Figure 7. Accumulation of H₂O₂ at the Bgt infection sites in wheat epidermal cells.

(A) Microscopic view of H₂O₂ production in wheat leaf epidermal cells. Two-week-old seedlings were inoculated with Bgt and sampled at different time points as indicated. H₂O₂ accumulation was detected by in situ histochemical staining using DAB and observed in bright field under an Olympus microscope. Enlarged views of marked red boxes in lanes 1 and 3 (scale bar = 30 μm) are shown in lanes 2 and 4. Scale bar = 20 μm. (B,C) Percentage of cells with H₂O₂ accumulation throughout the entire cell, and with accumulation only around the infection sites in Yangmai 158 and PDI-V-over-expressing plants. (D) Expression pattern of PDI-V in response to exogenous hormones. Each result is the mean of three independent biological repeats; bars show standard deviations. The Tubulin gene was used as an internal control to normalize qRT-PCR values. Asterisks indicate a significant difference (P < 0.05) from the control (0 hpi) based on Student’s t-tests. JA, methyl jasmonate; SA, salicylic acid; H₂O₂, hydrogen peroxide; ET, ethylene.