Immunological assessment of an insecticide resistance-associated esterase in the Western corn rootworm

Abstract

In previous investigations, we have determined that organophosphate resistance in the western corn rootworm, Diabrotica virgifera virgifera, is at least partially attributed to a group of non-specific carboxylesterases referred to as group II. Antiserum raised against a purified 66-kDa group II esterase is specific for the denatured enzyme. This antiserum reacts similarly with both beetle homogenates from resistant and susceptible populations, although there is much higher signal intensity in immunoblots of resistant relative to susceptible beetles. These results suggest that overproduction of group II esterases is the underlying basis of esterase-mediated resistance in D. v. virgifera by demonstrating that (1) group II esterases are immunologically indistinguishable between the resistant and susceptible populations, and (2) the intensity differences are due to increased group II esterase proteins in the resistant population. The diagnostic potential of immunological-based assays was tested with a traditional diagnostic concentration bioassay and a biochemical-based native PAGE assay. Significant correlations were observed among all three diagnostic assays (regression coefficients ranging from 0.95 to 0.96). These results demonstrate the importance of the 66-kDa protein as a resistance-associated biochemical marker, thus emphasizing the potential for 66-kDa protein-targeted immunoassays in resistance monitoring programs. Arch. Insect Biochem. Physiol. 58:157-165, 2005.

Western corn rootworm and Bt maize

“…With the exception of S3, we visited these fields in response to notifications from caused the evolution of esterase-mediated resistance in some populations. 27,29 Cases of resistance by western corn rootworm to crop rotation and to conventional insecticides raise concerns about resistance to other management tactics including Bt maize.…”

Genetic Assessment of Traits and Genetic Relationship in Blackgram (Vigna mungo) Revealed by Isoenzymes

“…Enzyme activity was developed by adding 0.04% w/v Fast Blue BB salt (4-benzoylamino-2,5-diethoxybenzenediazonium chloride hemi [zinc chloride] salt) after 30-45 min of incubation at 37°C (Zhou et al 2005;Kim et al 2006). The stained gel was fixed in methanol, double-distilled water, and acetic acid (5:5:1) for 3 min and washed with tap water.…”

Quantitative trait locus mapping and functional genomics of an organophosphate resistance trait in the western corn rootworm, Diabrotica virgifera virgifera

“…Detoxification of carbamates is the major mechanism of resistance in D. v. virgifera, involving up-regulation of cytochrome P450 monoxygenase and general esterase activities (Scharf et al, 1999). Similarly, OP resistance in field populations from Phelps and York Counties, Nebraska, is correlated with increased cytosolic esterase activity (Zhou et al, 2002(Zhou et al, , 2003, and partly attributed to a single 66-kDa group II esterase purified from resistant individuals (Zhou et al, 2004(Zhou et al, , 2005. Assaying for mutations that cause resistance represents a novel tool that allows the tracking of changes in resistance allele frequencies in field populations (Riveron et al, 2014).…”