In this blog post, we will take a close look at the technical principles behind GMOs, their applications in agriculture and medicine, and the ongoing safety debates.
With demand for GMOs rising, particularly among food companies, South Korea has become the world’s second-largest importer of GMOs. However, the numerous controversies surrounding their potential risks—which have persisted since the first non-browning GMO tomato was developed in 1994—continue to this day.
A genetically modified organism (GMO) is an organism created using genetic recombination technology to manipulate its original genes, insert new genes, or remove unnecessary or harmful genes. This term refers to organisms created using genetic recombination technology, which involves manipulating existing genes, inserting new genes, or removing unnecessary or harmful genes.
To discuss GMOs, one must first understand genetic recombination technology. Genetic recombination technology is a method of altering an organism’s traits by combining DNA fragments from one organism with DNA molecules from another. To cut and join DNA, suitable “scissors” and “glue” are required; the “scissors” are restriction enzymes discovered by Smith and Nathans in 1970, and the “glue” corresponds to DNA ligase (ligase), discovered by Gellert in 1967. Currently, more than hundreds of types of restriction enzymes are known, and each restriction enzyme recognizes a specific nucleotide sequence to cut the DNA.
For example, the restriction enzyme EcoRI recognizes the nucleotide sequence 5′-GAATTC-3′ and cuts between the G and A. When this occurs, the two strands of the double helix are cut in a way that leaves a few nucleotides at the ends as single strands; these are called sticky ends. These short single-stranded regions can form hydrogen bonds with the sticky ends of other DNA strands cut by the same restriction enzyme, and the two strands temporarily bound in this way are completely joined by a ligase, resulting in the creation of recombinant DNA.
Using this genetic recombination technology, genes with useful functions can be excised from specific organisms, ligated to a vector DNA, and then transferred into host cells to mass-produce those genes or express their functions. For example, a method widely used involves recombining the human insulin gene into an E. coli plasmid to obtain large quantities of insulin from E. coli.
The potential of genetic recombination technology has also been applied to plants, bringing about changes in food production. Starting with non-brooding tomatoes, a variety of agricultural products have emerged, including “Roundup Ready” soybeans with herbicide resistance, as well as crops that can be stored for long periods and have improved taste. Over the past few decades, thousands of genetically modified plant varieties have been researched worldwide, and many of these have been approved for sale. As a result, humans have been able to rapidly and significantly increase crop yields, improving quality of life and offering a potential solution to global food shortages.
However, the future is not entirely bright. Controversy over the potential risks of GMOs has hindered their widespread adoption, and boycotts against GMOs have occurred globally, particularly in Europe.
Despite the aforementioned advantages, opponents point out the possibility that externally introduced genes through genetic modification may produce unintended results or be unstable. For example, an attempt to recombine peanut genes into soybeans to enhance their taste and nutritional value was halted after findings showed that people allergic to peanuts could still experience allergic reactions after consuming the modified soybeans. Additionally, the introduced DNA can sometimes become unstable and degrade over time, which, in severe cases, could have a significant impact on the ecosystem.
There is also no shortage of controversy regarding the safety of GMOs. In 2012, a French research team published the results of an experiment on herbicide-resistant GM corn. After observing 200 mice for two years, they reported that mice fed the GMO corn exhibited notable mammary tumors and liver and kidney damage, sparking a major reaction within the academic community. In response, scientists supporting GMOs questioned the findings, pointing out that the study did not specify whether the corn was infected with mold and that some mice in the experimental group survived in good health. The controversy intensified and has not yet fully subsided.
As such, reports claiming that genetically modified plants are truly safe coexist with those claiming they are truly harmful. Whenever safety concerns are raised, a cycle of rebuttals and counter-rebuttals ensues, perpetuating the ongoing debate over GMOs.
Despite this controversy, GMO development continues. Moving beyond the original goals of simply improving plant nutritional content or preventing pests and diseases, therapeutic crops capable of producing medicinal compounds have also been developed. While the new possibilities opened up by GMOs are clear, this is a time when active discussion of their dual nature is needed, and greater attention must be paid to how GMOs should be evaluated and managed.
