SfRop is a potential target for controlling Spodoptera frugiperda through regulation of AcMNPV viral transportation.

Sec1/Munc18 (SM) proteins serve as core upstream regulators governing SNARE complex assembly. The SM protein Rop plays a critical role in SNARE-mediated membrane fusion, yet its function in baculovirus infection remains largely unexplored. Here, we demonstrate that SfRop, the Rop homolog in Spodoptera frugiperda, is essential for the infection cycle of Autographa californica multiple nucleopolyhedrovirus (AcMNPV). Knockdown of SfRop significantly reduced viral genome replication, early and late gene transcription, and intracellular viral genome copy numbers during the early infection stage. Confocal microscopy revealed that SfRop silencing impeded nucleocapsid trafficking to the nucleus, thereby blocking viral entry. At the late infection stage, SfRop deficiency impaired progeny virus release, accompanied by reduced GP64 envelope protein localization at the plasma membrane and intracellular accumulation of budded virions. Conversely, overexpression of SfRop via a recombinant virus enhanced progeny virus production. Mechanistically, silencing of the SNARE genes SfSyx1 and SfSNAP25 phenocopied the effects of SfRop knockdown, and SfRop overexpression partially rescued the defects, suggesting a cooperative role of SfRop-SfSyx1-SfSNAP25 in modulating viral replication. Importantly, in vivo assays showed that SfRop knockdown significantly increased larval survival upon AcMNPV challenge, highlighting SfRop as a host factor critical for viral propagation. Collectively, our findings establish SfRop as a key regulator of both AcMNPV invasion and budding, and suggest that targeting SfRop or its interacting SNARE partners may represent a promising strategy for pest control by disrupting virus-host interactions.