Figure 5: Levels of Mds-1 expression affect development of B. graminis f. sp. tritici.

(a) Mds-1 silencing inhibits virulence of B. graminis f. sp. tritici on the susceptible wheat Bobwhite. Large lesions (arrow) on a vector-transformed, Bobwhite plant (V-BW), small lesions on the Mds-1-silenced plant T1639. (b) Mds-1 transcript increases following B. graminis f. sp. tritici infection in susceptible cultivars Molly (M), Newton (N) and Bobwhite (B), but not in the resistant cultivar Duster (D) based on real-time PCR (qPCR) results of samples 24 h after inoculation. Three biological replicates were carried out for qPCR. Data were subjected to analysis of variance analysis. Tukey’s pairwise comparisons based on Student’s range statistics were then conducted. Tukey’s 95% simultaneous confidence intervals for pair-wise comparisons were used to separate data into groups with significant differences. Lower case letters indicate different groups at P≤0.05. Standard error is given in the figure. (c) Heat stress (HS, at 35 °C for 24 h) induces Mds-1 expression over 100 fold in the resistant cultivar Duster compared with control plants (CK) determined by qPCR. Three replicates were carried out and standard error is given in the figure. (d) HS compromises the resistance of Duster to B. graminis f. sp. tritici. The relative disease index was 1.3±0.5 on control plants (CK), but climbed to 3.6±0.4 on plants stressed at 35 °C for 24 h (HS) on a scale of 0–4.