Identification of Three Novel Conidiogenesis-Related Genes in the Nematode-Trapping Fungus Arthrobotrys oligospora

For filamentous fungi, conidiogenesis is the most common reproductive strategy for environmental dispersal, invasion, and proliferation. Understanding the molecular mechanisms controlling conidiation and increasing conidium yield may provide promising applications in commercial development in the future for nematode-trapping fungi. However, the molecular mechanism for regulating conidium production of filamentous fungi is not fully understood. In this study, we characterized three novel conidiogenesis-related genes via gene knockout in A. oligospora. The absence of the genes AoCorA and AoRgsD caused significant increases in conidia production, while the absence of AoXlnR resulted in a decrease in conidiogenesis. Moreover, we characterized the ortholog of AbaA, a well-known conidiogenesis-related gene in Aspergillus nidulans. The deletion of AoAbaA not only completely abolished conidium production but also affected the production of nematode-trapping traps.