| mortality of adult stomoxys calcitrans fed isolates of bacillus thuringiensis. | we examined the ability of five isolates of bacillus thuringiensis berliner to cause mortality in adult stable flies, stomoxys calcitrans (l.). isolates bacillus thuringiensis tolworthi 4l3 (serotype 9), bacillus thuringiensis darmstadiensis 4m1 (serotype 10a10b), bacillus thuringiensis thompsoni 401 (serotype 12), bacillus thuringiensis thuringiensis hd2 (serotype 1), and bacillus thuringiensis kurstaki hd945 (serotype 3a3b3c) were administered to adult flies in diets containing blood only, sug ... | 2012 | 23156187 |
| evaluation of corn hybrids expressing cry1f, cry1a.105, cry2ab2, cry34ab1/cry35ab1, and cry3bb1 against southern united states insect pests. | studies were conducted across the southern united states to characterize the efficacy of multiple bacillus thuringiensis (bt) events in a field corn, zea mays l., hybrid for control of common lepidopteran and coleopteran pests. cry1f protein in event tc1507 and cry1a.105 + cry2ab2 proteins in event mon 89034 were evaluated against pests infesting corn on above-ground plant tissue including foliage, stalks, and ears. cry34ab1/cry35ab1 proteins in event das-59122-7 and cry3bb1 in event mon 88017 w ... | 2012 | 23156183 |
| early season host plants of apolygus lucorum (heteroptera: miridae) in northern china. | apolygus lucorum (meyer-dür) (heteroptera: miridae) has become a severe pest of cotton and many other crops in northern china as a result of the widespread adoption of bacillus thuringiensis (berliner) cotton, with a corresponding reduction of broad-spectrum insecticide application in cotton fields. from the middle of april to middle june, a. lucorum feeds and develops on other host plants before dispersing to cotton fields. effective suppression of a. lucorum populations before they enter cotto ... | 2012 | 23156156 |
| effect of wolbachia on insecticide susceptibility in lines of aedes aegypti. | two stable infections of wolbachia pipientis, wmelpop and wmel, now established in aedes aegypti, are being used in a biocontrol program to suppress the transmission of dengue. any effects of wolbachia infection on insecticide resistance of mosquitoes may undermine the success of this program. bioassays of ae. aegypti were conducted to test for differences in response to insecticides between wolbachia infected (wmelpop, wmel) and uninfected lines. insecticides screened were bifenthrin, the pyret ... | 2013 | 23149015 |
| withdrawn: effects of oral administration of bacillus thuringiensis as spore-crystal strains cry1aa, cry1ab, cry1ac or cry2aa on hematologic and genotoxic endpoints of swiss albino mice. | this article has been withdrawn at the request of the author(s) and/or editor. the publisher apologizes for any inconvenience this may cause. the full elsevier policy on article withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy. | 2012 | 23146696 |
| dna-based diagnostics for genetically modified cotton: decaplex pcr assay to differentiate mon531 and mon15985 bt cotton events. | the adoption rate and global area under cultivation of genetically modified (gm) crops is dramatically increasing in recent past. gm cotton has occupied 25.0 million hectares (mha) comprising 15.6% of the global area under gm cultivation. bt cotton, expressing delta-endotoxins from bacillus thuringiensis (bt), is the only commercialized crop in india that is planted on an area of 10.6 mha. with the increase in development and commercialization of gm crops, it is necessary to develop appropriate ... | 2013 | 23143489 |
| cis-acting motifs in artificially synthesized expression cassette leads to enhanced transgene expression in tomato (solanum lycopersicum l.). | efficacy of artificial synthetic expression modules was compared with native camv35s and decamv35s promoter in transgenic tomato developed by agrobacterium-mediated transformation. the promoters under trial were camv35s-mec (pcami), camv35s (pcamii), decamv35s (pcamiii), synthetic minimal expression cassette (pmec), complete expression cassette (pcec), double enhancer expression cassette (pdec) and triple enhancer expression cassette (ptec) for driving the uida gene for β-glucuronidase (gus) act ... | 2012 | 23137727 |
| evaluation of a commercial bacillus thuringiensis var. israelensis formulation for the control of chironomid midge larvae (diptera: chironomidae) in establishing rice crops in south-eastern australia. | a commercial formulation of bacillus thuringiensis var. israelensis (b.t.i.) was evaluated for its potential to control chironomid midge larvae in newly sown rice crops in south-eastern australia. two replicated small-plot field trials were conducted using product application rates of 0.5-6 kg/ha. in trial 1 application rates between 2 and 6 kg product/ha all significantly (p<0.05) reduced populations of target chironominae/orthocladiinae by between 71% and 93% over the 19 day post-treatment mon ... | 2013 | 23131719 |
| construction and characterisation of an antifungal recombinant bacillus thuringiensis with an expanded host spectrum. | a novel antifungal bacillus thuringiensis strain 19-22, ssp. kurstaki (h3a3b3c), was characterised. this strain included cry1aa, cry1ab, cry1ac, and cry1d, which have high insecticidal activities against lepidopteran larvae other than spodoptera exigua. to expand the host spectrum, a cry1e gene whose product is active against s. exigua was introduced into the isolate. the transformant successfully expressed the cry1e protein without any loss of its original antifungal activities. these results i ... | 2012 | 23124760 |
| bacillus thuringiensis metalloproteinase bmp1 functions as a nematicidal virulence factor. | some bacillus thuringiensis strains have high toxicity to nematodes. nematicidal activity has been found in several families of crystal proteins, such as cry5, cry6, and cry55. the b. thuringiensis strain ybt-1518 has three cry genes that have high nematicidal activity. the whole genome sequence of this strain contains multiple potential virulence factors. to evaluate the pathogenic potential of virulence factors, we focused on a metalloproteinase called bmp1. it encompasses a consecutive n-term ... | 2013 | 23124228 |
| homology modeling of mosquitocidal cry30ca2 of bacillus thuringiensis and its molecular docking with n-acetylgalactosamine. | to investigate the theoretical model of the three-dimensional structure of mosquitocidal cry30ca2 and its molecular docking with n-acetylgalactosamine. | 2012 | 23122318 |
| [isolation of bacillus thuringiensis imv b-7324 fibrinolytic peptidase]. | fibrinolytic peptidase of bacillus thuringiensis imv b-7324 was isolated by ammonium sulfate fractionation, gel-filtration and ion exchange chromatography on tsk-gels--toyopearl hw-55 and deae 650 (m). fibrinolytic activity of the purified enzyme was 87.9 u/mg of protein that was 19.9 times higher compared with the supernatant cultural liquid, the yield on its activity reached 31%. the gel-filtration on sepharose 6b and by sds-page electrophoresis demonstrated the homogeneity of the purified fib ... | 2013 | 23120980 |
| synthesis of bioactive microcapsules using a microfluidic device. | bioactive microcapsules containing bacillus thuringiensis (bt) spores were generated by a combination of a hydro gel, microfluidic device and chemical polymerization method. as a proof-of-principle, we used bt spores displaying enhanced green fluorescent protein (egfp) on the spore surface to spatially direct the egfp-presenting spores within microcapsules. bt spore-encapsulated microdroplets of uniform size and shape are prepared through a flow-focusing method in a microfluidic device and conve ... | 2012 | 23112592 |
