The Integrated Virulence Network of Colletotrichum scovillei : Effector-Signaling Coordination in an Emerging Anthracnose Pathogen

Colletotrichum scovillei is an important and geographically expanding anthracnose pathogen of pepper ( Capsicum spp.) that causes serious pre- and post-harvest losses. This hemibiotrophic fungus employs a multilayered infection strategy, yet an integrated framework connecting its molecular mechanisms to disease development has been lacking. This review synthesizes current evidence to propose an integrated virulence network for C. scovillei . Conserved intracellular signaling pathways, including mitogen-activated protein kinase (MAPK), cyclic AMP (cAMP), calcium/calcineurin, cell-wall integrity, and small-GTPase modules, regulate key morphological transitions. Available genetic studies also connect selected regulators to host-defense suppression, while comparative genomic analyses identify strain-level differences in predicted secreted proteins and candidate virulence-associated regions. However, the identities, host targets, and stage-specific deployment of most C. scovillei effectors remain unresolved. We therefore distinguish direct evidence from the C. scovillei –pepper system from mechanisms inferred from other Colletotrichum species and position biotrophy, extended quiescence, ripening-associated reactivation, and necrotrophy within a testable framework. We further examine pepper resistance and management limitations and identify experiments needed to translate this framework into durable control strategies.