Dr Philip O'Brien
Email: obrien@murdoch.edu.au

Qulaifications:

• PhD in Molecular Microbiology, Nat University of Ireland, Galway 1981.

Research Experience:

• University of California, Berkeley:
  Radiation induced mutagenesis in E coli.
• Lawrence Berkeley Laboratory
  Analysis of photosynthetic gene expression in Rhodopseudomonas capsulata.
• CSIRO Division of Plant Industry
  Transformation of tobacco and lucern with genes for high sulphur proteins.

Research

Research Interests

• Development of tests for detection of fungal pathogens in soil and plant debris.
• Molecular genetics of fungal plant pathogens.
• Epidemiology of fungal plant pathogens.
• Genetics and molecular biology of fungal plant interactions.
• Mechanism of action of phosphite in protecting plants against infection by Phytophthora.

Research Outcomes.

In collaboration with researchers at Murdoch University, University of Western Australia, Western Australian Dept. of Conservation and Land Management (DEC), and the University of Adelaide, we have attracted over $3.5m in research funding since 1994, produced 19 undergraduate honours research theses, 6 PhD theses, and over 60 publications.

Current Research projects

1. The effect of phosphite on Arabidopsis thaliana.
   Phosphorus acid (phosphite) is used to control Phytophthora infection of native Australian plant species. The aim of this research is to identify the mechanisms by which phosphite protects the plant. To do this we are using the plant model system Arabidopsis thaliana because it is highly developed as a plant experimental system, it' s genome sequence is known, it can be transformed, and genome wide arrays are available.
   
2. The effect of phosphite on fungal species.
   Phosphite inhibits the growth of fungal species including Phytophthora in vitro. To understand the mechanism of this we are currently isolating genes from Phytophthora cinnamomi that respond transcriptionally to application of phosphite. We plan to extend this project to include Phytophthora sojae, and Saccharomyces cerevisiae as their genomes have been sequenced and S cerevisiae is a highly developed experimental system.
   
3. Molecular methods for detection of Phytophthora species.
   Dieback disease caused by Phytophthora species is ravaging the forests of Western Australia placing thousands of plant species at risk of extinction. Effective disease management depends on knowing where the pathogen is so that we can quarantine affected areas and avoid spreading the disease. We need a diagnostic test that is rapid, sensitive, and specific. We have developed detection tests based on detection of the pathogen' s DNA using microarray mass spec analysis of PCR amplified DNA to enable differentiation of multiple species within a single sample. To achieve the aim of analysing hundreds of samples per day we are developing a robotic system for manipulation of the samples.
   
4. Genetic transformation of Phytophthora species.
   We have successfully transformed Phytophthora cinnamomi with genes for antibiotic resistance and for a fluorescent protein. This has enabled us to identify structures of the pathogen that may be important in survival. The project will focus on developing new vectors and refining the method to get more efficient transformation.

Planned Projects

1. Reproductive biology of Phytophthora cinnamomi.
   This species is the main cause of the dieback epidemic currently raging in WA forests. The aim of this research is to investigate mechanisms of genetic variation in the pathogen, what are the mechanisms by which it survives and spreads, and whether any genetic changes have occurred in the population over time.
   
2. Analysis of virulence mechanisms in P cinnamomi.
   The aim is to identify P cinnamomi genes that determine virulence. We want to know why we get variation in virulence between isolates. This has important implications for disease management.
   
3. Proteomic analysis of phosphite treated host and pathogen.
   Whereas the current projects are focussed on identification of host and pathogens that respond at the transcriptional level to phosphite, this project looks at changes in the proteins. It uses an variety of analytical separation techniques to look at which proteins are labelled with phosphite. The research would also look at the effect of phosphite on protein-protein interaction. This project would use A thaliana as a host and both S cerevisiae and P sojae as pathogens.

For further Information:
If you are interested in entering any of these projects at the Honours, Masters, PhD level, or as a short term visiting researcher, please contact Phil O'Brien at (P.Obrien@murdoch.edu.au)

Click here to view a Selected Publications list...

Centre of Excellence for Climate Change Woodland and Forest Health
School of Biological Sciences and Biotechnology,
Murdoch University
Western Australia 6150
Australia

Ph: +61 (8) 9360 2785
Fax: +61 8 9310 7084
Email: [ Email Philip ]

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