Luminal proteinases from Plodia interpunctella and the hydrolysis of Bacillus thuringiensis CryIA(c) protoxin

Oppert, Brenda; Kramer, Karl J.; Johnson, D. E.; Upton, Steve J.; McGaughey, W. H.

doi:10.1016/s0965-1748(96)00013-6

Cited by 96 publications

(87 citation statements)

References 32 publications

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“…It has been reported in the case of the Mexican bean weevil (Zabrotes subfasciatus) that resistance to the AIs of common bean (Phaseolus vulgaris) follows a two-pronged strategy [68] -the insect adapted by synthesizing not only AI-resistant amylases, but also employed proteases that effectively degraded and inactivated the AI protein. In case of Bt, resistance to the toxin may arise due to the absence of protease isoforms that recognize the pro-toxin and convert it to the toxic form [69]. Indeed, varying levels of midgut proteases [70][71][72][73] have been linked to resistance/susceptibility to Bt.…”

Section: Proteases As Target In Insect Control Programsmentioning

confidence: 99%

Structural and functional diversities in lepidopteran serine proteases

Srinivasan

Giri

Gupta

2006

Cellular and Molecular Biology Letters

214

164

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Primary protein-digestion in Lepidopteran larvae relies on serine proteases like trypsin and chymotrypsin. Efforts toward the classification and characterization of digestive proteases have unraveled a considerable diversity in the specificity and mechanistic classes of gut proteases. Though the evolutionary significance of mutations that lead to structural diversity in serine proteases has been well characterized, detailing the resultant functional diversity has continually posed a challenge to researchers. Functional diversity can be correlated to the adaptation of insects to various host-plants as well as to exposure of insects to naturally occurring antagonistic biomolecules such as plant-derived protease inhibitors (PIs) and lectins. Current research is focused on deciphering the changes in protease specificities and activities arising from altered amino acids at the active site, specificity-determining pockets and other regions, which influence activity. Some insight has been gained through in silico modeling and simulation experiments, aided by the limited availability of characterized proteases. We examine the structurally and functionally diverse Lepidopteran serine proteases, and assess their influence on larval digestive processes and on overall insect physiology.

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Section: Proteases As Target In Insect Control Programsmentioning

confidence: 99%

Structural and functional diversities in lepidopteran serine proteases

Srinivasan

Giri

Gupta

2006

Cellular and Molecular Biology Letters

214

164

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“…However, despite the use of Bt endotoxins in transgenic crops covering Ͼ11.4 million hectares (2), the precise details of how endotoxins bind to gut cells to kill insects are poorly understood (3). This limitation impedes our understanding of potential mechanisms of insect resistance to Bt endotoxins other than the loss or modification of receptors (4,5), altered proteolysis of protoxin and͞or toxin (6,7), and repair and͞or replacement of damaged cells (8). Although few insect species have developed resistance in the field (3,9), genetic resistance to Bt-endotoxins has been selected in several species in the laboratory (3,10).…”

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confidence: 99%

Induction and transmission of Bacillus thuringiensis tolerance in the flour moth Ephestia kuehniella

Rahman

Roberts

Sarjan

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

157

120

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The use of Bacillus thuringiensis (Bt) endotoxins to control insect vectors of human diseases and agricultural pests is threatened by the possible evolution of resistance in major pest species. In addition to high levels of resistance produced by receptor insensitivity (5, 16, 17), several cases of tolerance to low to medium levels of toxin have been reported in laboratory colonies of lepidopteran species (3, 18). Because the molecular basis of some of these cases of tolerance to the toxin are not known, we explored alternative mechanisms. Here, we present evidence that tolerance to a Bt formulation in a laboratory colony of the flour moth Ephestia kuehniella can be induced by preexposure to a low concentration of the Bt formulation and that the tolerance correlates with an elevated immune response. The data also indicate that both immune induction and Bt tolerance can be transmitted to offspring by a maternal effect and that their magnitudes are determined by more than one gene.coagulation ͉ endotoxin tolerance ͉ immune induction ͉ maternal effect ͉ melanization

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“…All these enzymatic activities have already been characterized in P. interpunctella (Baker, 1986;Oppert et al, 1996).…”

Section: Discussionmentioning

confidence: 99%

Insecticidal effects of Moroccan plant extracts on development, energy reserves and enzymatic activities of Plodia interpunctella

Bouayad

Rharrabe

Ghailani

et al. 2012

Span. j. agric. res.

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The aim of this work was to study the effects of methanol extracts of ten plant species used in traditional medicine in Morocco (Peganum harmala, Ajuga iva, Rosmarinus officinalis, Lavandula stoechas, Lavandula dentata, Cistus ladanifer, Cistus salviaefolius, Cistus monspeliensis, Centaurium erythraea and Launaea arborescens) on Plodia interpunctella Hübner (Lepidoptera: Pyralidae) larvae. Firstly, we studied the effects of the ingestion of these extracts at 500 ppm on post-embryonic development parameters. Most plant extracts provoked a notable decrease of larval weight 8 days after treatment (up to 33% weight loss with C. erythraea) and caused significant alterations on pupation (ranging from 5% to 85%) and adult emergence (below 2.5% with R. officinalis, C. erythraea and A. iva). The plant extracts that showed strongest effects on post-embryonic development were selected to test their effects on the following physiological parameters: larval reserve substances (at 500 ppm); and midgut activities of hydrolytic and detoxification enzymes (at 500, 750 and 1000 ppm). All treatments provoked a significant reduction of protein and carbon hydrate larval contents, the inhibition of proteases and α-amylase activities in a dose depended manner, and the induction of glutathione S-transferase and esterase (using MtB as substrate) activities, whereas the activity of cytochrome P450 monooxygenases and esterases (using 1-NA as substrate) increase or decrease depending on the extract concentration and the plant analyzed.

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Luminal proteinases from Plodia interpunctella and the hydrolysis of Bacillus thuringiensis CryIA(c) protoxin

Cited by 96 publications

References 32 publications

Structural and functional diversities in lepidopteran serine proteases

Structural and functional diversities in lepidopteran serine proteases

Induction and transmission of Bacillus thuringiensis tolerance in the flour moth Ephestia kuehniella

Insecticidal effects of Moroccan plant extracts on development, energy reserves and enzymatic activities of Plodia interpunctella

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