The Wetterhahn Symposium took place Thursday, May 24th, at the new Class of 1978 Life Sciences Center, featuring 168 undergraduate researchers. Mary Lou Guerinot, a Dartmouth biology professor and renowned plant expert specializing in the transport of metal ions, delivered the keynote address for the evening. Guerinot began by describing her path to becoming a researcher. From secretly studying calculus in a corner of her Catholic high school to circumventing a rejection from graduate school because she was deemed unsuitable for scuba diving, Guerinot has encountered many obstacles in her career. She reminded students in the audience that the research that they present on now is unlikely to determine what they would study in the future. Indeed, Guerinot has mentored over 60 undergraduates in her 27 years at Dartmouth.

Guerinot is an unabashed proponent of genetically modified crops. She pointed out a book to the audience, Genetically Modified Foods: Debating Biotechnology, in which her writing is featured alongside that of the environmental advocacy group Greenpeace and Pope John Paul II, a point of personal pride for Guerinot. The primary area of research that Guerinot is involved in is the mechanisms of iron transport in plants, an understanding of which is critical to human nutrition. Iron deficiency affects more than 3 billion people worldwide, and manipulating iron transport pathways could aid plants growing in iron-poor soils and supplement the diets of the people who subsist on them.

While increasing iron uptake is desirable, plants transport toxic cadmium by the same protein in their roots. The Guerinot Lab has tuned the specificity of importer IRT1 by protein engineering. Their goal was to produce a transporter that was selective for iron. Iron transport is further complicated by the fact that iron, while an essential plant nutrient, is toxic at high concentrations. Storage molecules and intracellular sequestration are as important to regulated iron metabolism as its uptake in plants.

Seeds are an important foodstuff, and ion sequestration in seeds is another ongoing area of research in the lab. Research professor Sun Kim has studied the iron transporter VIT1, which moves iron into seed vacuoles. The protein is also expressed in the veins of mature plants. In this study, as well as other areas of research, the Guerinot Lab has made use of synchrotron X-ray fluorescence microspectroscopy, which enables three-dimensional visualization of the distribution of each element within whole plant structures. It was found in the same study that VIT1 excludes cadmium, which makes it an appealing choice for manipulating iron levels.

Together, the Guerinot Lab is inspiring not only new directions for the Green Revolution, which is responsible for supporting humanity’s ever increasing food needs, but also young researchers, which was the focus of her address and the Wetterhahn Symposium as a whole.