One of the central issues of our time is to implement measures to reduce the emission of greenhouse gases such as carbon dioxide to prevent global warming, and to achieve a reduction of the dependence of the United States on fossil fuels that need to be imported from politically unstable or even hostile states. During the last few years, it has become increasingly clear that the U.S. is capable of producing substantial amounts of fuel in the form of ethanol by microbial fermentation of plant cell wall material; however, optimization of these procedures requires a deep understanding how the synthesis of cell wall components is being regulated. Furthermore, researchers need to know how cell wall material can be modified by genetic engineering to facilitate its utilization without compromising the viability and vigor of the plants. During the last few years, the synthesis of the hemicellulose xyloglucan has been studied to address this issue, and it is now possible to determine how the formation of this polymer is being regulated on the molecular level. The NSF-funded research is designed to understand the relative contributions of different biochemical pathways toward the synthesis of xyloglucan and other cell wall components with the ultimate goal of optimizing the usefulness of photosynthetically fixed carbon toward the generation of environmentally friendly biofuels. The current project will provide training opportunities for students at the undergraduate, graduate, and postdoctoral levels to create a diverse work force that will be able to pursue these goals in the future for the benefit of the U.S. economy and to address environmental issues that affect all nations.