Project title

Ecometabolomics, environmental gradients and the growth-defense trade-off in tropical trees

Mentor's name(s)

Joe Wright, Senior Scientist

Location of internship. Will mentor be at this location?

Gamboa, Panama. The mentor(s) will be at this location.

Project summary

An intern position is available at the Smithsonian Tropical Research Institute in Panama. The intern will work with Drs. Dale L. Forrister, Brian E. Sedio, and S Joseph Wright, to understand the role that plant secondary metabolism and defense chemistry play in shaping plant-microbe and plant-insect interactions in tropical forests. This internship will prioritize professional development; the intern will have opportunities to conduct independent research, develop quantitative skills, and coauthor peer-reviewed publications. The intern will also have regular exposure to other on-going projects in our group and at STRI, including studies on plant metabolomics, plant-microbe interactions, tree mortality, forest dynamics, functional ecology, and more. We are seeking an aspiring scientist capable of working independently collecting data in the lab and in the field in tropical forest conditions. The internship will focus on the following project, with the expectation of developing an independent project related to this theme:
What is the role of secondary metabolism in tropical forest trees response to changing abiotic and biotic conditions? The isthmus of Panama represents one of the most striking examples strong ecological gradients that change over just 65 km. Between the Pacific and Atlantic Coasts, annual rainfall more than doubles from 1600 mm to 3400 mm, with dry season severity being 130% more severe on the dry side. Soil resin phosphorus also varies 200-fold among forests distributed across the rainfall gradient. These gradients influence the distribution of tree species, with 67% and 57% of species having distributions strongly associated with dry season severity and phosphorous, respectively. Partially owing to these gradients, beta diversity is higher in Panama than in Amazonian forests over similar distances. In this project, we will explore how the metabolome of tropical forest trees changes in response to these gradients. Specifically, we aim to test the hypothesis that plants invest more in defense when resources are limiting and under increased insect and pathogen pressure. We will integrate data from forest dynamics plots, untargeted metabolomics and from anti-herbivore and anti-fungal bioassays. The intern will contribute to broader project, while simultaneously developing an independent project studying one of these themes in depth.

Mentorship goals

The intern will have the opportunity to participate in field collection, develop laboratory techniques including the preparation of samples for metabolomic analysis, and the use of high-through put screening of chemical extracts to estimate activity against fungal isolates and insects.

• Mentor and intern will work together to establish a learning development plan, project objectives, and long-term career goals, with regular meetings to discuss progress.
• The intern will also have the opportunity to develop computational skills focused on data management and statistical analysis in R and Python.
• The intern will have the opportunity to coauthor at least one scientific paper as a result of their active participation in the project and develop their own independent project aimed for publication.
• Students from Panama and other Latin American countries are encouraged to apply. English proficiency is NOT a requirement for interns as all communication can be done in English or Spanish.
• Foster a scientific community that welcomes inclusion and safety, inspires collaboration, and empowers interns to pursue their own career and life goals.
• This intern will have many formal and informal interactions with STRI’s engaging scientific community. The intern will participate in weekly lab meetings with collaborators at UT Austin, and will have the opportunity to attend weekly seminars on BCI (Thursdays) and at Tupper (Tuesdays), as well as STRI training opportunities (e.g., periodic offerings in GIS, R programming). The intern will meet weekly with the mentor (Dale Forrister) and will also have the opportunity to informally interact with other STRI staff scientists, employees, visiting scientists, fellows, and interns.

Suggested background readings

• Forrister, D.L., Endara, M., Soule, A.J., Younkin, G.C., Mills, A.G., Lokvam, J., et al. (2022). Diversity and Divergence: Evolution of secondary metabolism in the tropical tree genus Inga. New Phytol., 631–642.
• Sedio, B. E. et al., (2021). Chemical Similarity of Co-occurring Trees Decreases With Precipitation and Temperature in North American Forests. Frontiers in Ecology and Evolution, 9 (May), 1–18. https://doi.org/10.3389/fevo.2021.679638
• Umaña, M.N., Condit, R., Pérez, R., Turner, B.L., Wright, S.J. & Comita, L.S. (2021). Shifts in taxonomic and functional composition of trees along rainfall and phosphorus gradients in central Panama. J. Ecol., 109, 51–61.
• Forrister, D. L., Endara, M. J., Younkin, G. C., Coley, P. D., & Kursar, T. A. (2019). Herbivores as drivers of negative density dependence in tropical forest saplings. Science, 363(March 15), 1213–1216. https://doi.org/10.1126/science.aau9460
• Whitehead, S. R., Bass, E., Corrigan, A., Kessler, A., & Poveda, K. (2021). Interaction diversity explains the maintenance of phytochemical diversity. Ecology Letters, 24(6), 1205–1214. https://doi.org/10.1111/ele.13736