A Baeyer-Villiger monooxygenase CgBVMO1 is involved in superoxide anion metabolism, cell wall synthesis, and pathogenicity of Colletotrichum gloeosporioides

Abstract

Baeyer-Villiger monooxygenases (BVMOs) represent a subset of flavin-dependent monooxygenases that facilitate the oxidation of a diverse range of substrates. Despite their significance, the functional aspects of BVMOs within fungal pathogens have remained relatively uncharted until now. Therefore, the objective of this study is to investigate the role of CgBVMO1 in the causal agent of anthracnose disease, Colletotrichum gloeosporioides. The findings revealed a substantial upregulation of CgBVMO1 transcription in the pathogen during both appressorium formation and the initial invasion to the plant host. Subsequent knockout of CgBVMO1 and related analyses elucidated the enzyme's involvement in various vital processes of C. gloeosporioides, including vegetative growth, conidiation, and the pathogenicity. It is noteworthy that the knockout of CgBVMO1 had no impact on the pathogen’s ability to penetrate the plant epidermis. Furthermore, this research uncovered CgBVMO1's essential role in superoxide anion production. Stress sensitivity assessments, on the other hand, established that CgBVMO1 does not participate in osmotic regulation or cell membrane biosynthesis, but rather actively contributes to cell wall synthesis by regulating chitin synthase. In conclusion, this study provides invaluable insights into the pivotal role played by CgBVMO1 in the pathogenicity of C. gloeosporioides.