My research is best described as applied chemical ecology. I focus on small bioactive molecules produced by plants and microorganisms that induce changes in other organisms. I seek to understand the origin, function, and significance of natural chemicals that mediate interactions within and between organisms. I have determined modes of action of toxic compounds produced by fungi designed to give the fungus a competitive edge in the obtaining nutrients from plants. I have analyzed alkaloids from plant-endophyte interactions that negatively impact animal production and behavior. I have determined the chemical basis of and developed means of utilizing natural compounds for pest and disease control that are biologically based and sustainable. I am skilled in the analysis and discovery of bioactive natural products and have participated in programs for the mathematical modeling of responses to these compounds. Currently we are applying the tools of bioinformatics to compare biosynthesis of terpenoid compounds in related plant species.

I have served as a mentor for ten M.S. students and two Ph.D. students. I have served as a research mentor for over 50 undergraduate students in my career. Many of these students are currently professionals in STEM fields, some in the health care fields. I was appointed as the first Coordinator for Undergraduate Research in the Herbert College of Agriculture. I serve on the university-wide Undergraduate Research Advisory Council. I also coordinate the Honors program for the Herbert College of Agriculture. I was recently awarded a USDA grant to develop courses for a new, peer-reviewed model for honors programming that helps students develop higher-order thinking and team skills, academic networks, and opportunities to engage in research activities.

Effective pesticides are needed in order to meet food, feed, and fiber needs of an expanding world population. My research focuses on bioactive natural products (extracted from plants and microorganisms) that are acaricidal, antibacterial, antifungal, insecticidal, or nematicidal. The program is grounded in ethnomedicine, ethnobotany, and ecology and is expanding into medicinal chemistry. My goal is to develop effective biopesticides and food additives that are effective, sustainable, and economical. Chenopods, such as epazote, lamb’s quarters, and quinoa are used as herbs and food crops (both in modern and ancient societies) but have chemical properties that make them well suited for use in biologically based management systems. Extracts from chenopods were active against Bacillus cereus, a food borne pathogen, and Caenorhabditis elegans, a model nematode. Bioactivity was correlated with concentrations of saponins and phenolics. Fermentation of switchgrass monosaccharides to biofuels is inhibited by extractives, a biomass fraction that contains phenolics and other antimicrobials. Food-borne pathogens are more sensitive to extractives than bacterial plant pathogens but concentrated extractives were effective as plant biopesticides. Bioactive latex from a basal conifer restricted growth of plant pathogenic bacteria and human cancer cells. Variations in chemical profiles within several species of Monarda used as medicinal herbs used by the Cherokee and other Native Americans allowed us to identify chemotypes; some chemotypes effectively reduced plant disease and some had no effect. Full development of these products will have a direct impact on disease prevention particularly in sustainable agriculture.

Another area of emphasis is science educational outreach. I have provided leadership for the regional science fair for over a decade, and recently, two students that I mentored attended and placed 4th in Plant Sciences at the International Science and Engineering Fair. I work with local school teachers to develop science fair projects for their middle- and high-school students. I serve on the IRB and Scientific Review committees. I was a co-investigator on “Fostering aGIRLculture: a girls STEM camp solving the Grand Challenges of the 21st century”. The goal of the camp was to recruit female Tennessee high school students to STEM disciplines, and introduce them to careers in agricultural and natural resource management.

I am the founding managing editor of the Professional Development Center (PDC) for the American Phytopathological Society (APS) and serve on the Office of Education. The mission of the PDC is to improve the professional skills of all APS members by providing a web-based collection of relevant and timely content addressing professional development needs.

EPP 531 Physiology of Plant Disease (3). Biochemical and physiological events involved in host-pathogen interactions. The information provided in course increases student understanding of complex interactions between plants and their pathogens. Understanding how plants defend themselves is important for students who are interested in plant growth, reproduction, and production.

AGNR 117 Herbert College of Agriculture Honors Freshman Seminar (1)
The freshman seminar addresses global challenges in the Food, Agriculture, Natural Resources, and Human Sciences like the “One Health” model.

AGNR 217 Research Ethics, Compliance, and Methods (2)
Scientific integrity and workplace safety require compliance from all personnel. The challenge of teaching research ethics to novice researchers will be addressed by interaction with compliance personnel, online training, and case studies. After completion of ethics and compliance training, students receive project-specific training.

AGNR 487: Honors Capstone. This course will build upon concepts introduced in AGNR 480, “How to Feed the World” or FWF 427 “International Natural Resource Issues” and is the second part of the two-semester capstone experience required for the Honors FANHS Minor. Students produce a project in conjunction with a faculty mentor.

AGNR 497: Honors Undergraduate Research. This course is the first part of a two-semester capstone experience (with AGNR 498) for the Honors FANHS Minor or Herbert College of Agriculture students in the Chancellor’s Honors Program (CHP). College-wide course involves substantial scholarly, scientific, or artistic endeavor.

AGNR 498 Honors Undergraduate Thesis. This course is the second part of a two-semester capstone experience (with AGNR 497) for the Honors FANHS Minor or Herbert College of Agriculture students in CHP. An undergraduate thesis is required for completion of this course.