Chlorpyrifos is a typical
organophosphate pesticide and is among the most widely used worldwide. The objective of the present investigation was to assess the effect of
chlorpyrifos exposure on
glutathione S-transferase in Locusta migratoria. In the present study,
chlorpyrifos (0.1, 0.2, and 0.4mgg(-1)
body weight) was topically applied in the abdomen of locusts. The GST activity,
mRNA levels of ten L. migratoria
GSTs and
protein levels of four representative
GSTs were detected. The results showed that
chlorpyrifos treatment caused significant decrease of
1,2-dichloro-4-nitrobenzene (DCNB) and p-nitro-
benzyl chloride (p-NBC) activities, whereas
1-chloro-2,4-dinitrobenzene (CDNB) activity was not altered in locusts. The
mRNA levels of seven L. migratoria
GSTs, including LmGSTs2, LmGSTs3, LmGSTs4, LmGSTs5, LmGSTs6, LmGSTt1, and LmGSTu1, were decreased after
chlorpyrifos exposure. The
protein levels of LmGSTs5, LmGSTt1 and LmGSTu1 were significantly decreased at higher doses of
chlorpyrifos. However,
chlorpyrifos elevated the
mRNA and
protein expression of LmGSTd1. It indicated that LmGSTd1 might contribute to the resistance of locust to
organophosphate pesticides such as
chlorpyrifos, whereas the decrease in other
GSTs might be an economic compensation by the insect to differentially regulate the expression of
enzymes involved in the detoxification of
insecticides on the expense of those that are not.