Figure 2.

flg22 application enhances resistance to Fusarium graminearum in Arabidopsis and wheat. (A) Top: F. graminearum disease severity in wild‐type (WT) Arabidopsis accession Columbia leaves treated with 50 ng of flg22 (+) and as control with water (–). Fungal inoculation was conducted 24 h after flg22 treatment and disease severity was monitored at 5 days post‐inoculation (dpi) with the fungus (n = 50). Bottom: leaf disease index in the above experiment. All values are means ± standard error (SE) (n = 50). Asterisks above the bars indicate values that are significantly different from the water‐treated control plants (P < 0.05; χ ² test). (B) Left: leaf disease index in F. graminearum‐inoculated WT accession Columbia plant and two independent PR1‐flg22 transgenic lines that are in the FLS2 background. All values are the means ± SE (n = 50). Asterisks above the bars indicate values that are significantly different from WT (P < 0.05; χ ² test). Right: Fusarium Arabidopsis Disease (FAD) score in inflorescences of the WT and PR1‐flg22 lines in the FLS2 background. All values are the means ± SE (n = 30). Asterisks above the bars indicate values that are significantly different from WT (P < 0.05; t‐test). (C) Fusarium head blight severity in flg22‐treated wheat cv. Bobwhite (Bw). The spikelets were treated with the indicated amounts of flg22 peptide at 24 h prior to fungal inoculation. The Ubi:NPR1 transgenic plant, which is in the cultivar Bw background, provided the FHB‐resistant control. Disease severity was monitored at 21 dpi. All values are the means ± SE (n = 10). Different letters above the bars indicate values that are significantly different from each other (P < 0.05; Tukey’s test).