Raspberry crop resilience: How a gene-editing breakthrough could reshape fruit farming

Earlier this week, Cranfield University (UK) scientists announced a new genome editing technique for raspberries, which they say could be the “future of fruit and farming.” The study leverages CRISPR-Cas9 biotechnology to edit single cells (protoplasts) from the leaf tissue of raspberry microplants and may create raspberry varieties with a longer shelf life in the future.

Raspberries usually have a short shelf life of 2-5 days due to high moisture content, leading to mold growth and rapid quality deterioration. Research shows their perishability has been limiting their market expansion and is a cause of food waste at retail stores and in households.

Food Ingredients First goes behind the scenes with author Ryan Creeth, PhD, a research scientist at Cranfield University who developed the new method. He discusses its impact on raspberry breeding and why gene-editing tools need legislative support to combat “serious threats” to food production, such as droughts, floods, and diseases.

What motivated you to choose raspberries as the focus of this gene-editing study?

Creeth: Raspberries are a fantastic soft fruit crop with great taste and nutritional benefits as a superfood. The process of changing a crop’s DNA with CRISPR is actually relatively straightforward, but the methods that enable gene-editing have to be developed on a species-by-species basis. Particularly in non-model crop species like raspberry, these methods have not been figured out at all by scientists. This presented an interesting research gap with a significant potential impact if a gene-editing method could be successfully developed. Our recent paper in June this year was the first time CRISPR has been used in a peer-reviewed journal in raspberry, whereas CRISPR was first used in wheat in 2013.

What are the potential commercial benefits of developing gene-edited raspberries, particularly regarding sustainability and reducing food waste?

Creeth: The potential benefits and impact of gene-edited raspberries are huge and could be transformational for raspberry breeding. If a full DNA-free gene-editing method can be developed, the sky is the limit in producing raspberries with new or improved traits. 

However, it’s important to emphasize that at this stage we’ve only edited the DNA of single cells, and we’re now working on regenerating these edited cells into whole raspberry plants. There are countless genes that could be targeted to improve sustainability and reduce food waste. Still, the power of developing the fundamental method is that it’s a platform to enable future research.

The gene-editing method could lead to sweeter, larger, and seedless raspberries or boost crop yields, say the researchers.

What challenges remain in regenerating whole raspberry plants from the gene-edited protoplasts, and how do you plan to overcome these hurdles?

Creeth: Regeneration from a single cell (protoplast) is the most complex and difficult stage of the DNA-free gene-editing pathway. It’s highly specific to each cultivar and species and further complicated by a near-total lack of existing raspberry-specific methods in the scientific literature. 

We are working to perfect every tissue culture stage, to induce division in the single cell, which forms a large unorganized mass of cells called a callus, and then to induce shoots from the callus to create a gene-edited plant. There’s no easy way around it; you have to spend a lot of time in the lab investigating all the different factors that affect protoplast regeneration and thinking deeply about your cells and what they need.

How do you see this research impacting the future of raspberry production?

Creeth: The research is in an early stage at this time. If a full regeneration method can be developed, and if we can better understand how genes contribute toward particular traits, then our research can be very influential in future raspberry production. But those are two big “ifs” that need much more development. 

What is important is that in the UK, the government recently passed the Genetic Technologies (Precision Breeding) Act, 2023, which permits this type of gene-edited crop (not genetically modified) to be grown in England. This is a huge vote of confidence for this technology and really helps stimulate interest from crop breeders, scientists, and consumers. We expect the European Commission will move in a similar direction soon. 

Gene-editing can offer future crop production a new tool to introduce new traits more rapidly. In other species, gene-editing has been shown to increase drought tolerance, flood tolerance, and disease resistance, among many other traits. So, it’s very important that legislation supports scientists and breeders in dealing with these very serious threats to food production.