Asexual development is the main propagation and transmission mode of
Beauveria bassiana and the basis of its pathogenicity. The regulation mechanism of conidiation and the key gene resources for utilization are key links to improving the conidia yield and quality of
Beauveria bassiana. Their clarification may promote the industrialization of fungal pesticides. Here, we compared the regulation of morphology, resistance to external stress, virulence, and nutrient utilization capacity between the upstream developmental regulatory gene
fluG and the key genes
brlA,
abaA, and
wetA in the central growth and development pathway. The results showed that the Δ
brlA and Δ
abaA mutants completely lost the capacity to conidiate and that the Δ
wetA mutant had seriously reduced conidiation capacity. Although the deletion of
fluG did not reduce the conidiation ability as much as deletions of
brlA,
abaA, and
wetA, it significantly reduced the fungal response to external stress, virulence, and nutrient utilization, while the deletion of the three other genes had little effect. Via transcriptome analysis and screening the yeast nuclear system library, we found that the differentially expressed genes in the Δ
fluG mutants were concentrated in the signaling pathways of ABC transporters, propionate metabolism, tryptophan metabolism, DNA replication, mismatch repair, and fatty acid metabolism. FluG directly acted on 40 proteins that were involved in various signaling pathways such as metabolism, oxidative stress, and cell homeostasis. The analysis indicated that the regulatory function of
fluG was mainly involved in DNA replication, cell homeostasis, fungal growth and metabolism, and the response to external stress. Our results revealed the biological function of
fluG in asexual development and the responses to several environmental stresses as well as its influence on the asexual development regulatory network in
B. bassiana.
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