How the Pathogenic Fungus Alternaria alternata Copes with Stress via the Response Regulators SSK1 and SHO1

摘要: The tangerine pathotype of Alternaria alternata is a necrotrophic fungal pathogen causing brown spot disease on number citrus cultivars. To better understand the dynamics signal regulation leading to oxidative and osmotic stress response infection citrus, phenotypic characterization yeast SSK1 regulator homolog was performed. It determined that responds diverse environmental stimuli plays critical role in pathogenesis. Experiments determine phenotypes resulting from loss reveal gene product may be fulfilling similar regulatory roles signaling pathways involving HOG1 MAP kinase during ROS resistance, fungicide sensitivity virulence. mutants display elevated oxidants, fail detoxify H2O2 effectively, induce minor necrosis susceptible leaves, displays resistance dicarboximide phenylpyrrole fungicides. Unlike SKN7 regulator, confer salt-induced via an unknown sensor rather than “two component” histidine HSK1. play moderate sugar-induced stress. We also show are impaired their ability produce germ tubes conidia, indicating for cell differentiation. involved multi-drug resistance. However, deletion SHO1 (synthetic high osmolarity) resulted no noticeable phenotypes. Nonetheless, our results A. can sense react different types SSK1, cooperative manner proper physiological pathological functions.