Puccinia striiformis is a fungus that causes stripe rust on cereal crops and grasses. Stripe rust appears as yellow powdery pustules on the leaf surface, arranged in stripes parallel to the veins in the leaf. It can affect plants at all stages of growth. Wind spreads spores within crops, and over long distances.

Puccinia graminis is is the casual agent of stem rust on wheat and barley. As infection damages the plant tissue through which nutrients are transported to the grain, shrivelled grain is produced by the diseased plants. Damage is greatest when the disease becomes severe before the grain is completely formed.

There are several species of Fusarium that infect cereals causing crown rot in arid regions like Australia and head blight in wetter areas, predominantly in North America, Europe and Asia. In Australia the two most prominent species are Fusarium pseudograminearum and F. graminearum.

Rhizoctonia solani is a soil borne, root infecting fungus that causes the broad spectrum bare patch, root rot and seedling damping off diseases to wheat. Diseases caused by R. solani have become more prevalent throughout Western Australia in recent years following the introduction of minimum tillage practices. The fungus primarily survives from year to year in intact roots and crop debris.

Pyrenophora tritici-repentis is the necrotrophic fungus which causes the disease tan spot (or yellow leaf spot) of wheat. The fungus produces small tan-brown flecks on lower leaves which expand into larger brown blotches. Large spots often coalesce when conditions are favourable for disease development and heavily infected leaves may wither and die.

Stagonospora nodorum is the fungus that causes the disease glume blotch (or Stagonospora nodorum blotch) in all wheat growing areas of the world. The disease affects all wheat growing regions of Australia and is responsible for estimated annual losses of over $100 million per annum¹.

Aphids are sap-sucking insects where feeding success involves a combination of disguising their presence and suppressing plant defences. In addition to direct damage caused by feeding, aphids are also major vectors for disease transmission, responsible for transmitting over 50% of insect vectored viruses.

Mycosphaerella graminicola is the casual agent of septoria leaf blotch, a disease which costs the Australian wheat industry over $100 million each year in damages¹. The fungus causes pale grey to dark brown blotches on the leaves, and to a lesser extent the stems and heads.

Plant-pathogen interactions involve complex chemical defence and counter-defence mechanisms produced by host and pathogen, respectively. Bioplatforms Australia metabolomics capabilities will be employed to generate datasets to address the critical gap in our knowledge of wheat chemical defences and pathogen metabolites. Further information will be posted as work in this area progresses.