Borrowing a Gene from the Burning Bush Plant Improves Oil Qualities in Bioenergy Crops

Scientists engineered camelina and pennycress seeds to produce nearly pure specialized oils, paving the way for improved biofuel production.

The Science

Plants store energy as oils in their seeds, which can be used to make biofuels. Some plants, such as the burning bush, produce oils with properties that are particularly good for biofuels, but are not suitable for being grown on a large scale. To solve this dilemma, scientists modified the seeds of camelina and pennycress to produce the same type of oil made by the burning bush plant. Camelina and pennycress are well-suited to growing for biofuel production on a large scale. The burning bush oil flows easily and stays liquid at relatively low temperatures, making it ideal for biofuel. By introducing a gene from burning bush into camelina and pennycress and making further changes, researchers created plants that produce nearly pure, high-quality oil with improved biofuel properties.

The Impact

This research could lead to the production of biofuels that cost less and have improved performance, such as easier flow and stability at lower temperatures. By engineering plants to produce a special type of oil, this work demonstrates the potential of genetic tools to improve crops not only for biofuels but also for other industrial applications. Farmers could grow these specialized plants on land not suited to food crops, creating new income opportunities. This would support rural economies and foster the development of a biotechnology-based agricultural sector.

Summary

Most plant oils consist of triacylglycerols, molecules with three fatty acids (long lipid molecules) linked to a glycerol backbone. However, throughout the plant kingdom, seeds from certain species produce different oil types with unique structures and properties. One such oil is acetyl-triacylglycerol (acetyl-TAG), found naturally in the burning bush plant (Euonymus alatus). Acetyl-TAG consists of only two fatty acids and a short acetate group. This different structure reduces the viscosity and lowers the freezing point of acetyl-TAG compared to conventional plant oils. Thes properties make acetyl-TAG useful for different applications, including as an improved diesel drop-in replacement.

To enable large-scale production of these useful molecules, researchers engineered camelina and pennycress—two oilseed crops well-suited for agriculture—to produce acetyl-TAG in their seeds. By introducing a gene from the burning bush that encodes the enzyme necessary for acetyl-TAG synthesis, the researchers redirected the plants’ oil biosynthesis pathways. Additional modifications using genome editing techniques disrupted competing pathways and increased the availability of precursors, further boosting acetyl-TAG accumulation to nearly pure levels (up to 98% of all seed lipids). Remarkably, this was achieved without significant effects on seed viability. This work highlights how advanced genetic engineering can optimize plants to produce valuable oils with tailored properties, opening the door to cost-effective biofuel production and other high-value industrial applications.

Contact

Funding

This work was supported by the U.S. Department of Energy Office of Science, Biological and Environmental Research program; the U.S. Department of Agriculture, National Institute of Food and Agriculture; the National Science Foundation, Division of Integrative Organismal Systems and Major Research Instrumentation program; the National Institutes of Health, K-IDeA Networks of Biomedical Research Excellence; and the Saudi Arabian Cultural Mission.

Publications

Alkotami, L., et al., Targeted engineering of camelina and pennycress seeds for ultrahigh accumulation of acetyl-TAG. Proceedings of the National Academy of Sciences 121 (47) e2412542121 (2024). [DOI: 10.1073/pnas.2412542121]

Related Links

K-State biochemists make significant breakthrough in increasing purity of specialized plant oils, Kansas State University News

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