In Kansas, 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. These 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.
