Purification and partial characterization of glutathione S‐transferase from insecticide‐resistant field populations of Liposcelis paeta Pearman (Psocoptera: Liposcelididae)

Abstract

Enzymes that possess glutathione S-transferase (GST) activity were purified to homogeneity by glutathione-agarose affinity chromatography from three field populations of Liposcelis paeta (Pearman). These populations were collected from Nanyang city of Henan Province (NY), Wuzhou (WZ) and Hezhou (HZ) cities of Guangxi Province, China, and had different susceptibilities to dichlorvos [LC(50)s of the NY (281.48 mg/m(2)), the WZ (285.07 mg/m(2)), and the HZ (243.52 mg/m(2)), respectively]. The specific activities of purified enzymes from these three populations increased 32.24-, 99.81-, and 42.52-fold, respectively. Kinetic analyses showed that the catalytic activity of purified GST from NY population towards GSH was much higher than the others, while WZ population reached the highest in V(max) (CDNB). SDS-polyacrylamide electrophoresis revealed that the purified GST had two subunits with a molecular mass of 23.31 and 20.43 kDa for NY, 53.14 and 20.13 kDa for WZ, and 50.79 and 19.42 kDa for HZ, respectively. The in vitro inhibition studies of GSTs indicated that three kinds of insecticides (chlorpyrifos, carbosulfan, and cypermethrin) and five metallic ions (Zn(2+), Ba(2+), Ca(2+), Hg(2+), Mn(2+), and Mg(2+)) all possessed inhibitory effects on purified GST, and ethacrynic acid (EA, a specific inhibitor of GST) expressed inhibitory effects. In the bioassay, three populations of L. paeta had different susceptibilities to different insecticides, even after they were reared on diets consisting of 25% EA. The GST activities of L. paeta from different areas also showed different temperature and pH stabilities. The differences in GST among the three populations may be attributed partially to the differences in control practices for psocids between Henan and Guangxi Provinces. (c) 2009 Wiley Periodicals, Inc.

De Novo Assembly, Gene Annotation, and Marker Discovery in Stored-Product Pest Liposcelis entomophila (Enderlein) Using Transcriptome Sequences

“…A total of 73 GSTs transcripts were identified from Nr annotation of L. entomophila transcriptomic sequences, and 37 putative GSTs genes were manually curated after removing short unigenes. The GSTs super-family members are proved to be involved in the resistance to phytotoxins and insecticide [49] . Insect GSTs can be divided into seven classes (Delta, Epsilon, Omega, Sigma, Theta, Zeta, and Microsomal), and Delta and Epsilon are two unique classes to insects and are thought to contribute to the environmental variation [10] .…”

Susceptibility and Activity of GlutathioneS-Transferases in Nine Field Populations ofPanonychus citri(Acari: Tetranychidae) to Pyridaben and Azocyclotin

“…Ethacrynic acid (EA) always presents a strong inhibitory effect on GSTs in many pests, i.e., Blattella germanica (L.) (Blattellidae) (Yu & Huang 2000), T. urticae (Konanz & Nauen 2004), and Liposcelis paeta (Pearman) (Liposcelididae) (Wu et al 2009). In our current study, azocyclotin had the greatest inhibitory effect on GSTs compared with EA and pyridaben, indicating that azocyclotin could be used as an effective pesticide synergist for the control of pesticide resistance caused Each value represents the mean (± SE).…”

A chromosome-level genome of the booklouse, Liposcelis brunnea, provides insight into louse evolution and environmental stress adaptation

“…A high level of resistance to phosphine has been observed in booklice, particularly during the egg stage, which significantly increases both the economic cost of treatments and environmental pollution [ 18 , 19 ]. Several gene families have been proven to be related to the high insecticide resistance of booklice, including esterases (ESTs) [ 20 ], glutathione S-transferase (GST) [ 21 ], and the cytochrome P450 monooxygenases (P450) [ 22 ]. These studies were mainly based on transcriptomic analyses and lacked whole-genome data.…”