Mycelia from the control DSBvec-1 strain (generated by transformation of NS4 with the pBSsC vector; open bars) and from two different ΔsplaB strains (DSB-1 and DSB-2; solid and hatched bars, respectively) were pre-cultured for 24 h at 30 °C on solid medium (PD) containing 0.25% Triton X-100, treated with 0, 5, 10, and 20 mM H2O2 for 10 min and allowed to grow for an additional 24 h at 30 °C prior to microscopic examination. The bar graph shows the relative survival rates of hyphae from the control, DSB-1, and DSB-2 strains. Data are expressed as in panel A.