular basis of synergy between PIs and defensins against fungi. The plant defensin nicotinamide adenine dinucleotide dehydrogenase subunit 1 (NaD1) has potent antifungal activity against agricultural and human pathogens and has potential in the treatment of serious diseases that affect crop production and human health. NaD1 has been found to permeabilise membranes and allows entry of other molecules into the fungal cytoplasm. While screening for molecules that enhance the activity of defensi ....Molecular basis of synergy between PIs and defensins against fungi. The plant defensin nicotinamide adenine dinucleotide dehydrogenase subunit 1 (NaD1) has potent antifungal activity against agricultural and human pathogens and has potential in the treatment of serious diseases that affect crop production and human health. NaD1 has been found to permeabilise membranes and allows entry of other molecules into the fungal cytoplasm. While screening for molecules that enhance the activity of defensins a number of proteinase inhibitors were identified that act synergistically with NaD1. This project aims to identify the molecular basis of this synergy which is expected to lead to better control of fungal diseases of crops and in humans.Read moreRead less
Genome evolution & adaptation of the multinuclear wheat stripe rust fungus. Animals and plants package their genomes into a single nucleus within each cell. In contrast, millions of fungal species accommodate multiple nuclei containing individual haploid genomes. It is currently unknown what the evolutionary implications are for this unusual genome division into multiple nuclei. Here we explore the evolutionary consequences of genome division into multiple nuclei for the first time by applying c ....Genome evolution & adaptation of the multinuclear wheat stripe rust fungus. Animals and plants package their genomes into a single nucleus within each cell. In contrast, millions of fungal species accommodate multiple nuclei containing individual haploid genomes. It is currently unknown what the evolutionary implications are for this unusual genome division into multiple nuclei. Here we explore the evolutionary consequences of genome division into multiple nuclei for the first time by applying cutting edge genome biology tools and algorithms. The economically significant study system is the devastating wheat stripe rust fungus. This pathogen costs Australian farmers over $100 million a year. New understanding is expected to lead to better disease management, reduced fungicide applications, and increased yields.Read moreRead less
Factors controlling ectomycorrhizal contributions to plant N nutrition. This project aims to define the mechanistic link between nitrogen metabolism in symbiotic ectomycorrhizal fungi and its effect on the quantity of nitrogen shared with a plant host. Using a genetically diverse population of a key Australian fungal species, the project expects to uncover genetic features related to nitrogen metabolism that correlate to improved support of plant nutrition. Expected outcomes include better under ....Factors controlling ectomycorrhizal contributions to plant N nutrition. This project aims to define the mechanistic link between nitrogen metabolism in symbiotic ectomycorrhizal fungi and its effect on the quantity of nitrogen shared with a plant host. Using a genetically diverse population of a key Australian fungal species, the project expects to uncover genetic features related to nitrogen metabolism that correlate to improved support of plant nutrition. Expected outcomes include better understanding of plant-microbe interactions, groundwork for tools to better model the role of fungi in soil nutrient cycling and guidelines for plant:fungal pairings in reforestation practices. Overall, these should provide significant benefit to the global effort in understanding the role of soil microbes in plant nutrition.Read moreRead less
Characterising controls of carbon flow from trees into mycorrhizal fungi. This project aims to improve our understanding of below-ground carbon sequestration. A significant portion of plant photosynthate is shuttled to root-associated mutualistic ectomycorrhizal fungi in forest ecosystems. Therefore, fungal partners of forest trees are valuable carbon sinks. One problem impeding below-ground carbon accounting in forest soils is a lack of understanding concerning the genetic control of how photos ....Characterising controls of carbon flow from trees into mycorrhizal fungi. This project aims to improve our understanding of below-ground carbon sequestration. A significant portion of plant photosynthate is shuttled to root-associated mutualistic ectomycorrhizal fungi in forest ecosystems. Therefore, fungal partners of forest trees are valuable carbon sinks. One problem impeding below-ground carbon accounting in forest soils is a lack of understanding concerning the genetic control of how photosynthetically fixed sugars are passed to root-associated microbes. This project aims to identify and characterise the sugar transporters that shuttle carbon in ectomycorrhizal plant–fungal interactions and investigate how these are affected by elevated carbon dioxide. It may also identify isolates of mutualistic fungi that could be paired with eucalypt hosts to maximise carbon sequestration and forest productivity.Read moreRead less
