Analysis of the transcriptional activation properties of P3 and RLI1b on the SERK4 promoter in N. benthamiana leaves. Left upper panel, the different combinations were co-transformed in N. benthamiana leaves and observed 2 days later. Left lower panel, immunoblot analysis of P3 and RLI1b protein expression. Right panel, LUC/REN ratio was calculated as the final transcriptional activity. Means ± SD were shown (n= 6). Data were analyzed by one-way ANOVA with Tukey’s test. Different letters indicate statistical significance (p< 0.05).