Fig. 4: Flavonoids mediate rhizosphere enrichment of Lysobacter soli P18 by enhancing bacterial motility and colonisation.

A Flavonoid-induced changes in twitching motility-related genes revealed by prokaryotic transcriptomic sequencing (n = 3 biological replicates, two-sided Student’s t-test, P < 0.05). B Increased rhizosphere colonisation of L. soli P18 in SlMYB12-overexpressing plants and flavonoid-treated wild-type plants (C) of Micro-Tom tomato compared to untreated wild-type plants (Con; n = 10 biological replicates, one-way ANOVA with correction by Tukey’s HSD test, P < 0.05). CFU, colony-forming units. C–E Effects of flavonoids on twitching (left), swarming (middle) and swimming (right) motility of L. soli P18 (n = 10 biological replicates, two-sided Student’s t-test, P < 0.05). F Growth curves of L. soli P18 with flavonoids (C) or not (Con; n = 6 biological replicates, two-sided Student’s t-test, P < 0.05). OD₆₀₀, optical density at 600 nm. G A hub gene identified in the co-expression network with edges carrying weights > 0.9. The hub gene is shown in red colour, with twitching motility-related genes in purple colour and spermidine biosynthetic-related genes in green colour. Positive correlations between RpoN and other genes are indicated by grey lines. H, I Effects of flavonoids on twitching motility and colonisation of L. soli strains (n = 10 biological replicates, one-way ANOVA with correction by Tukey’s HSD test, P < 0.05). P18 represents the wild-type strain, ΔRpoN is a RpoN mutant strain, and ΔRpoN-C is a complemented strain. J Bacterial twitching motility-related pathways in the two-component system (n = 3 biological replicates, two-sided Student’s t-test, P < 0.05). Bacterial growth, colonisation and motility data are presented as means ± SEM, and different letters above the error bars indicate significant differences between treatments. Source data are provided as a Source Data file.