Pathogenic co-infections in plants significantly impact microbial diversity and disease outcomes, yet their effects on microbial community structure and ecological processes remain unclear. Tobacco plants were co-infected with Ralstonia solanacearum and Neocosmospora falciformis. 16S ribosomal RNA and internal transcribed spacer amplicon sequencing were used to assess bacterial and fungal communities, respectively, in infected tobacco stems. The results were compared between co-infected and healthy control tobacco plants to assess the effects of infection. Co-infection reduced microbial divers...