Plants produce complex blends of structurally diverse metabolites, many of them having been recruited during evolution as chemical shields and/or signals which shape plants’ interaction with other organisms. The largest fraction of this plant chemodiversity, predicted to account for somewhere on the order of 100,000 to 1 million of chemically unique structures, derives from variations in so-called specialized metabolites (SMs). However, and by clear contrast to plant phylogenomics studies that have flourished as a result of both the increasing release of annotated genomes and of established comparative genomics pipelines, the study of plant chemodiversity evolution has lagged behind due to a lack standardized workflows.
In a new study published in the journal Science Advances, the team led by Emmanuel Gaquerel developed a metabolomics framework to infer diversification of plant SM pathways. The study builds on concepts elaborated by the team as part of a previous Science Advances publication, as well as on a portfolio of novel open-access bioinformatics tools, including the largest in silico spectral database comprising >1 million structures. By applying these tools to study of 20 Nicotiana species, the authors created and mined an unprecedented multi-tissue cartography of SM diversity in this genus. Finally, the authors dissected as a case study the evolutionary trajectory of N-acylnornicotines, key defensive innovations in the arms race between certain species of the Nicotiana genus and specialized herbivores. The fully open data and broad range of data integration approaches from this study provide an instrumental framework to revive plant chemodiversity studies.