Dr Peter Dodds has made internationally acclaimed contributions to understanding the molecular basis of fungal rust resistance in plants. Using the genetically defined flax-flax rust system, he isolated the first rust avirulence protein and showed it is secreted into the host plant cell during infection. Dodds showed that this pathogen protein triggers immunity by direct protein-protein interaction with a host resistance protein. He resolved the crystal structure of the avirulence protein and identified polymorphic surface residues as the keys for specific recognition. This work provided the first evidence for a postulate, based on the long standing gene-for-gene hypothesis that direct and specific protein interactions occurred between flax resistance and flax rust avirulence proteins. Dodds' innovative discoveries provide a foundation for the rational design of synthetic rust resistance genes to protect the world's most important food crops from rust diseases.