What Do You Know About Bioengineered Crops (a.k.a GMO’s)?

What Do You Know About Bioengineered Crops (a.k.a GMO’s)?

by Tawni Bull

I am sure most of us have heard of the term GMO or GM food, but how many of us know what this means. What about transgenic, genetically engineered (GE), or bioengineered? All of these terms, generally, refer to the same thing. As a reminder, GMO stands for genetically modified organism. Genetically modified organisms are organisms in which their natural DNA has been modified via genetic engineering techniques like those discussed in my last blog. Depending on where you are in the world, certain terms may be more commonly used. In 2016, the United States Congress passed the National Bioengineered Food Disclosure Law that requires the United State Department of Agriculture (USDA) to fully disclose foods and food products that contain bioengineered material (Figure 1).  For clarity, we will only use the term GMO/GM for the remainder of this story. What specifically causes a food or plant to be considered GM? What agencies oversee the regulation of GM crops? Today, we are going to discuss these questions. In addition to talking about what these are, we are going to go over the importance of GM crops, current statistics about GMOs in the United States, and GM food that is on the market. But first, let’s focus on a brief history of GMOs and how manipulating the genetic material of an organism has evolved to where it is today.

Are GMOs New?

Agricultural biotechnology practices to improve a crop’s quality and quantity can be traced back thousands of years. These practices were introduced during the domestication of plants and animals. This included selective breeding techniques to develop higher yielding and better performing crops. Breeding techniques were mainly used until the discovery of DNA structure in the 1950s. This discovery led to scientists altering  plant characteristics by changing the genetic code. This was first accomplished through mutagenesis. Mutagenesis can occur by applying ionizing irradiation or mutagenic chemicals to randomly disrupt DNA. The resulting plants are then screened for beneficial characteristics. The next step was the discovery of restriction and ligation enzymes that allowed for any isolated DNA sequences to be spliced together. Specifically, Stephen Cohen from Stanford and Herbert Boyer of UCSF demonstrated that it was possible to use restriction enzymes to cut DNA at specific sites and then use ligation enzymes to fuse DNA from different species together. Today, this is more commonly referred to as cloning. It was at this time when it was discovered that genes from one organism can be introduced into another (Parekh 2004). Concerns about recombinant DNA (rDNA) technology arose among the scientific community which led to the 1975 Asilomar conference to discuss the safety of this technology and how to regulate it. This led to the development of the Coordinated Framework for Regulation of Biotechnology. In 1994, the first GM crop, the Flavr Savr Tomato, was approved for sale in the US. Since then, the United States has approved GM papaya, corn, soybean, canola, sugar beet, cotton, alfalfa, potato, squash, and apple (Figure 1) with both agronomic and quality traits (Table 1).

 

One of the newer GM crops approved by the FDA is known as the “cancer-fighting pink pineapple.” This pineapple has been engineered to “turn down” an enzyme that targets lycopene. This allows for more lycopene production in the pineapple giving it a pink tint. Lycopene, a carotenoid, has been shown to have antioxidant properties, is essential for human health, and has been used to slow the spread of caner cells. These are approved, but not currently on store shelves.  As you can see, genetic engineering and modification have been occurring for thousands of years. The difference between then and now, is that now we can make more precise and efficient modifications in a shorter period of time. Figure 2 shows a visual representation of this brief history.

How are GMOs Regulated?

Let’s dive a bit deeper into the GMOs of today. Some of the first genetically modified crops that reached the market were developed using mutagenic methods. However, these are not always regulated as GMOs because the changes in DNA are not resulting from in vitro nucleic acid techniques. Generally, this type of mutagenesis is used to speed up mutations that would have occurred naturally. At the advent of rDNA and its use to directly improve crop varieties, scientists began to realize the potential benefits of this type of genetic engineering, but also realized there could be risks. This resulted in a cautious evaluation of rDNA products. Shortly after this, federally funded programs such as Environmental Protection Agency (EPA), Food and Drug Administration (FDA), and USDA were created. The USDA is primarily concerned with protecting the environment and agriculture from potential pests through two different offices: Biotechnology Regulatory Services (BRS) and Animal and Plant Health Inspection Agency (APHIS). The FDA’s main responsibility is to ensure safety and security of human and animal food. Last, the EPA focuses on regulating pesticide application on their effects on human health and the environment. This agency does not specifically regulate GM crops, but rather the pesticidal properties of GM crops (McHughen and Smyth 2007). In 2016, the United States Congress passed the National Bioengineered Food Disclosure Law that requires the United State Department of Agriculture (USDA) to fully disclose foods and food products that contain detectable amounts of bioengineered material. In cases where product uses highly refined ingredients but bioengineered material is not detectable, a “derived from bioengineering label” may be used.  Labels that you may see are represented in Figure 3.

