A New Phase for CRISPR-Cas in European Plant Breeding

Jan Schaart has worked in plant biotechnology at Wageningen University & Research for around forty years and focuses on gene editing and CRISPR-Cas applications. Martina Juranić joined WUR in 2020 and works on enabling technologies for plant breeding, including the processes needed to turn an edited plant cell into a complete plant. As the course leaders behind our Hands-on Course CRISPR-Cas in Plants, they bring decades of expertise in turning edited plant cells into complete plants.

Their expertise covers different parts of the same pipeline. Schaart focuses more on designing efficient gene-editing approaches and creating mutations, while Juranić works on delivering those constructs into plant cells and regeneration.

CRISPR-Cas is sometimes presented as the future of plant breeding, but Schaart and Juranić see it primarily as an additional tool.

Traditional crossing and selection will remain important, but for some traits gene editing can offer a much more targeted route. Apples are a good example. Developing a new generation through conventional breeding can take years. If an established variety has many desirable characteristics but is susceptible to a particular disease, gene editing may make it possible to change that specific characteristic while retaining the rest of the variety.

“You can add a plus to an already proven variety,” Schaart explains. Similar opportunities can exist for traits such as pest resistance or post-harvest quality. At the same time, CRISPR-Cas is not a solution for every breeding challenge. Whether it is suitable depends on the crop, the trait and the biological possibilities. 

One of those limitations is often underestimated. Designing the edit is only one step; the CRISPR-Cas system also has to be introduced into a plant cell, after which that cell needs to regenerate into a complete plant.

For some crops, those processes are well established. For others, they remain extremely difficult. There is no universal protocol: even varieties within the same crop can respond very differently.

The team has worked on projects where many varieties first had to be tested to identify one that responded sufficiently well. From there, the protocol could gradually be optimised. “These things can easily take a couple of years,” they explain. This makes transformation and regeneration one of the major bottlenecks in applying gene editing to new crops. 

That broader perspective is central to the Hands-on Course CRISPR-Cas in Plants. Participants do not only learn how CRISPR-Cas works, but follow the wider process from designing an edit to analysing the resulting mutations. The programme also covers transformation and regeneration, regulation, intellectual property and new developments in the field.

A practical laboratory component allows participants to carry out important steps themselves. Instead of simply following a ready-made protocol, they first have to think through how the experiment should be performed. According to the course leaders, that is an important difference. “It gives a better and deeper understanding of what you are exactly doing and not just following a protocol.”

Participants also consider how the technology could be used for a crop or trait relevant to their own work. Many come from breeding companies, but previous editions have also attracted educators and other professionals who want a better understanding of gene editing.

The interaction between participants is another valuable part of the course. People arrive with different crops, expertise and challenges, and gradually start comparing experiences and learning from one another.

For professionals exploring whether CRISPR-Cas could have a place in their organisation, that combination of theory, hands-on experience and practical discussion is the main aim: not simply to know what CRISPR-Cas is, but to understand what it takes to apply it successfully.