04 July 2015 | Online since 2003

Secrets of potato blight could help farmers fight back



2 February 2014 00:59:02|Arable,Cereal,Crops,News

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.

Download




Comments


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

To post comment without approval login or register

Display name

Please enter your name

Email (optional)
Comment

Please enter your comment

Post Comment

Your comment submitted successfully.Please wait for admin approval.

Some error on your process.Please try one more time.



Jobs


Start Date: 24 June 2015
Start Date: 3 July 2015
M486: Biosolids Advisor - Bucks/Beds/Herts

Advisory and liaison role, working for a leading UK company which is well known within the Agricultural Sector. Day to day re...


Start Date: 3 July 2015
M487: Junior Grain Trader / Commodity Trader - East

De Lacy Executive are working with our client, a leading UK commodity business, to find a talented Junior Grain Trader, or Tr...


Start Date: 20 June 2015
Experienced arable operator for job near Stonehaven, Scotland.

We are farming 1000 ac - primarily growing oil seed rape and other cereals and also doing additional contracting work in the ...


Start Date: 23 June 2015
Experienced 360 excavator driver - 14 tonner or General farm worker: Job in Oxfordshire

Experienced 360 excavator driver, required for 10 week contract in Oxfordshire. Ideal chance to earn good money over the...





Top stories you may have missed
5 June 2015 | Cattle

A strong pound and increased red meat imports coupled with a plentiful dome...


5 June 2015 | Arable

Depression is affecting Wales' farming industry and there is a need to use ...


5 June 2015 | Arable

With just one week to go before the final judging and announcement of the w...


5 June 2015 | Finance

A rural law expert has highlighted the importance of good succession planni...


5 June 2015 | Farmshops

A south Yorkshire dairy farming family is pulling out all the stops to prom...


4 June 2015 | Finance

Predicting what is going to happen to wheat prices is a challenge, but in s...


4 June 2015 | Agri Safety

A Lancashire based livestock theft prevention scheme is aiming to go nation...


4 June 2015 | News

A female farmer has been recognised by the farming and conservation industr...


4 June 2015 | Finance

The new Conservative government appears to be preparing to implement cuts f...


4 June 2015 | Arable

The Rural Payments Agency (RPA) will have mobile support units at the follo...