Decoding cereal rust virulence and resistance

Status: Complete

Host immunity as a driver of virulence evolution in cereal rust fungi

Rust diseases of wheat, barley and oats threaten cereal production worldwide. Resistance genes provide effective protection, but rust fungi can evolve to escape their recognition. This BBSRC/NSF-BIO-funded project brought together Niab, CSIRO and the University of Minnesota to investigate how variation in fungal avirulence (Avr) genes enables pathogens to overcome crop resistance.

The team generated high-quality, phased genome assemblies and pan-genome resources for wheat stem rust, barley brown rust and oat crown rust, revealing previously hidden genetic diversity. Comparative genomics and functional experiments characterised variation in wheat stem rust Avr genes and how it affects recognition by wheat resistance genes. The project also advanced virus-based tools for rapid gene function testing in wheat and developed a new gene silencing system for oats. Protein interaction studies identified candidate wheat proteins targeted by rust effectors, providing starting points for further investigation.

Together, these resources and methods deepen understanding of cereal rust evolution and support future pathogen surveillance, resistance gene discovery and more durable crop resistance.