Fig. 2

Inhibition of fungal spore germination by bacterial extracellular proteins. a, b Inhibition of M. robertsii (a) and B. bassiana (b) spore germination by the Ma. sciuri culture filtrates. Ma. sciuri was grown in the LB broth for the indicated times before being centrifuged, and the supernatants were used for germinating fungal spores. Germination of fungal spores in LB was included as mock controls. c, d The precipitated extracellular proteins of Ma. sciuri could inhibit the M. robertsii (c) and B. bassiana (d) spore germination. TP, total protein; Peptides (< 10 kD), and proteins (> 10 kD) were prepared using centrifugal filter units. e Heat mapping shows the differential expression of the Ma. sciuri extracellular proteins in different treatments. Ms, the proteins extracted from the pure Ma. sciuri culture. Mr + Ms, the proteins extracted from the M. robertsii and Ma. sciuri co-culture; Bb + Ms, the proteins extracted from the B. bassiana and Ma. sciuri co-culture. The protein intensity was obtained from three independent replicates by Log10 conversion. The proteins highlighted in bold were upregulated in challenging with fungi and selected for E. coli expression and antifungal activity assay. f Gel analysis of three expressed proteins. g–i The expressed Msp1 (g) but not Msp2 (h) and Msp3 (i) proteins could significantly inhibit the germination of M. robertsii spores. Panels c, d, g two-tailed Student’s t-test was conducted between each sample and mock control: ****, P < 0.0001. ns, not significant. Ten independent replicates were included for each sample