The authors believe that their research will contribute significantly to the design of new fungicides and resistance in food crops, as they now understand how the mildew can adapt so quickly. "With this knowledge of the genome we can now rapidly identify which genes have mutated, and then can select plant varieties that are more resistant," said Dr Spanu. The genetic codes will also help scientists monitor the spread and evolution of fungicide resistance in an emerging epidemic. "We'll be able to develop more efficient ways to monitor and understand the emergence of resistance, and ultimately to design more effective and durable control measures."
Mildew pathogens are a type of 'obligate' parasite, which means they are completely dependent on their plant hosts to survive, and cannot live freely in the soil. Because they are so dependent, the pathogens have devised a way to disguise themselves in order to avoid the immune response of the host plant and overcome its defences.
"We've now found this happening in lots of fungi and fungal-like organisms that are obligate pathogens," said Dr Spanu, adding that the costly genome inflation could therefore be a trade-off that makes these pathogens successful. "Non-obligate pathogens are not so dependent on their hosts, as they can live elsewhere," said Dr Spanu, "so they are less dependent on rapid evolution."
|Contact: Laura Gallagher|
Imperial College London