Closing the carbon cycle: an ecological understanding of wood decay. The project aims to understand the controls on the return of carbon to the atmosphere within forests, especially focusing on this problem from a microbial perspective. Microbial dynamics and wood decay are crucially important for the global carbon cycle. What the field is lacking is a trait-based ecology of wood decomposers. The project plans to examine the interactions among fungal and oomycete endophytes and decomposers throu ....Closing the carbon cycle: an ecological understanding of wood decay. The project aims to understand the controls on the return of carbon to the atmosphere within forests, especially focusing on this problem from a microbial perspective. Microbial dynamics and wood decay are crucially important for the global carbon cycle. What the field is lacking is a trait-based ecology of wood decomposers. The project plans to examine the interactions among fungal and oomycete endophytes and decomposers through a series of experiments. The expected outcome of this project is a clear understanding of the role of traits in wood decomposer communities, especially their influence on priority effects, competitive hierarchies, and the resultant wood decay rate.Read moreRead less
Plant : fungal symbioses in Australian forests - new perspectives using laser microdissection. Ericaceae are important components of the Australian flora in many habitats, including forests and fragile alpine regions that are significant to Australia's cultural and natural heritage, and several species are considered threatened. This project addresses the fundamental question of whether networks of symbiotic fungal mycelia act as below-ground bridges between Ericaceae plants and tree roots. If d ....Plant : fungal symbioses in Australian forests - new perspectives using laser microdissection. Ericaceae are important components of the Australian flora in many habitats, including forests and fragile alpine regions that are significant to Australia's cultural and natural heritage, and several species are considered threatened. This project addresses the fundamental question of whether networks of symbiotic fungal mycelia act as below-ground bridges between Ericaceae plants and tree roots. If demonstrated, this would alter current views of carbon and nutrient cycling in Australian forests and provide the basis for better informed decisions for the sustainable management of Australian forest resources. This is particularly important in the context of carbon sequestration and future climate change.Read moreRead less
Exploiting microbial metabolites to understand fungal biology. The project aims to investigate the principles of hyphal growth in fungi, by studying the mechanisms of action of a bacteria-derived compound that inhibits hyphae. Changing cell shape between yeast and hyphae is a prototype developmental switch enabling fungi to escape stressful environments, while hyphal invasion promotes fungal infections of animals and plants that endanger food security and biodiversity. By using interdisciplinary ....Exploiting microbial metabolites to understand fungal biology. The project aims to investigate the principles of hyphal growth in fungi, by studying the mechanisms of action of a bacteria-derived compound that inhibits hyphae. Changing cell shape between yeast and hyphae is a prototype developmental switch enabling fungi to escape stressful environments, while hyphal invasion promotes fungal infections of animals and plants that endanger food security and biodiversity. By using interdisciplinary approaches of microbiology and chemistry, the expected outcomes are to generate deep knowledge of an important microbial process and how it could be modulated, characterise a new bacterial compound and build research capacity at the nexus of biology and chemistry to benefit discoveries in academia and industry.Read moreRead less
Switching partners: a driving force for tree productivity in a changing environment? Eucalypts take part in a mutually beneficial association with diverse communities of mycorrhizal fungi to satisfy nutrient demands. The fungi that eucalypts interact with change as they grow but the reasons for this shift are not known. To improve forestry management strategies, the project will determine why and how this shift occurs.
Understanding the T cell repertoire in health and disease. Immune recognition of viruses usually involves a large number of different 'killer T cells' that kill cells infected by virus. However, during prolonged infection or in the elderly the number of different killer T cells that recognise the virus is greatly reduced. This reduction in the diversity of the immune response allows the virus to avoid immune recognition, and leads to more severe infection. We aim to understand how diversity is ....Understanding the T cell repertoire in health and disease. Immune recognition of viruses usually involves a large number of different 'killer T cells' that kill cells infected by virus. However, during prolonged infection or in the elderly the number of different killer T cells that recognise the virus is greatly reduced. This reduction in the diversity of the immune response allows the virus to avoid immune recognition, and leads to more severe infection. We aim to understand how diversity is generated in the immune response, and how it becomes narrowed with age or prolonged infection. This information can be used to design vaccines for persistent infections such as HIV, and to improve immune control of infection in the elderly.Read moreRead less