Scientists Reveal Secrets of Potato Blight

Scientists at Oxford University and The Sainsbury Laboratory discovered vital clues on how the pathogen Phytophthora infestans responsible for the Irish potato famine adapted to spread between plant species.

The study published in Science is the first to explain how pathogens switch from targeting one species to another through changes at the molecular level. The scientists investigated the key family of effectors called EPIC in Phytophthora infestans and sister species Phytophthora mirabilis, a pathogen that split from P. infestans around 1,300 years ago to target the four o'clock flower (Mirabilis jalapa). They found that EPIC effectors can sneak in the plants defences unnoticed to inactivate proteases (enzymes involved in defence systems). The EPIC effectors secreted by P. infestans have evolved to fit the structure of potato proteases just as P. mirabilis has evolved effectors that fit four o'clock proteases.

The researchers plant to breed plants with proteases that can detect the sneaky effectors to improve the resistance of plants. Potato and tomato plants with such proteases would be resistant to the blight pathogens, and combined with other resistant traits could provide another 'wall' of protection against the pathogens.

For more information, visit http://www.ox.ac.uk/media/news_stories/2014/140131_1.html.