In Vivo Characterization of Low Molecular Weight Components of Some Plant Parasitic Nematodes By 13c nUclear Magnetic Resonance Spectroscopy

Abstract

Investigations on the feasibility of using 13C NMR spectroscopy to identify in vivo the major low molecular weight chemical species in plant parasitic nematodes are described. Longidorus elongatus, Anguina tritici and Globodera pallida were used, the last two in both desiccated and hydrated forms. In all specimens the dominant contributions to the spectra arose from lipid components. The major species in L. elongatus was identified as an 18±1 carbon monounsaturated (18: 1) fatty acid or ester, although the position of the double bond could not be ascertained. Other unsaturated fatty acid components were present in minor amounts, but for these it was not possible to determine either the chain lengths or double bond positions. The spectra of L. elongatus contained additional peaks which could be assigned to glyceride, trehalose and glucose. Considerable variations in the sugar contents were observed between samples, and there was a possible relationship between the glyceride and fatty acid components, suggesting that the latter might occur, at least in part, as triglycerides. Desiccated specimens of A. tritici produced relatively broad peaks, all of which could be assigned to fatty acid species. On hydration there was a considerable decrease in peak widths and the fatty acid component resembled that of L. elongatus. Additional peaks from trehalose were also produced. No spectrum was obtained from desiccated specimens of G. pallida, but on hydration peaks from lipid and trehalose were revealed. Resolution of peaks was poorer than with the L. elongatus and hydrated A. tritici specimens and the lipid resonance indicated a greater degree of unsaturation than in the other nematodes.