Supplementary Figure 8: Effects of the root exudates on the growth of Ralstonia solanacearum and isolation of flavobacterial strains from the rhizosphere to screen for involvement in disease resistance.

Growth of R. solanacearum SL341 in M9 broth supplemented with glucose (2%) and/or root exudates of tomato cultivars, Hawaii 7996 and Moneymaker. (a) Growth rates of SL341 in M9 broth with glucose (M9G) shake-cultured at 120 rpm. Red color, SL341 in M9G supplemented with root exudate of Hawaii 7996; blue, SL341 in M9G with root exudate of Moneymaker; green, SL341 in M9G with aqueous extract of bulk soil; black, SL341 in M9G broth. (b) Growth of SL341 in M9 broth without glucose (M9) shake-cultured at 120 rpm. Red color, SL341 in M9 with root exudate of Hawaii 7996; blue, SL341 in M9 with root exudate of Moneymaker; green, SL341 in M9 with aqueous extract of bulk soil; black, SL341 in M9. Vertical bars indicate the standard deviations from 3 replications. (c) A scheme to isolate flavobacteria from the tomato rhizosphere. Bacteria from the tomato rhizosphere and bulk soil were grown on TSA or R2A medium, and compared to select apparently unique bacterial colonies. A total of 477 colonies were PCR-amplified to select 32 flavobacterial isolates. (d) Antifungal activities of selected Flavobacterium strains (colonies on the right) against Phytophthora infestans (white mycelia on the left). The antifungal activities of bacterial strains have been repeated at least three times independently.