title: Identification of ceramide-phosphorylethanolamine in oomycete plant pathogens: Pythium ultimum, Phytophthora infestans, and Phytophthora capsici.
abstract: Cellular lipids were extracted from three species of Oomycete plant pathogens (Pythium ultimum, Phytophthora infestans, and Ph. capsici) and analyzed via normal-phase high-performance liquid chromatography with flame-ionization detection. The most abundant polar lipids in each of the three species were the polar membrane lipids, phosphatidylethanolamine (PE), phosphatidylcholine, and a phosphosphingolipid that eluted soon after PE. Structural analysis via mass spectrometry and nuclear magnetic resonance spectrometry revealed that the phosphosphingolipid was ceramide phosphorylethanolamine (Cer-PE). The most abundant molecular species of Cer-PE in P. ultimum had a molecular weight of 670.5, contained an unusual 19-carbon branched triunsaturated sphingoid (C19-delta 4, 8, 10, 9-methyl long-chain base) and palmitic acid as the amide-linked fatty acid. The most abundant molecular species of Cer-PE in Ph. infestans had a molecular weight of 714.5, contained a common 16-carbon 1,3 di-OH sphingoid, and erucic (cis 13-docosenoic, C22-delta 13) acid as the amide-linked fatty acid. The Cer-PE in Ph. capsici comprised a mixture of each of the two molecular species found in P. ultimum and Ph. infestans.
authors.affiliation: Eastern Regional Research Center, U.S. Department of Agriculture, Agricultural Research Service, Wyndmoor, Pennsylvania 19038, USA. rmoreau@arserrc.gov
authors.forename: R A
authors.initials: RA
authors.lastname: Moreau
authors.forename: D H
authors.initials: DH
authors.lastname: Young
authors.forename: P O
authors.initials: PO
authors.lastname: Danis
authors.forename: M J
authors.initials: MJ
authors.lastname: Powell
authors.forename: C J
authors.initials: CJ
authors.lastname: Quinn
authors.forename: K
authors.initials: K
authors.lastname: Beshah
authors.forename: R A
authors.initials: RA
authors.lastname: Slawecki
authors.forename: R L
authors.initials: RL
authors.lastname: Dilliplane
mesh_terms: D002518:Ceramides / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000737:chemistry; D008055:Lipids / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D009868:Oomycetes / Q000737:chemistry / Q000472:pathogenicity; D010743:Phospholipids / Q000737:chemistry; D010838:Phytophthora / Q000737:chemistry* / Q000472:pathogenicity; D011775:Pythium / Q000737:chemistry* / Q000472:pathogenicity; D013107:Sphingolipids / Q000737:chemistry; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D002518:Ceramides; D005227:Fatty Acids; D008055:Lipids; D010743:Phospholipids; D013107:Sphingolipids; D013109:Sphingomyelins; C060281:ceramide phosphoethanolamine