Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural Universitygrid.411389.6, Hefei, China.
School of Plant Protection, Anhui Agricultural Universitygrid.411389.6, Hefei, China.
Microbiol Spectr. 2021 Oct 31;9(2):e0082321. doi: 10.1128/Spectrum.00823-21. Epub 2021 Sep 8.
Conidiation is a pivotal strategy for fungi to resist adverse environments and disperse to new habitats, which is especially important for entomopathogenic fungi whose conidia are infective as fungal pesticide propagules. However, the molecular mechanism for regulating conidiation in entomopathogenic fungi is not fully understood. Here, we characterized the regulatory mechanism of the key developmental transcription factor Mr-AbaA. Bioinformatic analysis, transcriptional profiles, and subcellular localization of indicated that AbaA functioned as a transcription factor in the conidiophore development and conidium stages. Microscopic examination showed that the null mutant of differentiated into defective phialides to produce an abacus structure instead of conidia. Loss of resulted in the inhibition of submerged blastospore separation . Moreover, yeast (Saccharomyces cerevisiae) one-hybrid assays of interactions between genes and deletion of showed that Mr-AbaA regulates conidiation by interacting with the promoter regions of and . These results demonstrate that Mr-AbaA positively regulates conidiation in Metarhizium robertsii by regulating the family ortholog gene and contributes to the separation of blastospores in submerged culture. Metarhizium robertsii is an emerging model entomopathogenic fungus for developing biopesticides; therefore, a comprehensive understanding of its conidiation is very important for its application. In this study, we revealed that the transcription factor Mr-AbaA is involved in the control of aerial conidiation and blastospore separation in submerged culture. Further yeast one-hybrid assays demonstrated that Mr-AbaA interacts with the promoter regions of and , which code for proteins involved in the control of conidiation. This finding provides new insight into the regulation of the conidiation of this important entomopathogenic fungi.
分生孢子形成是真菌抵抗不利环境和向新栖息地扩散的关键策略，对于昆虫病原真菌尤为重要，因为其分生孢子作为真菌农药的繁殖体具有感染性。然而，昆虫病原真菌分生孢子形成的分子调控机制尚未完全阐明。在这里，我们对关键发育转录因子 Mr-AbaA 的调控机制进行了表征。生物信息学分析、转录谱和亚细胞定位表明，AbaA 在分生孢子梗发育和分生孢子阶段作为转录因子发挥作用。显微镜检查显示，缺失突变体分化成有缺陷的产孢细胞，产生算盘结构而不是分生孢子。缺失导致淹没培养中分生孢子的芽生孢子分离被抑制。此外，酵母（酿酒酵母）单杂交试验表明，基因之间的相互作用和 的缺失表明 Mr-AbaA 通过与 和 的启动子区域相互作用来调节分生孢子形成。这些结果表明，Mr-AbaA 通过调节同源基因 和 正向调控 罗伯茨氏绿僵菌的分生孢子形成，并有助于淹没培养中芽生孢子的分离。罗伯茨氏绿僵菌是一种新兴的昆虫病原真菌模式生物，用于开发生物农药；因此，全面了解其分生孢子形成对其应用非常重要。在这项研究中，我们揭示了转录因子 Mr-AbaA 参与控制气生分生孢子形成和淹没培养中的芽生孢子分离。进一步的酵母单杂交试验表明，Mr-AbaA 与 和 编码蛋白的启动子区域相互作用，这些蛋白参与控制分生孢子形成。这一发现为理解这种重要的昆虫病原真菌的分生孢子形成调控提供了新的视角。
