IN-VIVO CHARACTERIZATION OF LOW-MOLECULAR-WEIGHT COMPONENTS OF SOME PLANT-PARASITIC NEMATODES BY C-13 NUCLEAR-MAGNETIC-RESONANCE SPECTROSCOPY

Investigations on the feasibility of using C-13 NMR spectroscopy to id entify in vivo the major low molecular weight chemical species in plan t parasitic nematodes are described. Longidorus elongatus, Anguina tri tici 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. elongatu s was identified as an 18+/-1 carbon monounsaturated (18:1) fatty acid or ester, although the position of the double bond could not be ascer tained. Other unsaturated fatty acid components were present in minor amounts, but for these it was not possible to determine either the cha in lengths or double bond positions. The spectra of L. elongatus conta ined additional peaks which could be assigned to glyceride, trehalose and glucose. Considerable variations in the sugar contents were observ ed 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 assigne d to fatty acid species. On hydration there was a considerable decreas e in peak widths and the fatty acid component resembled that of L. elo ngatus. Additional peaks from trehalose were also produced. No spectru m was obtained from desiccated specimens of G. pallida, but on hydrati on peaks from lipid and trehalose were revealed. Resolution of peaks w as poorer than with the L. elongatus and hydrated A. tritici specimens and the lipid resonance indicated a greater degree of unsaturation th an in the other nematodes.