| Title | FgFlbD Regulates Hyphal Differentiation Required for Sexual and Asexual Reproduction in the Ascomycete Fungus Fusarium graminearum |
|---|---|
| Author | Hokyoung Son1, Myung-Gu Kim1, Suhn-Kee Chae2, and Yin-Won Lee1* |
| Address | 1Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Republic of Korea, 2Department of Biochemistry, Paichai University, Daejeon 305-343, Republic of Korea |
| Bibliography | Journal of Microbiology, 52(11),930-939, 2014, |
| DOI | 10.1007/s12275-014-4384-6 |
| Key Words | conidiogenesis, Fusarium graminearum, flbD, fluffy genes |
| Abstract | Fusarium graminearum is a filamentous fungal plant pathogen that infects major cereal crops. The fungus produces both sexual and asexual spores in order to endure unfavorable environmental conditions and increase their numbers and distribution across plants. In a model filamentous fungus, Aspergillus nidulans, early induction of conidiogenesis is orchestrated by the fluffy genes. The objectives of this study were to characterize fluffy gene homologs involved in conidiogenesis and their mechanism of action in F. graminearum. We characterized five fluffy gene homologs in F. graminearum and found that FlbD is the only conserved regulator for conidiogenesis in A. nidulans and F. graminearum. Deletion of fgflbD prevented hyphal differentiation and the formation of perithecia. Successful interspecies complementation using A. nidulans flbD demonstrated that the molecular mechanisms responsible for FlbD functions are conserved in F. graminearum. Moreover, abaA-wetA pathway is positively regulated by FgFlbD during conidiogenesis in F. graminearum. Deleting fgflbD abolished morphological effects of abaA overexpression, which suggests that additional factors for FgFlbD or an AbaA-independent pathway for conidiogenesis are required for F. graminearum conidiation. Importantly, this study led to the construction of a genetic pathway of F. graminearum conidiogenesis and provides new insights into the genetics of conidiogenesis in fungi. |