A research team from the Scottish Agricultural College (SAC) has discovered a technique that for the first time allows barley – the fourth most important cereal crop grown across the globe – to pre-arm its seeds against attack in a process that may be passed on to subsequent crops.
The new weapon against agricultural pests will mean that farmers do not have to use so much pesticide, thus cutting costs and reducing the amount of chemicals entering the food chain.
The breakthrough is initially expected to help the Scottish barley industry, which supplies distillers with one of the main ingredients of whisky. But the research team hopes that similar benefits will be conferred on wheat, maize and rice as the technique is developed further and help prevent the loss of important food crops at an early stage in their life cycle.
Professor Dale Walters, who led the five-year £900,000 research project funded by the Scottish Government, said the work had found that if parent plants are stimulated to protect themselves against fungal attack the seeds they produce are also programmed with the same “self-defence” mechanism, so helping to protect the next generation. It suggests there could be new ways to help more of the world’s major food crops to resist infection.
“These results raise the possibility of producing seed already primed for resistance to pathogen [disease-causing organisms] attack,” Walters said. “Given the vulnerability of plants to pathogens in the early stages of growth, this kind of natural, in-built protection could be a very useful addition to our battery of crop protection methods.”
Walters, head of the SAC’s crop protection team and an expert in plant pathology, said that the research had mimicked what happens in the wild.
“If you have a plant and the plant is diseased, as it grows it develops an enhanced ability to defend itself against further attacks – similar to a person catching chicken pox.
“But instead of using a microbe which occurs in the wild we used a chemical,” he said.
During the experiment, Walters, helped by senior SAC technician Linda Paterson, sprayed two types of elicitors – chemicals which mimic a disease attack and stimulate the plant to defend itself – on two groups of barley plants at the centre’s greenhouses in Edinburgh. A control group was sprayed with distilled water.
The seeds from all three groups were then harvested, germinated and allowed to grow into a new generation of plants. They were then inoculated with Rhynchosporium commune, a common fungal disease affecting barley.
Walters said that plants grown from the seeds from the elicitor-treated parents exhibited significantly less disease symptoms than seeds from the control group.
The results represented the first report of “transgenerational effects” on pathogen infection resulting from the treatment of plants like barley with chemical elicitors, he added. The next stage would involve examining the results in more detail to see how many generations the effects lasted in barley before moving on to other crops.
The team’s research paper, “Parents lend a hand to their offspring in plant defence,” was published last week in the Royal Society journal Biology Letters.
Once the technique has been developed for commercial use, it promises to both reduce crop loss and cut the amount of chemicals that farmers need to use to protect plants from disease outbreaks. A spokesman for NFU Scotland said: “Barley is the cornerstone of our whisky and beer industries, and with more than 300,000 hectares of barley grown annually in Scotland, it is the most important and most valuable arable crop to Scotland’s farmers.
“Growing plants which are naturally resistant to some fungal diseases, and for that resistance to be passed on to the next generation through the seed, has the potential to strip out a lot of the cost associated with spraying our crops each year.”
Julie Hesketh-Laird, operational and technical affairs director at the Scotch Whisky Association, said: “As one of our key ingredients, barley is vital to our industry.
“In turn, farmers who grow barley benefit from the global success of Scotch. We welcome this research, which uses traditional plant breeding methods and which could help our barley supplies be more sustainable.”
The Scottish Government’s rural affairs secretary, Richard Lochhead, said: “Scotland has a well-earned reputation as a world leader in pioneering agricultural research, which is essential to the continued success of our food and drink industry. The scientific breakthrough on barley disease resistance by the Scottish Agricultural College is very promising and this research will help safeguard the future supply of environmentally sustainable, high quality Scottish barley.”