Figure 3.

BbCwp roles in the fungus-host interaction. (a) Insect bioassay. Fungal virulence was evaluated via intra-hemocoel injection method. Conidial suspension (5 µl) was directly injected into the host hemocoel. The infected insects were reared at 25°C, and the mortality was recorded every day. The median lethal time (LT₅₀) was calculated with Probit analysis. (b) BbCwp contributes to fungal development in the host hemocoel. Gene loss resulted in a significant reduction in the hyphal-body production. (c) Fungal colonization in the insect hemocoel. Conidial concentration (5 µl, 10⁵ spores/ml) was injected into the host hemocoel, and the hosts were reared at 25ºC. The host hemolymph was sampled every 6 h. Insect hemocyte encapsulation was observed after fungal invasion. After 48 h, the wild-strain formed detectable in vivo blastospores. However, the blastospores for ΔBbCwp mutant were seen at 60 h post infection. Red arrows indicate the fungal cells evading from hemocyte encapsulation, and green arrows indicate the free hyphal bodies (Tukey’s HSD: P < 0.05). Scale: 5 µm.