Quantitative Biology / Gene Expression in Development & Disease Seminar

Friday, 01 February 2013 at 11:30am

Room 1400 Biomedical and Physical Sciences Bldg.

Refreshments at 11:15

Speaker:  Wolf Frommer, Department of Plant Biology, Carnegie Institution for Science

Title:  In Vivo Biochemistry with the Help of Genetically Encoded Sensors

Plants are Sensei’s of nutrient acquisition and use efficiency. Individuals, e.g., bristle cone pine, can thrive for thousands of years in one location and acquire adequate amounts of nutrients and distribute them between the different tissues and organs. They control acquisition to avoid toxicity while securing access to the maximal nutrient availability for efficient growth and reproduction. Plants are also masters of distribution, using sophisticated and yet poorly understood regulatory networks to coordinate acquisition, assimilation and delivery with the needs to the various parts of the plant. Humans have been able to affect distribution to their favor, for example to increase the yield of harvestable material per acre. This has been achieved by 1000s of years of breeding; however, still today we do not understand the underlying mechanisms that led to the high efficiency of modern crop plants.

My lab has been interested in the mechanisms of nutrient acquisition and translocation in order to gain a better understanding of the underlying mechanisms as a basis for rational approaches to crop improvement. We identified many of the key transport proteins responsible for moving nutrients such as ammonium or sugars, amino acids, peptides and nucleobases across cell membranes. We have used heterologous expression systems to characterize these membrane proteins in detail, and we have determined their cellular and subcellular localization. We also determined the contribution of the transporters to the functioning of the plant using mutants.

Recently we have been able to determine the localization of the nutrients themselves (with the help of Förster Resonance Energy Transfer sensors) as well as the in vivo activity of the transporters using fluorescence imaging technologies. We have also started to systematically identify proteins that interact with the transporters; all with the ultimate goal of getting a hand on the regulatory networks that control nutrient acquisition and translocation in plants.