Speaker
Description
Untargeted metabolomics has transformed ecological research by revealing the extraordinary chemical diversity of organisms and their interactions. Yet most signals detected by LC-MS remain unannotated, forming the so-called ‘dark metabolome’. A contemporary and growing debate asks: does the dark metabolome reflect a vast unknown chemical space, or are we inflating chemical diversity through ionization artifacts?
One molecule rarely yields one signal. Electrospray ionization (ESI) commonly produces in-source (ISFs) and post-source fragments, adducts, multimers, and isotopologues. These additional ion forms can dominate metabolomics datasets, complicating annotation and contributing to the illusion of a vast dark chemical space. Estimates suggest that ISFs only may already explain 70% of LC-MS features in a dataset.
For ecometabolomics, this raises critical challenges. Misassigning fragments or adducts as unique metabolites risks distorting our understanding of ecological strategies such as plant defense, signaling, and adaptation. At the same time, unannotated signals should not be dismissed outright: they may also represent true, previously undescribed metabolites with important ecological roles. Grappling with this duality is essential for robust ecological interpretation.
In this talk, I will highlight recent advances in redefining the dark metabolome, discuss how ionization artifacts reshape ecological metabolomics, and argue that confronting “one molecule, many signals” is not only a technical necessity but a scientific opportunity. I will illustrate these points with two real-world examples: (1) in-source fragmentation of steroidal glycosides in Solanum dulcamara in positive mode, and (2) adduct and multimer formation of monoterpenol glycosides in Vitis vinifera in negative mode. These cases underscore both the pitfalls of misinterpretation and the potential to refine discovery in ecometabolomics.
| Status Group | Postdoctoral Researcher |
|---|---|
| Poster Presentation Option | No, I prefer to present only as a talk. |
