qRT–PCR results showed that PDI transcript levels were upregulated nearly two-fold (P<0.01, one-way ANOVA, n=3) within 1.5 h after infection by wild-type P. sojae (Fig. 6c), whereas during infection by the PsAvh262-silenced transformants, minimal changes were observed in the levels of PDI transcripts prior to 9 h.p.i. This evidence concerns the gene P4HB and infection.