Blog •  2/1/2017

How GMOs Are Made: Selective Breeding Edition

Written By Holly Loucas 
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Genetic engineering techniques are used to insert genetic material (DNA) from one plant type to another to enhance the foods we eat almost every day, but making a GMO plant is a process not taken lightly.

Scientists, like me, first evaluate if conventional breeding methods and wild relative species are able to solve the issue. Now, thanks to GMO practices, we have the Arctic Apple. These apples have been engineered with a gene to prevent browning after cutting! Scientists also are working on engineering nuts that don’t contain the protein that causes nut allergies and potatoes resistant to late blight, which caused the potato famine in Europe.

One technique that makes these beneficial plants possible is selective breeding. With this technique, I can pass on positive traits (sets of characteristics desired for things such as disease resistance) to the next generation of plants.

Here’s how I do it:

Removing plant cells to relay the trait

When genetically engineering a plant, I first will isolate the genes involved in the “trait of interest” in the “ancestor plant”. This means I remove cells from the plant and grow them on special petri dishes that have nutrients the cells need. This process is easy for some plant species and extremely difficult for others.

Next, I harvest the plant cells and complete a process that allows them to revert back to an early phase in their development. At this stage, they have the natural ability to become ANY cell type (we call cells in this stage undifferentiated).

Then, I place the cells into new petri plates that have been specially prepared to imitate the natural processes that occur when cells are differentiating into plant parts. The cells will grow into different plant parts dependingon the how the dish was prepared in a process called plant regeneration.

The most common approach is to regenerate a plant shoot first. Once it grows, I will cut it off from the other cells on the petri dish, similar to a cutting you would take from a house plant. It has a stem, leaves and a growing point at the top. Instead of rooting the shoot in dirt, I transfer the shoot to a sterile rooting media similar to what you would buy at your local gardening store as a root stimulator for cuttings. I root these shoots in the lab because they are very valuable and, in the lab, I can maintain the rooting environment free from diseases.

Once the shoot has roots, I’ll transfer it to soil in a greenhouse where the plant continues to develop the same way a plant grown from a seed or a cutting would. For some plants, this is very quick and easy, and only takes two to three months. Tobacco and petunias are two examples of plants that are easy to regenerate. For other plants, such as soybeans and cotton, the process can take a year or more and is much more complicated.

Inserting the trait to reproduce improved plants

Now, the fun starts–inserting the gene of interest! There have been several methods of plant gene insertion developed over the years to become more natural, accurate and efficient. The latest gene editing methods allow scientists to manipulate gene sequences within the plant and insert new genes of interest directly into the existing plant DNA.

I’ll typically produce 20 to 100 genetically engineered plants with the desired trait. I’ll grow them in a greenhouse and screen them for plant abnormalities. Then I’ll identify one or two individuals that express the trait of interest to give to the breeding department.

At this point, plant breeders start making crosses with non-GMO plants to develop new varieties that are now GMO and now offer a trait that was unavailable in the past.

Ensuring a positive eating experience for you

During this GMO development phase, another process has started in parallel. To release GMO plants into the environment, a very thorough regulatory process must be undertaken to ensure that the gene will not pose an environmental or health threat. This process is carried out by the governmental regulatory bodies of an individual country, and you can be assured that the product is safe to grow and consume.

Now that you know the process of selective breeding, you know that GMOs are the sharing of natural traits between plants. This genetic engineering technique is one of many that help plants gain the strength and appeal to feed more families around the world.

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