| effects of cry34/35ab1 corn on the survival and development of western corn rootworm, diabrotica virgifera virgifera. | the western corn rootworm, diabrotica virgifera virgifera leconte, is a major agricultural pest that is managed with transgenic corn, zea mays l., expressing genes from bacillus thuringiensis berliner (bt). the effects of bt corn producing cry34/35ab1 (event das-59122-7) and entomopathogens on the survival and development of larval d. v. virgifera were examined in laboratory, field and greenhouse experiments. | 2013 | 23109348 |
| bacillus thuringiensis cry1a toxin-binding glycoconjugates present on the brush border membrane and in the peritrophic membrane of the douglas-fir tussock moth are peritrophins. | bacillus thuringiensis (bt) cry1a toxin-binding sites in the douglas fir tussock moth (dftm) larval gut were localized using immunofluorescence microscopy. cry1aa, cry1ab and cry1ac all bound strongly to the dftm peritrophic membrane (pm); weaker binding of the cry1a toxins was observed along the apical brush border of the midgut epithelium. comparative analysis of the cry1a toxin-binding molecules in the pm and brush border membrane vesicles (bbmvs) showed that a similar toxin-binding complex w ... | 2013 | 23108174 |
| transgenerational effects of feeding genetically modified maize to nulliparous sows and offspring on offspring growth and health. | this study assessed the effect of feeding genetically modified maize expressing a truncated form of the cry1ab protein from bacillus thuringiensis (bt mon810 maize) to sows during gestation and lactation and their offspring from weaning to 115 d postweaning on offspring growth and health. after weaning at approximately 28 d of age (d 0), individually penned, mixed sex pigs (approximately 8 kg bw) from sows fed isogenic or bt maize diets were blocked by sow treatment, sex, and bw and randomly ass ... | 2013 | 23097397 |
| spray application of bacillus thuringiensis israelensis (bti strain am65-52) against aedes aegypti (l.) and ae. albopictus skuse populations and impact on dengue transmission in a dengue endemic residential site in malaysia. | a one year study was conducted to evaluate the impact of spray application of bacillus thuringiensis israelensis (bti), strain am65-52 on vector populations and dengue transmission in a dengue endemic state in malaysia. residential sites with similar populations of aedes aegypti (l.) and aedes albopictus skuse were studied. one site was treated with spray application of bti into all outdoor target vector habitats, which consisted of natural and artificial containers. the other site was not treat ... | 2012 | 23082582 |
| neurobactrus, a novel, highly effective, and environmentally friendly recombinant baculovirus insecticide. | a novel recombinant baculovirus, neurobactrus, was constructed to develop an improved baculovirus insecticide with additional beneficial properties, such as a higher insecticidal activity and improved recovery, compared to wild-type baculovirus. for the construction of neurobactrus, the bacillus thuringiensis crystal protein gene (here termed cry1-5) was introduced into the autographa californica nucleopolyhedrovirus (acmnpv) genome by fusion of the polyhedrin-cry1-5-polyhedrin genes under the c ... | 2013 | 23064343 |
| risk assessment of cry toxins of bacillus thuringiensis on the predatory mites euseius concordis and neoseiulus californicus (acari: phytoseiidae). | genetically modified plants carrying cry toxins of bacillus thuringiensis (bt) are widely used for pest control. possible adverse effects as a result of the use of this control technique to non-target organisms is still a concern; however, few studies have addressed the effects of bt crops on phytoseiid predatory mites. phytoseiids are important for the natural control of phytophagous mites, but they can also feed on pollen, plant exudates, etc. thus, phytoseiids may ingest bt toxins through sev ... | 2013 | 23053912 |
| a new gene superfamily of pathogen-response (repat) genes in lepidoptera: classification and expression analysis. | repat (response to pathogens) genes were first identified in the midgut of spodoptera exigua (lepidoptera: noctuidae) in response to bacillus thuringiensis and baculovirus exposure. since then, additional repat gene homologs have been identified in different studies. in this study the comprehensive larval transcriptome from s. exigua was analyzed for the presence of novel repat-homolog sequences. these analyses revealed the presence of at least 46 repat genes in s. exigua, establishing a new gen ... | 2013 | 23036664 |
| system wide analysis of the evolution of innate immunity in the nematode model species caenorhabditis elegans and pristionchus pacificus. | the evolution of genetic mechanisms used to combat bacterial infections is critical for the survival of animals and plants, yet how these genes evolved to produce a robust defense system is poorly understood. studies of the nematode caenorhabditis elegans have uncovered a plethora of genetic regulators and effectors responsible for surviving pathogens. however, comparative studies utilizing other free-living nematodes and therefore providing an insight into the evolution of innate immunity have ... | 2012 | 23028509 |
| ph-controlled bacillus thuringiensis cry1ac protoxin loading and release from polyelectrolyte microcapsules. | crystal proteins synthesized by bacillus thuringiensis (bt) have been used as biopesticides because of their toxicity to the insect larval hosts. to protect the proteins from environmental stress to extend their activity, we have developed a new microcapsule formulation. poly (acrylic acid) (pah) and poly (styrene sulfonate) (pss) were fabricated through layer-by-layer self-assembly based on a caco(3) core. cry1ac protoxins were loaded into microcapsules through layer-by-layer self-assembly at l ... | 2012 | 23024810 |
| capillary electrophoretic profiling of tryptic digests of water soluble proteins from bacillus thuringiensis-transgenic and non-transgenic maize species. | capillary zone electrophoresis (cze) has been applied to separation and characterisation of enzymatic (tryptic) hydrolysates of water-soluble proteins from bacillus thuringiensis (bt)-transgenic (aristis-bt) and two native non-transgenic (aristis and coventry) maize varieties. water-soluble proteins were extracted from the flour of these maize species and digested by bovine pancreatic trypsin immobilised on agarose gel in 100 mm ammonium hydrocarbonate buffer, ph 7.9. the yielded tryptic digests ... | 2012 | 25005989 |
| detection and tracking of a novel genetically tagged biological simulant in the environment. | a variant of bacillus thuringiensis subsp. kurstaki containing a single, stable copy of a uniquely amplifiable dna oligomer integrated into the genome for tracking the fate of biological agents in the environment was developed. the use of genetically tagged spores overcomes the ambiguity of discerning the test material from pre-existing environmental microflora or from previously released background material. in this study, we demonstrate the utility of the genetically "barcoded" simulant in a c ... | 2012 | 23001670 |
| microbial ecology and association of bacillus thuringiensis in chicken feces originating from feed. | to explain the association of bacillus thuringiensis (bt) with animal feces, an ecological analysis in chickens was conducted by introducing a cry(-) strain marked by production of green fluorescent protein (gfp). after feeding with the tagged bt strains, the feces of the tested chickens were collected at different times, isolated, and the morphology of bt was observed. it was shown that bt strain hd-73gfp in spore form could be isolated from feces of chickens for a period of 13 d, and then it d ... | 2012 | 22986821 |
| microbial control of the cotton leafworm spodoptera littoralis (boisd.) by egyptian bacillus thuringiensis isolates. | four local bacillus thuringiensis (bt) isolates that had been serologically identified as bt var. kurstaki (btk2, btk3, and btk66) and bt var. mexicanensis (btm27), in addition to two reference strains (4d20 and 4ac1), were laboratory assayed as microbial control agents against the egyptian cotton leafworm spodoptera littoralis (boisd.). polymerase chain reaction (pcr) amplification analysis revealed that each of the six experimental strains carries, at least, a cry1 type gene which expresses a ... | 2013 | 22983675 |
