Fig. 3.

Fold change of cucumber biomass relative to control in treatments with inoculation of different microbe-consuming protists in a first greenhouse experiment (a) (for the confirmatory second greenhouse experiment see Fig. S3). Cucumber biomass of the third greenhouse experiment testing plant growth promotion capability of Trichoderma stimulated by the inoculation of microbe-consuming protist (b). In panel (a), control indicates that no protists were inoculated; S_ indicates that protists were inoculated into sterilized soil. In panel (b), control indicates that no microbe was inoculated; S_ indicates that protists and fungi were inoculated into sterilized soil. T: Trichoderma; T+C: Trichoderma+Cercomonas lenta. Asterisks indicate significant difference of cucumber biomass in treatments compared with control (Student’s t test, ***indicates P < 0.001; **indicates P < 0.01; NS indicates not significant). The P values indicate significance between T and T+C or S_T and S_T+C under Student’s t test