Dr. Webb's research interests center on biomineralization, biologically controlled mineral deposition, in plants. In the same way that animals fabricate biominerals in precise forms, such as bones, teeth, seashells, and spicules, plants also produce specific kinds of biominerals with distinct characteristics. Although biominerals in animals have clearly defined functions, relatively little is known about their roles in plants. Most seed plants accumulate some type of biomineral, usually calcium oxalate, calcium carbonate, or silica, and divergent plant taxa exhibit species-specific patterns of mineral type, structure, and distribution. Dr. Webb's interests have focused on understanding how certain plants synthesize unique needle-shaped crystals of calcium oxalate, called raphides, that provide defense against herbivory. Raphides develop inside membrane compartments, surrounded by a carbohydrate-rich matrix, within vacuoles of highly specialized cells. To define the role of the vacuolar matrix in raphide initiation and growth, her group has been working to identify and characterize proteins or other macromolecules associated with raphide development. A second area that has captured Dr. Webb's interest focuses on plants that form deposits of calcium carbonate. In some plants calcium carbonate accumulates within a complex of cell wall materials to form specialized structures called cystoliths. In other plants, including the model plant Arabidopsis, calcium carbonate accrues within cell walls of epidermal hairs, or trichomes. Dr. Webb and her students have applied a variety of methods, including molecular/genetic approaches, to characterize the structure and development of mineralized trichomes in Arabidopsis and its close relatives. These studies contribute to understanding how plants control partitioning of calcium, an element with critical functions in cell physiology, as well as plant growth and development. They also have potential applications in such diverse areas as medicine, materials engineering, and bioenergy.
Dr. Webb currently teaches an undergraduate course in Plant Anatomy (BTNY 31600) for plant biology majors, and she also enjoys working with undergraduates on independent research projects. Dr. Webb has taught a training course in Scanning Electron Microscopy (SEM) for graduate students. She is currently developing a new graduate course that will focus on contemporary microscopy with emphasis on tailoring microscopy approaches to research needs and applications. Demonstrations of the SEM will be included in BTNY 59000, her new summer course in plant biology for high school teachers.