Fig. 5: Sucrose selectively shapes rhizomicrobiome and enhances disease control by B. subtilis.

A The relative abundance of 18 top genus groups. Community barplot analysis of bacterial taxonomic groups (genus level) in the tomato root rhizosphere with B. subtilis 3610 or ΔsacB, and with or without the addition of sucrose. Different treatments are marked as: A (WT), AS (WT + sucrose), B (ΔsacB), BS (ΔsacB + sucrose), C (-sucrose), and CS (+sucrose). The numbers 1–3 represent three repetitions. The 18 different colors represent different bacterial genus. The Bacillus and Pseudomonas groups are highlighted by arrows. B The ratio of Bacillus and Pseudomonas species in the microbiome samples based on the relative value of averaged 16S rRNA gene copies per sample (16S rRNA copies/g soil) in the rhizomicrobiome samples with B. subtilis 3610 or ΔsacB mutant in sucrose and no sucrose conditions. Note: A B. subtilis 3610, AS B. subtilis 3610 plus sucrose, B ΔsacB mutant, BS ΔsacB mutant plus sucrose, C no 3610 and sucrose, and CS with only sucrose. Values are given as means of three independent biological replicates and the bars represent the standard error. The letters above the columns indicate statistically significant differences based on the 16S rRNA gene copies of Bacillus or Pseudomonas per sample and using the Student’s t test (p < 0.01). C Combination of sucrose and the B. subtilis improved the biological control efficiency against the soil-borne disease (fusarium wilt) and the resistance to the air-borne disease (gray mold) in tomato. ** indicates p value < 0.01; NS no statistical difference. The error bars represent standard deviations from triplicate assays.