Immunocytochemical analysis of specific binding of Bacillus thuringiensis insecticidal crystal proteins to lepidopteran and coleopteran mudgut membranes

Bravo, Alejandra; Hendrickx, Koen; Jansens, Stefan; Peferoen, M.

doi:10.1016/0022-2011(92)90005-o

Cited by 96 publications

(77 citation statements)

References 19 publications

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“…Various other works report the cellular changes produced in the midgut of larvae intoxicated with the Cry proteins of B. thuringiensis, such as: an increase in the volume of the epithelium cells, rupture of microvilosities, vacuolisation of the cytoplasm, changes in the organelles of the cytoplasm and cell hypertrophy (Griego et al, 1980;Mathavan et al, 1989;Bravo et al, 1992). Similar changes were observed in intoxications with Cry1Ac and Cry1D in S. frugiperda (Aranda et al, 1996), thus confirming the data reported in this study for the Cry1Ac protein synthesised by the B. thuringiensis kurstaki HD-73 isolate.…”

Section: Resultsmentioning

confidence: 99%

Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae)

Knaak

Franz²,

Santos

et al. 2010

Braz. J. Biol.

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Among the phytophagous insects which attack crops, the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae) is particularly harmful in the initial growth phase of rice plants. As a potential means of controlling this pest, and considering that the entomopathogen Bacillus thuringiensis Berliner demonstrates toxicity due to synthesis of the Cry protein, the present study was undertaken to evaluate this toxic effect of B. thuringiensis thuringiensis 407 (pH 408) and B. thuringiensis kurstaki HD-73 on S. frugiperda. The following method was used. Both bacterial strains were evaluated in vitro in 1 st instar S. frugiperda caterpillars, by means of histopathological assays. The Cry1Ab and Cry1Ac proteins, codified by the respective strains of B. thuringiensis, were evaluated in vivo by bioassays of 1 st instar S. frugiperda caterpillars in order to determine the Mean Lethal Concentration (LC 50 ). The results of the histopathological analysis of the midget of S. frugiperda caterpillars demonstrate that treatment with the B. thuringiensis thuringiensis strain was more efficient, because the degradations of the microvilosities started 9 hours after treatment application (HAT), while in the B. thuringiensis kurstaki the same effect was noticed only after 12 HAT. Toxicity data of the Cry1Ab and Cry1Ac proteins presented for the target-species LC 50 levels of 9.29 and 1.79 µg.cm , respectivamente. As cepas e proteínas sintetizadas por B. thuringiensis thuringiensis e B. thuringiensis kurstaki são eficientes no controle de S. frugiperda, e poderão ser usadas na produção de novos biopesticidas ou a utilização dos genes na transformação genética de Oryza sativa L. Histopatologia e efeito letal de cepas e proteínas Cry de Bacillus thuringiensis

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Section: Resultsmentioning

confidence: 99%

Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae)

Knaak

Franz²,

Santos

et al. 2010

Braz. J. Biol.

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“…Observations on binding of other B. thuringiensis ICPs CryIA(b), CryIA(c), CryIB and CryIIIA to lepidopteran and coleopteran midgut cells indicated that these 0-endotoxins bind in vitro to peritrophic membranes, but without any correlation with toxicity [12,13]; in contrast, the in vitro binding of these toxins to apical midgut microvilli correlated well with the susceptibility of the target insect to specific toxins [12]. In our study, no binding to the peritrophic membrane was observed, while the in vitro binding seems to be limited to some cellular types (especially the posterior stomach and the gastric caecae), except for CytA which also bind to the anterior stomach.…”

Section: Discussionmentioning

confidence: 99%

“…Indeed, it has been previously demonstrated that CrylVD and CytA were immunologically detected, both bound on apical microvilli of A. gambiae larval midgut cells, after in vivo intoxication with purified Bti crystals [11]. Other B. thuringiensis ICPs have also been shown to bind specifically, in vivo and in vitro, to midgut brush border membranes of Lepidoptera and Coleoptera larvae [12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

In vitro binding of Bacillus thuringiensis var. israelensis individual toxins to midgut cells of Anopheles gambiae larvae (Diptera: Culicidae)

Ravoahangimalala¹,

Charles²

1995

FEBS Letters

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“…These proteins, which are released with the endospore upon lysis of the sporangium, exhibit, after appropriate processing, specific toxicities to insects, many of which are economically important crop pests. The primary site of action of the insecticidal toxins of various subspecies of B. thuringiensis is the brush border membranes of the midgut epithelium of susceptible larvae of Lepidoptera, Coleoptera, and Diptera [1,2]. The nontoxic, parasporal, crystalline inclusions (protoxins) are solubilized after ingestion by larvae in the alkaline midgut (pH>10) and proteolytically activated into toxins by specific proteases [3].…”

Section: Bacillus Thuringiensis (Bt) As a Biological Pesticide/biopesmentioning

confidence: 99%

Fate and Effects in Soil of Cry Proteins from Bacillus thuringiensis: Influence of Physicochemical and Biological Characteristics of Soil

Saxena¹,

Pushalkar

Stotzky³

2013

TOTNJ

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Bacillus thuringiensis (Bt) is a useful alternative or supplement to synthetic chemical pesticides in agriculture, forest management, and control of mosquitoes and some other biting insects. When modified Bt cry genes are inserted into a plant species (e.g., corn, cotton, potato, canola, rice), the plant expresses active larvicidal proteins in its tissues. The toxins continue to be synthesized during growth of the plants, making the plant toxic to various insect pests throughout their life or as biomass incorporated into soil. If production exceeds consumption, inactivation, and degradation, the toxins could accumulate to concentrations that may enhance the control of target pests or constitute a hazard to nontarget organisms, such as the soil microbiota, beneficial insects (e.g., pollinators, predators and parasites of insect pests), and other animal classes. The accumulation and persistence of the toxins could also result in the selection and enrichment of toxin-resistant target insects. Persistence is enhanced when the toxins are bound on surface-active particles in the environment (e.g., clays and humic substances) and, thereby, rendered more resistant to biodegradation while retaining toxic activity. Moreover, major problem we face today is of "Molecular pharming" that utilizes transgenic plants and animals for production of pharmaceuticals and chemicals for their use in human beings and industries respectively. Their release to the environment, especially to soil and potentially to waters of the pharmaceutical and industrial products of transgenic plant and animal "pharms" could pose a hazard to the environment. In contrast to the products of most transgenic plants currently available commercially (e.g., the insecticidal proteins from subspecies of Bt) that primarily target insects and other pests. These "pharms" are being genetically engineered to express products for use primarily in human beings. Consequently, these products constitute a class of compounds that is seldom found in natural habitats and that primarily target "higher level" eukaryotes. Hence, they are xenobiotics with respect to the environment, and their persistence in and effects on the environment have not been adequately studied and sober risk assessments on a case-bycase basis must be made before major releases of such transgenic organisms.

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Immunocytochemical analysis of specific binding of Bacillus thuringiensis insecticidal crystal proteins to lepidopteran and coleopteran mudgut membranes

Cited by 96 publications

References 19 publications

Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae)

Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae)

In vitro binding of Bacillus thuringiensis var. israelensis individual toxins to midgut cells of Anopheles gambiae larvae (Diptera: Culicidae)

Fate and Effects in Soil of Cry Proteins from Bacillus thuringiensis: Influence of Physicochemical and Biological Characteristics of Soil

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