Unravelling the Molecular Dialogue of Beneficial Microbe-Plant Interactions

Plants are an intrinsic part of the soil community, which is comprised of a diverse range of organisms that interact in the rhizosphere through continuous molecular communications. The molecular dialogue within the plant microbiome involves a complex repertoire of primary and secondary metabolites that interact within different liquid matrices and biofilms. Communication functions are likely to involve membrane-less organelles formed by liquid-liquid phase separation of proteins and natural deep eutectic solvents that play a role as alternative media to water. We discuss the chemistry of inter-organism communication and signalling within the biosphere that allows plants to discriminate between harmful, benign and beneficial microorganisms. We summarize current information concerning the chemical repertoire that underpins plant-microbe communication and host-range specificity. We highlight how the regulated production, perception and processing of reactive oxygen species (ROS) is used in the communication between plants and microbes and within the communities that shape the soil microbiome.