There are many terms and acronyms used to describe genetically modified organisms or biotechnologies. Genetically engineered (GE), genetically modified (GM), bioengineered, genetically modified organism (GMO), and transgenic are all adjectives used to describe an organism that has a copy of a gene not previously found in the species. The BE Disclosure law went into effect in January 2022 and uses "bioengineered" as the term of choice for these products of biotechnology. Throughout the lesson, determine the terminology students are familiar with and provide clarification to prevent misconceptions.
Farmers face risks everyday—weather extremes, pests, and other factors that can negatively affect a plant growing in a field. Drought, flooding, hail, wind, frost, heat, weed population, insect infestations, disease outbreaks, and numerous other elements can adversely impact food production. Despite all that can go wrong, grocery store shelves are stocked and livestock are well fed. Farmers are able to grow usable crops all the way to completion. How is this possible? How are farmers today able to use less land and grow 430% more corn than was grown in 1950?1 The answer is science, technology, and the ability to harness and apply new ideas and discoveries to improve crop resiliency. Genetic engineering is a development that has majorly impacted agriculture.
Genetic engineering is the deliberate modification of the characteristics of an organism by manipulating its genetic material. The Rainbow papaya is an example of a plant that has been genetically engineered. In the 1990s, the papaya ringspot virus had nearly wiped out the entire papaya industry on the island of Hawaii. However, a scientist named Dennis Gonsalves engineered a papaya tree to be resistant to the virus and provided hope and sustainability to papaya producers who were facing the loss of their livelihood.2 Along with papaya, other GE crops that are on the market as of 2023 in the United States include corn (field and sweet), cotton, canola, apples, alfalfa, potatoes, pink pineapple, soybeans, summer squash, and sugar beets. Each crop was engineered for different reasons, including drought tolerance, herbicide tolerance, insect resistance, disease resistance, and non-browning ability. Along with protecting the livelihoods of farmers, GE can benefit the environment due to less pesticide use, less soil tillage, and less greenhouse gas emissions.
Corn: Most of the corn grown in the United States is genetically engineered to resist insect pests or tolerate herbicides. Bacillus thuringiensis (Bt) corn is GMO corn that produces proteins toxic to certain insect pests but not to humans, pets, livestock, beneficial insects (such as ladybugs), or other animals.4 Some genetically modified corn in used in processed foods and drinks, but most is used in livestock feed.
Canola: Most genetically engineered canola is resistant to herbicides, allowing farmers to use herbicide sprays to control weeds in their fields. GMO canola is used to make cooking oil, margerine, and canola seed meal for animal food.
Cotton: Genetically engineered cotton is resistant to bollworms. GMO cotton is used in the textile industry, to make cottonseed oil (used in packaged foods and for frying), and animal feed.
Apple: GMO apples are resistant to browning after being cut.
Alfalfa: Most genetically engineered alfalfa is resistant to herbicides. GMO alfalfa is used to feed cattle, primarily dairy cows.
Papaya: A GMO papaya, named the Rainbow papaya, is resistant to the ringspot virus.
Potato: Some genetically engineered potatoes are resistant to insect pests and disease. Other GMO potato varieties are resistant to bruising and browning.
Pink Pineapple: The GMO pink pineapple is sweeter than other varieties and has pink flesh because of the increased levels of lycopene, a pigment naturally found in pineapples.
Soybean: Most of the soybeans grown in the United States are genetically modified. Some GMO soybean varieties are resistant to herbicides, some varieties are tolerant of abiotic stress such as drought or hypersaline conditions, some varieties are resistant to pests, and some varieties are resistant to soy oil rancidity. Most GMO soybeans are used for soybean oil, in processed foods, and animal feed.
Sugarbeet: Genetically engineered sugar beets are resistant to herbicides. More than half of the granulated sugar in grocery stores is made from GMO sugar beets.
Summer Squash: GMO summer squash are resistant to some plant viruses.
There are currently two GMO animals in the food supply, the AquAdvantage Salmon and the GalSafe pig. The FDA has determined that these animals are as safe and nutritious to eat as food from non-GMO salmon and pigs.4
Salmon: AquAdvantage salmon has been genetically modified to grow faster than other salmon varieties.
Pig: The GalSafe pig has been genetically modified to be free of alpha-gal sugar. People who have allergic reactions to alpha-gal sugar (Alpha-gal syndrome) can safely eat meat from Gal-safe pigs.
To learn more about GMO crops and animals in the United States, see the U.S. Food & Drug Administration (FDA) article GMO Crops, Animal Food, and Beyond.
The process of genetically engineering a plant has four main steps—identifying the problem, finding the solution, inserting the desired gene, and growing the engineered plant. Identifying the problem that needs to be solved for a specific crop is the most straightforward step. In the case of the papaya, the problem was the ringspot virus. After identifying the problem, scientists search for the specific gene sequence that expresses the desired trait. When insect-resistant corn was being developed, scientists found the desired gene sequence in the Bacillus thuringiensis (Bt) bacteria. Once the desired gene is found, it needs to be inserted into the plant. Originally, this was accomplished by a machine called the gene gun, which bombarded plant tissue with microscopic pieces of gold covered with millions of copies of the desired gene; however, the method used today is far more advanced and precise. Scientists genetically engineer plants through agrobacterium. Agrobacterium is a bacteria found naturally in soil. It infects wounded plants and inserts a portion of its own DNA into the plant's DNA, forcing the plant to create food for the bacteria and killing the plant. Scientists used this knowledge and were able to engineer the bacteria to insert one special gene, such as the Bt gene in corn, in place of the bacteria of the gene that kills the plant. Finally, the plant is grown in order to determine if the desired trait is expressed and to test for possible consumer health and environmental impacts.
Genetically Modified Organism (GMO) is the broad term for any organism that has undergone the process of genetic engineering. GMOs go through an extensive testing process that lasts many years. Testing is implemented by the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), and the United States Department of Agriculture (USDA). Once all regulatory processes are complete, the plant or animal can be approved for commercial use. Scientists and the majority of health organizations around the world agree that GMO foods are safe for human and animal consumption.3
Consumers who prefer not to eat GMOs have options. In recent years, some agricultural producers have made the decision to produce organic food which is grown without the aid of synthetic pesticides or chemical fertilizers, and produced without the use of genetically modified organisms or chemical food additives.
