Journal of Parasitology (2005) 91, 988-994

Ganpati B. Jagdale, Parwinder S. Grewal and Seppo O. Salminen (2005)
Both heat-shock and cold-shock influence trehalose metabolism in an entomopathogenic nematode
Journal of Parasitology 91 (5), 988-994
Abstract: Heat-shock response is highly conserved in animals and microorganisms, and it results in the synthesis of heat-shock proteins. In yeast, heat-shock response has also been reported to induce trehalose accumulation. We explored the relationship between heat- (35 C) or cold-shock (1 and 10 C) and trehalose metabolism in the entomopathogenic nematode, Heterorhabditis bacteriophora. Because both heat- and cold-shocks may precede desiccation stress in natural soil environments, we hypothesized that nematodes may accumulate a general desiccation protectant, trehalose, under both situations. Indeed, both heat- and cold-shocks influenced trehalose accumulation and activities of enzymes of trehalose metabolism in H. bacteriophora. Trehalose increased by 5- and 6-fold in heat- and cold-shocked infective juveniles, respectively, within 3 hr of exposure, compared with the nematodes maintained at 25 C (culture temperature). The activity of trehalose-6-phosphate synthase (T6PS), an enzyme involved in the synthesis of trehalose, also significantly increased in both heat- and cold-shocked nematodes during the first 3 hr of exposure. Generally, the trehalose levels and activities of T6PS declined to their original levels within 3 hr when nematodes were transferred back to 25 C. In both heat- and cold-shocked nematodes, trehalase activity decreased significantly within the first 3 hr and generally returned to the original levels within 3 hr when these nematodes were transferred back to 25 C. The results demonstrate that the trehalose concentrations in H. bacteriophora are influenced by both heat- and cold-shocks and are regulated by the action of 2 trehalose-metabolizing enzymes, T6PS and trehalase. The accumulated trehalose may enhance survival of nematodes under both cold and warm conditions, but it may also provide simultaneous protection against desiccation that may result from subsequent evaporation or freezing. This is the first report of the relationship between trehalose metabolism and heat-shock for the Nematoda.
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Link to article at publishers website
Database assignments for author(s): Ganpati B. Jagdale, Parwinder S. Grewal

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
molecular biology - genes
classical biocontrol/new introduction

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Heterorhabditis bacteriophora/Photorhabdus (entomopathogen)