ΔBcMkk1 exhibited more serious defects in response to cell wall and oxidative stresses than ΔBcBck1 and ΔBcBmp3.

<p>(A) Sensitivity of 38B1, ΔBcBck1, ΔBcMkk1, ΔBcBmp3, ΔBcBck1-C, ΔBcMkk1-C and ΔBcBmp3-C to Congo Red (CR) and glucanase after incubation at 25°C for 3 days. (B) Mycelial growth inhibition of each strain shown in (A). Values on the bars followed by the same letter are not significantly different at <i>P</i> = 0.05. (C) Mycelia of ΔBcMkk1 not ΔBcBck1 and ΔBcBmp3 were well digested and released abundant protoplasts after treatment with glucanex at 25°C for 2 h. Bar = 20 μm. (D) Protoplast amount of each strain shown in (C). Values on the bars followed by the same letter are not significantly different at <i>P</i> = 0.05. (E) ΔBcMkk1, but not ΔBcBck1 and ΔBcBmp3, exhibited thickened septa (up panels of ΔBcMkk1) and occasionally with a larger central pore indicated by blue arrows (low panels of ΔBcMkk1) through transmission electron microscopic examination. (F) Comparisons of BcBmp3 phosphorylation among the above strains. After grown in PDB for 2 days, mycelia of each strain treated with 0.3 mg ml<sup>–1</sup> of CR for 0 and 2 h were collected for protein extraction. BcBmp3 and phosphorylated BcBmp3 proteins were detected with the anti-Mpk1 and phospho-p44/42 MAPK antibodies, respectively. (G) Sensitivity of the above strains to H<sub>2</sub>O<sub>2</sub> and paraquat after incubation at 25°C for 3 days. (H) Mycelial growth inhibition of each strain shown in (G). Values on the bars followed by the same letter are not significantly different at <i>P</i> = 0.05. (I) ROS content in vegetative hyphae of each strain. Values on the bars followed by the same letter are not significantly different at <i>P</i> = 0.05.</p>