Evolution of diverse symbiotic phenotypes among native soil bacteria following spread of a genomic island from a rhizobial inoculant. The quality of legume protein depends on symbiotic nitrogen fixation by root nodule bacteria (RNB). Sustainable legume production in Australian agriculture depends on legume inoculation with effective strains of these bacteria. Unfortunately inoculant strains transfer DNA to other soil bacteria resulting in soil populations of RNB that compete for nodulation but a ....Evolution of diverse symbiotic phenotypes among native soil bacteria following spread of a genomic island from a rhizobial inoculant. The quality of legume protein depends on symbiotic nitrogen fixation by root nodule bacteria (RNB). Sustainable legume production in Australian agriculture depends on legume inoculation with effective strains of these bacteria. Unfortunately inoculant strains transfer DNA to other soil bacteria resulting in soil populations of RNB that compete for nodulation but are less effective in nitrogen fixation. This transfer of DNA threatens a $2 billion asset in Australian agriculture. We will use molecular microbial ecology to investigate the mechanisms of genetic transfer of symbiotic DNA in RNB, and use this knowledge to prevent it.Read moreRead less
Race status, resistance mechanisms, and new sources of resistance to Phytophthora clandestina, a major threat to subterranean clover production. Devastating outbreaks of disease caused by Phytophthora clandestina (Phytophthora root rot) since the late 1970s demonstrated the capacity of this disease to impact severely on clover pasture production across southern Australia, particularly as new races of Phytophthora have rapidly emerged to overcome the resistance of all commercial cultivars. The p ....Race status, resistance mechanisms, and new sources of resistance to Phytophthora clandestina, a major threat to subterranean clover production. Devastating outbreaks of disease caused by Phytophthora clandestina (Phytophthora root rot) since the late 1970s demonstrated the capacity of this disease to impact severely on clover pasture production across southern Australia, particularly as new races of Phytophthora have rapidly emerged to overcome the resistance of all commercial cultivars. The proposed research seeks to delineate new races of the pathogen, to identify the histological and biochemical mechanisms by which resistance to Phytophthora root rot is expressed, and to identify new sources of host resistance. This proposed research will enable breeders, for the first time, to incorporate multiple types of resistance and against different races into new host varieties.Read moreRead less
Harnessing horizontal gene transfer for sustainable nitrogen fixation. This project aims to investigate natural deoxyribonucleic acid (DNA) transfer from nitrogen-fixing bacteria to indigenous bacteria in Australian soils. This project expects to significantly expand our understanding of the molecular and genetic factors contributing to the evolution of ineffective symbiotic bacteria in these soils. An expected outcome of this project is support development of genetically stable bacterial inocul ....Harnessing horizontal gene transfer for sustainable nitrogen fixation. This project aims to investigate natural deoxyribonucleic acid (DNA) transfer from nitrogen-fixing bacteria to indigenous bacteria in Australian soils. This project expects to significantly expand our understanding of the molecular and genetic factors contributing to the evolution of ineffective symbiotic bacteria in these soils. An expected outcome of this project is support development of genetically stable bacterial inoculants for use in agriculture. Inoculation of legumes with nitrogen-fixing symbiotic bacteria is a cheap and environmentally-friendly alternative to chemical fertilisers and contributes $3-4 billion per annum to Australian economy.Read moreRead less
Molecular dissection of resistance to subterranean clover mottle virus using Medicago truncatula. Plant virus diseases cause economic losses in most crop plants. Grain and pasture legumes are an important component of Australian agricultural cropping sytems, and provide human food and animal feed: they also contribute to higher yields of crops like cereals when grown in rotation, by providing nitrogen and a disease break. In this project, the 'model' legume, Medicago truncatula ('Barrel Medic') ....Molecular dissection of resistance to subterranean clover mottle virus using Medicago truncatula. Plant virus diseases cause economic losses in most crop plants. Grain and pasture legumes are an important component of Australian agricultural cropping sytems, and provide human food and animal feed: they also contribute to higher yields of crops like cereals when grown in rotation, by providing nitrogen and a disease break. In this project, the 'model' legume, Medicago truncatula ('Barrel Medic') will be used to identify a new virus resistance gene. The knowledge gained will be used to improve resistance to viruses in crop legumes, so reducing losses and aiding sustainability of production. This will support rural communities and the national economy.Read moreRead less
Molecular approaches for the exploitation of genetic diversity in subterranean clover (Trifolium subterraneum L.) for profitable Australian farming systems. Subterranean clover is the most widely sown annual pasture legume species in southern Australia. It is native to the Mediterranean basin and has been sown over an estimated area of 22 million ha. This project will provide breeders with a focused core germplasm collection representing the range of genetic diversity of the around 8000 accessio ....Molecular approaches for the exploitation of genetic diversity in subterranean clover (Trifolium subterraneum L.) for profitable Australian farming systems. Subterranean clover is the most widely sown annual pasture legume species in southern Australia. It is native to the Mediterranean basin and has been sown over an estimated area of 22 million ha. This project will provide breeders with a focused core germplasm collection representing the range of genetic diversity of the around 8000 accessions in the original collection. The focused core collection will lead to more efficient and effective breeding of elite cultivars for sustainable and profitable farming systems to benefit wool, meat and grains industries.Read moreRead less
