DEVELOPMENT OF BIOCHEMICAL AND GENETIC RESOURCES FOR SPECIALTY OIL CROPS

Essential oils are obtained by hydrodistillation from various aromatic herbs and trees. These distilled oils are then used in formulations for cosmetics, food items and beverages, but also directly in aromatherapy. Unfortunately, efforts aimed at enhancing existing cultivars have met critical challenges. Prior breeding programs focusing on improving oil and agronomic traits in mint were frustrated by the fact that commercially grown mint cultivars are sterile, polyploid hybrids. We have made considerable progress with an approach that builds on the understanding the determinants of oil biosynthesis in diploid accessions of species ancestral to commercial polyploids. With this proposal, we are addressing the USDA-NIFA-AFRI program area priority 1b. Foundational Knowledge of Plant Products, by performing research on industrially important essential oils and individual aroma chemicals using a commodity (mint) that is important to small- and medium-sized farming operations. Our goal is to contribute to meeting the long-term demand for agricultural value-added products. Building on the substantial body of experimental data (more details under II. and III.), we propose to engage in research to meet four complementary objectives, thus building the knowledge base for a specialty oil breeding program:Objective 1. Assessing the specificity of cytochrome P450-dependent monooxygenases for the formation of different monoterpene alcohols and epoxides.Objective 2. Investigating the specificity of (-)-trans-isopiperitenol dehydrogenases for diverse monoterpene alcohols as substrates.Objective 3. Evaluating the specificity of (+)-pulegone reductases for unsaturated monoterpene ketones as substrates.Objective 4. Demonstrating translational capabilities using knowledge-based approaches for breeding mints accumulating specialty oils.