Deficiencies of micronutrients such as Iron and Zinc commonly limit plant growth and crop yields. Dartmouth Professor Mary Lou Guerinot is conducting research to better understand the mechanisms of micronutrient uptake, distribution and regulation.
Guerinot's findings are making it feasible to engineer nutrient-rich plants better able to grow in soils now considered marginal and to increase crop biomass in soils now in cultivation. Guerinot presented her findings 2 p.m. today (Wednesday, August 7) at the Annual Meeting of the American Society of Plant Biologists (ASPB) in the Hynes Convention Center, Boston.
Most people rely on plants for their dietary source of micronutrients. Therefore, plants engineered to be better sources of essential elements would offer humans improved nutrition. For example, over three billion people worldwide suffer from Iron and/or Zinc deficiencies. Food consumption studies suggest that doubling the Iron in rice can increase the Iron intake of the poor by 50 percent. Rice is a staple food in many of the countries with widespread Iron deficiencies in human diets.
Guerinot's lab has previously identified the essential Iron transporter responsible for Iron uptake from the soil. This Iron transporter is IRT1. In addition to transporting iron, IRT1 can also transport Manganese, Zinc, Cobalt and Cadmium. Thus, any attempts to increase Iron uptake via IRT1 must consider the transport of unwanted substrates such as Cadmium.
Industrial, mining, and agricultural activities, particularly the excessive use of phosphate fertilizers, have led to high levels of Cadmium contamination at many locations worldwide. Utilizing DNA shuffling and heterologous expression in yeast, Guerinot and her colleagues isolated alleles of IRT1 that no longer facilitate the accumulation of Cadmium yet retain the crucial ability to transport Iron. When the engineered IRT1 alleles are expressed in plants that no longer express
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Contact: Brian Hyps
bhyps@aspb.org
301-251-0560
American Society of Plant Biologists
7-Aug-2006