Turning sand into sheep feed - Lebeckia ambigua an agricultural perennial! This project aims to develop nitrogen-fixing legumes adapted to the changing climate. Nitrogen fixation from legumes is worth $3 billion to the Australian agricultural economy, but changing rainfall patterns threaten much of this. One solution is to transition pasture growth to a reliance on perennial plants, which are less affected by unseasonal rain. Lebeckia ambigua is an outstanding perennial legume to begin this chan ....Turning sand into sheep feed - Lebeckia ambigua an agricultural perennial! This project aims to develop nitrogen-fixing legumes adapted to the changing climate. Nitrogen fixation from legumes is worth $3 billion to the Australian agricultural economy, but changing rainfall patterns threaten much of this. One solution is to transition pasture growth to a reliance on perennial plants, which are less affected by unseasonal rain. Lebeckia ambigua is an outstanding perennial legume to begin this change, but its nitrogen fixation is compromised by nodulation failure caused by death of its symbiotic rhizobia. This project intends to improve the survival in acid and infertile soils of the unique rhizobial symbionts the research team has discovered for Lebeckia ambigua in South Africa.Read moreRead less
Practical application of gene silencing: is delivery of long double stranded ribonucleic acid (dsRNA) by plant cells efficient in conferring host resistance to parasitic nematodes? Nematode that attack plants cause $120 billion of crop losses worldwide. Chemicals used for their control are being phased out because of environmental concerns, and natural resistance is limited. The aim of this project is to use Australian IP to develop a new form of resistance to nematodes based on knowledge of th ....Practical application of gene silencing: is delivery of long double stranded ribonucleic acid (dsRNA) by plant cells efficient in conferring host resistance to parasitic nematodes? Nematode that attack plants cause $120 billion of crop losses worldwide. Chemicals used for their control are being phased out because of environmental concerns, and natural resistance is limited. The aim of this project is to use Australian IP to develop a new form of resistance to nematodes based on knowledge of the host-pathogen interactions. A successful outcome could contribute an additional 5-20% increase in crop yields (depending on the crop) through inherent resistance of crops to nematode pests. This would benefit rural communities and the national economy, and could also generate international royalties.Read moreRead less
The response of mitochondria to oxidative stress in plants. Crops encounter many situations in their environment which place them under stress. Reactive oxygen molecules produced in these situations act as messengers to trigger defence mechanisms but also cause cellular damage. Mitochondria are the subcellular compartments involved in energy production and are essential for plant development and growth. However, they also have been implicated in the response of plants to stress and pathogen atta ....The response of mitochondria to oxidative stress in plants. Crops encounter many situations in their environment which place them under stress. Reactive oxygen molecules produced in these situations act as messengers to trigger defence mechanisms but also cause cellular damage. Mitochondria are the subcellular compartments involved in energy production and are essential for plant development and growth. However, they also have been implicated in the response of plants to stress and pathogen attack, and in production of reactive oxygen molecules. This proposal seeks to investigate how mitochondria are involved in these processes, focusing on the role of terminal oxidases. Potential outcomes include crops better able to cope with environmental stress.Read moreRead less
Field based molecular diagnostics for identification of plant parasitic nematodes. Nematodes are economically important pests of many agricultural and commercially grown plants. We have shown 'proof-of-concept' that plant parasitic nematodes can be identified by protein profiling using MALDI-TOF mass spectroscopy. In this project advanced techniques of proteomics and associated bioinformatics will be used to identify, isolate and characterise proteins that are specific to economically important ....Field based molecular diagnostics for identification of plant parasitic nematodes. Nematodes are economically important pests of many agricultural and commercially grown plants. We have shown 'proof-of-concept' that plant parasitic nematodes can be identified by protein profiling using MALDI-TOF mass spectroscopy. In this project advanced techniques of proteomics and associated bioinformatics will be used to identify, isolate and characterise proteins that are specific to economically important nematode species and races, and to identify diagnostic proteins or epitopes. The diagnostic proteins will be used to generate specific monoclonal antibodies that will be incorporated into immunochemical 'Lateral Flow' devices. These will provide on-site tests to identify nematodes for growers and quarantine services. Read moreRead less
Combinatorial controlled gene expression delivering crops resistant to nematodes. Root-knot nematodes cause US$130 billion crop losses worldwide pa, and at least AUS$ 450 pa in Australia. Current control methods involve fumigation, chemicals (mainly carbamates and organophosphates), natural plant resistance and biological control. The fumigants (eg methyl bromide) are being phased out because they damage the ozone layer, most of the non-fumigants are being banned because of environmental damag ....Combinatorial controlled gene expression delivering crops resistant to nematodes. Root-knot nematodes cause US$130 billion crop losses worldwide pa, and at least AUS$ 450 pa in Australia. Current control methods involve fumigation, chemicals (mainly carbamates and organophosphates), natural plant resistance and biological control. The fumigants (eg methyl bromide) are being phased out because they damage the ozone layer, most of the non-fumigants are being banned because of environmental damage and persistence in groundwater, and biological control has had limited success. These problems are addressed in this project with development of synthetic plant resistance to nematodes, which will benefit horticultural and broadacre farming by reducing pathogen losses and improving quality.Read moreRead less