Glycerophosphocholine acyltransferase <scp>BbGpc1</scp> regulates phosphatidylcholine composition, conidial development, and fungal virulence in <i>Beauveria bassiana</i>

BACKGROUND: Glycerophosphocholine acyltransferase Gpc1 catalyzes the reacylation of glycerophosphocholine (GPC) and is a key enzyme in the phosphatidylcholine (PC) remodeling pathway (Land's cycle). It is involved in a variety of cellular processes. But its role in entomopathogenic fungi remains partially understood. RESULTS: Here, we show that BbGpc1 in the entomopathogenic fungus Beauveria bassiana plays an important role in fungal development and infection. Deletion of BbGpc1 reduced hyphal branching, conidial germination, and tolerance to cell wall stressors. The BbGpc1 mutant also formed fewer infection structures, resulting in decreased fungal penetration ability and virulence. Subcellular localization revealed that BbGpc1 is localized in small vesicles that traffic toward hyphal tips and newly formed septa. Although BbGpc1 deletion did not significantly alter lysophosphatidylcholine levels, it reduced specific species of PC and triacylglycerol, as well as the accumulation of lipid droplets. CONCLUSION: These results indicate that BbGpc1 regulates PC content and mediates lipid homeostasis, vesicle formation, and fungal development. This provides a new theoretical basis for elucidating the lipid regulation mechanism of B. bassiana. © 2026 Society of Chemical Industry.