| isolation of single chain variable fragment (scfv) specific for cry1c toxin from human single fold scfv libraries. | as bioinsecticides bacillus thuringiensis cry1c δ-endotoxins also have been used in genetically modified crops worldwide since last century. in this study, single chain variable fragments (scfvs), which could specifically recognize and detect cry1c in food samples, were isolated from naive phage displayed human antibody libraries (tomlinson i + j) by iterative affinity selection procedure instead of immunization process. with increasing selection pressure, after four rounds of panning, three ind ... | 2012 | 22982116 |
| development of dipsticks for simultaneous detection of vip3a and cry1ab/cry1ac transgenic proteins. | the number of genetically modified (gm) crops being cultivated and its produce reaching market is increasing every year. the transgenes (vip3a, cry1ab, and cry1ac) from bacillus thuringiensis are being used by plant breeders, apart from other transgenes for developing insect pest-resistant gm crops. it is therefore necessary to develop an easy, rapid, and reliable detection assay to discriminate gm crops and non-gm crops. dipstick strips using colloidal gold-labeled polyclonal antibodies were de ... | 2012 | 22970582 |
| qualitative analysis of the fluorophosphonate-based chemical probes using the serine hydrolases from mouse liver and poly-3-hydroxybutyrate depolymerase (phaz) from bacillus thuringiensis. | the serine hydrolase family consists of more than 200 members and is one of the largest enzyme families in the human genome. although up to 50 % of this family remains unannotated, there are increasing evidences that activities of certain serine hydrolases are associated with diseases like cancer neoplasia, invasiveness, etc. by now, several activity-based chemical probes have been developed and are applied to profile the global activity of serine hydrolases in diverse proteomes. in this study, ... | 2012 | 22941070 |
| mathematical relationships between spore concentrations, delta-endotoxin levels, and entomotoxicity of bacillus thuringiensis preparations produced in different fermentation media. | mathematic relationships between spore concentrations, delta-endotoxin concentrations and entomotoxicity (tx) of bacillus thuringiensis var. kurstaki hd-1 (btk hd-1) preparations produced in six different media were analysed. the relationship between delta-endotoxin and spore concentration and sptx-spore (specific tx per 1000 spore) and spore concentration produced in the different media (starch industry wastewater (siw) with total solids (ts) concentration of 15g/l, siw with ts of 30g/l, siw su ... | 2012 | 22940334 |
| observations on house fly larvae midgut ultrastructure after brevibacillus laterosporus ingestion. | the pathological and histopathological course caused by brevibacillus laterosporus on house fly larvae has been investigated conducting observations on insect behavior and midgut ultrastructure. after dissection and fixation, gut tissues were analyzed under transmission electron microscopy (tem) in order to compare in vivo-treated and non-treated (control) fly specimens. treated larvae showed extensively reduced feeding and growth rate, then became sluggish and died within 72 h. a progressive mi ... | 2012 | 22935249 |
| adaptation by western corn rootworm (coleoptera: chrysomelidae) to bt maize: inheritance, fitness costs, and feeding preference. | we examined inheritance of resistance, feeding behavior, and fitness costs for a laboratory-selected strain of western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), with resistance to maize (zea maize l.) producing the bacillus thuringiensis berliner (bt) toxin cry3bb1. the resistant strain developed faster and had increased survival on bt maize relative to a susceptible strain. results from reciprocal crosses of the resistant and susceptible strains indicate ... | 2012 | 22928323 |
| western corn rootworm larval movement in smartstax seed blend scenarios. | insect resistance management (irm) can extend the lifetime of management options, but depends on extensive knowledge of the biology of the pest species involved for an optimal plan. recently, the environmental protection agency (epa) registered seed blends refuge for two of the transgenic bacillus thuringiensis (bt) corn products targeting the western corn rootworm, diabrotica virgifera virgifera leconte. larval movement between bt and isoline plants can be detrimental to resistance management f ... | 2012 | 22928304 |
| dispersal behavior of neonate european corn borer (lepidoptera: crambidae) on bt corn. | european corn borer, ostrinia nubilalis (hübner) (lepidoptera: crambidae), has historically been a significant economically important insect pest of corn (zea mays l.) in the united states and canada. the development in the 1990s of genetically modified corn expressing genes derived from bacillus thuringiensis (bt) that encodes insecticidal crystalline (cry) proteins has proven to be effective in controlling this insect as well as other corn pests. the purpose of this study was to assess the mov ... | 2012 | 22928300 |
| the utility of camptothecin as a synergist of bacillus thuringiensis var. kurstaki and nucleopolyhedroviruses against trichoplusia ni and spodoptera exigua. | we studied the effect of combining microbial pesticides with camptothecin (cpt) on the mortality of two lepidopteran insects: trichoplusia ni (hübner) and spodoptera exigua (hübner). cpt is an alkaloid that is often used as an anticancer agent. here, cpt was evaluated as a microbial pesticide synergist of bacillus thuringiensis (bt) and insect baculovirus. the toxicity of cpt and its synergistic effects on two microbial pesticides were studied using the diet overlay method. bioassay results show ... | 2012 | 22928294 |
| acute toxicities and sublethal effects of some conventional insecticides on trichogramma chilonis (hymenoptera: trichogrammatidae). | the acute toxicity of 10 conventional insecticides to adult of trichogramma chilonis ishii (hymenoptera: trichogrammatidae) was bioassayed by membrane method, and then their sublethal effects on the parasitoid were evaluated in the laboratory. based on sublethal concentration (lc30) values at 8 h after treatment, we determined that adult t. chilonis were the most susceptible to chlorfenapyr, followed by fipronil, spinosad, avermectins, beta-cypermethrin, and cartap, with lethal concentration (lc ... | 2012 | 22928293 |
| screening and identification of a bacillus thuringiensis strain s1/4 with large and efficient insecticidal activities. | the bacterium bacillus thuringiensis was recognized for its entomopathogenic activities related to cry and cyt proteins forming the δ-endotoxins and some extracellular activities like the vegetative insecticidal proteins (vip) and cry1i. these activities may act specifically against diverse organisms and some of them typically characterize each strain. here, we screened a set of 212 b. thuringiensis strains to search the higher insecticidal activities. these strains had bipyramidal and cubic cry ... | 2013 | 22915162 |
| inheritance, stability, and dominance of cry resistance in culex quinquefasciatus (diptera: culicidae) selected with the three cry toxins of bacillus thuringiensis subsp. israelensis. | mendelian crosses were used to study the mode of inheritance of cry toxin resistance in a culex quinquefasciatus say (diptera: culicidae) colony (cqab11a) that evolved insecticide resistance under laboratory selection with a deletion mutant of bacillus thuringiensis subsp. israelensis de barjac lacking the cyt1aa toxin component but containing its three major cry toxins, cry4aa, cry4ba, and cry11aa. high levels of resistance were observed to cry toxins. f1 offspring of reciprocal crosses to a se ... | 2012 | 22897049 |
