These authors have equally contributed to this work.
Detoxification enzymes of Bemisia tabaci B and Q: biochemical characteristics and gene expression profiles
Version of Record online: 8 APR 2014
© 2014 Society of Chemical Industry
Pest Management Science
Special Issue: Whitefly Special Issue
Volume 70, Issue 10, pages 1588–1594, October 2014
How to Cite
Guo, L., Xie, W., Wang, S., Wu, Q., Li, R., Yang, N., Yang, X., Pan, H. and Zhang, Y. (2014), Detoxification enzymes of Bemisia tabaci B and Q: biochemical characteristics and gene expression profiles. Pest. Manag. Sci., 70: 1588–1594. doi: 10.1002/ps.3751
- Issue online: 19 SEP 2014
- Version of Record online: 8 APR 2014
- Accepted manuscript online: 31 JAN 2014 09:37AM EST
- Manuscript Accepted: 28 JAN 2014
- Manuscript Received: 19 NOV 2013
- Bemisia tabaci;
- detoxification enzymes;
- quantitative real-time PCR analysis;
- cytochrome-P450-dependent monooxygenase;
- glutathione S-transferase
The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most invasive and destructive pests of field crops worldwide. The sibling species B and Q are the two most damaging members of the B. tabaci species complex. That Q is more resistant than B to many insecticides has been well documented. Over the last decade, Q has gradually displaced B and has become the dominant form of B. tabaci in field agricultural systems in most parts of China. To help understand the differences in insecticide resistance, the activities and gene expression profiles of detoxification enzymes in B. tabaci B and Q were investigated.
The activity of P450 towards 7-ethoxycoumarin was significantly higher (1.46-fold higher) in Q than in B. The expression of 43 of 65 P450 genes was higher (>1-fold) in Q than in B, and expression for eight P450 genes was more than 50-fold greater in Q than in B. The increased expression of selected P450 genes in Q relative to B was confirmed with two other B strains and two other Q strains. On the other hand, carboxylesterase (CarE) activity was significantly lower (0.71-fold lower) in Q than in B; the Km value of CarE was significantly lower in B than in Q, but the opposite was true for the Vmax value of CarE. Glutathione S-transferase activity and values of Km and Vmax did not differ between B and Q.
Enhanced metabolic detoxification of insecticides by P450s may be an important reason why B. tabaci Q is more resistant than B. tabaci B to insecticides. © 2014 Society of Chemical Industry