British study opens up new ways to fight widespread potato disease
British scientists have discovered a gene in the bacterium that causes a plant disease known as blackleg that could help to fight the disease. When the particular gene in the bacterium Erwinia
carotovora is inactivated, its ability to damage the plant is severely inhibited, found researchers at the University of Cambridge.
Erwinia caritivora affects a wide range of plants, including carrots, tomatoes, onions and potatoes, causing blackleg and soft rot. It does so by producing enzymes that break down its host’s
cell walls. The degraded cell walls provide nutrients to the bacterium. In the case of potatoes, the disease caused by the bacterium is particularly economically damaging. The newly discovered
gene helps the bacterium recognise when nutrients are running low. When it is inactivated, the bacterium can no longer export enzymes to break down the cell walls.
‘We have shown that the production of cell wall degrading enzymes is genetically linked to not only signalling abilities but also to the bacterium’s nutritional status,’ says research leader Dr
Martin Welsh from the University of Cambridge. ‘This has important implications for researchers looking for new ways to control the disease. By improving our understanding of how Erwinia
carotovora rots the plant, we can reveal additional, possibly novel targets for the eventual development of anti-rot agents. We have also opened up the potential to develop pesticides.’
‘Blackleg is one of the key diseases across all sectors of the British potato industry,’ Dr Mike Storey, research and development director of the British Potato Council, comments. ‘The findings
from the University of Cambridge are important as they could offer novel solutions, both to help store potatoes and to control the disease. Soft rots in particular are a concern for many crops
going in store this season because of the warm and wet growing conditions. We rely on careful storage management as most varieties of potato have no inbuilt resistance to soft rot and there are
no available pesticides.’