FIGURE 7.

Reduced H₂O₂ accumulation in TaTypA knock-down plants challenged by avirulent race CYR23. (A) Wheat leaves previously treated with recombinant BSMV:γ or BSMV:TaTypA were inoculated with Pst race CYR23. H₂O₂ accumulation at infection sites was detected by staining with 3,3′-diaminobenzidine (DAB). Infection sites were observed by light microscopy. SV, substomatal vesicle; IH, initial hyphae; SH, secondary hyphae. Bar, 20 μm. (B) The amount of H₂O₂ production was measured by calculating the DAB-stained area at each infection site using DP-BSW software. Values represent mean ± standard errors of three independent assays. (C) Expressions of two ROS-scavenging enzyme genes were assayed in TaTypA knock-down plants compared to control plants. The data were normalized to wheat the TaEF-1a gene. Asterisks indicate significant difference (P < 0.05) from BSMV:γ using Tukey’s HSD test.