Appressorium-localized NADPH oxidase B is essential for aggressiveness and pathogenicity in the host-specific, toxin-producing fungus Alternaria alternata Japanese pear pathotype.

ABSTRACT: Black spot disease, Alternaria alternata Japanese pear pathotype, produces the host-specific toxin AK-toxin, an important pathogenicity factor. Previously, we have found that hydrogen peroxide is produced in the hyphal cell wall at the plant-pathogen interaction site, suggesting that the fungal reactive oxygen species (ROS) generation machinery is important for pathogenicity. In this study, we identified two NADPH oxidase (NoxA and NoxB) genes and produced nox disruption mutants. ΔnoxA and ΔnoxB disruption mutants showed increased hyphal branching and spore production per unit area. Surprisingly, only the ΔnoxB disruption mutant compromised disease symptoms. A fluorescent protein reporter assay revealed that only NoxB localized at the appressoria during pear leaf infection. In contrast, bo

SUBMITTER: Morita Y 

PROVIDER: S-EPMC6638787 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature