Harnessing microbial inoculants for sustainable medicinal plant cultivation

Medicinal plant cultivation confronts distinct challenges, including soil degradation from continuous cropping, diminished regional specificity, and heavy metal contamination, all of which compromise both biomass yield and accumulation of bioactive compounds. Microbial inoculants represent a sustainable strategy to enhance medicinal plants' productivity and quality through improved nutrient uptake and stress tolerance, alongside promotion of secondary metabolite biosynthesis. This review systematically examines the mechanisms through which microbial inoculants regulate plant development, enhance stress resistance, and stimulate bioactive compound synthesis. We emphasize organ-specific application approaches tailored to root, leaf, and flower/fruit medicinal species, and explore advances in alleviating continuous cropping obstacles and reinforcing region-specific microecosystems. Key factors affecting inoculant performance are also identified, including the microbial consortium's composition, carrier materials, soil characteristics, and host genetics. Though significant progress has been made, challenges related to colonization stability and mechanistic clarity persist. Future prospects involve developing synthetic microbial communities, integrating multi-omics technologies, and designing smart delivery systems to advance ecological cultivation practices. This review highlights the potential of microbial inoculants in supporting sustainable production of high-quality medicinal plants while minimizing environmental footprints.