Breeanna Rae Urbanowicz

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Graduate Student

I received my bachelor's degree with Honors from Purdue University in Molecular Biology and Genetics. At Purdue I was a research assistant in Dr. Nick Carpita's lab in the Department of Botany and Plant Pathology. I contributed to a number of projects involving the biosynthesis and architecture of Arabidopsis thaliana and Zea mays cell walls. My principal project in the Carpita lab was elucidating the mechanism of biosynthesis of mixed-linkage (1 -> 3),(1 -> 4)- b -D-glucan ( b -glucan) in Zea mays. I also did some early work that involved correlating shifts in Fourier transform infrared (FTIR) spectra of maize cell walls from seedlings at different time points during development with the chemical changes in primary wall composition.

As a graduate student in the Department of Plant Biology, my project involved the characterization of a novel tomato endo-ß-1,4-glucanase that has an unusual carbohydrate-binding domain and that is expressed during tomato cell expansion and fruit ripening. My research focused on identifying the substrates for this enzyme, characterizing its mechanism of action and evaluating its role in vivo. The lab has previously shown that this new CBM does indeed bind to crystalline cellulose, making this the first time a plant EGase has been shown to exhibit such properties. Ongoing studies include an investigation of the activities of purified domains from a tomato EGase on various plant polysaccharide substrates and an evaluation of the functions of this class of proteins in Arabidopsis in which expression of orthologous EGases is suppressed.