| the lack of effect of low temperature and high turbidity on operational bacillus thuringiensis subsp. israelensis activity against larval black flies (diptera: simuliidae). | black fly suppression programs are conducted across a wide range of environmental conditions, targeting a variety of pest species with diverse life histories. operational applications of vectobac 12as (bacillus thuringiensis subsp. israelensis) were conducted during times characterized by water temperature and turbidity extremes. applications were conducted in the yellow river in central wisconsin targeting simulium annulus and s. johannseni when water temperatures were 1-2 degrees c. applicatio ... | 2012 | 22894128 |
| heliothis virescens and bt cotton in the united states. | the tobacco budworm (tbw), heliothis virescens (f.), has been responsible for substantial economic losses, environmental pollution and a great challenge to the united states' economy, environment, researchers and cotton and tobacco producers during most of the past two hundred years. if a historical description of this pest problem should be written, it would necessarily be divided into two main events; the pre- and post-bacillus thuringiensis-expressing (bt)-cotton era. before the advent of bt- ... | 2014 | 22892654 |
| deltamethrin-induced genotoxicity and testicular injury in rats: comparison with biopesticide. | deltamethrin is a synthetic pyrethroid insecticide used extensively in pest control. aim of the current study was to investigate the ability of deltamethrin-based commercial formulation to induce genotoxicity and testicular injury in rats in comparison to the use of the biopesticide; bacillus thuringiensis. rats were divided into three groups: group i (del) received deltamethrin, 5 mg/kgb.w./day orally, in corn oil. group ii (biopesticide, b. thuringiensis) received oral suspension of the biopes ... | 2012 | 22889898 |
| testing potential effects of maize expressing the bacillus thuringiensis cry1ab endotoxin (bt maize) on mycorrhizal fungal communities via dna- and rna-based pyrosequencing and molecular fingerprinting. | the cultivation of genetically modified (gm) crops has increased significantly over the last decades. however, concerns have been raised that some gm traits may negatively affect beneficial soil biota, such as arbuscular mycorrhizal fungi (amf), potentially leading to alterations in soil functioning. here, we test two maize varieties expressing the bacillus thuringiensis cry1ab endotoxin (bt maize) for their effects on soil am fungal communities. we target both fungal dna and rna, which is new f ... | 2012 | 22885748 |
| functional significance of membrane associated proteolysis in the toxicity of bacillus thuringiensis cry3aa toxin against colorado potato beetle. | bacillus thuringiensis cry toxins are widely used as biocontrol agents in bioinsecticides and transgenic plants. in the three domain-cry toxins, domain ii has been identified as an important determinant of their highly specific activity against insects. in this work, we assessed the role in membrane associated proteolysis and toxicity in colorado potato beetle (cpb) of a previously reported adam recognition motif present in cry3aa toxin domain ii. we used site-directed mutagenesis to modify the ... | 2012 | 22884605 |
| cytolytic peptide fragments of cyt1aa from bacillus thuringiensis subsp. israelensis. | cyt1aa is the major and most active component of the parasporal crystal of the gram-positive soil entomopathogenic bacterium bacillus thuringiensis subsp. israelensis. the cyt1aa protoxin exhibits some hemolytic and cytolytic activity. however, highly active 22-25 kda toxins are obtained after proteolysis of cyt1aa from both the n- and the c-termini. as shown in this study, preliminary binding of the protoxin to polylamellary liposomes or partial denaturation of cyt1aa and further processing by ... | 2013 | 22875467 |
| ser-substituted mutations of cys residues in bacillus thuringiensis vip3aa7 exert a negative effect on its insecticidal activity. | vegetative insecticidal proteins (vips), which were produced by bacillus thuringiensis during its vegetative growth stage, display a broad insecticidal spectrum to lepidoptera larvae. sequence alignment of the vip3a-type indicates that three cysteine residues were conserved in vip3a-type proteins. to determine whether these conserved cysteine residues contributed to the insecticidal activity, the three residues were respectively substituted with serine in the vip3aa7 protein by site-directed mut ... | 2012 | 22875104 |
| improvement of crystal solubility and increasing toxicity against caenorhabditis elegans by asparagine substitution in block 3 of bacillus thuringiensis crystal protein cry5ba. | the crystal proteins from bacillus thuringiensis are widely used for their specific toxicity against insects and nematodes. the highly conserved sequence blocks play an important role in cry protein stability and flexibility, the basis of toxicity. the block 3 in cry5ba subfamily has a shorter sequence (only 12 residues) and more asparagine residues than that of others which harbor about 48 residues but only one asparagine. based on the theoretical structure model of cry5ba, all three asparagine ... | 2012 | 22865071 |
| vip3c, a novel class of vegetative insecticidal proteins from bacillus thuringiensis. | three vip3 genes were identified in two bacillus thuringiensis spanish collections. sequence analysis revealed a novel vip3 protein class (vip3c). preliminary bioassays of larvae from 10 different lepidopteran species indicated that vip3ca3 caused more than 70% mortality in four species after 10 days at 4 μg/cm(2). | 2012 | 22865065 |
| the halo effect: suppression of pink bollworm on non-bt cotton by bt cotton in china. | in some previously reported cases, transgenic crops producing insecticidal proteins from bacillus thuringiensis (bt) have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce bt toxins. here we used 16 years of field data to determine if bt cotton caused this "halo effect" against pink bollworm (pectinophora gossypiella) in six provinces of the yangtze river valley of china. in this region, the percentage of cotton hectares pl ... | 2012 | 22848685 |
| production of the 14c-labeled insecticidal protein cry1ab for soil metabolic studies using a recombinant escherichia coli in small-scale batch fermentations. | insecticidal cry proteins naturally produced by bacillus thuringiensis are a major recombinant trait expressed by genetically modified crops. they are released into the soil during and after cropping. the objective of this study was to produce (14)c-labeled cry1ab proteins for soil metabolic studies in scope of their environmental risk assessment. cry1ab was synthesized as a protoxin by escherichia coli hb101 pmp in 200-ml liquid batch culture fermentations and purified from inclusion bodies aft ... | 2012 | 22846901 |
| identification of a calmodulin-binding site within the domain i of bacillus thuringiensis cry3aa toxin. | bacillus thuringiensis cry3aa toxin is a coleopteran specific toxin highly active against colorado potato beetle (cpb).we have recently shown that cry3aa toxin is proteolytically cleaved by cpb midgut membrane associated metalloproteases and that this cleavage is inhibited by adam metalloprotease inhibitors. in the present study, we investigated whether the cry3aa toxin is a calmodulin (cam) binding protein, as it is the case of several different adam shedding substrates. in pull-down assays usi ... | 2012 | 22836907 |