Are GMOs Important?

Now, let’s talk about the importance of GM crops and what GM crops are on the market today. The original goal of using GM crops was to help farmers prevent crop loss. This was accomplished by using varieties that were developed with insect resistance, pest resistance, and herbicide tolerance. This led to lower crop losses due to abiotic and biotic stressors which resulted in less revenue loss. Insect and pest resistance allows for the plant, itself, to fight off pests rather than spraying chemical pesticides in the field. In fact, a study conducted by Klumper and Qaim in 2014 found that the GMO technology has reduced the use of chemical pesticides by 37%. This also resulted in increased crop yields by 22%. Overall, the use of GMO crops created a 68% higher farmer profit when compared to non-GMO crops. Also, yield and profit gains are higher in developing countries than in developed countries (Klumper and Qaim 2018). Along with this, herbicide tolerant varieties allow for higher levels of weed control in the field which results in less tilling. No-till farms have healthier soil that can retain more water and nutrients, therefore, increasing the sustainability of farming. Currently, there is also research being conducted to improve plant nutrient uptake which could result in lower need for fertilizer applications. 

Now, consumer-focused varieties are also being developed with characteristics such as improved nutritional content, improved taste, and better post-harvest quality to reduce food waste. An example of these includes Golden Rice which is a variety of rice that can biosynthesize beta-carotene (a precursor of vitamin A). This was designed to help combat vitamin A deficiencies in humans (Kettenburg et al. 2018). One of the biggest drivers of new GM crop development is the need for food security. A report by the United Nations in 2019 estimated the global population to increase by approximately 26%, growing to 9.7 billion by 2050. This poses a big threat to food security. Food requirements are going to continue to increase while arable land continues to decrease. GMO crops have the capability to produce higher yielding crops that are more nutritious and require fewer chemical applications. In summary, this helps increase agricultural revenue, improve agricultural sustainability, improve human health, and decrease environmental pollution from chemicals and fertilizers. Genetically modified organisms have potential to help fight malnutrition and increase food security.

GMOs are Fun!

The last thing I would like to discuss is the new and exciting pink pineapple made by Del Monte Fresh Produce (Figure 4.). Also known as the “cancer-fighting pink pineapple,” this fruit was approved by the FDA in 2016. This pineapple has been engineered to “turn down” an enzyme that targets lycopene. This allows for more lycopene production in the pineapple giving it a pink tint. Lycopene, a carotenoid, has been shown to have antioxidant properties, is essential for human health, and has been used to slow the spread of cancer cells. Not only do they have health benefits, but they are said to taste sweeter and juicer. These are not currently available in stores, but you can order your own PinkGlowTM pineapple from this Del Monte website. Pretty cool right? 

References

Cohen S.N., Chang A.C., Boyer H.W., Helling R.B. Construction of biologically functional bacterial plasmids in vitro. Proc Natl Acad Sci, 70(11):3240-4. 1973.

Kettenburg, A.J. 2018. From disagreements to dialogue: unpacking the Golden Rice debate. Sustainability Science. 13(5): 1469-1482.

Klümper W, Qaim M (2014) A Meta-Analysis of the Impacts of Genetically Modified Crops. PLoS ONE 9(11).

McHughen A, and Smyth, S. 2008. US regulatory system for genetically modified [genetically modified organism (GMO), rDNA or transgenic] crop cultivars. Plant Biotechnology Journal. 6(1):2-12.

Parekh, S.R. 2004. The GMO Handbook: Genetically Modified Animals, Microbes, and Plants in Biotechnology.

United Nations Department of Economic and Social Affairs. 2019. How certain are the United Nations global population projections? Population Facts. No. 2019/6.

Agriculture Marketing Service. BE Disclosure. United States Department of Agriculture  

 

Editor's Note

This is the fifth blog by Tawni Bull in a five-part series "The Biotechnology Rainbow", including:

• The Biotechnology Rainbow (August 18, 2020)
• Red Meets Green Biotech: Plants in Medicine (September 15, 2020)
• Blue Meets Green Biotech: Plants in Water (January 19, 2021)
• Green Biotech: Methods of Genetic Engineering in Plants (February 24, 2021)