Fig. 5.

Inhibition of fungal mycelial growth by recombinant Cc‐PRI3(37–95). (A) Mycelia of Aspergillus nidulans, Alternaria porri, and Fusarium oxysporum were cultivated on potato dextrose agar (PDA) containing recombinant Cc‐PRI3(37–95) at final concentrations of 0.01–0.4 mg·mL⁻¹. The area of mycelial colonies developed on the medium was recorded (n = 3). Typical images for 0.2 and 0.4 mg·mL⁻¹ Cc‐PRI3(37–95) are shown. The recombinant protein inhibited mycelial growth of the fungi. (B) Thermal stability of the antifungal activity of recombinant Cc‐PRI3(37–95). The recombinant protein in 50 mm Tris–HCl (pH 7.5) was kept at room temperature (RT) or 100 °C for 10 min and then tested in the A. nidulans mycelial growth inhibition assay at a final concentration of 0.1 mg·mL⁻¹. The antifungal activity of the recombinant protein was maintained even after treatment at 100 °C for 10 min, but was diminished by treatment with 5 mm dithiothreitol (DTT) in 50 mm Tris–HCl (pH 7.5) at 100 °C for 10 min. In the control, the same amount of 5 mm dithiothreitol in 50 mm Tris–HCl (pH 7.5) was added to PDA medium. Each experiment was performed in triplicate, and all data are displayed as mean values ± SD. Statistically significant differences from control were determined using Student's t‐test and indicated as **P < 0.01.