Integrated Microbiology and Metabolomics Analysis Reveal Responses of Soil Bacterial Communities and Metabolic Functions to N-Zn Co-Fertilization in the Rhizosphere of Tea Plants ( L.).

The co-fertilization of nitrogen (N) and zinc (Zn) offers significant advantages in improving the growth and development of tea plants ( L). However, the corresponding responses of rhizosphere microecology remain unclear. In this study, a pot experiment was performed to investigate the effects of N-Zn co-fertilization on rhizosphere soil's N availability, the rhizobacterial community and the metabolism of tea plants. N-Zn co-fertilization significantly increased the soil total of N, NH-N and NO-N contents. 16S rRNA sequencing found that N-Zn co-fertilization recruited rhizobacteria associated with N cycling and Zn activation, including , and , resulting in complex rhizobacterial networks. Metabolomics analysis indicated obvious interferences in the metabolisms of lipids, amino acids and cofactors and vitamins after fertilization. PLS-PM analysis suggested that fertilization had both direct and indirect influences on the rhizobacterial community and differential metabolites. RDA models identified pH (R = 0.734, < 0.01; R = 0.808, < 0.01) and total N (R = 0.633, < 0.05; R = 0.608, < 0.01) as dominant factors influencing both the rhizobacterial community and differential metabolites. Finally, network analysis found significant associations between rhizobacteria related to N cycling and Zn mobilization and metabolic processes involved in N metabolism and responses to Zn stress. These findings underscored that appropriate N-Zn co-fertilization is crucial for the rhizosphere soil's N availability and the microenvironment of tea plants.