Burkholderia gladioli Strain GXSB Promotes Sugar Cane Growth and Mitigates Smut Disease Caused by Sporisorium scitamineum : Insights from Genomics, Metabolomics, and Greenhouse Assays

Sugar cane ( Saccharum spp.) productivity is constrained by suboptimal growth and smut disease, underscoring the need for microbial strategies that integrate both plant growth promotion and disease suppression. Here, 59 sugar cane-associated bacterial isolates were screened for both plant growth-promoting and antifungal activities; selected strains were further evaluated by biosafety assays, whole-genome sequencing, and untargeted LC–MS/MS metabolomics. The Burkholderia gladioli strain GXSB was prioritized as the lead candidate, and GXSA was included as a biologically relevant reference strain. Both strains inhibited Sporisorium scitamineum, but GXSB exhibited stronger inhibition than GXSA (86.1% vs 81.3%) and was enriched in cyclic-nucleotide-associated metabolites. In greenhouse assays, GXSB reduced smut symptoms by 65.5%, increased plant height by 85%, and enhanced biomass by more than 3-fold relative to controls, with no detectable hemolytic activity. These findings identify GXSB as a promising dual-function candidate for further validation in promoting sugar cane growth and managing smut management.