Metabolomics in plant-herbivore interactions: challenges and applications

Metabolomics as the study of the entire set of metabolites of a given organismis an important frontier in life sciences. As a tool that captures the 'front end' of cellular machineries, metabolomics is particularly suited to investigate biotic interactions, including for instance the interplay between plants and insects. In this review, we discuss the opportunities and challenges of metabolomics to study plant-herbivore interactions. We first present a brief overview of the typical analytical workflows used in metabolomics and their associated issues, in particular those related to metabolome coverage and compound identification. Second, recent advances in the field of plant-herbivore relationships that are promoted by non-targeted approaches are reviewed, with examples ranging from classical herbivore resistance patterns to plant-mediated interactions across different spatial scales and volatile-mediated tritrophic interactions. Through general considerations and the discussion of a few selected case studies, our review highlights the potential and challenges of metabolomics as a research approach to understand biological interfaces.