FIG 1.

VdMRTF1 negatively regulates melanin biosynthesis in Verticillium dahliae. (A) Colonies of the wild-type strain (VdLs.17), the ΔVdMRTF1 strain, and the complemented strain (ΔVdMRTF1/VdMRTF1) were grown on PDA for 10 days at 25°C. Bar, 1 cm. (B) Conidial suspensions (10⁶/mL) of the indicated strains of V. dahliae were shaken for 10 days at 25°C in liquid BM. (C) Conidia (10⁶/mL) of each strain were sprayed on the cellulose membrane overlaid onto BM plates and cultured at 25°C. Photographs were taken after 4, 7, and 14 days. Bar, 3 cm. (D) and (E) Melanized fractions of the colonies were determined using ImageJ at 4 and 14 dpi. Error bars represent the standard deviations based on three independent replicates. Asterisks indicate significant differences (***P < 0.001, *P < 0.5).