Developmental and stress-induced expression of Choristoneura fumiferana glutathione S-transferase (CfGST) mRNA and protein were examined using Northern blots and Western blots. High levels of CfGST mRNA and protein were detected in 1st instar larvae and diapausing 2nd instar larvae. Expression of CfGST gradually decreased during larval development from 3rd to 5th instar, after which the expression increased once again, reaching peak levels in 6th instar larvae. CfGST mRNA and protein were undetectable in the pupal stage. Exposure to low temperature did not induce an increase in CfGST expression. Feeding on balsam fir foliage resulted in an increase in the expression of CfGST as compared to larvae that fed on artificial diet. The bacterial insecticide, Bacillus thuringiensis delta-endotoxin (Bt), the non-steroidal ecdysone analog, tebufenozide, and the synthetic pyrethroid, permethrin, induced the expression of CfGST mRNA in 5th instar larvae, whereas the chitin synthesis inhibitor, diflubenzuron, did not have any such effect. These results suggest that CfGST plays an important role in detoxifying various allelochemicals and insecticides in the spruce budworm. The developmental expression pattern strongly suggests that in addition to detoxification, CfGST might be involved in other functions. Crown Copyright (C) 2000 Published by Elsevier Science Ltd.
|Number of pages||10|
|Journal||Journal of Insect Physiology|
|State||Published - 2001|
Bibliographical noteFunding Information:
This research was supported in part by the National Biotechnology Strategy Fund and the Science and Technology Opportunities Fund of Canadian Forest Service to the Biotechnology group at the Great Lakes Forestry Centre and grants from the Natural Sciences and Engineering Research Council of Canada to K.G. Davey of York University.
- Bacillus thuringiensis
ASJC Scopus subject areas
- Insect Science