Binding of Bacillus thuringiensis Cry1 Toxins to the Midgut Brush Border Membrane Vesicles of Chilo suppressalis (Lepidoptera: Pyralidae): Evidence of Shared Binding Sites

Fiúza, Lidia Mariana; Nielsen-LeRoux, Christina; Goze, E; Frutos, Roger; Charles, Jonathan R.

doi:10.1128/aem.62.5.1544-1549.1996

Cited by 41 publications

(30 citation statements)

References 23 publications

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“…Other studies have shown that Cry1Ab was more toxic than Cry1Ac to DBM (Tang et al 1996;Mohan and Gujar 2002;Kumar and Gujar 2005). Cry1Ac plus Cry2A were found to be a good combination for the control of lepidopteran species, because of the binding of produced proteins by these genes to different receptors in the insect midgut and being driven through different molecular mechanisms (Fiuza et al 1996;Lee et al 1997). In this research, the tested field populations were found to express higher resistance to crystal protein Cry1Ac than to Btk, and the resistance to Cry1Ac was 2.67-fold higher than that of Btk in Guangdong field population.…”

Section: Discussionmentioning

confidence: 71%

Monitoring of resistance for the diamondback moth to Bacillus thuringiensis Cry1Ac and Cry1Ba toxins and a Bt commercial formulation

Wang

Zhang

et al. 2007

J Applied Entomology

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To monitor the resistance of field populations of the diamondback moth Plutella xylostella in China to the insecticidal protein Cry1Ac, Cry1Ba and commercial formulation Bacillus thuringiensis var. kurstaki (Btk), six representative populations of the diamondback moth were collected from Shanghai, Shandong, Hubei, Hunan, Zhejiang and Guangdong provinces of China where crucifer crop plants are intensively planted. Bioassay results showed that the populations of the diamondback moth from different locations exhibited different levels of resistance, compared with a susceptible laboratory population. The Guangdong field population was 56.15-and 21.90-fold resistant to Cry1Ac and Btk, respectively. Shanghai, Hunan, Shandong and Zhejiang populations were 37.85-, 17.24-, 10.24-and 9.41-fold resistant to Cry1Ac, respectively, but were not resistant to Btk. The Hubei population did not show resistance to Cry1Ac and Btk. Almost all tested populations were susceptible to Cry1Ba, but the Guangdong population showed some tolerance to Cry1Ba with a LC 50 of 0.69 lg/ml which was 6.17-fold higher than that of the susceptible population. The results suggested that the complex resistance patterns of field populations of P. xylostella need to be considered for expression of Bt toxin genes in genetically-engineered crop plants and commercial formulations.

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Section: Discussionmentioning

confidence: 71%

Monitoring of resistance for the diamondback moth to Bacillus thuringiensis Cry1Ac and Cry1Ba toxins and a Bt commercial formulation

Wang

Zhang

et al. 2007

J Applied Entomology

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“…Our objective was to identify toxins that can be combined with Cry1Ab to produce two-toxin rice with durable resistance to SSB and YSB. Four of the five toxins used in our study (Cry1Ab, Cry1Ac, Cry1C, and Cry2A) have been shown to be toxic to YSB and SSB when administered in artificial diet and/or transgenic plants (Fiuza et al, 1996, Lee et al, 1997, Nayak et al, 1997, Cheng et al, 1998, Maqbool et al, 1998. We have determined that the fifth, Cry9C, is toxic when administered in artificial diet to SSB (this study) and YSB (R.M.A.…”

Section: Archives Of Insect Biochemistry and Physiologymentioning

confidence: 74%

“…Nayak et al (1997) used ligand blot analysis to characterize the number and molecular weight of midgut binding proteins for Cry1Ab and Cry1Ac in YSB. Competition binding was used by Fiuza et al (1996) to study the binding properties of Cry1Aa, Cry1Ac, and Cry1B in SSB; and by Lee et al (1997) to examine the binding properties of Cry1Aa, Cry1Ac, Cry1C, and Cry2A in SSB and YSB. In this report, we extend the competition binding studies to include Cry1Ab, the toxin that has been most widely used in rice transformation (e.g., Fujimoto et al, 1993;Ghareyazie et al, 1997;Alam et al, 1998;Cheng et al, 1998), and Cry9C, a toxin with a broad spectrum of activity against Lepidoptera (Lambert et al, 1996).…”

