Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: August 20, 1998
Publication Date: N/A
Technical Abstract: Nematode glycolipids have putative structural and bioregulatory roles; monoglycosylceramides (MGCs) consist of a single sugar residue attached to a long chain sphingoid base connected to a fatty acid molecule via an amide linkage. HPLC-purified MGCs comprised 0.17% (dry wt basis) of eggs of Meloidogyne incognita and mixed stages of Caenorhabditis elegans. Structures were determined with mass spectrometry, nuclear magnetic resonance spectroscopy, and analysis of methanolysis products of the parent glycolipids via gas chromatography-mass spectrometry of appropriate derivatives. Interestingly, the only long chain sphingoid base detected was an unusual iso-branched, 17-carbon compound with a C-4 double bond (i.e., 15-methyl- 2-aminohexadec-4-en-1,3-diol). Glucose was the only sugar moiety detected. Although the fatty acids of the C. elegans material consisted primarily of straight-chain, saturated, 2-hydroxylated C-20 to C-26 acids, in M. incognita, these acids were largely unsaturated, with nearly two-thirds being a hydroxylated 24-carbon monounsaturated acid. Surprisingly, monoglycosylceramides in cysts of Heterodera glycines were not detected (threshold of detection = 0.005% of dry weight).