Expression of cell wall integrity (CWI) pathway genes (VdMKK1 (VDAG_09823) and VdMK1 (VDAG_09461)), and chitin synthesis genes (VdChi1 (VDAG_10179), VdChi3 (VDAG_08591), VdChi4 (VDAG_00419) and VdChi7 (VDAG_01790)) in the ΔVdPLP mutant strains (ΔVdPLP-1 and ΔVdPLP-4) was lower than in the V. dahliae wild type (Vd-wt) strain and complementary ΔVdPLP strains (ΔVdPLP-1-C and ΔVdPLP-4-C). Total RNA was extracted from mycelia of seven-day-old Vd-wt, ΔVdPLP (ΔVdPLP-1 and ΔVdPLP-4), and complementary ΔVdPLP (ΔVdPLP-1-C and ΔVdPLP-4-C) strains were grown in liquid complete medium (CM). Quantitative real-time reverse-transcription PCR was used to measure expression levels: VdMKK1 (A); VdMK1 (B); VdChi1 (C); VdChi3 (D); VdChi4 (E); and VdChi7 (F). The β-tubulin gene was used as an internal standard. Values are means ± SD of three independent experiments performed in duplicates, significant differences are indicated by letters (a,b), and data were analyzed with the Duncan’s multiple range test (p-value < 0.05).