From Past to Fruit-ture: How Genetic Modification and Selective Breeding Changed Produce

In 1973, twenty years following the discovery of DNA structure, two biochemists Boyer and Cohen invented recombinant DNA technology. This advancement involved altering DNA at the molecular level to produce transgenic crops, also known as genetically modified (GM) organisms. There’s a variety of reasons for this process: enhanced yield, resistance to disease, higher sucrose content, or the ability to withstand diverse environments. However, the dramatic transformation of crops began as early as circa 8000 BCE, with selective breeding allowing farmers to cultivate desired traits. (FDA, 2024)

The Aesthetic Upgrades of Fruits

Watermelon, the popular summer fruit of the gourd family, Cucurbitaceae, was initially thick-rinded, with sparse segments of bland, pale flesh. Descending from the Citrullus lanatus variety, they have been cultivated in northeastern Africa for over 4,000 years. Seeds found within Egyptian tombs, alongside paintings depicted watermelons as oblong, not small and spherical, suggesting selective breeding had already begun. (Strauss, 2015) From here, they were introduced to Asia and then Europe in the 1500s. (Colla et al., 2018) Selective breeding continued throughout Europe, causing the fruit to develop its modern appearance with bright red flesh whilst still keeping its rigid segments and thick, white rind; depicted most notably in Baroque paintings.

Giuseppe Recco’s ‘Still life with fruit’. 

Centuries of unnatural breeding for genotypic traits, like size, resulted in “the cultivated watermelon having very, very narrow genetic diversity that causes problems for breeding,” said Zhangjun Fei, from the Boyce Thompson Institute (Waldron, 2016) Something we readily ingest having narrow genetic diversity can cause a plethora of problems. Most notably, the lack of variation can leave produce susceptible to biotic and abiotic stress (Chauhan, Salgotra, 2023) or more difficulty fending off disease. Because of this low diversity, watermelons only have 82 SNP loci in their chloroplast genome, which represents the points of variation. (Cui et al., 2020) However, this is the first study which takes into account the whole chloroplast genome and should be considered with caution. As the product of both early selective breeding and modern genome editing, transforming it from the slow accumulation of favourable traits to a precise, targeted approach. 

Selective Breeding Versus Genetic Modification 

Firstly, it’s important to make the distinction that although these methods share clear similarities, selectively bred organisms are not GMO. As they have not had their genetic code altered through tools like CRISPR. There’s a vast amount of negatives associated with selective breeding, with its primary concerns being inbreeding and linebreeding. Inbreeding involves the mating of closely related species, resulting in a higher chance of recessive genetic disorders due to reduced genetic diversity, as discussed with watermelons. Although this can occur unintentionally through self-pollination, it is exponentially worse when seeds from a single parent species are used repeatedly. Whereas, linebreeding consists of individuals that are distantly related to stabilise desirable traits over generations. Though, they are still genetically homogeneous, which increases the difficulty of surviving in harsh, changing environments. (Do, 2023) This poses a threat to global food security. Although, it is important to increase crop yield in order to meet the growing population’s demands. It is imperative that we don’t sacrifice nutritional quality, which should be the priority. As selectively bred crops may fall short of bio active compounds which are vital for human health. (DellaPenna, 1999)

Alternatively, genome editing can produce crops with reduced gluten (Niiler, 2018) as well as tomatoes that have five times the regular amount of GABA, an amino acid linked to lower blood pressure. (Global Gene Editing Regulation Tracker, 2019) Which benefits the entire population’s heart health and those with celiac who require reduced-gluten or gluten-free diets. Economically, it reduces the cost for farmers, which in turn produces cheaper food for consumers. These advantages are met with unreliability as the consequences of genetic engineering haven’t been fully explored yet, and may not always work as intended. There’s a chance of unintended side effects being produced. (Dace, 2021) And with this fact, there is the potential to deter consumers from purchasing out of fear of the unknown. 

Equality or Elitism?

