Abstract Detail

Evolution of Plant Chemical Diversity: Renaissance of comparative biochemistry

Sedio, Brian [1], Parker, John [2], McMahon, Sean [2], Wright, Joseph [3].

Comparative metabolomics of forest communities: Species differences in foliar chemistry are greater in the tropics.

A coevolutionary arms race between herbivores and plant defenses has been hypothesized to drive diversification of plants and their enemies. This hypothesis predicts that plant defenses should diverge rapidly, minimizing phylogenetic signal. To evaluate this prediction, we quantified metabolomic similarity for 203 tree species that represent >89% of all individuals in large forest plots in Maryland and Panama. We constructed molecular networks based on mass spectrometry of all 203 species, quantified metabolomic similarity for all pairwise combinations of species, and used phylogenetically independent contrasts to evaluate how pairwise metabolomic similarity varies phylogenetically. Leaf metabolomes exhibited clear phylogenetic signal for the temperate plot, which is inconsistent with the prediction. In contrast, leaf metabolomes lacked phylogenetic signal for the tropical plot, with particularly low metabolomic similarity among congeners. In addition, community-wide variation in leaf metabolomes was much greater for the tropical community, with single tropical genera supporting greater metabolomic variation than the entire temperate community. Our results are consistent with the hypothesis that stronger plant-herbivore interactions lead to more rapid divergence and greater metabolomic variation in tropical than temperate plants. Additional community-level foliar metabolomes will be required from tropical and temperate forests to evaluate this hypothesis.

1 - University of Texas at Austin, Integrative Biology, 2415 Speedway #C0930, Austin, TX, 78712, USA
2 - Smithsonian Environmental Research Center, Edgewater, MD, USA
3 - Smithsonian Tropical Research Institute, Panama City, Panama

community ecology
tropical forest
Temperate trees
Barro Colorado Island
mass spectrometry
phylogenetic signal.

Presentation Type: Symposium Presentation
Abstract ID:676
Candidate for Awards:None

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