Detoxification enzymes of Bemisia tabaci B and Q: biochemical characteristics and gene expression profiles. Issue 10 (8th April 2014)

• Record Type: Journal Article
• Authors: Guo, Litao; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Li, Rumei; Yang, Nina; Yang, Xin; Pan, Huipeng; Zhang, Youjun
• Is Part Of: Pest management science. Volume 70:Issue 10(2014:Oct.)
• Page Start: 1588
• Page End: 1594
• Publication Date: 2014-04-08
• Subjects: Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.3751
• Languages: English
• ISSNs: 1526-498X

Abstract

<abstract abstract-type="main" id="ps3751-abs-0001"> <title>Abstract</title> <sec id="ps3751-sec-0001" sec-type="section"> <title>BACKGROUND</title> <p id="ps3751-para-0001">The sweetpotato whitefly, <italic>Bemisia tabaci</italic> (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 <italic>B. tabaci</italic> 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 <italic>B. tabaci</italic> 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 <italic>B. tabaci</italic> B and Q were investigated.</p> </sec> <sec id="ps3751-sec-0002" sec-type="section"> <title>RESULTS</title> <p id="ps3751-para-0002">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 <italic>K</italic><sub>m</sub> value of CarE was significantly lower in B than in Q, but the opposite was true for the <italic>V</italic><sub>max</sub> value of CarE. Glutathione <italic>S</italic>‐transferase activity and values of <italic>K</italic><sub>m</sub> and <italic>V</italic><sub>max</sub> did not differ between B and Q.</p> </sec> <sec id="ps3751-sec-0003" sec-type="section"> <title>CONCLUSION</title> <p id="ps3751-para-0003">Enhanced metabolic detoxification of insecticides by P450s may be an important reason why <italic>B. tabaci</italic> Q is more resistant than <italic>B. tabaci</italic> B to insecticides. © 2014 Society of Chemical Industry</p> </sec> </abstract>