Associate Professor of Molecular, Cellular and Developmental Biology
Associate Chair, Research & Facilities
Professor Nielsen’s research involves the study of how plant cell walls synthesized during growth and development. Because the majority of a plant’s biomass is accumulated in cell walls, understanding how carbohydrates are incorporated into this structure has important ramifications for the use of plants as a source of biofuels and in food-based applications. In particular we have been interested in how enzymes are involved in the synthesis and deposition of cellulose function during plant cell wall assembly. Plant cell walls are comprised of a complex mixture of polysaccharides, lignin, suberin, waxes, and proteins. The cell wall provides mechanical support and serves as the interface to neighboring cells and the environment. Many cell wall components are synthesized inside the plant cell, and must then be secreted via membrane trafficking pathways. Despite the importance of these processes in growth and development, there is still little understanding of the mechanisms by which sorting and delivery of these components is accomplished. In order to study membrane trafficking pathways involved in cell wall deposition, research has focused on the growth and development of root epidermal cells in the model plant; Arabidopsis thaliana. In growing root hairs, new cell wall deposition is restricted to the extreme tips of growing root hairs. Because secretion of cell wall components is restricted to this site, identification of tip-localized subcellular compartments may allow insight into the cellular mechanisms involved in plant cell wall biogenesis and lead to a better understanding of how this important source of biomass is generated.