A novel system for probing belowground volatile-mediated interactions

1. Root volatile organic compounds are key mediators of belowground ecological interactions. However, current experimental systems cannot simultaneously perform in situ volatile collection and expose multiple targets, limiting our ability to investigate complex belowground chemical networks.
2. Here we present a modular multi-chamber system consisting of a central glass chamber connected to three peripheral chambers, which allows multiple targets to be exposed simultaneously to root volatiles from a single plant. The detachable design supports flexible experimental configurations, and a custom hemispherical adapter enables in situ volatile collection using either solid-phase microextraction (SPME) or dynamic push-pull methods.
3. Using two phytotron case studies, we showed that the system supports effective in situ volatile collection via SPME, capturing both spatial variation and species specificity of root emissions. Moreover, by accommodating multiple targets simultaneously, we identified soil microbes as a key mediator of weed root volatile effects on maize, demonstrating the system’s capacity to dissect complex ecological interactions.
4. This system provides a flexible platform for investigating belowground interaction networks, offering broad adaptability to studies of plant-plant, plant-microbe, and plant-insect interactions mediated by root volatiles. By integrating flexible volatile sampling with multi-target experimental design, this approach advances tractable investigation of belowground chemical ecology and ecosystem functioning.