Manipulate plant cell structure to increase nutrient content.

Manipulating the cell structure in grains boosts essential micronutrients, such as iron and zinc, increases plant yield, improves seedling viability and decreases the need for fertilizing crops. About 1 billion to 2 billion women, infants and children worldwide have a deficiency in micronutrients such as iron and zinc. These are especially crucial for women of child-bearing age. Without iron, women become anemic, and anemia has a negative effect on the cognitive development of the fetus.

USDA/ARS investigators (U.S. Plant, Soil and Nutrition Laboratory, Cornell University, Power Road, Ithaca, NY 14853) have found that by manipulating the cellular structure in corn, they can manufacture more micronutrient-rich cell layers. More nutrient capacity translates into more healthful foods and a decrease in fertilization at the farming level. In the years of the Green Revolution, scientists managed to stave off world famine by introducing calorie-enriched plants. But agriculture paid a price for more calories: nutrient-poor plants. Such staples as rice and beans can grow in mineral-poor soils, but nutrients are needed in the seed.

To improve the nutrient composition, scientists must get under a grain's skin. Beneath the corn's hull is the aleurone layer, where beneficial micronutrients are stored. In a normal corn seedling, there's a single layer of aleurone cells. By taking mutant corn seedlings, where there are several aleurone layers, and cross-breeding them with normal seedlings, corn seed with several aleurone layers begins to develop. The multiple aleurone layer looks like a normal seedling, but it packs a stronger micronutrient punch. In its work, the ARS has used classical plant breeding techniques.

Rice has a similar cellular structure to corn. However, grain-processing techniques, such as milling, displace the micronutrients. Milling or processing strips the aleurone layer, and the grains contain fewer essential micronutrients. Scientists are working on ways to recapture them, and they have bred rice with more aleurone layers. They've doubled the iron and zinc content of rice. The rice is undergoing field tests. Human clinical trials will be performed to determine if the nutrients are bioavailable.

Researchers also are working on wheat, maize and beans. They've been able to triple the iron and zinc content of beans. Field trials are ongoing. A commercial version of the micronutrient-enriched seed should be available in a few years.

Further information. Ross Welch; phone: [phone]; fax: [phone].