Project Leader, Organisation

Michelle Moffitt, University of Western Sydney




Before disease symptoms appear, plant pathogens deploy chemical cues, including metabolies and proteins, that impact the speed and degree of pathogenesis.  Some chemical cues act as molecular ‘fingerprints’ as they are pathogen-specific. Plants that are able to recognise these cues are more likely to mount an effective immune response and defend against the disease.  We need to identify the specific chemical cues used by Austropuccinia psidii (myrtle rust) to develop novel screening tools to track early disease occurrence, identify disease tolerant germoplasm and to monitor changes in A. psidii populations.

Objectives and impact

Objectives: This project will identify A. psidii-specific chemical cues produced prior to visible disease and investigate how these cues influence pathogenesis and relate to plant susceptibility. 

Methods: We will employ next-generation sequencing to identify novel fungal protein-coding genes correlated with disease and combine untargeted metabolomics with isotopic tracing to identify A. psidii-specific chemical cues expressed during pathogenesis.  Specifically, we will consider small molecules and proteins released during the interaction between A. psidii and host plants (e.g. Syzygium sp.) exhibiting different disease susceptibility.  This will be complemented with novel mass spectrometry imaging techniques to understand how the distribution of these molecules alters on resistant versus susceptible hosts.


  • Identification of A. psidii-specific chemicals enabling novel, sensitive screening/genetic tests
  • Data on plant traits associated with disease resistance
  • Scoping of new resistance pathways and control options for future research
  • Identification of fast-evolving proteins in A. psidii for use in future population and evolutionary studies

Outcomes/Impact: These data will make significant contributions toward the Myrtle Rust Action Plan including screening for A. psidii and informing breeding strategies (Action 4.3.1), specialist scoping new areas for research (Actions 4.3.3; 4.3.5) and contributing to the methodologies associated with monitoring changes in Australian A. psidii populations (Action 5.3.1).