Modulation of microbial communication by lipid exudates

Root exudates comprise a diverse mixture of nonpolar and amphiphilic compounds that are only partially recovered by aqueous extraction methods, yet can rival polar metabolites as carbon sources for microorganisms. Because many quorum sensing (QS) signals are fatty-acyl derivatives, lipid-rich microhabitats at the root-soil interface are likely to influence signal partitioning, persistence, and local QS thresholds. We propose a lipid-mediated framework in which plant-derived lipids modulate QS through four nodes: receptor mimicry/antagonism, quorum quenching, membrane/microenvironment regulation, and lipid-dependent resource gating. These mechanisms operate across two lipid-rich interfaces-the rhizosphere and the arbuscular mycorrhizal fungi hyphosphere-where host lipid fluxes may restructure microbial community composition. Combined with QS-sensitive changes in root exudation, this spatially structured lipid circuit could generate feedbacks influencing microbiome composition and function, with potential implications for microbiome engineering.