Potato famine pathogen packs unusual, sneaky genome
Quick-changing zones may be key to the microbe’s vexing adaptability
By Susan Milius
No cheese, but there’s extra stuffing in a potato pathogen’s genome.
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A supersized, unusual arrangement of DNA could help explain why the microbe that caused the Irish potato famine continues to overwhelm plants bred to resist it, says Sophien Kamoun of Sainsbury Laboratory in Norwich, England. He and 94 other researchers from around the world unveil the genome of Phytophthora infestans online September 9 in Nature.
This funguslike microbe causes a fatal crop disease called late blight in potatoes and tomatoes. In the 1840s, the blight began destroying Ireland’s mainstay potato crops, eventually leaving some million people to starve and driving others to migrate in history-making waves. Potatoes remain important worldwide, now the fourth largest food crop, and late blight continues to give farmers nightmares, destroying some $6.7 billion of harvest a year.