As multicellular organisms, plants rely on a highly organized system of metabolic pathways. Compared to the animal immune system, plants have developed a complex and diverse 'specialized', or secondary, metabolism as an important defense mechanism against attack by other organisms. Since insects and microbial pathogens use different strategies of feeding or invasion, plant chemical defenses need to be tissue and cell-type specific but, at the same time, maintain a sufficient level of plasticity. This project investigates how plants coordinate and fine-tune specialized metabolic pathways in different cell types and subcellular compartments. Focus is placed on the metabolism of volatile terpenes in roots of the model plant Arabidopsis thaliana. Terpenes are the most common specialized metabolites with significant functions in plant defense. The study explores the genetic organization and biochemical function of terpene biosynthesis modules consisting of enzymes coordinated by root cell-type specific and stress-induced expression. Furthermore, the project addresses the question of how strictly the formation of terpene metabolites is limited to particular root cell types and examines aspects of the organelle-specific regulation of terpene metabolism in roots.
Broader Impacts: Expected results may allow developing novel strategies for sustainable control of agricultural soil-borne pests and pathogens by engineering root chemical defenses in crop plants. The project integrates high school and undergraduate student education into an active research project by introducing novel experimental concepts for the pre-college education program "Partnership for Research and Education in Plants (PREP)" and its undergraduate-level extension (PREPu), developed at Virginia Tech. For PREPu, experiments will be implemented as a laboratory module in the undergraduate/graduate course "Introduction to Chemical Ecology". Plant mutants generated in this research project will be tested in both educational programs for their defense properties against root-attacking organisms. The study integrates K-12 and undergraduate student learning through investigation and promotes understanding of interdisciplinary and translational life science. The project further provides interdisciplinary training and transformative education for one postdoctoral fellow, one graduate student, and two undergraduate students. Research on this project strongly supports graduate education in the Molecular Plant Sciences Program at Virginia Tech and recruitment of individuals from groups underrepresented in science.
