Advances in Rhizosphere Microbiome and Rhizosphere Immunity Effect: A Review

Rhizosphere immunity, an emerging concept, involves complex interactions among plant roots, rhizospheric microbiota, and the soil environment that collectively safeguard plant health. Although extensively studied, the mechanisms driving rhizosphere immunity remain insufficiently elucidated. Rhizosphere microbes enhanced plant immunity through colonization, ISR/SAR induction, and interactions with root exudates and endophytes, triggering defense signals, producing antimicrobials, and modulating host metabolism. Organic and bioorganic fertilizers enhanced these effects by reshaping microbial communities, enriching beneficial taxa, and indirectly promoting resistance via improved nutrient cycling and soil health. Synthetic microbial communities (SynComs) have been developed to stabilize and enhance biocontrol. Four scalable SynComs design strategies have emerged: reductionist approaches for mechanistic insight, antagonistic combinations, core microbiome-based assemblies using keystone taxa, and resource competition to outcompete pathogens. Together, these approaches offer scalable solutions to construct stable and functional SynComs that enhance rhizosphere immunity. Future efforts should focus on translating rhizosphere immunity into agriculture by elucidating microbiome-plant-soil interactions and optimizing long-term soil management.