Crop breeding

Are there edible cotton seeds?

Most of us associate cotton with its fiber. A by-product of cotton fiber production is the leftover seeds. One item that can be made from the seed is cottonseed oil, but that market is limited. The rest of these seeds are fed to ruminant animals, like cows.

This seemed like a waste to us in our lab because cotton seeds are high in protein. Humans can’t eat the typical cotton seeds, which contain a toxin called gossypol. In 2014, cotton growers produced about 47 million tons of cotton seed. That amount of cotton seed contained more protein than the 1.27 trillion eggs produced globally that year1.

two clear dishes with seeds. on the left the seeds are darker. on the right seeds are lighter in color meaning they have less gossypol
Comparison of regular cotton seed on left, with TAM66274 on the right. Notice the darker color of regular cotton seeds – this indicates the presence of gossypol, a substance toxic to humans. Gossypol plays a major role in protecting cotton plants from pests, but making the seeds available for human consumption of this high-protein seed was a research goal at Texas A&M for several years. Credit: Devendra Pandeya

These are huge numbers. But that amount of protein from cotton seed could meet the basic protein requirements of about 590 million people!

Gossypol is toxic to red blood cells. Consuming gossypol can cause anemia and even death.

For the past two decades, my lab has been working to find a way to create cotton seeds that don’t contain gossypol. We couldn’t take gossypol out of the entire cotton plant because it is a natural toxin which protects the cotton plant from insects and some diseases.

dark seeds and white balls of cotton on a piece of paper
Wild cotton, on the left, is not good for spinning. On the right, the soft, spinnable, weavable cotton fiber that U.S. customers are used to. Both naturally contain gossypol, which protects against pests. Credit Jonathan Wendel.

Recently, my lab succeeded in creating a type of cotton seed without gossypol – making it a good source of protein for humans!

How did we reduce the amount of this toxic substance to make high-protein cotton seed available for humans?

Using genetic engineering, we were able to identify and shut down a gene exclusively in the cotton seed. This gene controls the amount of gossypol produced in various parts of the cotton plant. Gossypol was not produced in the seeds but continued to be produced in the leaves, flowers, roots, etc.

man's hand with seeds
Dr. Rathore holding edible cotton seeds. These seeds are safe for human consumption – bred to have no gossypol in them. Credit: Beth Luedeker

Of course, creating this new type of cotton seed, currently named TAM66274, took many years. We had to conduct field trials over several years and in several states. This helps us to know how TAM66274 will do under various weather conditions, and in different soils. The multiple-year study also allows us to confirm that each generation of TAM66274 will maintain the traits we want: high protein content and low gossypol content.

By reducing the amount of gossypol in this new cotton seed, we’ve expanded a grower’s potential market. Not only can they sell their fiber, but they now also have an excellent human protein source for sale.2 This, we hope, should get a better price than the current ruminant feed. This boost in food security and farmer’s incomes doesn’t require additional inputs, like land, water or fertilizer! In this way, TAM66274 can be one answer to the solution of a sustainable, secure food supply.

Answered by Keerti Rathore, Texas A&M

This blog is part of Crop Science Society of America’s Seed Week celebration. Why celebrate seeds? Anyone who plants a seed is investing in hope. That’s one of the attractions of seeds. For the gardener, it could be hope for a beautiful flower, or perhaps a delicious zucchini squash. For our farmers, seeds are the hope of this year’s yields of produce, cash crops or forage. No matter the size or shape of the seed, they all can bring forth new life. At Crop Science Society of America, we hold seeds in very high regard. Please visit our Seed Week webpage for news stories, blogs and more information about seed research and facts.

  2. We are happy to announce that as of fall 2019 that both the USDA and FDA have allowed TAM66274 to be used for healthy, nutritious food sources for humans (as well as farm animals).

Read the other blogs in our seed series!

How can you prevent weed seeds from germinating in your garden?

How are seeds labeled for a farmer’s purchase?

How does the USDA help make global seed trade safer?

The Incredible, Edible Seed

Why are seeds of different sizes and shapes?

What are seeds made of – and how can they grow into fruitful plants?!

Protecting seeds: The what, why, and how of seed treatments

About us: This blog is sponsored and written by members of the American Society of Agronomy and Crop Science Society of America. Our members are researchers and trained, certified, professionals in the areas of growing our world’s food supply while protecting our environment. We work at universities, government research facilities, and private businesses across the United States and the world.

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