The (Lost?) Promise of Genome Editing (And How to Rediscover the Promise)
Co-author: Martin Bwalya Martin Bwalya is ag director, Knowledge Management and Programme Evaluation (KMPE) at the African Union Development Agency-New Partnership for Africa’s Development (AUDA-NEPAD).
The pace of research in the field of genome editing — understanding, modifying and altering gene function — has quickly accelerated in the past 10 years. The first novel methods — zinc finger nuclease (ZFN), transcription activator-like effector nucleases (TALEN) and meganucleases — made it quicker and easier to modify genes. This was followed by CRISPR/Cas9 gene editing, with improved precision, speed and flexibility, and the potential to change the field of plant breeding, improve food security and stay a step ahead of climate change.
Yet, due to policy and regulatory uncertainty around the world and some technical obstacles, very few products have attained commercialization, indicating a lack of follow-through on the incredible depth and breadth of research and investment. And in regions where CRISPR/Cas9 could have perhaps the greatest impact, like Africa, scientists are engaging but not fully participating due to policy incoherence as well as technical and the usually mind-set barriers.
We are posing two questions:
- Why has CRISPR/CAS9 genome editing created so much excitement and investment?
- Can we deliver and expand on the promise and investments made? This is especially important for catalyzing the agriculture and food systems transformation that is able to provide for resilient and viable systems from production through to consumption.
Why All the Excitement?
- Genome editing is quick (relatively). By coupling genome editing with the latest genomic tools, like genome sequencing, fewer breeding cycles are needed to produce improved crop varieties. Traditional breeding involves plenty of art along with the science. With editing, we can cut down on the guesswork and minimize trial and error.
- Genome editing offers new options for neglected crop species, sometimes referred to as orphan crops. Because these crops have received limited research attention or breeding improvement, they are more susceptible to climate change than the more “industrialized” crops of the world. Cassava is a great example. In Africa, the crop has seen little improvement since its introduction from the Amazon over 300 years ago. Flowering is one of the main obstacles for cassava breeders — cassava plants produce flowers infrequently, and when they do, the male and female flowers are often not in sync. Scientists have now identified the genes responsible for flowering and, through editing, have developed plants that flower consistently (as shown in the above image). With improved flowering, breeders will have far more opportunities to make crosses and improve the crop.
- The opportunity for improving crops is practically infinite. Cassava flowering is just one example. Disease and insect resistance, better nutrition, improved yield, improved adaptation to agro-ecological zones and plant and floral “architecture” to better capture sunlight or produce and receive more pollen for improved breeding, respectively, can happen more quickly than through traditional breeding, or is now even possible where it wasn’t before.
- Genome editing offers more tools for climate change adaptation and even mitigation. Traits that offer greater tolerance to drought, heat, soil salinity and greater disease and insect pressures brought on by climate change have, in many cases, already been identified. Editing is a powerful tool to quickly move valuable traits into desirable varieties and stay a step ahead of climate change while lowering the environmental footprint of agriculture.
- Genome editing is safe. Regulatory organizations around the world have noted that many edits could occur through natural means, or could be made via previously available and unregulated tools (although not as precisely or as efficiently). As a result, only very limited cost and time will be required in these countries for regulation of edited crops. This supports a highly democratized and useful technology.
The Promise Unfulfilled
For all the promise of the technology, we have to consider that the promise remains unfulfilled. Only two products from editing have attained any kind of commercial scale — a soybean in the United States with a higher quality oil and a tomato in Japan with heart-healthy nutrition.
The major challenges:
- Regulation of editing is a policy patchwork around the world. Across Africa, regulation on editing has been slow to develop, preventing investment and even research. Europe, while indicating openness to editing, still considers it no different than transgenic technology. And China, while leading the way on research, has only vague and somewhat opaque language on genome editing regulation.
- Intellectual property rights and the numerous patents mean that legal expertise and agreements are key to expanding use of the technology.
- The greatest technical challenge remains efficient plant transformation in many crop species, now most widely done through sensitive tissue culture techniques. Inefficient transformation means that editing often remains difficult, especially for under-utilized crops. Yet, rapid progress is possible. Cowpea is a great example, which went from unmanageable to one of the more efficiently transformed crops available in a few months time. Resourcing, creativity and focus make all the difference.
Another technical challenge is molecular characterization and genomics. Quality genetic sequence data is necessary to identify targets across varieties. This capability needs to be established for the under-utilized crops and made accessible to researchers everywhere. But, as with cowpea transformation, rapid progress is possible.
Until progress is made on these challenges, genome editing will remain in the domain of western scientists and China, with very few products reaching the commercialization phase.
Delivering on the Promise
- We must develop and nurture global collaboration and cooperation for capacity building of scientists, but also for policymakers and harmonized, science-based regulations. An atmosphere of trust must be fostered.
- Intellectual property rights must be respected among all providers and practitioners of genome editing. This will optimize sharing, use and development of the technology, and build the needed trust. An orderly assessment and agreement on intellectual property protection encourages investment, not just in western countries, but also in regions where impact will be greatest.
- Greater technical development and training are needed to ensure plant transformation and the lack of genetic sequence data does not remain a bottleneck. Highly beneficial edits would be within immediate reach if plant transformation techniques were more robust.
- Locally and demand-led development of genome editing in Africa is needed to foster greater acceptance of the technology, and to ensure the needs of African farmers and consumers are being met.
For More Detailed Information, Please See:
Jenkins, D., Dobert, R., Atanassova, A. and Pavely, C. 2021. “Impacts of the regulatory environment for gene editing on delivering beneficial products.” In Vitro Cellular & Developmental Biology — Plant, 57, 609-626. https://doi.org/10.1007/s11627-021-10201-4.
Karavolias, N.G., Horner, W., Abugu, M.N. and Evanega, S.N. 2021. “Application of Gene Editing for Climate Change in Agriculture.” Frontiers in Sustainable Food Systems, 5. https://www.frontiersin.org/articles/10.3389/fsufs.2021.685801/full.
Massel, K.S., Lam, Y., Wong, A.C.S., Hickey, L.T., Borrell, A.K. and Godwin, I.D. 2021. “Hotter, drier, CRISPR: the latest edit on climate change.” Theoretical and Applied Genetics, 134, 1691-1709. https://doi.org/10.1007/s00122-020-03764-0.