Project Number: 1907-42520-003-00
Project Type: Appropriated

Start Date: Jan 29, 2004
End Date: Jan 28, 2009

Objective:
This research focuses on integrating soil, agronomic, physiological and nutritional research to provide criteria needed to design cultural practices and allow genetic modifications of staple food crops to improve human health. It will lead to the development of sustainable ways to improve the nutritional quality and safety of principal plant foods with respect to micronutrient elements (e.g., Fe and Zn), certain vitamins and heavy metals (e.g., Cd) that are considered to be significant human health problems. These objectives will be achieved through research directed at obtaining a better understand of the chemistry and availability of these elements in soil, their spatial distribution and variability in areas of crop production, their absorption by roots, their translocation to and deposition in edible portions of food crops, the identification of selection criteria for identifying genetic factors involved in controlling their accumulation by plants, and identifying food substances that effect their bioavailability to humans from typical diets and their mechanisms of action in the gut.

Approach:
Effects of soil chemical and physical factors (e.g., elemental form, salinity, landscape position) on availability of important health-related elements (e.g., Fe, Zn, Cu, Se, Cd, etc.) to crops and their accumulation in human foods will be studied. Cereal genotypes will be studied for differences in grain-Cd accumulation and interactions with Zn fertilizers to improve food safety. Mechanisms of micronutrient homeostasis will be studied in whole plants and reproductive organs to improve their density and bioavailability in edible products. Genetic modifications will be used to increase health-promoting substances in food crops and to identify important plant food inhibitors (e.g., certain polyphenols) of Fe and Zn bioavailability to humans. In vitro or animal models will be used to study enteric bioavailability of important nutrients, and examine mechanisms of action of promoter and inhibitor substances in human diets. An in vitro Caco-2 cell model will be modified to study interactions of diet with nutrient bioavailability (e.g., Fe, Zn, provitamin A carotenoids), test the role of hind-gut microorganisms on nutrient absorption from foods, and assess the role of non-digestible carbohydrates (e.g., inulin) in this process.