Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2002
Publication Date: 7/15/2002
Citation: GRUSAK, M.A. RELEVANT MECHANISMS AND POTENTIAL STRATEGIES FOR IMPROVING THE IRON CONTENT OF PLANT FOODS FOR HUMAN NUTRITION. ABSTRACTS OF THE XI INTERNATIONAL SYMPOSIUM ON IRON NUTRITION AND INTERACTIONS IN PLANTS. 2002. p.156. Interpretive Summary:
Technical Abstract: There is growing interest in strategies to improve the nutritional quality of our food supply, especially with respect to essential micronutrient minerals, such as iron. Recent estimates indicate that one-third of the world's population is at risk for iron-deficiency induced anemia, a condition considered to be the most prevalent nutrient-related human disease on the planet. The primary reason for this problem is that most individuals, especially in developing countries, consume diets comprised mainly of plant foods, and these plant foods are generally low in Fe concentration (relative to animal-derived foods). Furthermore, the iron in these foods is of low bioavailability. Thus, we and others have been attempting to develop approaches that would facilitate significant increases in the Fe content, and/or Fe bioavailability, of plant foods; we are particularly interested in improving the nutritional value of staple crops such as rice, wheat, maize, bean and cassava, as this would have the most significant nutritional impact on at-risk human populations. Our scientific approach has been to identify and characterize the underlying mechanisms and regulatory components that are responsible for whole-plant Fe homeostasis. Because iron acquisition appears to be homeostatically regulated in order to ensure adequate iron nutrition, without excess iron intake, the integration of these homeostatic mechanisms is ultimately responsible for determining Fe content in edible organs. Thus, we believe that by identifying the rate-limiting mechanisms at the root-soil interface, at the boundary of various compartments within roots, at the point of phloem loading in leaves, etc., we should be able to determine what steps must be taken to effectively manipulate Fe levels within plants. In this talk, we will present working models of whole-plant Fe homeostasis, and will review our current understanding of the identified components and control points in these models. We will propose likely candidates within the whole-plant continuum that would be important targets for manipulation, and will discuss how these must be coordinated to achieve significant increases in Fe concentration, without detrimental side effects to the plant. We also will assess the limitations of our current understanding as a means to identify critical genes and processes that still require discovery.