What’s in a Name? GMOs

At this year’s Iowa State Fair, the Iowa Agriculture Literacy Foundation hosted a screening of FOOD EVOLUTION every day at 1 p.m. If you are unfamiliar with FOOD EVOLUTION, it is a 90-minute documentary (soon to be available on iTunes and Hulu) that essentially outlines modern uses of genetic engineering and the scientific consensus about their usefulness, oversight, and safety.

This documentary brought forth many conversations about genetic engineering and food issues as a whole. While I always try to encourage open dialogue and a healthy level of skepticism, I soon noticed a pattern. Genetically modified organisms (or GMOs) tend to get jumbled up with a plethora of other perceived issues. Upon noticing that, I thought I would try to separate and define those issues via blog post.

O.K., folks, here we go.

Before we can really talk about GMOs, we have to understand a small bit of genetics – the root of the G in GMO.

Genetics is the study of heredity and the variation of inherited characteristics. So at the basic level, we know that organisms tend to look or behave like their parents, because they inherit those traits. The thing that codes for those traits is DNA, or deoxyribonucleic acid. All living organisms – plants, animals, and microorganism included – have DNA.

The cool thing about DNA isn’t just that everything has it, it’s that it’s all made of the same stuff. DNA is made up of four nitrogenous bases (chemical compounds containing nitrogen) called adenine, guanine, thymine, and cytosine, or A, G, T, and C for short. These bases are then lined up in specific orders, and groups of these bases will code for a specific protein to be made. Those proteins are synthesized and sent on to a specific place where they are necessary. It’s like computer coding, but biological!

DNA_simple2.svg

This can sometimes be hard for people to wrap their minds around. How can we be made of the same stuff as potatoes or rattlesnakes? While that is pretty crazy to think about, it is just nature, and isn’t necessarily something to be worried by.

So now that we have the first letter of GMO down, what’s the rest all about?

GMO may stand for “Genetically Modified Organism,” but GMO itself doesn’t have a really concrete definition. Some folks say that only things that have had their DNA altered in a lab are genetically modified, while other folks say that by artificially selecting for better crops or fruit or health, you are genetically modifying that plant.

Personally, I tend to favor the term genetic engineering, because it seems more specific. Genetic engineering, engineers the genetic code to solve specific issues.

But wait, there’s more! Genetic engineering still isn’t completely specific, because there are multiple ways to change genetic code! Genetic modification then becomes an umbrella term that includes genetic engineering, which then becomes an umbrella term including specific methods, like CRISPR-Cas9, agrobacterium-mediated transformation, and particle bombardment. The variety of genetic engineering methods can help scientists insert a helpful gene, remove a problematic gene, or even turn off production of a specific enzyme.

Concept map

The thing about talking about GMOs in terms of how they’re produced, though, is that most people don’t see that side of it. Instead, they will hear about a specific crop or trait. This can cause confusion, because scientists can look more at the accuracy and ease of use of the specific method; whereas the public may look more at the traits that are expressed or where those traits came from, which we now know doesn’t matter much, since all organisms share a similar genetic code.

One well-known trait is the Bt trait. Bt crops are named after Bacillus thuringiensis, the naturally occurring soil bacterium a specific protein was taken from. This soil bacterium is common, but when specific kinds of insects eat it, a protein within the bacterium causes complete failure of the insect’s digestive system. The protein only affects certain kinds of insects, and does not harm humans. This protein is used on many farms as an insecticide to spray on the crops. However, with the trait is inserted into the plant’s genetic code, producers don’t have to take the extra step.

This can provide many benefits, including saving time and money, as well as protecting producers from being impacted by too many pesticides. The problem, however, is that it often gets confused with another common trait, which is the Roundup® Ready trait.

Roundup® Ready is the brand name for crops that are tolerant to the herbicide glyphosate. Monsanto’s brand name for glyphosate is Roundup®, therefore, Roundup® and Roundup® Ready can be used together. Herbicides have been used for a long time, and different herbicides might target only broadleaf plants or only grasses, and some are nonselective, meaning they will kill all plants. Glyphosate is a nonselective herbicide, is very effective, and has a toxicity less than that of caffeine or salt. Really, it’s quite an amazing piece of technology.

Basically, the Roundup® Ready trait enabled farmers to spray for weeds while their crops were in the field. Prior to this, farmers either had to pull those weeds by hand, or use tillage to dig the plants up. Herbicide tolerant crops meant that farmers could spend less time managing weeds, while being able to drastically slow soil erosion by practicing no-till and conservation tillage. No-till farming is also being shown to improve other things, like soil structure and health, decrease soil compaction, and improve nutrient and water-holding capacities of the soil.

Let’s review. Bt and Roundup® Ready are two of the main traits people think about when discussing GM technology, especially in Iowa. Bt means that the plant will kill harmful insects without extra pesticides. Roundup® Ready means the crop won’t die if glyphosate is used on it. There are only a select few species of plants that have these technologies, including corn and soybeans, but because of the types of crops associated, they are the most commonly talked about in Iowa.

weekly food menu

Sometimes these two can get mixed up with each other, which can be easy to do since genetic engineering is a complicated topic. However, it is important to understand the differences in certain things to be able to discuss them well. Especially since these are only two of the applications of genetic engineering. Some others are papaya trees resistant to the debilitating Papaya Ring Spot Virus; potatoes resistant to bruising, which reduces food waste; bananas that are resistant to the Banana Wilt Disease; and rice fortified with beta carotene, which can keep children from developing blindness due to vitamin A deficiencies.

Each one of these applications is tested vigorously by the group creating it, as well as specific government agencies. In the U.S., GMOs are overseen by the USDA, EPA, and FDA to ensure safety to humans, to the environment, and other factors. This testing and approval process can take 7 to 20 years. Each application has different nuances that need to be analyzed. But to reiterate, each application only has a small change in one or a very few number of genes. These genes are made up of a common genetic code across all species. Modern technologies for editing these genes are precise and accurate, and testing of these organisms costs an average of $130 million.

In the film FOOD EVOLUTION, the scientists make it clear that they want the data to help them form their opinions. Currently, there is no evidence that shows any negative health effects of consuming GMOs, but many still agree that testing needs to continue to happen with every application to ensure that no mistakes happen in the future.

If you still have questions about GMOs, or are interested in learning more, I’ll put below some good resources to check out. If you have some other favorite resources, please put them in the comments below!

Happy learning!

GMO Answers

What is CRISPR-Cas? Video

How does Agrobacterium-mediated gene transfer work? Video

How are GMOs Created? Video

 

–Chrissy

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