Organic food is known to have a higher price tag relative to non-organic because it is treated with labour-intensive practices. Genetically engineered food similarly undergo more rigorous conditions than regular produce. So, there’s a possibility for modified food to exponentially increase in price, alienating consumers and only allowing the rich to buy these products. Based on the 1996 World Food Summit, food security is defined as “people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life” (Bryne, et al., 2014) If GM produce has a costly price, which the average family couldn’t afford, it subverts this principle. Particularly in low-income households where affordable, nutritious food can be a scarcity. There is also the chance for widespread GMO consumption to create a divide between socioeconomic classes, exacerbating inequality, while richer communities can access premium food whereas the poorer cannot. 

Considering all these factors, we should create a balance between sustainability and innovation, not prioritising yield overall nor the aesthetics of fruit. CRISPR/ gene editing technology must ensure sustainability for everyone above anything else. In order for GMO to provide long-term benefits, agribusiness must be transparent so that the consumer can choose whether to purchase.

References

Bryne, D., Crosby, K., Hirschi, K., Patil, B. (2014, February 1) The Intersection of Plant Breeding, Human Health, and Nutritional Security: Lessons Learned and Future Perspectives

(https://journals.ashs.org/hortsci/view/journals/hortsci/49/2/article-p116.xml.)

Chauhan, B., Salgotra, R. (2023, January 9) Generic Diversity, Conservation, and Utilization of Plant Genetic Resources, 

(https://pmc.ncbi.nlm.nih.gov/articles/PMC9859222/)

Colla, G., Kyriacou, M., Leskovar, D., Rouphael, Y. (2018, April 14) Watermelon and melon fruit quality: The genotypic and agro-environmental factors implicated. 

(https://www.sciencedirect.com/science/article/abs/pii/S0304423818300384)

Cui, H., Ding, Z., Gao, P., Wu, Y., Zhu, Q. (2020, August 4) Population structure and genetic diversity of watermelon (Citrullus lanatus) based on SNP of chloroplast genome.

(https://pmc.ncbi.nlm.nih.gov/articles/PMC7403291/)

Dace, H. (2021, March 17) Gene Editing in Food Production: Charting a Way Forward.

(https://institute.global/insights/tech-and-digitalisation/gene-editing-food-production-charting-way-forward)

DellaPenna, D. (1999) Nutritional genomics: manipulating plant micronutrients to improve human health.

(https://scholar.google.com/scholar_lookup?title=Nutritional+genomics%3A+Manipulating+plant+micronutrients+to+improve+human+health&author=D.+DellaPenna%2C&publication_year=1999&journal=Science&volume=285&pages=375-379#d=gs_qabs&t=1733371956526&u=%23p%3D_PqHKuWzCZgJ)

Do, P. (2023, December 6) Selective Breeding: Unraveling the Methods, Motivations, and Implications.

(https://www.newrootsinstitute.org/articles/selective-breeding-unraveling-the-methods-motivations-and-implications)

FDA (2024, May 3) Science and History of GMOs and Other Food Modification Processes.

(https://www.fda.gov/food/agricultural-biotechnology/science-and-history-gmos-and-other-food-modification-processes)

Global Gene Editing Regulation Tracker(2019, October 11) Japan: Crops / Food - Global Gene Editing Regulation Tracker.

(https://www.printfriendly.com/print?url=https://crispr-gene-editing-regs-tracker.geneticliteracyproject.org/japan-crops-food/#&encodeImages=false&showHiddenContent=false&imagesSize=full-size&fallbackStrategy=algo&primaryImage=all&fetchOriginalPage=default)

Niiler, E. (2018, August 10) Why Gene Editing Is the Next Food Revolution.

(https://www.nationalgeographic.com/environment/article/food-technology-gene-editing

Strauss, M. (2015, August 21) The 5,000-Year Secret History of the Watermelon.

(https://www.nationalgeographic.com/history/article/150821-watermelon-fruit-history-agriculture)

Waldron, P. (2016, June 1) The Watermelon’s Past, Present, and Future.

(https://btiscience.org/explore-bti/news/post/watermelons-past-present-future/)