Fig. 2

Environmental and biological factors induce bikaverin production in Fusarium oxysporum f. sp. cubense TR4 (Foc TR4). a Bikaverin production by wild-type (WT) and FocBik1 knockout mutant (ΔFocBik1) strains cultured in minimal medium with yeast extract (YE) or sodium nitrate (NaNO₃) as the nitrogen source under different pH conditions (pH 4, pH 7, and pH 9). b Relative expression levels of FocBik1 in WT strains grown in YE or NaNO₃ at pH 4, 7, and 9. The mycelium cultured at pH 7 was used as the reference samples. Data are presented as mean ± standard deviations. Letters indicate statistical significance determined by one-way ANOVA with Duncan’s multiple range test (P < 0.05). c Dual culture assays of WT and ΔFocBik1 strains with Botrytis cinerea, Bacillus velezensis, and Actinomycetes strain DMS16689. d Relative expression levels of FocBik1 in WT strains during dual culture with B. cinerea, B. velezensis, and Actinomycetes. Data are presented as mean ± standard deviations. Letters indicate statistical significance determined by one-way ANOVA with Duncan’s multiple range test (P < 0.05)