Project Number: 6250-21520-042-02
Project Type: Specific Cooperative Agreement

Start Date: Oct 01, 2005
End Date: Sep 30, 2010

Objective:
The objectives of this research are to identify plant genes involved in root to seed iron content; determine the processes occurring within pods that regulate calcium movement into seeds; develop cost-effective methods for the intrinsic stable isotope labeling of plants; demonstrate the ability to alter nutrient uptake in plants by expression of calcium exchanger 2; elucidate the regulation of CAX2 and characterize plants perturbed in CAX2 expression; characterize Arabidopsis CAX2 homologs; identify calcium oxalate defective mutant genes by positional cloning; determine if multiple pathways of oxalate biosynthesis exist in plants; and determine the influence of light on calcium oxalate formation in plants. 1) Understanding Plant Nutrient Transport to Improve Food Crop Nutritional Quality and to Assess Phytonutrient Bioavailability - Understand the physiological, biochemical, and molecular mechanisms that contribute to the acquisition, transport, and accumulation of nutrients, specifically iron, in plants. 2) Genetic Engineering of Vacuolar H+/metal Antiport Activity - Determine how edible plants transport and store nutrients and metals, and thereby increase the nutrients and decrease the harmful metals in the edible portions of plants. 3) Investigations into Calcium Oxalate Formation in Plants - Investigate the mechanism(s) regulating calcium oxalate crystal formation.

Approach:
1) Understanding Plant Nutrient Transport to Improve Food Crop Nutritional Quality and to Assess Phytonutrient Bioavailability - Conduct whole-plant analyses of mineral levels, functional analysis of physiological processes, novel gene identification, global analysis of gene expression, quantitative genetic analyses, and development of new methodologies. 2) Genetic Engineering of Vacuolar H+/metal Antiport Activity - Assess the biological impact and plant phenotypes of the vacuolar antiporter CAX2 variants through analyzing transport in both yeast and plant systems. To understand the functional and regulatory diversity among transporters, CAX2 homologs will be cloned and characterized. 3) Investigations into Calcium Oxalate Formation in Plants - Use an integrated genetic, molecular, and cellular approach.