Boosting Vitamin E in Corn and Other Crops

An Agricultural Research Service scientist and cooperators are developing new varieties of corn and other food crops that have higher levels of vitamin E.

Twenty-five percent of Americans do not get enough vitamin E. It is particularly important for pregnant women, and some researchers have shown that it can decrease the risk of heart disease.

The research was done by molecular biologist Edgar B. Cahoon of the ARS Plant Genetics Research Unit at the Donald Danforth Plant Science Center in St. Louis, along with his former colleagues at DuPont Crop Genetics, Wilmington, Del. The scientists used genes found in rice, barley and wheat, each of which contains high levels of vitamin E.

Now that their three years of research have led to a safe, healthful variety of corn, Cahoon and his colleagues are working on similar studies with soybeans. He believes many other crops would benefit from the new approach.

Vitamin E is a generic name for naturally occurring compounds called tocotrienols and tocopherols. Cahoon looked at the pathway that leads to tocotrienols, something that had not been studied much. The scientists were able to isolate a gene for the enzyme homogentisic acid geranylgeranyl transferase. This enzyme is responsible for producing a tocotrienol form of vitamin E in cereal grains. When the gene was added to corn plants, the kernels' vitamin E content increased sixfold.

In addition to making the crop more nutritious, boosting vitamin E levels is likely to increase the crop's shelf life. Vitamin E occurs naturally in vegetable oils, nuts and green leafy vegetables.

The research was reported in the September issue of Nature Biotechnology.

ARS is the U.S. Department of Agriculture's chief scientific research agency.