CRISPR: A Climate Change Resilience and Food Safety Milestone

By Jeffrey Wang, Associate, Global Food Safety Forum

Special to The Digest

Developing a sustainable global food system that ensures access to a sufficient supply of nutritious, diverse and safe food for all, and simultaneously limits the impact on the environment, is one of the key challenges in the next few decades. Therefore, identifying technologies and sustainable agricultural practices that can adapt to climate change as well as reduce agricultural carbon intensity is a crucial task for policymakers, food suppliers, and even institutional and private investors. In this newsletter, we focus on one such technology that could potentially be an integral part of solving the food system challenge — Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR).

CRISPR technology is the latest watershed advance in genome-editing that has particularly significant implications for crop-engineering and agriculture. Researchers at the Innovative Genomics Institute (IGI), a joint partnership between UC Berkeley and UCSF, discovered a particular protein that can target and cut specific viral DNA, known as the CRISPR-Cas9. Using CRISPR genome-editing, researchers were able to remove, insert, and change sequences of DNA in nearly any organism.

Due to CRISPR’s specific nature, the application of the technology can improve the conventional food crop in several ways. For example, publications on CRISPR’s application in tomatoes alone demonstrate the promising prospects of the technology in tackling food security, safety and environmental sustainability challenges.1 CRISPR’s ability to target viral DNA sequences can allow crops to develop resistance to diseases. By modifying the tomato genes that confer antiviral characteristics, researchers have successfully engineered tomato plants’ immunity to RNA viruses, thus significantly boosting crop yield.2

The same concept could be used to target pathogenic bacterial infections that conventional agricultural chemicals find hard to control. By building genetic resistance to Pseudomonas syringae, the causative agent of bacterial speck disease in tomato plants, the technology could significantly reduce the exposure of humans to food-borne diseases.

Aside from the resistance to the biotic stress researchers were able to develop using CRISPR, tomato plants could also be genetically engineered to withstand abiotic stress, including drought, flooding, heat, and chilling. As climate change increases the frequency of those extreme weather events and poses high risks for crops, researchers have shown that tomato plants can be fortified with anti-chilling as well as drought resistant capabilities to ensure crop yield.

Moreover, researchers have further shown that CRISPR is a crucial piece of technology that can reduce agriculture’s carbon intensity through three main pathways. First, the use of synthetic fertilizers could be drastically reduced through CRISPR’s potential to engineer plants to receive nitrogen from nitrogen-fixing bacteria. This will not only cut carbon emissions associated with the heavy fossil fuel reliant fertilizer production process, but it will also limit the flow of excess nitrogen polluting waterways and further threatening aquatic species. Second, researchers have developed plants that are more resistant to insects and invading species, thereby cutting back on pesticide and herbicide use. Lastly, CRISPR-engineered rice plants and paddies produce less methane and cattle feed that is much easier to digest, which will significantly lower emissions of a GHG that is as much as 25 times as potent as carbon dioxide.

The main challenge to implementing this technology on a much larger scale is, however, government regulation and public acceptance. Although CRISPR technology and products are not regulated in the US, a sizeable population in the US and a much larger voice in Europe associate CRISPR gene-editing technology with other GMO technology and foods. CRISPR and GMO fundamentally differ because GMOs are made through the introduction of foreign DNA into a given organism, whereas the process of the particular protein (CRISPR-associated protein 9; Cas9) in CRISPR editing its own DNA sequence does not require foreign DNA. In addition, the New Genomic Technique (NGT) produces food products that have been scientifically proven to cause no harm to the human body.

Currently, CRISPR faces little federal regulation in the US and researchers, from private companies and academic institutions, are rapidly field testing with newly CRISPR-engineered plant crops. As of this year, there are 87 independently run field tests in the US. In April of 2016, the FDA even allowed CRISPR-edited white button mushrooms to enter the market, bypassing GMO regulations. Recently, the UK allowed the first CRISPR-edited wheat to enter field trials in an effort to make healthier bread with lower levels carcinogenic chemicals.3 However, regulators in European Union held CRISPR to the same strict testing standards as GMO foods, and lobbyists in the US continued the push for additional safety test requirements for CRISPR, citing gene-editing’s high risk of adversely affecting human health. The result of all these policies is low public acceptance and dismal consumer confidence, such that no CRISPR-edited foods are available on the market currently. Therefore, in order for the CRISPR technology to actually begin transforming the food system to become more sustainable and resilient, it is important for policymakers and the public to understand the technology. Only then can regulators and stakeholders provide the incentives for widespread development and implementation.

1 Nature: CRISPR technology is revolutionizing the improvement of tomato and other fruit crops. https://www.nature.com/articles/s41438-019-0159-x

2 Wang, Z. et al. A novel DCL2-dependent miRNA pathway in tomato affects susceptibility to RNA viruses. Gene. Dev. 32, 1155–1160 (2018).

3 Food Navigator: ‘News of this trial will likely be welcomed by the food industry’: Europe’s first CRISPR-edited wheat set to be grown https://www.foodnavigator.com/Article/2021/09/03/News-of-this-trial-will-likely-be-welcomed-by-the-food-industry-Europe-s-first-CRISPR-edited-wheat-set-to-be-grown

This article was reprinted with permission from Global Food Safety Forum (a 501 c-3) newsletter, FOCUS.