| isolation and molecular characterisation of alkaline protease producing bacillus thuringiensis. | proteases are of particular interest because of their action on insoluble keratin substrates and generally on a broad range of protein substrates. proteases are one of the most important groups of industrial enzymes used in detergent, protein, brewing, meat, photographic, leather, dairy, pharmaceutical and food industry. in the present study, the organism isolated from the protein rich soil sample was identified by biochemical and molecular characterisation as bacillus thuringiensis and further ... | 2013 | 22826099 |
| novel bacteriophages containing a genome of another bacteriophage within their genomes. | a novel bacteriophage infecting staphylococus pasteuri was isolated during a screen for phages in antarctic soils. the phage named spaa1 is morphologically similar to phages of the family siphoviridae. the 42,784 bp genome of spaa1 is a linear, double-stranded dna molecule with 3' protruding cohesive ends. the spaa1 genome encompasses 63 predicted protein-coding genes which cluster within three regions of the genome, each of apparently different origin, in a mosaic pattern. in two of these regio ... | 2012 | 22815791 |
| effects of entomopathogenic nematodes on evolution of pink bollworm resistance to bacillus thuringiensis toxin cry1ac. | the evolution of resistance by pests can reduce the efficacy of transgenic crops that produce insecticidal toxins from bacillus thuringiensis (bt). however, fitness costs may act to delay pest resistance to bt toxins. meta-analysis of results from four previous studies revealed that the entomopathogenic nematode steinernema riobrave (rhabditida: steinernematidae) imposed a 20% fitness cost for larvae of pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), that were homo ... | 2012 | 22812141 |
| effect of temperature on the fitness of a vip3a resistant population of heliothis virescens (lepidoptera: noctuidae). | microbial insecticides derived from the soil bacterium bacillus thuringiensis (bt) have become increasingly important for pest management. in addition to crystal (cry) insecticidal protein toxins formed during sporulation, vegetative insecticidal protein (vip) toxins can be produced during the vegetative phase. resistance to cry toxins has been reported in laboratory- and field-selected populations of various lepidoptera species and several studies have identified fitness costs associated with c ... | 2012 | 22812137 |
| delaying corn rootworm resistance to bt corn. | transgenic crops producing bacillus thuringiensis (bt) toxins for insect control have been successful, but their efficacy is reduced when pests evolve resistance. to delay pest resistance to bt crops, the u.s. environmental protection agency (epa) has required refuges of host plants that do not produce bt toxins to promote survival of susceptible pests. such refuges are expected to be most effective if the bt plants deliver a dose of toxin high enough to kill nearly all hybrid progeny produced b ... | 2012 | 22812111 |
| evaluation of rhizospheric pseudomonas and bacillus as biocontrol tool for xanthomonas campestris pv campestris. | xanthomonas campestris pv campestris (xcc), causing black rot, is one of the most yield-limiting and destructive pathogens of cruciferous crops. the intention of this study was to evaluate the potential of rhizobacteria in black rot management. fifty-four isolates from rhizosphere soil of brassica campestris were screened against xcc. two isolates namely, ka19 and se, with inhibition radius >11 mm were selected. the combined use of them produced an average inhibition zone of 18.1 ± 1.4 mm radius ... | 2012 | 22806865 |
| preliminary comparing the toxicities of the hybrid cry1acs fused with different heterogenous genes provided guidance for the fusion expression of cry proteins. | in order to provide guidance for selecting suitable heterogenous gene that can efficiently enhance toxicity or broaden insecticidal spectrum of cry1ac through fusion expression, two hybrid cry1acs fused with chitinase-encoding gene tchib and neurotoxin gene hwtx-1 respectively were constructed and their toxicities were compared. a bacillus thuringiensis strain harboring the cry1ac gene in vector pht315 was used as control. bioassay revealed that lc(50) (after 72 h) of cry1ac protoxin was 41.01 μ ... | 2012 | 22806817 |
| impact of transgenic cotton varieties on activity of enzymes in their rhizosphere. | the impact of five bacillus thuringiensis (bt) cotton varieties and their respective isogenic non-bt(nbt) isolines (ankur-2534, mech-6304, rch-317, ankur-651 and mech-6301) was assessed on the key soil enzymes i.e., dehydrogenase, alkaline phosphatase and urease in their rhizosphere at four growth stages of the crop, namely vegetative, flowering, bolling and harvesting. these varieties were grown on farmer's field in villages 22 miles and 24 miles of ganganagar district of rajasthan state in ind ... | 2012 | 22803335 |
| effects of two varieties of bacillus thuringiensis maize on the biology of plodia interpunctella. | on the market since 1996, genetically modified plants expressing an insecticidal toxin (cry toxin stemmed from bacillus thuringiensis) target several lepidopteran and coleopteran pests. in this study, we assessed the impact of two varieties of bt maize producing different toxins (cry1ab or cry1fa, respectively) on the biology of a storage pest: plodia interpunctella (hübner) (lepidoptera: pyralidae). the indianmeal moths were susceptible to both toxins but showed an escape behavior only from cry ... | 2012 | 22778907 |
| lack of cry1fa binding to the midgut brush border membrane in a resistant colony of plutella xylostella moths with a mutation in the abcc2 locus. | previous studies reported "mode 1" bacillus thuringiensis resistance in a colony of diamondback moths (no-qa), and recently, this resistance has been mapped to an abc transporter (abcc2) locus. we report the lack of binding of cry1fa to insects derived from this colony and compare our data with those from other insects with abcc2-associated resistance. | 2012 | 22773634 |
| weak transcription of the cry1ac gene in nonsporulating bacillus thuringiensis cells. | the cry1ac gene of bacillus thuringiensis subsp. kurstaki hd-73 (b. thuringiensis hd-73) is a typical example of a sporulation-dependent crystal gene and is controlled by sigma e and sigma k during sporulation. to monitor the production and accumulation of cry1ac at the cellular level, we developed a green fluorescent protein-based reporter system. the production of cry1ac was monitored in spo0a, sige, and sigk mutants, and these mutants were able to express the cry1ac-green fluorescent protein ... | 2012 | 22773626 |
| alteration of leaf metabolism in bt-transgenic rice (oryza sativa l.) and its wild type under insecticide stress. | insecticide is always used to control the damage from pests, while the potential influence on plants is rarely known. time-course metabolic changes of wild and bacillus thuringiensis (bt) transgenic rice (oryza sativa l.) plants after insecticide treatment were investigated by using gas chromatography-mass spectrometry (gc-ms). a combined statistical strategy of 2-way anova and multivariate analyses (principal component analysis and hierarchal cluster analysis) was performed to find the stress-a ... | 2012 | 22768924 |
| the dynamics of cooperative bacterial virulence in the field. | laboratory experiments have shown that the fitness of microorganisms can depend on cooperation between cells. although this insight has revolutionized our understanding of microbial life, results from artificial microcosms have not been validated in complex natural populations. we investigated the sociality of essential virulence factors (crystal toxins) in the pathogen bacillus thuringiensis using diamondback moth larvae (plutella xylostella) as hosts. we show that toxin production is cooperati ... | 2012 | 22767928 |
