Petroleum, a finite fossil fuel, has powered modern society for centuries. However, its extraction and consumption have contributed significantly to climate change and pollution. These pressing global challenges demand innovative solutions. As we seek to transition to a more sustainable future, perennial grasses emerge as a promising avenue for a greener tomorrow.
These hardy plants, capable of thriving in diverse environments, offer a wealth of potential benefits. By harnessing their photosynthetic efficiency and rapid growth, we can produce a wide range of bioproducts, from renewable fuels to sustainable materials. Furthermore, their deep root systems can sequester significant amounts of carbon dioxide, helping to mitigate climate change.
While domesticated species like sugarcane and maize are already used for various bioproducts, undomesticated species like miscanthus and switchgrass hold even greater potential because of their wider genetic diversity and resilience. By tapping into the genetic potential of undomesticated perennial grasses, researchers and farmers can develop more sustainable and productive agricultural systems.
Genetics to improve perennial grasses for bioproducts
Researchers are turning to genetics to develop these species into competitive crops for use in sustainable products. By understanding their genetic makeup, researchers can identify and manipulate specific genes to improve key traits, such as biomass yield, drought tolerance, disease resistance, nutrient use efficiency, and cell wall composition.
HudsonAlpha Faculty Investigator Kankshita Swaminathan, PhD, and her lab are at the forefront of this research. By combining genomics, gene editing tools like CRISPR-Cas9, and advanced phenotyping techniques, they are conducting in-depth analyses of genes and key traits in Miscanthus, switchgrass, and sorghum. This integrated approach promises to significantly accelerate the development of sustainable bioenergy crops and the creation of new, high-yielding cultivars within a reasonable timeframe.
Traditional breeding methods, such as directed breeding, rely on crossing plants with desirable traits to produce offspring with those traits. While effective, this process can be time-consuming and often results in the introduction of unintended genetic changes. Gene editing, on the other hand, offers a more precise and efficient approach.
In a groundbreaking study, scientists in the Swaminathan lab, along with collaborators at the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), successfully used CRISPR gene editing to modify genes in several varieties of miscanthus, a feat that had never been successfully done before. As proof of concept, they edited a gene called lemon white which is involved in chlorophyll and carotenoid biosynthesis, which affects leaf color. Editing out the gene causes a visible change in the color of leaves, confirming a successful transformation. This achievement paves the way for creating miscanthus varieties with improved traits for biofuel and bioproduct production.
While the miscanthus study demonstrated the feasibility of genome editing across the entire plant, perennial grasses’ complex cellular structure presents a nuanced challenge. To fully unlock their potential for sustainable bioproducts, precise genetic modifications may be required in specific cell types rather than a blanket approach.
A seminal study by the Swaminathan lab, in collaboration with CABBI, is helping illuminate the path forward. The collaborative team generated the first comprehensive gene expression atlas of major types of cells from the stems of the sorghum plant. Having genetic information at the cell-type-specific level is important for having precise control over the development and composition of different plant tissues. For example, by specifically targeting genes involved in cell wall biosynthesis and growth in cell types that contribute most to biomass, researchers can increase the overall biomass yield of the plant.
This proof-of-concept study lays the foundation for similar exploration in perennial grasses like miscanthus and switchgrass. By understanding and manipulating cell-type-specific gene expression, scientists can develop perennial grasses with improved yield, quality, and stress tolerance, ultimately contributing to a more sustainable and environmentally friendly bioproduct industry.
“Genomic research provides invaluable insights into plant genomes, facilitating the development of plant-based alternatives to fossil fuels, waste reduction strategies, and economically viable, environmentally sustainable systems.”
– Kankshita Swaminathan
Green, circular bioeconomy
By understanding the genetic basis of key traits, researchers are paving the way for the development of high-yielding, climate-resilient perennial grasses that can be used to produce a wide range of sustainable bioproducts. The Greening the Southeast initiative aims to do just that, creating a green, circular bioeconomy in the Southeast US. Led by HudsonAlpha, the initiative also includes collaborators from the University of Tennessee, Auburn University, and more than 70 other institutes, companies, and organizations. The primary goal is to mitigate climate change impacts from manufacturing by transitioning from petroleum and environmentally harmful fibers to sustainable, locally sourced materials while creating new jobs in rural areas.
The project centers on converting perennial agricultural grasses into a range of consumer goods. Potential applications include packaging, automotive components, and construction materials. By utilizing underutilized marginal land, this approach aims to create new markets for farmers and stimulate rural economic development.
Expected benefits of the project include:
- Reduced carbon footprint: Improved carbon sequestration through grass cultivation and reduced reliance on fossil fuels.
- Increased sustainability: Decreased dependence on imported materials and a shift towards sustainable practices.
- Job creation: Development of new industries and employment opportunities in the region.
- Economic growth: Stimulation of local economies through the creation of new markets for agricultural products.
- Initially focused on Alabama and Tennessee, this project has the potential to influence the national bioeconomy landscape.
The team was one of 44 recipients of $1 million each in the first-ever “NSF Regional Innovation Engines Development Awards” program, announced in May 2023. These planning awards help establish collaborations to create economic, societal, and technological opportunities for their regions. In late 2024, the team was invited to compete in the next stage of the second-ever US National Science Foundation (NSF) “Regional Innovation Engines” (NSF Engines) program for awards potentially totaling $160 million.
