Biochemistry of Anhydrobiosis in Beddingia siricidicola, a Biological Control Agent of Sirex noctilio

Michael J. Lacey, Robin A. Bedding

Abstract


Proto-anhydrobiosis of the nematode, Beddingia siricidicola, was achieved by incubation in polyethylene glycol or various concentrations up to 4 M of glycerol. The associated changes in the levels of glycerol, unbound proline, trehalose, lipids, and glycogen were determined by alkylation strategies, followed by gas chromatography or gas chromatography/mass spectrometry. The level of glycerol reached 8.9% of dry weight, proline 2.4% of dry weight, and trehalose 8.0% of dry weight within B. siricidicola that were incubated in 1.5 M glycerol over 6 d, while glycerol reached 17.9% of dry weight after incubation for the same period in 4 M glycerol. Movement was thereby reduced but the nematodes from 1.5 M glycerol revived after a few minutes upon rehydrating and they were able to avoid osmotic damage by rapidly excreting the glycerol, much of it being expelled within the first hour. The potential for storage and transport of this nematode for the biological control of the pine-killing wasp, Sirex noctilio, was greatly improved when nematode suspensions were maintained in 1.5 M glycerol under refrigeration.

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