In review: the role of genetic editing in crops

The process of plant domestication has been ongoing for thousands of years. Expanding the genetic diversity of crops has mostly relied on naturally occurring variations selected for their beneficial impact. However, this approach as used throughout most of the history of agriculture, lacks control and precision, is slow to yield results and depends on an element of luck. In this next guest blog, Hannah Senior and Dr Jamie Claxton provide us with a deep dive into how genetic editing in plants can help boost food production whilst diversifying our crops, reducing waste and minimising risk to pest and diseases.

Nowadays, we have numerous ways to control introduction of heritable mutations into a plant’s genetic material. For instance, the development of computing and genotyping has allowed marker assisted breeding, better informing the recognition and use of the genetic indicators of beneficial traits. In addition, creating a large pool of genetic variants to select from became easier by using chemical compounds and irradiation to increase the background mutation rate. Unfortunately this also creates drawbacks such as deletion and rearrangement of big genomic fragments.

A major step forward happened with the discovery of a new, powerful tool: the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and the CRISPR associated protein (Cas9), CRISPR-Cas system. This game changing approach has since been utilised in many crops to target genes linked to traits such as shelf life or taste profile.

One of the key advantages of the CRISPS-Cas system (and similar approaches developed subsequently) is the high precision it provides by enabling the introduction of specific changes at selected sites in the DNA. This not only accelerates the plant breeding process but also lowers cost and increases accuracy.

The implications could be wide-reaching, helping to rapidly develop plants with high resistance to climatic stress, emerging pests and diseases or increased content of chemicals for use in the medical sector. Yet, as with all new technologies, full consideration must be given to how these crops will be cultivated and ensure alignment with sustainability, climate changes and food security goals both in the UK and globally.

Hannah Senior CHAP Non-Executive Director and CEO of PBS International works extensively with plant breeders and seed producers worldwide. Below she provides her outlook on the value of gene editing in building a sustainable and resilient agriculture sector.

“Dramatic shifts caused by climate change, demographics and the economy have accelerated the need for new crop varieties. Successfully cultivating crops in a variable climate with the added challenges of lower inputs and less labour will require accessing every tool in the box. To help jump-start the process, it’s great news that the Genetic Technology (Precision Breeding) Bill has passed through Parliament.

Gene editing has met with concerns from the public, yet recent data presented by The Food Standards Agency indicated that around 74 percent of people are comfortable with gene editing, especially in plants, when they understand it. The problem is that inadequate representation of what genetic engineering is and can achieve limits this understanding, especially when the pros and cons of the technology itself are confused with other issues.

An example of this is a concern that if we allow genetic engineering, a handful of multinational corporations will be in control of all our crop genetics. ‘Seed sovereignty’ and the implications of consolidated agribusinesses are legitimate concerns, of course. Ironically, concerns about the safety of genetically modified organisms (GMOs) – gene editing’s predecessor’s technology – added fuel to consolidation that was already happening across seed companies.  Regulators made the process of launching biotechnology-enhanced crops very onerous, and as a result, only very large companies working on the biggest crops (e.g. soy and maize), could afford it. With appropriate regulation, gene editing has the potential to work against this trend because it is faster, cheaper and more accessible which enables small companies, start-ups, NGOs and researchers to use this technology to develop new varieties and work on a wider range of crops.

Gene editing is not the answer to all our problems. Achieving our sustainability goals and future-proofing food production in an ever-changing climate will require other tools such as including higher investments in preserving genetic diversity, scientific research more generally, and farming systems research.  But gene editing is a valuable and welcome addition to the options available.”

Next, Dr Jamie Claxton, Director of Research and Development at Tozer Seeds, discusses current industry challenges and how genetic editing could accelerate crop breeding to benefit and support food production.

“We are the largest UK-based independent vegetable, salad and herb seed breeding company but small compared to many of our multinational competitors, so we have to be really innovative to successfully compete in the commercial marketplace. We primarily use traditional plant breeding techniques but the timescale for developing new varieties is long. This is particularly true for the biennial crops we work on, such as parsnip and celery. Developing a new variety of a biennial crop can take 10-15 years which is a huge investment in resources. Even new varieties of our annual crops such as wild rocket take up to 10 years to develop.

The commercial fresh produce sector is facing huge challenges due to many interacting factors; climate change, Brexit, Covid-19, pesticides withdrawal and huge inflation of input costs for growers, threatening UK food security. It is becoming apparent to us as a company that in order to remain competitive we need to embrace new technologies to speed up the release of new varieties to market and meet these fast-changing demands to help secure UK food supplies. Traits such as pest and disease resistance, resistance to drought, improved shelf life and slower bolting to reduce food waste as well as improved nutritional content to maintain public health will need to come to market in a much shorter timeframe than can be achieved by traditional plant breeding techniques. We are also looking at quickly developing varieties for new growing technologies such as urban vertical farms to reduce food miles.

Gene editing is an efficient precision breeding tool that I believe will allow us to overcome these hurdles. It is important to distinguish this technique from genetic modification, which is the introduction of a fragment of DNA into a crop form an unrelated species. Gene editing does not involve any DNA from any other organism being introduced into a plant, it is simply a powerful and fast tool that allows very precise edits to be made to the genome that will, for example switch on a gene that codes for disease resistance or drought tolerance. The results are no different to traditional plant breeding – it is a faster and more precise technique.

We currently have an Innovate UK – funded Knowledge Transfer Partnership with a scientist from University of York, working with us to develop the protocols for gene editing within our economically important crops. The government’s Precision Breeding Bill last year has recognised that gene editing is distinct from genetic modification with an aim to remove some of the tight regulation around gene editing. This is vital to secure food security within the UK as other countries outside Europe are already pushing forward with this new technology and releasing new varieties. Public perception, understanding and approval are key to highlighting the huge benefits of this new technology and its essential role in securing food production in the UK.”

CHAP aims to build networks of leading scientists, farmers, advisors, businesses, and academia to understand industry priorities and develop innovative solutions. To be our next guest contributor, e-mail enquiries@chap-solutions.co.uk

Please note, the opinions expressed in this article do not necessarily reflect the views or opinions of CHAP.