What makes a mycoparasite? Similarities between fungi that attack other fungi and fungal and oomycete plant pathogens based on structural homology of their candidate effectors

The paper operates within the established paradigm of mycology that defines mycoparasitism as a fungal lifestyle. However, it challenges the paradigm's lack of molecular-level explanation by proposing a new conceptual framework: that the molecular machinery of mycoparasitism (specifically effector proteins) is analogous to that of fungal plant pathogenesis. This connects two previously distinct areas of host-parasite interaction research.

This preprint is classified as Model Drift because it introduces a significant and unexpected finding that the current paradigm cannot fully accommodate without expansion. While mycoparasitism is a known phenomenon, its molecular basis is poorly understood. The authors reveal that candidate effector proteins from specialist mycoparasites are structurally homologous to those from well-studied plant pathogens. This discovery doesn't create a crisis but introduces a novel perspective and a powerful new explanatory model, suggesting a convergent evolution of parasitic mechanisms and pushing the existing paradigm into new territory by linking it to plant pathology.