Enhanced resistance of GhMPK16 -overexpressing Arabidopsis to P. solanacearum infection. (A) RNA blot analysis of GhMPK16 expression in T1 transgenic plants. (B) Disease symptoms of wild-type (WT) and transgenic plants (#2 and #5) at 6 d post-inoculation with P. solanacearum (105 cfu/ml). Magnified images are shown in the lower photographs. (C) Growth of P. solanacearum in wild-type and transgenic plants (#2 and #5) after infecting the plants using the dipping method. Data are the mean ± SE (n = 6) from three independent experiments. Different letters at 3- or 6-d data points indicate significant differences with P < 0.05 according to Duncan's multiple range test. (D) RT-PCR analysis of the expression of Arabidopsis AtPR1, AtPR4 and AtPDF1.2 genes in wild-type and transgenic plants (#2 and #5) inoculated with P. solanacearum. Arabidopsis elongation factor EF-1α was used as an internal control.