December 10, 2003

By: Sara Collin
Website: http://www.1st-in-vitamins.com

Danforth Center researcher Edgar Cahoon deciphers genetic basis for vitamin E biosynthesis in cereal grains

As reported in the September 2003 issue of the journal Nature Biotechnology, Dr. Edgar Cahoon, a researcher with the USDA-ARS Plant Genetics Research Unit at the Donald Danforth Plant Science Center and his colleagues from DuPont Crop Genetics have increased the Vitamin E content of corn seeds by six-fold. The research team used a gene which produces the enzyme homogentisic acid geranylgeranyl transferase (HGGT), the catalyst for tocotrienol biosynthesis in most monocot plants. Tocotrienols are the primary form of vitamin E in the seeds of plants, including staple food cereals such as rice and wheat.

Cahoon and his colleagues isolated the HGGT gene sequence from barley and used genetic transformation techniques to introduce the gene into the model plant Arabidopsis thaliana. This resulted in increased accumulation of Vitamin E in the leaves of Arabidopsis by a factor of 10 to 15 times.

Similarly, insertion and over-expression of the barley HGGT gene in corn seeds resulted in a six-fold increase of Vitamin E.

The tocotrienol form of Vitamin E has potent antioxidant properties and has been shown to reduce both human serum cholesterol levels and also inhibit the growth of breast cancer cells.

Until now, tocotrienol biosynthesis in plants had not been extensively studied. Cahoon’s findings could lead to a new generation of grain crops and other foods that possess therapeutic and health promoting properties for both humans and animals.

An additional benefit to this work is that it may lead to foods with a longer shelf life. Scientists have proposed that foods with higher levels of Vitamin E are protected from oxidative stress and that increasing the levels of these compounds may lead to enhanced agricultural productivity, as well as seeds and vegetable oils with improved storage properties.

“We were really quite amazed that this relatively small genetic change could result in such a large increase in the antioxidant content of Arabidopsis and corn,” Cahoon said. “These results demonstrate the power of biotechnology for improving the nutritive value of crop plants.”

About The Author:

Sara Collin is a successful author and regular contributor to http://www.1st-in-vitamins.com.  Recommending the best vitamins, minerals, herbs and weight loss products for optimum health.