The Woronin body in the nematophagous fungus Arthrobotrys oligospora is essential for trap formation and efficient pathogenesis.

The Woronin body is a unique organelle in Pezizomycotina species. Following the injury of hyphae, it can quickly seal the septal pores to reduce the loss of cytoplasm and promote hyphal healing. The Woronin body is also considered a significant factor in efficient pathogenesis in many fungal pathogens. In this study, we identified AoHex1, a homologue of Neurospora crassa Hex1, a main component of the Woronin body in the genome of the nematode-trapping fungus Arthrobotrys oligospora. To study the biological function of the AoHex1 gene, the gene was deleted and its phenotypes assessed. Inactivation of this gene led to the loss of the Woronin body. The ΔAoHex1 strain showed compromised growth rate, conidiation, and anti-stress abilities. Moreover, trap formation was completely absent in the mutant strain, which could no longer capture nematodes. Our results suggest that the Woronin body plays an important role in growth, conidiation, anti-stress, trap formation, and virulence against nematodes in A. oligospora.