He has maintained a long term interest in various aspects of biological nitrogen fixation. His seminal research identified key components of the molecular dialogue between rhizobia and legumes. He was an early pioneer of the application of proteomics and mass spectrometry to address problems in biology with a focus on nitrogen fixation. A long term interest is the molecular analysis of the flavonoid biosynthesis pathway and the role of flavonoids in regulating plant development. In collaboration with Professor Parish at The John Curtin Medical School of Medical Research he has identified Rhizobium-derived Nod factors, potent regulators of plant development, as modulators of mammalian angiogenesis. He initiated research to understand the lipid biosynthesis pathway in Chlamydomonas reinhardtii and the application of this research to biofuel production. Research interests Regulators of root and shoot architecture Secreted regulatory peptides and flavonoids Biological nitrogen fixation and root nodulation by Rhizobia The identification and characterization of new angiogenesis therapeutics.