Agri-Shop Ltd
23 October 2016 | Online since 2003
Briefing Media - FG Classified

FarmingUK Logo
2 February 2014 00:59:02 |

Secrets of potato blight could help farmers fight back

Scientists have discovered vital clues as to how the pathogen responsible for the Irish potato famine adapted to spread between different plant species.
Researchers at Oxford University and The Sainsbury Laboratory, Norwich, looked in unprecedented detail at how Phytophthora infestans, a pathogen that continues to blight potatoes and tomatoes today, evolved to target other plants.
The study, published in the journal Science, is the first to show how pathogens switch from targeting one species to another through changes at the molecular level. Researchers examined the biochemical differences between Phytophthora infestans and sister species Phytophthora mirabilis, a pathogen that split from P. infestans around 1300 years ago to target the Mirabilis jalapa plant, commonly known as the four o'clock flower. They found that each pathogen species secretes specialised substances to shut down the defences of their target hosts.
"Plants have these enzymes called proteases that play a key role in their defence systems," said Dr Renier van der Hoorn, co-author of the study from Oxford University's Department of Plant Sciences.
"When a plant becomes infected, proteases help plants to attack the invading pathogens and trigger immune responses. P. infestans secretes substances called effectors that disable proteases in potatoes and tomatoes. These are highly specialised to block specific proteases in the host plant, fitting like a key into a lock."
The effectors secreted by P. infestans are less effective against proteases in other plants such as the four o'clock, as they do not fit well into the 'locks'. The researchers found that P. mirabilis evolved effectors that disable the defences of the four o'clock plant but are no longer effective against potatoes or tomatoes.
"For the first time, we have found a direct molecular mechanism underpinning the change in host specialisation,' said Dr van der Hoorn. 'We looked at specialisation in the blight pathogens' secret weapon, a key family of effectors called 'EPIC' that can pass through plants' defences undetected to disable the proteases. 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.
"If we could breed plants with proteases that can detect these stealthy EPIC effectors, we could prevent them from 'sneaking in' and thus make more resistant plants. Within the next decade, we plan to exploit the specialised nature of these effectors to develop proteases that are resistant to their action or can even trap them and destroy the pathogen. 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 defence against the pathogens."
The study was funded by the Gatsby Charitable Foundation, the UK Biotechnology and Biological Sciences Research Council, Ohio State University and the US Department of Agriculture.


0 Comment


Please enter your name


Please enter your email

Please enter valid email


Please enter your comment

Post Comment

Your comment has been submitted successfully. Please wait for admin approval.


No comments posted yet. Be the first to post a comment

Australia | 21 October 2016
Local bloc seeks to counter bid for Australian cattle empire

Nationalist lawmakers have teamed up with local ranchers to try to counter a bid involving Chinese buyers for the S. Kidman & Co. cattle empire, in what would be one of Australia’s biggest agribusines...

USA | 21 October 2016
Arizona farmers give back by donating milk to food banks

43 million gallons of milk have been dumped in fields across the country since the start of the year. That's why many American farmers have been forced to do with lower milk prices not bringing in...

USA | 21 October 2016
Your groceries may be cheaper, but farmers and supermarkets feel the pain

If you’re just a little irked that gasoline prices have edged up recently, maybe this will cheer you up: Groceries are a bargain. Average supermarket prices fell 2.2% in September from a year ago, ...

Canada | 21 October 2016
Farmers fail to rally to tax revolt talk

If farmland property taxes are too high, don’t pay them. That’s what Dugald farmer Edgar Scheurer suggested while commenting on Facebook about Manitoba Co-operator stories on skyrocketing farmland ...

United Kingdom | 21 October 2016
Woman killed in cattle attack on family farm

A woman has been killed after she was attacked by cattle on a family farm in Co Derry. The pensioner, who has been named locally as Brigid McKeefry and is aged in her 70s, was rushed to the Causewa...

Trending Now


Top stories you may have missed