Impact of phosphine exposure on development in Caenorhabditis elegans: Involvement of oxidative stress and the role of glutathione

• Published in: Pesticide biochemistry and physiology 2012-09, Vol.104 (1), p.38-43
• Main Authors: Leelaja, B.C, Rajini, P.S
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; C. elegans; Caenorhabditis elegans; Development; developmental toxicity; Diethyl maleate; eggs; embryogenesis; enzymes; fecundity; fumigants; Glutathione; hatching; insect control; maleates; mortality; oxidative stress; Phosphine; storage insects; stored grain
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1016/j.pestbp.2012.06.007

Phosphine (PH3) is a widely used and ideal fumigant employed to control insect pests in stored grains and other commodities. Chemically, PH3 is a strong reducing agent and mainly affects the mitochondrial transport system in insects. PH3 toxicity to insects is also associated with oxidative imbalances. Besides inducing mortality, PH3 is shown to delay hatching and adversely affect fecundity/fertility of several stored product insect pests. Recent studies have demonstrated the utility of Caenorhabditis elegans as a model organism to obtain basic insights on the toxic implications of PH3. In the present study, we have examined the impact of PH3 on the development of C. elegans and the involvement of glutathione (GSH) in its developmental toxicity. We exposed eggs of C. elegans to two concentrations of PH3 (0.04 and 0.06mg/L) either in the presence or absence of a GSH depleting agent, diethyl maleate (DEM, 5mM) for 72h. PH3 exposure caused significant delay in the post embryonic development among worms as characterized by the inability of hatched worms to attain gravid adult stage by the end of 72h. Interestingly, among worms co-exposed to DEM+PH3, the decrease in GSH levels was associated with more pronounced developmental delay compared to that of worms exposed to PH3per se. Concomitantly, PH3-induced depletion of glutathione was associated with significant alterations in activities of key antioxidant enzymes. Our data demonstrate the vital role of GSH and antioxidant defenses among worms developing under PH3 exposure. Interestingly, this finding also unfolds newer possibilities for developing strategies to disrupt antioxidant defenses in insect pests to enhance the efficacy of PH3 treatment for the control of stored product insects.