Summary We are looking for a highly motivated, recent college graduate with a major in the sciences, bioinformatics or computer science who intends to get a PhD but who would like additional research experience. The start date is May, 2018 or after. The job focuses on (1) running and collecting data from a state-of-the-art UPLC-Mass Spectrometry system, a Waters Acquity I-class UPLC with a Xevo G2-qToF (quadrupole, time-of-flight), that we own, is based in our lab, and that we use for the analysis of plant secondary metabolites and (2) organizing and analyzing large datasets about plant secondary metabolites. Experience with R and Python is recommended, or interest in learning. Knowledge of organic chemistry and mass spectrometry is helpful but not required. The work is based in the laboratory of Tom Kursar and Lissy Coley in the Biology Department, University of Utah, Salt Lake City. The position is for at least a year (after a 2 month trial period). Please send a CV and a statement regarding your interest in this position and your career goals to Tom Kursar at kur...@biology.utah.edu
Details We study the ecology and evolution of plant defenses against herbivores in tropical plants, with a focus on the tree genus Inga (Leguminosae). Secondary metabolites are traits that have remained largely cryptic. Recent results show that plant chemistry is key for coexistence and the high local diversity of tropical forests, and possibly, for the evolution of new species. Moreover, recent advances in technology, particularly metabolomics, have improved our ability to quantify plant secondary chemistry. Our goal is to characterize the full range of chemical defenses in many species of Inga. The work focuses on analyses of samples collected in Panama, Peru, Ecuador, Brazil, and French Guiana. This requires dedication and attention to detail with both instrumentation and data management. The work in our lab is part of a larger project that includes a DNA-based phylogeny and transcriptomics of Inga being carried out by collaborators at the Royal Botanic Garden Edinburgh and the University of Edinburgh. Below we have copied an abstract from our 2018 paper that exemplifies the major scientific issues. Coley, P.D., M-J. Endara, and T.A. Kursar. 2018. Consequences of interspecific variation in defenses and herbivore host choice for the ecology and evolution of Inga, a speciose rainforest tree. Oecologia doi.org/10.1007/s00442-018-4080-z Abstract: We summarize work on a speciose Neotropical tree genus, Inga (Fabaceae), examining how interspecific variation in anti-herbivore defenses may have evolved, how defenses shape host choice by herbivores and how they might regulate community composition and influence species radiations. Defenses of expanding leaves include secondary metabolites, extrafloral nectaries, rapid leaf expansion, trichomes, and synchrony and timing of leaf production. These six classes of defenses are orthogonal, supporting independent evolutionary trajectories. Moreover, only trichomes show a phylogenetic signature, suggesting evolutionary lability in nearly all defenses. The interspecific diversity in secondary metabolite profiles does not arise from the evolution of novel compounds, but from novel combinations of common compounds, presumably due to changes in gene regulation. Herbivore host choice is determined by plant defensive traits not host phylogeny. Herbivore pressure selects for neighboring plants with divergent traits, thereby enforcing the high local diversity typical of tropical forests. Related herbivores feed on hosts with similar defenses, implying that there are phylogenetic constraints placed on the herbivore traits that are associated with host use. Divergence in defensive traits among Inga appears to be driven by herbivore pressure. However, the lack of congruence between herbivore and host phylogeny suggests that herbivores are tracking defenses, choosing hosts based on traits for which they already have adaptations. There is therefore an asymmetry in the host-herbivore evolutionary arms race.
