Modulation of microbial communication by lipid exudates

Root exudates comprise a diverse mixture of non-polar 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 (AM 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.