Fig. 3: Dysbiosis of Firmicutes and Actinobacteria in the tomato rhizosphere.

a Disease severity and viable Firmicutes ratio in HRS and DRS samples pretreated with or without 500-μg/mL vancomycin. After 3-h incubation at 30 °C, soil fractions were washed twice with 2.5-mM MES buffer. The prepared soil fractions pretreated with or without vancomycin were applied to tomato roots via the root-dipping method. b Severity of bacterial wilt disease in tomato plants treated with HRS and DRS fractions, with or without 500-μg/mL vancomycin pretreatment. HRS HRS fraction, HRS + vancomycin HRS pretreated with 500-µg/mL vancomycin, DRS DRS fraction, DRS + vancomycin DRS pretreated with 500-µg/mL vancomycin, 500-mg/mL vancomycin root-dipping treatment with 500 mg/mL vancomycin. Data represent mean ± SEM. Different letters indicate significant differences between treatments (P < 0.05; least significant difference [LSD] test). c Changes in R. solanacearum cell density in HRS and DRS fractions pretreated with or without 500-μg/mL vancomycin. d Changes in Firmicutes abundance in HRS and DRS fractions pretreated with or without 500-μg/mL vancomycin. The ratio of viable Firmicutes bacteria was measured using the 3% KOH string test and by the quantification of the CFU values of bacterial isolates grown on TSA medium containing 20-μg/mL polymyxin B or 5-μg/mL vancomycin.