Figure 4.

Hordeum vulgare cysteine‐rich receptor‐like protein kinase (HvCRK1) transcript accumulation in the epidermis and total leaves of barley in response to virulent Blumeria graminis f.sp. hordei (Bgh). (A) HvCRK1 transcript accumulation in abaxial epidermal tissue of the barley line P01 at 6, 12 and 24 h after inoculation (hai) of Bgh. (B) HvCRK1 transcript accumulation in total leaves of barley line P01 and the near‐isogenic mlo5‐resistant P22 barley line between 2 and 72 hai. Inset: transcript accumulation of peroxidase (HvPrx) and the pathogenesis‐related protein (HvPR‐1b) gene in the same P22 cDNA. (C) HvCRK1 transcript accumulation in response to 250 µm salicylic acid (SA) or 5 mm hydrogen peroxide (H₂O₂) 24 h after infiltration into leaves of P01. Values represent the fold induction in Bgh‐inoculated or SA/H₂O₂‐treated plants. Asterisks indicate significant differences in Bgh‐infected samples compared with uninfected epidermis or leaf samples at the respective time points (n= 5, ***P < 0.001, **P= 0.01–0.001, *P= 0.05–0.01).