Abstract: Glutathione S-transferases (GSTs) play an important role in detoxification and antioxidation. In order to study the molecular mechanisms of insecticide resistance in the wild mulberry silkworm, Bombyx mandarina, we detected the transcription levels of GST genes in different tissues of the fifth instar larvae and those treated with dichlorovos and deltamethrin using real-time quantitative RT-PCR method, and took Actin3 gene as reference to dispose the results. The results showed that the expression levels of GST genes induced by dichlorovos and deltamethrin were different in various tissues, the highest expression level was found in fat body, and the second was in the midgut, and this might be due to that both tissues are major organs involved in detoxication of the pesticides. Furthermore, the GSTe2 and GSTe5 genes were highly expressed, so it is inferred that these genes may be mainly responsible for detoxification of xenobiotics.

Key words: Bombyx mandarina, GST genes, tissue, induced expression, real-time RT-PCR