The sweet potato is a staple food for millions, valued for its nutritional benefits and versatility. As public interest in the genetic makeup of food has grown, many have become curious about this root vegetable’s origins. With the discussion around genetically modified organisms (GMOs), people wonder where the sweet potato fits into the conversation.
The Unexpected Genetic History of Sweet Potatoes
The genetic history of the sweet potato contains a surprising element, leading scientists to label it a “natural GMO.” Researchers discovered that genes from a soil bacterium, Agrobacterium, are naturally present in the sweet potato’s genome. This discovery was made by scientists from Ghent University and the International Potato Institute while studying the plant for viral diseases.
Their analysis revealed the bacterial DNA was fully integrated into the sweet potato’s genetic code. This process, known as horizontal gene transfer, involves the exchange of genetic material between different species. The Agrobacterium transferred a portion of its DNA, called T-DNA, into the plant thousands of years ago, long before humans began cultivation.
Further research confirmed these foreign genes are active within the plant, suggesting they may provide a beneficial trait favored during domestication. The presence of this Agrobacterium T-DNA was confirmed in 291 cultivated sweet potato varieties and some wild relatives, indicating a stable and ancient integration.
Distinguishing Natural vs. Lab-Engineered Modification
The foreign genes in sweet potatoes highlight the distinction between naturally occurring genetic modification and modern, lab-engineered methods. The process in sweet potatoes was a natural instance of horizontal gene transfer, an event that happens in nature without human intervention. This transfer was a random byproduct of the interaction between the plant and Agrobacterium in the soil.
In contrast, modern genetic engineering is a deliberate and targeted laboratory process. Scientists identify a gene for a desired trait, such as pest resistance, and use biotechnology to insert it into the plant’s genome. This method allows for precise changes to the plant’s genetic makeup.
The term “genetically modified organism,” or GMO, in a regulatory and consumer context, refers to organisms created through this modern technology. The difference lies in the precision and intent behind the modification.
Modern Genetically Engineered Sweet Potatoes
Separate from the naturally occurring modification, scientists have also been creating lab-engineered sweet potatoes. These projects focus on addressing agricultural challenges in developing countries, particularly in Sub-Saharan Africa. One main goal is to develop varieties resistant to viruses, like the Sweet Potato Feathery Mottle Virus, which can cause crop losses and threaten food security.
Researchers use modern biotechnology to introduce genes that provide virus resistance. By creating these strains, the projects aim to improve crop yields and ensure a more stable food supply for communities that rely on sweet potatoes.
These genetically engineered sweet potatoes are distinct from those containing the ancient Agrobacterium genes. The development of these crops is often a collaborative effort between international research institutions and local agricultural organizations to improve food production in vulnerable regions.
The Sweet Potato in Your Supermarket
For consumers in North America and Europe, the sweet potatoes available in local supermarkets are not genetically modified in a lab. The common varieties sold, such as Beauregard and Covington, are not the engineered versions developed for disease resistance in Africa.
These lab-created sweet potatoes are not approved for commercial sale in most Western markets, as their use is concentrated in specific regions. The sweet potatoes on store shelves are the result of traditional crossbreeding and cultivation methods.