| investigation of the cry4b-prohibitin interaction in aedes aegypti cells. | bacillus thuringiensis (bt) produces insecticidal toxins active against insects. cry4b, one of the major insecticidal toxins produced by bt subsp. israelensis, is highly toxic to mosquitoes in the genus aedes: the major vectors of dengue, yellow fever, and chikungunya. previous work has shown that cry4b binds to several mid-gut membrane proteins in aedes aegypti larvae including prohibitin, a protein recently identified as a receptor that also mediates entry of dengue virus into aedes cells. thi ... | 2012 | 22767320 |
| vip3a resistance alleles exist at high levels in australian targets before release of cotton expressing this toxin. | crops engineered to produce insecticidal crystal (cry) proteins from the soil bacterium bacillus thuringiensis (bt) have revolutionised pest control in agriculture. however field-level resistance to bt has developed in some targets. utilising novel vegetative insecticidal proteins (vips), also derived from bt but genetically distinct from cry toxins, is a possible solution that biotechnical companies intend to employ. using data collected over two seasons we determined that, before deployment of ... | 2012 | 22761737 |
| economic impacts and impact dynamics of bt (bacillus thuringiensis) cotton in india. | despite widespread adoption of genetically modified crops in many countries, heated controversies about their advantages and disadvantages continue. especially for developing countries, there are concerns that genetically modified crops fail to benefit smallholder farmers and contribute to social and economic hardship. many economic studies contradict this view, but most of them look at short-term impacts only, so that uncertainty about longer-term effects prevails. we address this shortcoming b ... | 2012 | 22753493 |
| a tenebrio molitor gpi-anchored alkaline phosphatase is involved in binding of bacillus thuringiensis cry3aa to brush border membrane vesicles. | bacillus thuringiensis cry toxins recognizes their target cells in part by the binding to glycosyl-phosphatidyl-inositol (gpi) anchored proteins such as aminopeptidase-n (apn) or alkaline phosphatases (alp). treatment of tenebrio molitor brush border membrane vesicles (bbmv) with phospholipase c that cleaves out gpi-anchored proteins from the membranes, showed that gpi-anchored proteins are involved in binding of cry3aa toxin to bbmv. a 68 kda gpi-anchored alp was shown to bind cry3aa by toxin o ... | 2013 | 22743140 |
| in vitro uptake of 140 kda bacillus thuringiensis nematicidal crystal proteins by the second stage juvenile of meloidogyne hapla. | plant-parasitic nematodes (ppns) are piercing/sucking pests, which cause severe damage to crops worldwide, and are difficult to control. the cyst and root-knot nematodes (rkn) are sedentary endoparasites that develop specialized multinucleate feeding structures from the plant cells called syncytia or giant cells respectively. within these structures the nematodes produce feeding tubes, which act as molecular sieves with exclusion limits. for example, heterodera schachtii is reportedly unable to ... | 2012 | 22737212 |
| two new brazilian isolates of bacillus thuringiensis toxic to anticarsia gemmatalis (lepidoptera: noctuidae). | bacillus thuringiensis is a bacterium used for biopesticides production and pest-resistant plants due to the synthesis of protein crystals by cry genes, which are effective in controlling several insect orders such as lepidoptera. this work aimed at the evaluation and characterisation of two new b. thuringiensis isolates active against a. gemmatalis (hübner 1818) larvae, which is the soybean major pest. the results showed that bt117-4 isolate amplified fragments corresponding to cry2 and cry9 ge ... | 2012 | 22735145 |
| isolation of bacillus thuringiensis strains that contain dipteran-specific cry genes from ilha bela (são paulo, brazil) soil samples. | the entomophatogenic bacterium bacillus thuringiensis produces crystal proteins, named cry proteins which are encoded by the cry genes. this bacterium is used on biological control of important economical pests, as well as in the control of disease´s vectors, such as aedes aegypti, a mosquito that transmits the dengue viruses. isolates of this bacterium can be characterized by the content of cry genes and this prediction helps target different insect orders. in this research, we isolated 76 colo ... | 2012 | 22735130 |
| widespread adoption of bt cotton and insecticide decrease promotes biocontrol services. | over the past 16 years, vast plantings of transgenic crops producing insecticidal proteins from the bacterium bacillus thuringiensis (bt) have helped to control several major insect pests and reduce the need for insecticide sprays. because broad-spectrum insecticides kill arthropod natural enemies that provide biological control of pests, the decrease in use of insecticide sprays associated with bt crops could enhance biocontrol services. however, this hypothesis has not been tested in terms of ... | 2012 | 22722864 |
| determination of cry toxin activity and identification of an aminopeptidase n receptor-like gene in asymmathetes vulcanorum (coleoptera: curculionidae). | an emergent pest is the weevil asymmathetes vulcanorum, an insect that attacks colombian potato areas. here, some cry proteins from the entomopathogenic bacteria bacillus thuringiensis were evaluated as biological control strategy. it was found that cry1b protoxin caused a mortality of 40% with a dose of 8000 ng/cm(2). also in this research, it was identified a full length cdna of an aminopeptidase n, a possible cry protein receptor located in the insect midgut. this is the first report about b. ... | 2012 | 22721915 |
| fusing the vegetative insecticidal protein vip3aa7 and the n terminus of cry9ca improves toxicity against plutella xylostella larvae. | bacillus thuringiensis insecticidal crystal proteins (icps) and vegetative insecticidal proteins (vips) have been widely used as a kind of safe bio-insecticides. a problem that has been of concern worldwide is how to improve their insecticidal activities. in this study, to determine the synergism between vips and icps effect on insecticidal activity, a construct that produces a chimeric protein of the vip3aa7 and the n terminus ofcry9ca, named v3ac9c, was expressed in escherichia coli bl21 cells ... | 2012 | 22718249 |
| phenotypic and genotypic characterization of b.t.ldc-391 strain that produce cytocidal proteins against human cancer cells. | an indigenous bacillus thuringiensis strain b.t.ldc-391 producing cytocidal proteins against human colon cancer cell line, hct-116, was subjected to phenotypic and genotypic characterization to evaluate its relatedness to b.anthracis. the morphological features of this strain were meta-analyzed with data of other parasporin and insecticidal protein producing bacillus thuringiensis strains. the conventional biochemical analysis and antibiotic sensitivity test proved it as an ampicillin resistant ... | 2012 | 22715300 |
| a 90-day subchronic feeding study of genetically modified maize expressing cry1ac-m protein in sprague-dawley rats. | the cry1ac-m gene, coding one of bacillus thuringiensis (bt) crystal proteins, was introduced into maize h99 × hi iib genome to produce insect-resistant gm maize bt-38. the food safety assessment of the bt-38 maize was conducted in sprague-dawley rats by a 90-days feeding study. we incorporated maize grains from bt-38 and h99 × hi iib into rodent diets at three concentrations (12.5%, 25%, 50%) and administered to sprague-dawley rats (n=10/sex/group) for 90 days. a commercialized rodent diet was ... | 2012 | 22709787 |
| proteomic analysis of bacillus thuringiensis δphac mutant bmb171/phb(-1) reveals that the phb synthetic pathway warrants normal carbon metabolism. | a phac knockout mutant from bacillus thuringiensis (bt) strain bmb171, named bmb171/phb(-1), was constructed. a physiological and metabolic investigation and a proteomic analysis were conducted for both δphac mutant and its parent strain. grown in peptone medium with 5 gram glucose per liter as sole carbon source, bmb171/phb(-1) produced various organic acids. here the excreted pyruvate, citrate, lactate, acetate and glutamate were quantitatively analyzed. deletion of phac gene from the bmb171 s ... | 2012 | 22705120 |
