Involvement of the E2-like enzyme Atg3 in fungal development and virulence of Botryosphaeria dothidea

Autophagy is a fundamental cellular degradation and recycling system that is crucial for maintaining cellular homeostasis, responding to stress, and ensuring the proper functioning of cells. To date, the biological functions of autophagy in the plant-pathogenic fungus <i>Botryosphaeria dothidea</i> remains largely unknown. In this study, we identified and characterized the E2-like enzyme Atg3 in <i>B. dothidea</i>. The autophagic process was blocked in the <i>BdATG3</i> deletion mutant Δ<i>BdAtg3</i>, and the Δ<i>BdAtg3</i> mutant showed serious defects in mycelial growth, conidiation, perithecium formation and virulence. In addition, the Δ<i>BdAtg3</i> mutant exhibited an increased number of nuclei in mycelial compartment. All of the phenotypic changes of the Δ<i>BdAtg3</i> mutant were restored by gene complementation. These results indicate that the E2-like enzyme Atg3 plays an important role in various developmental processes and pathogenesis of <i>B. dothidea</i>, which provides a potential target for developing novel fungicides.