Engineering Nootkatone Biosynthesis in .

Nootkatone is a valuable sesquiterpene widely used in the food, fragrance, and flavor industries. Its price is very high due to its limited production in grapefruit peels or Alaska cypress heartwoods. Chemical synthesis of nootkatone uses heavy metals, highly flammable compounds, and strong oxidants, which cause severe damage to the environment. In this study, nootkatone is synthesized in , using synthetic biology methods. Engineered coexpressing valencene synthase (VS) and valencene oxidase (VO) in the cytosol produced nootkatone ranging from 0.89 to 8.52 μg/g fresh weight (FW). Furthermore, transgenic coexpressing farnesyl diphosphate synthase (FPS), VS, and VO in plastids produced nootkatone ranging from 12.11 to 47.80 μg/g FW. These results indicated that engineering nootkatone biosynthesis in plastids was superior to that in the cytosol. Meanwhile, artemisinin production was unaltered in nootkatone-producing . Our study developed a green approach for producing nootkatone in with great market potential.