Humans have been modifying plant traits for thousands of years, first through breeding and in the last 30 years, through biotechnology. These modifications have increased yield, improved agronomic practices, and enhanced traits of interest such as flavor, nutrition, and appearance. Today, advancements in biotechnology permit precision changes in the genetic blueprint of all organisms thereby enabling fabrication of crop plants with multiple purposes such as use as biofuels, sources of chemicals, and carbon sequestration. Currently, there is a growing need for sustainable sources of not only biofuels but also bioproducts and plant-based materials. Poplars are among the fastest growing trees in the United States and are important for both carbon sequestration and global carbon cycling. The objective of this research is to use state-of-the-art biotechnology approaches to re-engineer poplar as a multipurpose crop that can be used for bioenergy, biomaterial, and bioproduct production. Specifically, this project will fabricate new types of poplar with altered ratios of wood and leaves that will be modified to produce new biofuels and biopolymers. The change in wood to leaf ratios will be exploited to permit production of bioproducts such as precursors for drop-in fuels in leaves, modified composition in wood for biomaterials production, as well as changes in agronomic production practices such as increased stand density leading to increased yield. Collectively, these engineered poplars will not only provide a platform for a new era for poplar biology, agronomy, and processing but they will also contribute to mitigate the effects of climate change.