Current Projects

Chemical ecology of seed dispersal and fruit defense

Fruits are in a tough place ecologically. They are directly linked to reproductive output and are therefore critical for plants to defend against herbivores and pathogens. Yet, for plants that depend on animal seed dispersal, fruits must also be attractive and tasty. We hypothesize that the primary toolkit plants use to balance attraction of seed dispersers with defense against pests is phytochemistry. Yet, chemical ecology has been largely absent from the rich history of research on seed dispersal and frugivory. And, in turn, frugivory has been a largely underappreciated force in the ecology and evolution of phytochemical traits. Our current NSF-funded research seeks to unite these disparate fields with the hopes of gaining a better understanding of the complex roles of phytochemicals in fruits and seeds. We use the hyperdiverse tropical plant genus Piper as a model system. We integrate modern analytical chemistry with experiments involving the numerous organisms that consume Piper fruits: short-tailed fruit bats (Carollia spp.), frugivorous birds, ants, hemipteran seed predators, fungal pathogens, and more. It's a complex, ever-evolving saga that will take many lifetimes to complete. Most of this work currently takes place at La Selva Biological Station in Costa Rica. 

Origins and consequences of secondary metabolite diversity

​A single plant can contain thousands of different specialized metabolites. Most still await structural elucidation, but recent advances in metabolomics and bioinformatics have propelled us into an era of rapid discovery in chemical ecology. We are now able to broadly characterize the near-complete diversity of metabolites in a plant sample and specifically link that diversity to ecological and evolutionary variables.  Research in our lab aims to use these new tools to better understand both the evolutionary forces that drive phytochemical diversity and the ecological consequences of that diversity. For example, we are currently involved in an NSF-funded collaborative project based on Barro Colorado Island in Panama that will involve comparative metabolomics across fruits and leaves in 50+ tropical trees and shrubs. We aim to understand the extent to which interactions surrounding fruits (with seed dispersers and fruit pests) might have driven phytochemical diversification. 
Collaborators: Noelle Beckman (USU),  Ray Dybzinski (Loyola), Jerry Schneider (USU), Will Wetzel (MSU), Ethan Bass (Cornell), Katja Poveda (Cornell), André Kessler (Cornell)

Fruit microbiome impacts on phytochemistry, insect resistance, and fruit quality

Plants have evolved for hundreds of millions of years in close association with microbial partners. Microbes cover every plant surface and impact all aspects of plant physiology and health. As new technologies have enabled rapid characterization of plant microbiomes, we are poised for transformative advances in agriculture that will use microbiome management to increase the sustainable production of healthy food. Our current USDA, FFAR, and BARD-funded research is using apples as a model system to understand the factors shaping the fruit microbiome and the downstream consequences of microbes for fruit chemistry, quality, and resistance to pests. We are working with commercial growers in the eastern US and using an experimental orchard at VT's Kentland Farm to examine how: 1) organic and conventional pest management practices shape microbe communities surrounding fruits, 2) microbe communities, in turn, affect fruit quality traits that determine market and nutritional value and, 3) microbial communities and fruit quality traits affect hard cider production, a fast growing segment of the American beverage industry.
Collaborators: SeJin Song (UCSD), Justin Shaffer (UCSD), Rob Knight (UCSD), ​Loren Rivera Vega (VT), Tori Meakem (VT alum), Amanda Stewart (VT), Jacob Lahne (VT), Michael Wisniewski (USDA), Samir Droby (The Volcani Center, Israel), Carolina Quintero (CONICET-U.N. Comahue, Argentina) & Gustavo Teixeira (São Paulo State, Brazil)

Other things

  • Evolutionary and chemical ecology of multi-species interactions in Physalis (groundcherries)
  • Chemical ecology of ant-mediated seed dispersal in Sanguinaria (bloodroot)
  • Using experimental manipulations to investigate of the impacts of phytochemical diversity on insect herbivores and fungal pathogens
  • Using experimental evolution to investigate how microbes evolve in response to secondary metabolite mixtures
  • Investigating how crop domestication has impacted plant defense using meta-analysis and experiments with model systems
  • Developing agricultural applications of chemical ecology, especially with apples and their insect herbivores
  • Investigating intraplant allocation to chemical defenses in fruits and leaves using meta-analysis 

“The important thing is not to stop questioning. Curiosity has its own reason for existing.”
~ Albert Einstein