Pathogenesis-related proteins in near-isogenic barley lines induced by powdery mildew infection

Induction of pathogenesis-related (PR) proteins in intercellular spaces of near-isogenic barley leaves was examined after inoculation with a virulent and an avirulent race of powdery mildew (Erysiphe graminis f. sp. hordei) 24, 48, 72h post-inoculation. Induction of two the pathogen-induced proteins was ascertained 24 h post inoculation. 72h post-inoculation 7 to 8 major pathogen-induced proteins (bands on native PAGE) were identified. The accumulation pattern of PR proteins was very similar in both compatible and incompatible host-pathogen interaction but it was more expressive and appeared earlier at host-parasite incompatibility than at compatibility. These results have confirmed that the resistance gene plays a key role in early recognition of pathogenes as well as in early activation of the defence response.