摘要
Introduction Plant growth-promoting rhizobacteria (PGPR) colonize the rhizosphere and enhance plant growth, stress tolerance, and soil properties. To better harness these benefits, this study investigates the synergistic interaction between two PGPR strains— Bacillus subtilis SL-44 and Klebsiella oxytoca RS-5—and evaluates their combined effects on rapeseed growth through integrated direct and indirect mechanisms. Methods The plant growth-promoting traits (e.g., phosphate solubilization, siderophore and indole-3-acetic acid (IAA) production) and biofilm-forming capacity of individual strains and their consortium were characterized in vitro. Subsequently, pot experiments were conducted to evaluate their effects on rapeseed growth parameters and rhizosphere soil quality. Finally, the rhizosphere microbial communities were analyzed via high-throughput sequencing on the Illumina NextSeq platform. Results The co-culture consortium (SR) demonstrated synergistic enhancements in key plant growth-promoting traits and biofilm stability in vitro. Pot experiments confirmed that SR treatment most effectively promoted rapeseed biomass accumulation, improved physiological status, and elevated antioxidant capacity. It also optimally enhanced rhizosphere soil nutrient availability, enzyme activities, and selectively reshaped the microbial community by enriching beneficial taxa and increasing ecological network complexity. Ultimately, plant growth promotion was achieved through an integrated mechanism combining direct stimulation and microbiome-mediated soil improvement. Conclusion In summary, this study demonstrates that functional complementarity between PGPR strains drives synergistic growth promotion through combined direct stimulation and rhizosphere microbiome engineering, offering a framework for developing effective microbial consortia for sustainable agriculture. Graphical
危险品化学品经营许可证（带存储）