Plants produce diverse chemical compounds, including pigments for attracting pollinators and toxins for deterring herbivores. These chemical compounds are often unique to certain plant parts in different plant groups. This project seeks to understand the evolution of plant-derived chemical compounds and how these compounds promote plant diversity. To address these questions, the project will focus on the plants within the Caryophyllales, a group that includes cacti and many alpine and arctic plants known for extraordinary adaptations to warm, dry, or cold environments. Many Caryophyllales species produce unusually large amounts of diverse compounds derived from the amino acid tyrosine. Due to inherent biochemical trade-offs, the production of these tyrosine-derived compounds may come at the expense of other compounds derived from the amino acid phenylalanine. We will study the balance of the production of these two amino acids and its effect on the production of myriad compounds important in UV shielding, pollination, and herbivore deterrence. The work will inform the biotechnological production of natural plant pigments and will help to elucidate biosynthetic pathways of a number of high-value plant-derived chemicals with pharmaceutical value. The collaborative US-UK team will provide multidisciplinary training opportunities for students and post-doctoral scholars in genetic and biochemical methods in an evolutionary context. Workshops at professional society meetings, a K-12 summer camp module, and multiple public outreach modules will bring these concepts to the public and highlight the relationship between biodiversity and high-value plant chemical compounds. <br/><br/>This study will perform an extensive survey to establish the occurrence and distribution of key tyrosine- and phenylalanine-derived metabolites in 600 species across Caryophyllales; examine the association of these tyrosine-derived metabolic traits with organismal adaptation and diversification patterns; and determine the evolutionary genetic mechanisms responsible for the biosynthesis of these metabolites. New tools will be developed to model the hierarchical nature of metabolite evolution and will be made available to the broader community of scientists. This project will comprehensively describe the extent of tyrosine-enriched metabolism in Caryophyllales, define the degree to which these metabolites are associated with organismal diversification patterns across Caryophyllales, and resolve the evolutionary assembly of the genetic pathways underlying complex tyrosine-derived metabolic traits. This award was co-funded by the Systematics and Biodiversity Science Cluster in the Division of Environmental Biology and the Integrative Ecological Physiology Program in the Division of Integrative Organismal Systems.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.