Microbial fertilizers modulate tobacco growth and development through reshaping soil microbiome and metabolome

To elucidate the mechanisms of microbial fertilizers in enhancing tobacco growth and quality, this greenhouse-based pot experiment conducted over 40 days post-transplanting employed integrated microbiomics and metabolomics approaches to conduct a comparative analysis among conventional chemical, organic, and microbial fertilizers. Plant agronomic traits were systematically assessed at 20, 30, and 40 days post-transplanting, while soil physicochemical parameters were analyzed at the experimental terminus (40 days). The findings underscored the remarkable potential of microbial fertilizers in augmenting soil's quick-release nutrient pool and bolstering soil enzymatic activity, surpassing both chemical and organic counterparts. The application of microbial fertilizers accelerated tobacco growth and development, and significantly elevated agronomic indices, including plant stature, stem girth, leaf extension, and the abundance of aromatic precursors, thereby facilitating a marked improvement in tobacco leaf quality. Furthermore, the microbial community composition underwent pronounced alterations subsequent to the application of microbial fertilizers, with the emergence of pivotal microorganisms such as <i>Rhodanobacter</i> and <i>Pseudolabrys</i> within the treatment group. These microorganisms emerged as vital players in nutrient cycling processes, fostered plant growth, and mitigated the incidence of plant diseases. Microbial fertilizers demonstrated a significantly superior capacity to stimulate metabolic vigor in tobacco plants compared to other treatments, concomitant with a substantial enrichment of several metabolites, such as 3-methylindole. These data collectively imply that microbial fertilizers represent a more efficacious means of ameliorating soil physicochemical attributes, thereby fostering superior tobacco growth, development, and quality enhancement.IMPORTANCEIn recent years, there has been a surge in research examining the impacts of various fertilizers on the microbial composition of tobacco rhizosphere soils, and numerous studies have consecutively reported the growth-promoting mechanisms of diverse fertilizers on tobacco plants. However, despite these advancements, the existing body of literature remains inadequate in conclusively demonstrating the superiority of microbial fertilizers over traditional organic and inorganic fertilizers in tobacco cultivation. Consequently, our research aims to demonstrate the superiority of microbial fertilizers in enhancing plant growth by utilizing a comprehensive approach that integrates microbiomics and metabolomics techniques.