Manipulation of Lignin Biosynthesis to Maximize Ethanol Production from Populus Feedstocks

NON-TECHNICAL SUMMARY: High gasoline prices, global warming, national security, and the limitations of global petroleum resources have reinvigorated worldwide interest in renewable resources as a feedstock for liquid transportation fuels, particularly those derived from cellulose. As a perennial woody plant, hybrid poplar (genus Populus) offers several advantages with regard to cellulosic biofuel production including rapid growth rates, the ability to cycle nutrients, a wide geographic distribution, genetic diversity, amenability to genetic engineering, and abundant genomic resources. The phenolic cell wall polymer lignin constitutes a significant barrier to biomass conversion but, at the same time, it is essential to normal plant growth and development. Recent advances in our understanding of how lignin monomers are synthesized provide us with an opportunity to modify the content and composition of the lignin polymer. The research to be conducted will enable us to rationally assess the cost savings that could result from using genetically engineered poplar, instead of corn, as a feedstock for producing biofuels.