Fig. 3

Disruption of fungal spores by Msp1 with a chitinase activity. a Disruption of M. robertsii spores by Msp1. The conidia of M. robertsii were incubated with or without Msp1 (at a final concentration of 10 μg/ml) in LB for 12 h before being fixed for SEM observation. Cells with lytic lesions are arrowed. Bar, 5 μm. b Examination of spore leakage after Msp1 treatment by ninhydrin staining. The conidia of M. robertsii (Mr, 5 × 10.⁶ conidia/ml) were suspended in sterile PBS buffer with or without Msp1 (10 μg/ml) for 12 h. The supernatant was then collected and treated with ninhydrin (2%, w/v). c Comparison of A570 absorbance after sample reaction with ninhydrin. d Formation of a chitin hydrolytic zone by Msp1. The water agar was prepared by containing 5% (w/v) colloidal chitin, and 20 μl of Msp1 (100 μg/ml) was loaded for 12 h. e Activity assays showing the chitinase activity of Msp1. The commercial chitinase isolated from S. griseus was used as a positive control. f, g Comparison of the inhibition of M. robertsii spore germination among the different dosage of WT Ma. sciuri (Ms) and ΔMsp1 cells (f), and among LB culture filtrates (g). Panels c, e–g Two-tailed Student’s t-test was conducted between samples: ns, not significant; *, P < 0.05; ***, P < 0.001; ****, P < 0.0001