Researchers develop low-carb corn with enhanced protein and oil

May 4 2004

Researchers at the University of California, Riverside reported the development of technology that doubles the protein and oil content of corn while reducing its carbohydrate content, a boost for growers to feed both people and livestock.

Biochemist Daniel R. Gallie and his research team, Todd Young and Jane Giesler-Lee, published their findings this week in the June issue of The Plant Journal.
Flowers in the corn ear develop in pairs but one from each pair aborts before pollination can occur. Because of the role that the plant hormone, cytokinin, plays in preventing organ death, the authors reasoned that cytokinin might rescue those flowers, which were destined to abort. The research team introduced a gene that enabled the production of cytokinin in developing flowers.

“Surprisingly, not only did we observe rescue of flower abortion but the kernels produced from pairs of flowers fused into a single normal-sized kernel that contained two embryos and a smaller endosperm,” said Gallie. “Because it is the embryo that contains the majority of protein and oil, the presence of two embryos doubles their content in corn grain. The reduction in the size of the endosperm in the kernel, the tissue that contains most of the carbohydrate, means that the nutritional value of the grain has been improved considerably.”

The U.S. Department of Agriculture, National Science Foundation, and California Agricultural Experiment Station funded the seven years of research in this area.

Cereal grains are the most important crops to humanity, used for animal feed, for production of oil, protein, and starch, and for feeding the majority of the world's population. In a field in which increases in oil, protein, or starch content as small as 1 percent are considered a significant achievement, the ability to double their amount is a considerable advancement.

“Our findings are important to the field of flower development in corn in that they suggest that the level of cytokinin may determine whether abortion occurs and this knowledge can be used to engineer grain to improve its nutrient and economic value.

“Such improvement would be particularly important for those who depend on grain as their primary source of dietary protein which includes many people in the third world,” said Gallie.

Although food production is currently sufficient to feed the world’s population, projected population growth is expected to outstrip food production by mid-century. The traditional approaches and improvements in agricultural practices used in the past to increase grain productivity are unlikely to generate the productivity gains needed for the future according to the Food and Agriculture Organization of the United Nations.

Gallie’s findings may provide a useful approach toward the goal of feeding the world’s population.