Genomic Science Program
U.S. Department of Energy | Office of Science | Biological and Environmental Research Program

BioPoplar: A Tunable Chassis for Diversified Bioproduct Production

Authors:

C. Robin Buell1* (Robin.Buell@uga.edu), Christopher Dardick2, Wayne Parrott1, Robert Schmitz1, Patrick Shih3, Chung-Jui Tsai1, Breeanna Urbanowicz1

Institutions:

1University of Georgia–Athens; 2UDSA-ARS; 3University of California–Berkeley

Goals

This project will yield poplar chassis with multipurpose uses including bioenergy, biomaterials, and bioproduct production. The generation of a robust cell type–specific set of transcription factors and cis-regulatory elements and the ability to modulate gene expression in a high-resolution manner (i.e., that of specific cell types) will enable precision genome engineering of metabolism, a significant advancement in capabilities in modulating plant biochemistry. The change in architecture will be exploited to permit production of bioproducts (drop-in fuel precursors in leaves), biomaterials (modified wood composition) in wood, and changes in agronomic production practices such as increased stand density leading to increased yield. Collectively, these engineered chassis and tools provide the platform of a new era for poplar biology, agronomy, and processing.

Abstract

Domestication and breeding efforts have shown that selection of specific plant architecture traits across a wide array of plant species, both annuals and perennials, results in improved traits for human use, either for food, feed, or fuel. Similarly, selective breeding can yield distinct chemotypes of crops with desired chemical profiles or compositions. Today, researchers can generate precision knowledge of gene regulation and function through high-resolution omics technologies and construct a synthetic biology toolkit to engineer plant genomes at the DNA sequence, chromatin accessibility, and expression levels. Thus, science has entered an era where scientists can model, design, and then engineer precise changes in plant genomes that will lead to predictive, modified traits.

This project will re-engineer poplar as a multipurpose crop that can be used for bioenergy, biomaterial, and bioproduct production. The team will generate a cell atlas that encompasses gene expression, gene regulatory networks, and cis-regulatory elements responsible for gene expression at the cell-type level, providing the requisite knowledge base and tools for precision biobased design and fabrication of multipurpose poplar. Researchers will couple single-cell datasets with new genome and epigenome editing tools to develop new morphotypes of poplar that have altered tree and leaf architecture. These morphotypes will substantially improve biomass potential via increased stand density and tree integrity, photosynthetic capture, and trichome density and serve as the foundational chassis. These chassis will have altered ratios of leaves to stems and/or trichome density in which researchers can further engineer cell wall composition and/or novel molecules such as precursors for drop-in fuels, thus making chemotypes of poplar that are “customized” to their biomaterial or bioproduct applications and simultaneously “maximized” in optimal morphotypes. The team will employ an iterative design process in which metabolic pathways are optimized to create unique chemotypes with tailored biomaterial and bioproduct composition.

Funding Information

This material is based upon work supported by the U.S. DOE, Office of Science, BER program under Award Numbers DE-SC0023338 and 89243023SSC000102 and the Center for Bioenergy Innovation.