Analysis Of Plant Lignin Formation And Engineering For Biofuels Production

ANALYSIS OF PLANT LIGNIN FORMATION AND ENGINEERING FOR BIOFUELS PRODUCTION Deborah L. Petrik 149 Pages August 2015 Grasses such as switchgrass and Miscanthus are attractive feedstock candidates for second generation biofuels because they are perennials that can grow on less fertile or marginal lands not used for food crops, require little fertilizer and modest pest and disease management, and are not a human food source. Releasing the energy potential contained in plant-based cellulosic material requires either conversion to a liquid biofuel such as ethanol or burning. Thus, much of the current research focuses on not only understanding grass development as it relates to yield, but how to best enhance traits affecting the quality of biomass for its efficient conversion to biofuels. In order to efficiently extract the sugars making up the cellulose and hemicelluloses components of the plant cell wall, the phenolic polymer lignin in which they are embedded and crosslinked to must be removed. To lower the cost of biomass conversion, approaches to decrease lignin content or alter its structure to allow ease of removal may be employed. This work aims to study genes involved in lignin biosynthesis and modification, in order to identify points in the pathway that can be targeted to ease lignin recalcitrance. Efforts to modify plant cell walls must be done without harming plant fitness, thus cell wall related gene promoters hold value as switches for transgenic modification in a cell specific and developmental timing specific manner. Therefore, the second goal of this work was to clone into monocot transformation vectors and thoroughly characterize the expression patterns of three secondary cell wall gene promoters. These utility vectors will be made available to the scientific community for use in driving genes of interest in a secondary cell wall-specific manne