| immunosuppressive properties of a protein (rvpr1) from the venom of the endoparasitic wasp, pimpla hypochondriaca: mechanism of action and potential use for improving biological control strategies. | previously, it was determined that the presence of rvpr1 (a recombinant pimpla hypochondriaca venom protein), in the haemocoel of two lepidopteran larvae, significantly increases their susceptibility to the biological control agents (bcas), bacillus thuringiensis (bt) and beauveria bassiana (richards and dani, 2010; richards et al., 2011). the current work examines the mechanism of action of rvpr1 and demonstrates that it binds to the surface of some haemocytes and disrupts the organization of t ... | 2013 | 22698823 |
| cyt toxins produced by bacillus thuringiensis: a protein fold conserved in several pathogenic microorganisms. | bacillus thuringiensis bacteria produce different insecticidal proteins known as cry and cyt toxins. among them the cyt toxins represent a special and interesting group of proteins. cyt toxins are able to affect insect midgut cells but also are able to increase the insecticidal damage of certain cry toxins. furthermore, the cyt toxins are able to overcome resistance to cry toxins in mosquitoes. there is an increasing potential for the use of cyt toxins in insect control. however, we still need t ... | 2013 | 22691603 |
| diverse genetic basis of field-evolved resistance to bt cotton in cotton bollworm from china. | evolution of pest resistance reduces the efficacy of insecticidal proteins from bacillus thuringiensis (bt) used in sprays or in transgenic crops. although several pests have evolved resistance to bt crops in the field, information about the genetic basis of field-evolved resistance to bt crops has been limited. in particular, laboratory-selected resistance to bt toxin cry1ac based on recessive mutations in a gene encoding a toxin-binding cadherin protein has been identified in three major cotto ... | 2012 | 22689968 |
| understanding successful resistance management: the european corn borer and bt corn in the united states. | the european corn borer, ostrinia nubilalis hübner (lepidoptera: crambidae) has been a major pest of corn and other crops in north america since its accidental introduction nearly a hundred years ago. wide adoption of transgenic corn hybrids that express toxins from bacillus thuringiensis, referred to as bt corn, has suppressed corn borer populations and reduced the pest status of this insect in parts of the corn belt. continued suppression of this pest, however, will depend on managing potentia ... | 2014 | 22688691 |
| the design and implementation of insect resistance management programs for bt crops. | cotton and corn plants with insect resistance traits introduced through biotechnological methods and derived from the bacterium bacillus thuringiensis (bt) have been widely adopted since they were first introduced in 1996. because of concerns about resistance evolving to these bt crops, they have been released with associated irm programs that employ multiple components and reflect the input of academic, industrial and regulatory experts. this paper summarizes the current status of bt crop techn ... | 2014 | 22688689 |
| western corn rootworm and bt maize: challenges of pest resistance in the field. | crops genetically engineered to produce insecticidal toxins from the bacterium bacillus thuringiensis (bt) manage many key insect pests while reducing the use of conventional insecticides. one of the primary pests targeted by bt maize in the united states is the western corn rootworm, diabrotica virgifera virgifera leconte. beginning in 2009, populations of western corn rootworm were identified in iowa, usa that imposed severe root injury to cry3bb1 maize. subsequent laboratory bioassays reveale ... | 2014 | 22688688 |
| extended monitoring of resistance to bacillus thuringiensis cry1ab maize in diatraea saccharalis (lepidoptera: crambidae). | the sugarcane borer, diatraea saccharalis (f.), is a major target of transgenic maize expressing bacillus thuringiensis (bt) proteins in south america and the mid-southern region of the united states. during 2007-2009, a total of 986 feral individuals of d. saccharalis were collected from maize fields in six locations of louisiana and mississippi and examined for resistance to cry1ab maize using f 1/f 2 screens. major resistance alleles to cry1ab maize in the populations sampled from non-bt maiz ... | 2014 | 22688686 |
| molecular typing of native bacillus thuringiensis isolates from diverse habitats in india using rep-pcr and eric-pcr analysis. | bacillus thuringiensis is a bacterium of great agronomic and scientific interest. the subspecies of this bacterium colonize and kill a large variety of host insects and even nematodes, but each strain does so with a high degree of specificity. therefore molecular typing and diversity analysis of b. thuringiensis has enormous importance for discrimination of strains isolated from different sources. in this study, 113 native b. thuringiensis isolates collected from diverse habitats and locations i ... | 2012 | 22688239 |
| efficacy of sunlight-activatable porphyrin formulates on larvae of anopheles gambiae m and s molecular forms and an. arabiensis: a potential novel biolarvicide for integrated malaria vector control. | biolarvicides, such as microbial formulations based on bacillus thuringiensis and b. sphaericus, have been found to be highly effective against mosquito larvae and are currently employed as eco-friendly alternatives to synthetic chemical insecticides for vector control. recently, a porphyrin of natural origin has been suggested as a sunlight-activatable larvicide against the dengue vector aedes aegypti. in order to validate the approach for the control of the malaria vector, we tested the photo- ... | 2012 | 22668835 |
| insecticidal activity of bacillus thuringiensis strains isolated from soil and water. | we attempted to search novel bacillus thuringiensis strains that produce crystals with potential utility in plant protection and with higher activity than strains already used in biopesticide production. seven b. thuringiensis soil and water isolates were used in the research. we predicted the toxicity of their crystals by cry gene identification employing pcr method. the isolate mpu b63 with interesting, according to us, genes content was used in evaluating its crystal toxicity against cydia po ... | 2012 | 22666145 |
| effectiveness of gambusia holbrooki fish in domestic water containers and controlling aedes aegypti larvae (linnaeus, 1762) in southwest saudi arabia (jeddah). | the objective of this study was to estimate the survival of gambusia holbrooki (cyprinodontiformes: poeciliidae) fishin domestic containers in jeddah, as well as its effectiveness in the control of immature a.aegypti. the use of g. holbrooki compared to bacillus thuringiensis israelensis (b.t.i.)was donein domestic containers. in a first home visit, g. holbrooki or b.t.i were applied to water containers. two follow-up visits were conducted after 3-4 & 5-6 months to assess the presence of viable ... | 2012 | 22662590 |
| preparation of silver nanoparticles in the presence of chitosan by electrochemical method. | the present study involves the development of stabilized and densely dispersed chitosan-silver nanoparticles using a green approach based on electrochemical oxidation/complexation process followed by uv irradiation reduction. formation of the nanoparticles was confirmed by appearance of surface plasmon absorption around 420 nm. the nanoparticles were characterized using transmission electron microscopy, x-ray diffraction, elemental analysis, atomic absorption, energy dispersive x-ray, fourier tr ... | 2012 | 24750629 |
