Gene editing is a new tool in the fight against devastating crop disease. It is hoped that when the government reports on its consultation into the regulation of genetic technologies, a distinction will be made between techniques for editing and modification, accelerating the development of disease resilience in crops like the banana.
Tropic Biosciences, based on the Norwich Research Park, is focussed on improving disease resistance and performance of commercial crops.
The company has developed a novel gene editing technique that could allow breeders to achieve a desired trait in a matter of months, rather than the years it takes to achieve the same result through more traditional methods of breeding.
Improving the plant’s immune response
Gilad Gershon, CEO of Tropic Biosciences, explains that bananas are particularly vulnerable to disease: “Almost all bananas produced globally for export are from the same variety known as the Cavendish, which is being attacked by a strain of fusarium fungus called TR4.”
TR4 causes the ‘Panama disease’ which began in South East Asia in the 1990s and is now spreading across the world, to Australia and the Middle East. In 2019 it was detected in the Americas, where 85% of the world’s bananas are grown.
“The United Nations deems the banana the world’s fourth most important food crop, and the disease will have a catastrophic effect on the fragile economy of the countries that produce bananas,” says Gilad. “We are working on developing a new variety of banana that is more resistant to Panama disease.”
Role of genes in resistance to disease
The blueprint for designing any organism is in its genetic code. The genes control the expression of traits – these are desirable characteristics that help the plant survive and reproduce. Genetic variation results in a diverse population of individuals, which ensures that some will have resistance to disease. There is very little variation in the banana crop and this means that disease will spread rapidly, killing all the plants.
Tropic Biosciences has developed a technique called Gene Editing induced Gene Silencing (GEiGS) which enables subtle changes to the way the plant expresses its genes. The novel gene editing technique could allow breeders to achieve a desired trait in a matter of months, rather than the years it takes to achieve the same result through more traditional methods of breeding.
Gilad explains: “All plants produce small strands of RNA that control the activity of some of their own genes. Recent studies have shown that some of these RNA strands are used within the plant’s immune system to suppress the genes in pathogens such as TR4, crippling the invaders.”
GEiGS can potentially be applied to any plant species, and Tropic Biosciences is currently undertaking tests of the technology in rice and other commercial crops.
Gene editing vs genetic modification
Unlike Genetic Modification (GM), which introduces genes from another species, gene editing makes alterations to the plant’s own genetic code, producing changes that could be made, more gradually, using traditional breeding methods.
At the moment, due to a legal ruling from the European Court of Justice in 2018, gene editing is regulated in the same way as GM. However, the UK government is currently in the process of reviewing this ruling, and a public consultation on the regulation of genetic technologies ran from 7th January to 17th March 2021.
Huge worldwide potential for novel gene editing technique
Gilad sees huge potential for the GEiGS technology in areas of the world where gene editing is allowed, as it is step forward from existing gene editing techniques.
“Previous gene editing work is primarily designed to ‘knock out’ genes, and the success is often binary – it either causes a dramatic effect or nothing at all – and can take years to introduce as the plant has multiple copies of the gene. Our technology overcomes both these issues as it focusses on the regulatory pathway of the gene, not the gene itself, which means the desired trait can be achieved much faster than ever before.”
Gilad is one of the speakers at the Agri-TechE event ‘Advances in Breeding for Agriculture – New Tools for New Solutions’ on 23rd September from 1.30pm – 5pm.
Gilad will be joined by Helen Sang of the Roslin Institute, Ingo Hein of the James Hutton Institute, Thomas Ferrugia, CEO of Betabugs, Liz Jenkinson, CEO of Biocleave, Mike Coffey of the SRUC, and others.