Section: Archives Of Insect Biochemistry and Physiologymentioning

confidence: 99%

Bacillus thuringiensis δ‐endotoxin binding to brush border membrane vesicles of rice stem borers

Alcantara

Aguda

Curtiss

et al. 2004

Arch Insect Biochem Physiol

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The receptor binding step in the molecular mode of action of five delta-endotoxins (Cry1Ab, Cry1Ac, Cry1C, Cry2A, and Cry9C) from Bacillus thuringiensis was examined to find toxins with different receptor sites in the midgut of the striped stem borer (SSB) Chilo suppressalis (Walker) and yellow stem borer (YSB) Scirpophaga incertulas (Walker) (Lepidoptera: Pyralidae). Homologous competition assays were used to estimate binding affinities (K(com)) of (125)I-labelled toxins to brush border membrane vesicles (BBMV). The SSB BBMV affinities in decreasing order was: Cry1Ab = Cry1Ac > Cry9C > Cry2A > Cry1C. In YSB, the order of decreasing affinities was: Cry1Ac > Cry1Ab > Cry9C = Cry2A > Cry1C. The number of binding sites (B(max)) estimated by homologous competition binding among the Cry toxins did not affect toxin binding affinity (K(com)) to both insect midgut BBMVs. Results of the heterologous competition binding assays suggest that Cry1Ab and Cry1Ac compete for the same binding sites in SSB and YSB. Other toxins bind with weak (Cry1C, Cry2A) or no affinity (Cry9C) to Cry1Ab and Cry1Ac binding sites in both species. Cry2A had the lowest toxicity to 10-day-old SSB and Cry1Ab and Cry1Ac were the most toxic. Taken together, the results of this study show that Cry1Ab or Cry1Ac could be combined with either Cry1C, Cry2A, or Cry9C for more durable resistance in transgenic rice. Cry1Ab should not be used together with Cry1Ac because a mutation in one receptor site could diminish binding of both toxins.

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“…The effect of the immune response on IRP/IRE binding activity in insects has only been demonstrated in A. gambiae where exposure to LPS increased binding activity in Sua1B cells. Of the two ferritin subunits characterized from A. aegypti, HCH has a 5 UTR IRE (Fiuza et al, 1996;Geiser et al, 2003) and because insect IRP/IRE binding activity in response to immune challenge has been examined in a singular insect (Zhang et al, 2002), translational regulation of ferritin by IRP during an immune response is difficult to predict, warranting further analysis.…”

Section: Introductionmentioning

confidence: 99%

The effect of bacterial challenge on ferritin regulation in the yellow fever mosquito, Aedes aegypti

et al. 2012

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Secreted ferritin is the major iron storage and transport protein in insects. Here we characterize the message and protein expression profiles of yellow fever mosquito (Aedes aegypti) ferritin heavy chain homologue (HCH) and light chain homologue (LCH) subunits in response to iron and bacterial challenge. In vivo experiments demonstrated tissue specific regulation of HCH and LCH expression over time post-blood meal (PBM). Transcriptional regulation of HCH and LCH was treatment specific, with differences in regulation for naïve versus mosquitoes challenged with heat-killed bacteria (HKB). Translational regulation by iron regulatory protein (IRP) binding activity for the iron responsive element (IRE) was tissue specific and time-dependent PBM. However, mosquitoes challenged with HKB showed little change in IRP/IRE binding activity compared to naïve animals. The changes in ferritin regulation and expression in vivo were confirmed with in vitro studies. We challenged mosquitoes with HKB followed by a blood meal to determine the effects on ferritin expression, and demonstrate a synergistic, time-dependent, regulation of expression for HCH and LCH.

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Binding of Bacillus thuringiensis Cry1 Toxins to the Midgut Brush Border Membrane Vesicles of Chilo suppressalis (Lepidoptera: Pyralidae): Evidence of Shared Binding Sites

Cited by 41 publications

References 23 publications

Monitoring of resistance for the diamondback moth to Bacillus thuringiensis Cry1Ac and Cry1Ba toxins and a Bt commercial formulation

Monitoring of resistance for the diamondback moth to Bacillus thuringiensis Cry1Ac and Cry1Ba toxins and a Bt commercial formulation

Bacillus thuringiensis δ‐endotoxin binding to brush border membrane vesicles of rice stem borers

The effect of bacterial challenge on ferritin regulation in the yellow fever mosquito, Aedes aegypti

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