Project Background

Professor Mary Lou Guerinot is an eminent plant molecular geneticist, whose principal area is metal transport and regulation of gene expression by metals in plants. Professor Guerinot has identified many key genes, including one encoding a transporter essential for iron uptake from the soil. Iron deficiency anemia is the most prevalent mineral nutrient disorder in humans and Professor Guerinot's impressive body of work has made a highly significant impact on developing crops that offer sustainable solutions for malnutrition. In collaboration with Professor David Salt, Guerinot developed the ionomics database, a unique collection of the elemental profiles of over 11,000 lines in Arabidopsis, which also contains rice ionomic data. This open-access database allows researchers to literally browse through metals to find the genes associated with them, and is an invaluable tool in our research.

Dr. Tracy Punshon has worked for almost ten years in imaging various metals and metalloids in biological materials, plants in particular, with synchrotron x-ray fluorescence microspectroscopy (SXRF). SXRF can be compared to an x-ray or CAT scan where the metals can be seen within the tissues without the need to section or destroy the sample. Dr. Punshon was one of the first biologists to apply SXRF to the analysis of plants, and alongside Professor Guerinot was the first to use SXRF as a way of characterizing genes.

This is an interdisciplinary project, which combines bioinformatics in the PiiMS database, molecular genetics of the model plant Arabidopsis and synchrotron imaging techniques to understand, and hopefully solve, the public health issue of arsenic in seed. It has also provided collaboration between projects in the Dartmouth Superfund Program--using the information from plant molecular genetics to inform gene searches in mammalian model organisms and clinical studies, as well as launching pilot projects to survey the forms and amount of arsenic in rice-based foods.