Overexpression of enhances the monoterpene content in .

Monoterpenes are important components of plant essential oils and have long been used as raw materials for spices and food flavorings. is an economically aromatic plant species, the fruits of which produce essential oil with monoterpenes as the dominant components. As a branch point of carbon flow in the methyl erythritol phosphate (MEP) biosynthesis pathway, 1-deoxy-D-xylo-5-phosphate reductoisomerase (DXR) is a key rate-limiting enzyme that catalyzes the MEP pathway's second committed step. Therefore, has become an effective regulation target to improve the biosynthesis of plant monoterpenes. In this study, we identified a from , which was highly expressed in fruits, induced by MeJA and repressed by darkness. An enzyme assay showed that recombination LcDXR protein catalyzed with NADPH as the cofactor. Transient overexpression of significantly increased the content of monoterpenes in . Furthermore, -overexpressing tobaccos were conducted and showed almost 5.9-fold increase in monoterpenes production, including limonene, α-pinene, eucalyptol, linalool, terpineol and camphor. Overexpression of activated the metabolic flux of monoterpene biosynthesis through crosstalk and feedback mechanism. In addition, -overexpressing tobaccos had no effect on phenotype of transgenic tobaccos. Our results demonstrate that is a critical regulator of the monoterpene production in and other plants.