Digging into the Rhizosphere Chemistry: How Plants Engineer their Soil Environment

April 22, 2026

Location

Online

Presenters

Adrien Frémont
Environmental Genomics and Systems Biology division
Lawrence Berkeley National Laboratory, USA

Outline

Plants actively shape their surrounding soil environment through root exudation—the release of thousands of metabolites via their roots. This complex chemical exchange forms the foundation of plant-microbe interactions and significantly drives soil biogeochemistry. Yet, our understanding of the rhizosphere chemical profile and how it impacts ecosystem functioning remains limited. Our research focuses on decoding this chemical dialogue by establishing mechanistic links between root exudates and the abiotic and biotic components of the rhizosphere across diverse environments.

Characterizing the rhizosphere metabolome presents significant challenges due to its remarkable complexity, with each plant species harboring a unique set of thousands of metabolites, most of which remain unidentified. Through a combination of hydroponics, large-scale greenhouse experiments, and advanced metabolomic approaches, we’re investigating how these chemical profiles both respond to and mediate environmental challenges, while connecting specific metabolites to shifts in microbial community structure and function.

Recent research on salinity and heavy metal contamination has revealed how plants rewire their metabolome and use diverse root exudates to detoxify contaminants directly in the rhizosphere. Our further work investigating cover crops demonstrates how different plant functional groups—from legumes with nitrogen-fixation-promoting flavonoids to brassicas with pathogen-suppressing coumarins—create distinct chemical niches that select for specific microbial assemblages.

These studies highlight the rhizosphere as a dynamic interface where plant-exuded metabolites actively shape soil chemistry and modulate microbiome composition and function. By understanding these complex interactions, we aim to develop principles for leveraging plant-derived chemistry to enhance critical soil functions including carbon sequestration, nutrient cycling, and greenhouse gas mitigation.