Untargeted lipidomics reveals lipid metabolism disorders induced by oxathiapiprolin in Phytophthora sojae

BackgroundOxathiapiprolin, an oxysterol-binding protein inhibitor (OSBPI), shows unexceptionable inhibitory activity against plant pathogenic oomycetes. FRAC (Fungicide Resistance Action Committee) classifies it into the mode of action group F9 (lipid homeostasis and transfer/storage), but very little is known about the lipid metabolism of oomycete pathogens when subjected to oxathiapiprolin. ResultsIn this study, seven lipid categories and 1435 lipid molecules were identified in Phytophthora sojae, among which glycerolipids, glycerophospholipids, and sphingolipids account for 30.10%, 50.59%, and 7.28%, respectively. These lipids were categorized into 31 subclasses, which varied to different extents when treated with oxathiapiprolin. A total of 11 lipid subclasses showed significant changes. Among them, 10 lipid subclasses, lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), phosphatidylcholine (PC), phosphatidylserine (PS), ceramide (Cer), triglyceride (TG), (o-acyl)-1-hydroxy fatty acid, diglycosylceramide, sphingoshine (So), and sitosterol ester, were significantly up-regulated, while digalactosyldiacylglycerol was the only lipid that was significantly down-regulated by a factor of almost three. These lipid molecules were further analyzed at the lipid species level. A total of 542 species were significantly altered when treated with oxathiapiprolin, including 212 glycerolipids [186 TG and 26 diglycerides (DG)], 167 glycerophospholipids (38 PC, 15 LPC, 19 LPE, seven PS, etc.), 156 sphingolipids (146 Cer, four So, etc.), and some other lipid molecules. Finally, from the orthogonal partial least-squares discrimination analysis model, variable importance for the projection score analysis showed that Cer, TG, and some glycerophospholipids contribute to the metabolic disorder when subjected to oxathiapiprolin. ConclusionGlycerolipids, glycerophospholipids, and sphingolipids in P. sojae undergo significant changes with oxathiapiprolin treatment. These results provided valuable information for further understanding the function of the target protein and the mode of action of OSBPIs in oomycetes. (c) 2022 Society of Chemical Industry.

Automated summary

This study investigated the effects of oxathiapiprolin on the lipid metabolism of Phytophthora sojae. It was found that glycerolipids, glycerophospholipids, and sphingolipids showed significant changes when treated with oxathiapiprolin. Specifically, 11 lipid subclasses were affected, with 10 up-regulated and 1 down-regulated. Further analysis revealed numerous altered lipid species in response to oxathiapiprolin treatment.