Mechanistic analysis of rhizosphere promoting bacteria on tobacco growth, continuous cropping soil, and root microbiota

Continuous cropping refers to the prolonged cultivation of the same crop on a specific piece of land over successive growing seasons. Plant growth-promoting rhizobacteria (PGPR) play a crucial role in enhancing plant growth, improving soil properties, and modulating the soil microbial environment. In this study, a variety of PGPGs, C1 for Bacillus paranthracis, C2 for Paenibacillus hunanensis, and C3 for Bacillus subtilis, were screened, and the mechanisms of action on the successional soils were investigated. The results demonstrated that the C1 treatment markedly enhanced the growth and development of tobacco plants while also exhibiting significant efficacy in improving soil physicochemical properties. To further investigate the impact of strains with strong growth-promoting effects, soil enzyme activities, microbial community composition, and functional diversity were analyzed in both the C1 treatment and CK control groups. The findings indicated that there were significant increases in sucrase, catalase, and urease in the C1 treatment when compared to the CK. Beneficial microflora were increased and functions such as metabolism and synthesis of amino acids and secondary metabolite synthesis in soil microorganisms were promoted by C1. In summary, C1 is capable of efficiently enhancing soil characteristics, facilitating the growth of tobacco, and laying a foundation for the advancement of microbial fertilizers aimed at mitigating the issues of continuous cropping obstacles..