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Secondary metabolites play an important role in determining the diversity and behavior of arthropods associated with focal plant species, in addition to mediating interactions between different trophic levels. CBI Fellows expand the interdisciplinary potential of our established study system by integrating the use of tools such as Liquid and Gas Chromatography coupled with Mass Spectrometry, Nuclear Magnetic Resonance and Infrared Spectroscopy to investigate community wide consequences based on variation in plant secondary metabolites. Fellows are a part of a new effort to quantify community-level changes in phytochemistry under the increasing aridity in the Great Basin Desert and be able to assess feedback changes in arthropod communities.

To provide a deeper contextual understanding of how chemically mediated systems evolve, our research applies genomic and metabolomic approaches to understand patterns of population genetic variation across sets of interacting taxa. We are identifying the genetic architecture of metabolomic phenotypes and the traits under selection in our study systems. CBI Fellows are pinpointing the biochemical or physiological targets of the chemical agents that drive coevolutionary interaction and quantify these traits under selection. Fellows are broadening the phylogenetic and geographic scope of novel systems and are one of the first to investigate the functional significance of NSF-ESPCoR enabled in woodrats.

Secondary metabolites not only mediate complex interactions between species, but lead to the emergence of networks of co-evolved species. CBI Fellows are investigating patterns of chemically mediated co-diversifications among lineages and the role host switching and diet specialization play in hybridization and speciation. This is modeled in our focal plant (Medicago, Juniperus, and Piper), plant chemical defenses, herbivore families (Geometridae and Lycaenidae), and parasite families (Braonidae and Tachinidae). Fellows are generating population genomic data using a genotype-by-sequencing approach to apply how mammalian hosts interact with gut microbial communities to metabolize plant secondary compounds that they consume and how they influence and maintain the host species boundaries.

There is a physiological effect on insect herbivores and pollinators based on the chemistry of a plant. Specialist insect herbivores exhibit a decreased immune function due to the sequestration of plant secondary metabolites, however, these same metabolites protect them against viral infection. Our research with generalist insect consumers indicates that plant chemistry can help defend against parasitism. CBI fellows are focused on the different immunological effects plant chemistry has on pathogen infection in insect systems and how plant metabolites protect them.

Through this program, the À¶Ý®ÊÓƵ, Reno offers one of the only chemical ecology groups in the world to utilize ion mobility mass spectrometry, allowing CBI fellows unparalleled potential to detect and determine the structure of phytochemical mixtures. Fellows are able to apply a combination of organic synthesis, chromatography and spectroscopic analysis to address problems in chemical ecology such as the elucidation of secondary metabolites in both ecologically and economically important plants such as Piper in the tropics and pine trees in the Great Basin. Our interdisciplinary collaboration provides a comprehensive understanding of the causes and consequences of mixtures in plant natural products.