Abstract

This research evaluated the biocontrol potential of the bacterial flora from cured sugarcane bagasse (SCB) against Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of tomato Fusarium wilt. Screenings of twenty SCB-derived isolates revealed consistent antagonistic activity, inhibiting mycelial growth from 32.08% to 55.00%. The most effective isolate, 100MTN1, was identified via 16S rRNA sequencing (GenBank: PX506225) as Bacillus atrophaeus. Interaction between B. atrophaeus 100MTN1 and Fol FOLViF has revealed a distinct profile of bioactive metabolites produced specifically during co-cultivation. Transcriptomic profiling of Fol FOLViF exposure to 100MTN1 identified 189 differentially expressed genes, with downregulation of genes involved in DNA replication, translation, and membrane transport, and upregulation of those linked to secondary metabolism and oxidative stress. KEGG pathway mapping further supported the possible causes of disruptions within the pathogen. Molecular docking suggested that the B. atrophaeus 100MTN1 derived metabolite, 6-Hydroxy-3′-methoxyflavone and exhibits binding affinity for key Fol proteins that compares favorably with the commercial fungicides. Greenhouse trials using tomato cv. Kalyan confirmed that treatment with strain 100MTN1 was associated with reduced disease severity and enhanced plant growth. These findings suggest that B. atrophaeus 100MTN1 suppresses Fol FOLViF through a combination of metabolite-driven inhibition and transcriptional interference, signifying its potential as a biological control agent for managing Fusarium wilt.

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