The main reproductive mode of aspergilli is the formation of conidia. BrlA, AbaA, and WetA are the central regulators of conidiation in aspergilli. BrlA and AbaA are transcription factors, yet the WetAmediated regulatory mechanism is still unknown. Here, we characterized WetA’s functions and further investigated the underlying molecular regulatory mechanism along with genetics, transcriptomics, and metabolomics approaches. The deletion of wetA causes conidia autolysis, disrupted conidia wall integrity, and reduced stress tolerance. Moreover, in A. flavus, WetA is involved in light-stimulated hyphae development, vegetative growth, and aflatoxin production. Northern analysis shows that WetA is a negative regulator of its upstream regulators and exerts feed-back control for development in both species. We further carried out RNA-seq of WT and wetA-null mutant conidia from A. nidulans, A. flavus, and A. fumigatus. The genome-wide expression studies showed that WetA has a broad effect on development and metabolism in conidia. For in vivo WetA-DNA interaction studies, ChIP-seq was performed on A. nidulans WT conidia. The result showed that WetA directly interacts with several transcription factors in conidia, suggesting that WetA may be a transcription factor. Overall, WetA is an evolutionarily conserved central developmental regulator in Ascomycetes. This is the first study demonstrating that WetA is a DNA-binding protein, which plays multiple regulatory roles of development and metabolism in Aspergillus.
Full conference title:
- Asperfest 14 (2017)