1. The future for gene editing in agriculture

1.1 How safe are gene-edited crops?

Gene editing permits small, targeted and permanent changes to the DNA sequence of an organism that are passed on to subsequent generations. This technology can be used to engineer more productive crops, better able to tolerate disease and extreme environmental stress. In contrast to traditional breeding, it enables precise changes in the genome and therefore more predictable results.

Gene editing is not currently used for food production in the UK. Some researchers believe that gene-edited plants should be utilised in agriculture. They have argued that gene editing introduces changes that could occur ‘naturally’. A survey of 113 academic experts published in the journal Plant Biotechnology found that 76% of respondents believed gene-edited crops posed ‘fewer risks to society’ than conventionally bred counterparts.

Academics have argued that the health risks of gene editing are overstated. The Royal Society has said that there is no reason to believe changes made using gene editing “present a greater risk to human health” than equivalent changes achieved using traditional breeding. Indeed, they stated that genome editing is likely to involve fewer unexpected changes in the DNA sequence than traditional breeding.

Some scientists have made clear that although they support utilisation of gene editing, robust measures are required to ensure safety. Professor John Dupre from the University of Exeter said that “a robust regulatory process” was needed. Agreeing, Professor Lesley Torrance, director of science at the James Hutton Institute, said “it is important to thoroughly scrutinise new breeding technologies to ensure the highest standards for food safety”.

Other researchers have raised concerns that unexpected changes in the plant DNA sequence due to gene editing can be inherited by the next generation with unknown consequences. Studies have shown that such changes are more likely to occur in staple food crops including wheat, barley and maize. Growers have responded by insisting that these changes would be detected either via the characteristics of the plant in field trial or by genome sequencing.

Gene editing alone may not be sufficient to solve food shortages. Nick Talbot, executive director of the Sainsbury Laboratory, has said that genome modification (GM)—the transfer of genes from one plant to another—is required to meet production challenges. In his opinion, the perception of GM as “more disruptive, and therefore less safe, than genome editing is not based in scientific evidence”. He also noted that GM crops have been consumed by “350 million people for more than 25 years with no recorded ill-effects”.

Commentators have also flagged potential ethical issues around use of new technology. Concerns that have been raised include the prospect of gene editing for plants being followed by animals. They have argued that this could lead to lower animal welfare as increased disease resistance permits closer crowding of livestock. In response, some analysts have said that gene editing could also improve animal health problems caused by decades of selective breeding.

1.2 How will gene editing technology be utilised?

In April, the UK Genetically Modified Organisms (Deliberate Release) (Amendment) (England) Regulations 2022 amended previous rules to simplify the approval process for researchers to take crops to field trial.

Since a European Court of Justice ruling in 2018 which found that all organisms produced by biotechnology would be classified as genetically modified organisms (GMO), their development has been heavily regulated. Despite this, some field trials of gene-edited crops have taken place, including the first trial of CRISPR-edited wheat in Europe beginning in Hertfordshire in August 2021. CRISPR is a tool that can be used to edit genes by making a cut at a predetermined location in the genome.

In addition to restrictions on field trials, high regulatory burdens have made the commercialisation of gene-edited crops in the UK unviable. Rebecca Nesbit from the Royal Society of Biology said that “the effect of the EU’s GMO regulatory system has effectively been to prevent the cultivation of GM crops in Europe”. The Royal Society has argued that regulation should be “based on the trait that has been introduced rather than on the process used to introduce the trait”.

Whilst the commercialisation of genetically modified crops in Europe has remained challenging, gene-edited products have reached the consumer elsewhere. In September 2021, Japan approved tomato plants modified for better stress tolerance as the first commercialised CRISPR-generated food product. In China, Japan and the US, gene-edited crops containing no foreign DNA are not classified as GMO and are therefore less stringently regulated.

Scientists have said that regulatory changes in England will enable researchers to conduct more field trials of gene-edited crops. Since the changes, DEFRA has been notified of field trials commencing for oilseed modified for higher oil production and tomato plants able to accumulate vitamin D.

Other pipeline UK studies may have a positive environmental impact by reducing dependency on insecticides. This includes yellows virus resistant sugar beet varieties: emergency use of a banned insecticide was authorised in March 2022 to control a severe yellows virus outbreak. The simpler approval process could also permit development of products tailored to consumer preference such as naturally decaffeinated coffee.

Gene editing can introduce novel characteristics without transferring DNA from another species. For example, using CRISPR, scientists at Rothamsted Research have switched on a dormant gene without inserting foreign DNA, increasing vegetable oil production by 30%. Professor Peter Eastmond said “we’ve come up with a simple solution to a difficult problem”. He stated that “There are many barriers to commercialisation of GM crops and so it may be desirable to achieve gain-of-function by other means”.

Despite changes to the safety requirements for field trial, no changes in the regulations permitting commercialisation of gene-edited crops in the UK have been made. However, the UK Government plans to relax these regulations “to make the UK the best place in the world to invest in agri-food research and innovation”. The Genetic Technology (Precision Breeding) Bill was introduced in the House of Commons on 25 May 2022 for this purpose. As stated in the 2022 Queen’s Speech, this legislation will also update regulations for gene editing of animals in England.

Cover image by Sangharsh Lohakare on Unsplash.