Researchers discover a gene that could lead to drought-resistant and allergy-free peanuts
In what could well be a boost for peanut farmers and reprieve for anaphylaxis sufferers worldwide, a team of researchers from International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and University of Western Australia (UWA) have decoded the gene structure of arachis hypogaea – the humble, versatile yet recently much maligned peanut.
Triggered by certain medication, insect venoms and foods such as peanuts, fish and eggs, anaphylaxis, a potentially life-threatening allergic reaction is an ever-increasing phenomenon in modern society. With one in 70 children across the globe seriously affected by peanut allergies alone, stringent measures have had to be implemented, including total ban on nuts.
An important and affordable food source that is extremely rich in proteins and healthy fats, approximately 42 million tonnes of peanuts is produced each year, both as cash and subsistence crop.
The world first study has identified genes in peanuts responsible for both yield and allergy levels, enabling scientists to target both problems at once, according to lead researcher Dr Rajeev Varshney.
“This is an important achievement for the farming community and agricultural industry. This discovery brings us one step closer to creating peanuts that will have significant benefits globally. It has potential to greatly improve the lives of farmers in developing nations by improving nutritional profile and crop yield,” said Varshney, Research Program Director at ICRISAT and Winthrop Research Professor with UWA’s Institute of Agriculture and School of Plant Biology.
Part of the legume family, peanut pods mature below the ground in a root system (therefore erroneously referred to as a “ground” nut), where it could potentially come into contact with contaminants such as broad spectrum herbicides including glyphosate as well as other toxins.
Exposure to aflatoxins (poisonous, cancer causing chemicals produced by moulds due to poor storage) has been identified as the cause of peanut allergy, with 3 per cent of Australians estimated to suffer.
“Major global producers like India as well as countries in Central and West Africa will directly benefit from these findings. Sometimes, the peanuts they produce have high levels of microtoxins. As a result, the produce is not allowed into US and European markets,” he explained.
“If we develop superior varieties, which give greater yield, it will be good for health, and at the same time the farmers who are producing these [low allergen] peanuts will be able to sell those products in the international market,” he said.
Developing drought resistant peanuts will involve genetic selection techniques in practice since the nineteenth century, added Varshney.
He said those varieties could be perfected within the next few years, through the work of specialist scientists known as breeders.
“If you have the markers of the genes associated with those drought problems and disease resistance, we can screen those [selected varieties] in the lab and tell breeders to take only suitable lines into the field. Development times can be reduced from seven or eight years down to three to four.”
Professor Varshney however indicated that producing allergen free peanuts was more complicated, and would take longer and require the use of genetically modified organisms (GMOs).
“And of course you also have the issue of public acceptance,” he pointed out. “So that’s a different story, and I can’t predict how much time that might take.”
But he noted that scientists in countries like the US, where GMOs were less controversial, would be able to make use of the team’s research, which he said could also be helpful in exploring other nut allergies.
“Aflatoxin is also a problem in other nuts as well. So this research will provide some leads to help identify those kinds of genes in other nuts as well.”
Professor Varshney said the next step would be to alter the genes the researchers had identified in the study and test the results in geocarpy (the productive process in the peanut), to develop new varieties of peanuts.
The findings have been published in the journal Proceedings of the National Academy of Sciences (PNAS).
