Scientists unravel DNA puzzle
20 October 2009
Scientists have unravelled the DNA of the pathogen which causes late blight in potatoes, Phytophthora infestans, for the first time. The breakthrough revealed why the disease is so rampant and difficult to eradicate, showing it to be highly adaptable and able to change quickly in response to new circumstances.
The international team of researchers discovered blight has very large genomes – more than twice as large as its closest relatives - with a highly unusual structure. This combination allows the pathogen's genes to evolve rapidly, adapting to infect new plant hosts including previously resistant potato crops.
“It gives us many clues as to which genes might be absolutely required for late blight disease development,” said Dr Stephen Whisson of the Scottish Crop Research Institute, which along with the University of Dundee contributed the British input to the research.
It's hoped that with the genetic blueprint of the pathogen at their disposal, scientists can now develop better disease-resistant varieties and more specific – and environmentally-friendly – controls.
Potato late blight costs the agricultural industry more than £3 billion in crop failures every year, as well as laying waste to home-grown harvests. It thrives in cool, damp weather and, as well as potatoes, can infect tomatoes and other members of the family Solanaceae such as aubergines, Datura, petunias and the weed black nightshade (Solanum nigrum).
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