| proteomic analysis of bacillus thuringiensis strain 4.0718 at different growth phases. | the growth process of bacillus thuringiensis bt4.0718 strain was studied using proteomic technologies. the proteins of bt whole cells at three phases-middle vegetative, early sporulation, and late sporulation-were extracted with lysis buffer, followed with separation by 2-de and identified by maldi-tof/tof ms. bioactive factors such as insecticidal crystal proteins (icps) including cry1ac(3), cry2aa, and btrx28, immune inhibitor (inha), and inha precursor were identified. inha started to express ... | 2012 | 22649324 |
| bacillus thuringiensis cry3aa protoxin intoxication of tenebrio molitor induces widespread changes in the expression of serine peptidase transcripts. | the yellow mealworm, tenebrio molitor, is a pest of stored grain products and is sensitive to the bacillus thuringiensis (bt) cry3aa toxin. as digestive peptidases are a determining factor in cry toxicity and resistance, we evaluated the expression of peptidase transcripts in the midgut of t. molitor larvae fed either a control or cry3aa protoxin diet for 24 h (rna-seq), or in larvae exposed to the protoxin for 6, 12, or 24 h (microarrays). cysteine peptidase transcripts (9) were similar to cath ... | 2012 | 22640634 |
| proteomic analysis of bacillus thuringiensis at different growth phases by using an automated online two-dimensional liquid chromatography-tandem mass spectrometry strategy. | the proteome of a new bacillus thuringiensis subsp. kurstaki strain, 4.0718, from the middle vegetative (t(1)), early sporulation (t(2)), and late sporulation (t(3)) phases was analyzed using an integrated liquid chromatography (lc)-based protein identification system. the system comprised two-dimensional (2d) lc coupled with nanoscale electrospray ionization (esi) tandem mass spectrometry (ms/ms) on a high-resolution hybrid mass spectrometer with an automated data analysis system. after deletio ... | 2012 | 22636013 |
| single amino acid mutation in an atp-binding cassette transporter gene causes resistance to bt toxin cry1ab in the silkworm, bombyx mori. | bt toxins derived from the arthropod bacterial pathogen bacillus thuringiensis are widely used for insect control as insecticides or in transgenic crops. bt resistance has been found in field populations of several lepidopteran pests and in laboratory strains selected with bt toxin. widespread planting of crops expressing bt toxins has raised concerns about the potential increase of resistance mutations in targeted insects. by using bombyx mori as a model, we identified a candidate gene for a re ... | 2012 | 22635270 |
| how the insect pathogen bacteria bacillus thuringiensis and xenorhabdus/photorhabdus occupy their hosts. | insects are the largest group of animals on earth. like mammals, virus, fungi, bacteria and parasites infect them. several tissue barriers and defense mechanisms are common for vertebrates and invertebrates. therefore some insects, notably the fly drosophila and the caterpillar galleria mellonella, have been used as models to study host-pathogen interactions for several insect and mammal pathogens. they are excellent tools to identify pathogen determinants and host tissue cell responses. we focu ... | 2012 | 22633889 |
| rapid isolation of single-chain antibodies from a human synthetic phage display library for detection of bacillus thuringiensis (bt) cry1b toxin. | single chain variable fragment antibody (scfv) is capable of binding its target antigens and is one of the most popular recombinant antibodies format for many applications. in this study, a large human synthetic phage displayed library (tomlinson j) was employed to generate scfvs against cry1b toxin by affinity panning. after four rounds of panning, six monoclonal phage particles capable of binding with the cry1b were isolated, sequenced and characterized by enzyme-linked immunosorbent assay (el ... | 2012 | 22627013 |
| current models of the mode of action of bacillus thuringiensis insecticidal crystal proteins: a critical review. | bacillus thuringiensis (bt) cry toxins constitute the active ingredient in the most widely used biological insecticides and insect-resistant transgenic crops. a clear understanding of their mode of action is necessary for improving these products and ensuring their continued use. accordingly, a long history of intensive research has established that their toxic effect is due primarily to their ability to form pores in the plasma membrane of the midgut epithelial cells of susceptible insects. in ... | 2012 | 22617276 |
| effects of temperature on mortality of larval stable fly (diptera: muscidae) caused by five isolates of bacillus thuringiensis. | we examined the effects of temperature on mortality of larval stable fly [stomoxys calcitrans (l.)] caused by bacillus thuringiensis tolworthi 4l3, b. t. darmastedensis 4m1, b. t. thompsoni 401, b. t. thuringiensis hd2, and b. t. kurstaki hd945. at moderate doses, mortality caused by all isolates ranged from 87 to 99% at 15 degrees c and declined to 29-63% as temperature increased to 30 degrees c. a similar pattern was seen when a higher dose was used, except that the reduction in mortality at w ... | 2012 | 22606847 |
| cotton plants expressing a hemipteran-active bacillus thuringiensis crystal protein impact the development and survival of lygus hesperus (hemiptera: miridae) nymphs. | the plant bugs lygus hesperus knight (hemiptera: miridae) and l. lineolaris (palisot de beauvois) have emerged as economic pests of cotton in the united states. these hemipteran species are refractory to the insect control traits found in genetically modified commercial varieties of cotton. in this article, we report the isolation and characterization of a 35 kda crystal protein from bacillus thuringiensis, designated tic807, which causes reduced mass gain and mortality of l. hesperus and l. lin ... | 2012 | 22606834 |
| resistance of trichoplusia ni to bacillus thuringiensis toxin cry1ac is independent of alteration of the cadherin-like receptor for cry toxins. | alteration of binding sites for bacillus thuringiensis (bt) toxins in insect midgut is the major mechanism of high-level resistance to bt toxins in insects. the midgut cadherin is known to be a major binding protein for bt cry1a toxins and linkage of bt-resistance to cadherin gene mutations has been identified in lepidopterans. the resistance to bt toxin cry1ac evolved in greenhouse populations of trichoplusia ni has been identified to be associated with the down-regulation of an aminopeptidase ... | 2012 | 22606242 |
| bacillus thuringiensis parasporal proteins induce cell-cycle arrest and caspase-dependant apoptotic cell death in leukemic cells. | bacillus thuringiensis (bt) parasporal proteins with selective anticancer activity have recently garnered interest. this study determines the efficacy and mode of cell death of bt 18 parasporal proteins against 3 leukemic cell lines (cem-ss, ccrf-sb and ccrf-hsb-2).cell-based biochemical analysis aimed to determine cell viability and the percentage of apoptotic cell death in treated cell lines; ultrastructural analysis to study apoptotic changes and western blot to identify the parasporal protei ... | 2012 | 22591286 |
| computational tridimensional protein modeling of cry1ab19 toxin from bacillus thuringiensis btx-2. | we report the computational structural simulation of the cry1ab19 toxin molecule from b. thuringiensis btx-2 based on the structure of cry1aa1 deduced by x-ray diffraction. validation results showed that 93.5% of modeled residues are folded in a favorable orientation with a total energy z-score of -8.32, and the constructed model has an rmsd of only 1.13. the major differences in the presented model are longer loop lengths and shortened sheet components. the overall result supports the hierarchi ... | 2012 | 22573155 |