Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| inheritance of resistance to bacillus thuringiensis cry1ab protein in the sugarcane borer (lepidoptera: crambidae). | inheritance traits of a cry1ab-resistant strain of the sugarcane borer, diatraea saccharalis (f.) were analyzed using various genetic crosses. reciprocal parental crosses between cry1ab-susceptible and cry1ab-resistant populations, f(1) by f(1) crosses, and backcrosses of f(1) with the cry1ab-resistant population were successfully completed. larval mortality of the parental and cross-populations were assayed on cry1ab diet and bacillus thuringiensis (bt)-corn leaf tissue. maternal effects and se ... | 2009 | 19527726 |
| cloning and characterization of two novel crystal protein genes, cry54aa1 and cry30fa1, from bacillus thuringiensis strain btmc28. | bacillus thuringiensis strain btmc28 was isolated from the soil sample in china. two novel crystal protein genes were found by using the pcr-rflp method. moreover, the full-length sequences of two novel genes were obtained by a single oligonucleotide nested (son)-pcr upstream and downstream strategy. sequence analysis revealed that one gene encoded a polypeptide of 673 amino acid residues with a molecular mass of 76.3 kda, 38% identical to cry10aa, and the other encoded a polypeptide of 687 amin ... | 2009 | 19280260 |
| the oral toxicity of the transgenic bt+cpti cotton pollen to honeybees (apis mellifera). | transgenic insect-resistant cotton has been planted in china in a large scale and may have adverse impacts on honeybees. pollens from the transgenic cry1ac+cpti cotton zhong-41 and the parental cotton zhong-23 were collected from the field and their impacts on adult worker bees were assessed. experimental results showed that zhong-41 pollen had no acute oral toxic effect on worker bees. no significant differences were observed in the superoxide dismutase activity or in the longevity of worker be ... | 2009 | 19285343 |
| elaboration of an electroporation protocol for large plasmids and wild-type strains of bacillus thuringiensis. | to elaborate an effective electroporation protocol for large plasmids and wild type strains of bacillus thuringiensis. | 2009 | 19291242 |
| biological and microcalorimetric studies of the toxic effect of organoarsenic(v) compounds to wild strain of bacillus thuringiensis. | microcalorimetric and biological methods were carried out to determine the toxicity of dimethylarsinic acid (dma) and monomethylarsonic acid (mma) to wild strain of bacillus thuringiensis. thermokinetic parameters were obtained from the power-time curves, showing that the peak-heat output power, total heat output, and number of colonies decreased with the increases in concentration of dma and mma. in addition, the generation time and peak maximal time increased with the increases in the dosage o ... | 2009 | 19294342 |
| natural isolates of bacillus thuringiensis display genetic and psychrotrophic properties characteristic of bacillus weihenstephanensis. | to determine the potential of bacillus thuringiensis, known primarily for its entomopathogenicity, to be a psychrotolerant contaminant of stored products. | 2009 | 19228255 |
| impact of cry1ac-carrying brassica rapa subsp. pekinensis on leaf bacterial community. | the effects of chinese cabbage (brassica rapa subsp. pekinensis) carrying cry1ac derived from bacillus thuringiensis (bt) on leaf bacterial community were examined by analyzing the horizontal transfer of trans-gene fragments from plants to bacteria. the effect of plant pathogenic bacteria on the gene transfer was also examined using pseudomonas syringae pathovar. maculicola. the frequency of hygromycin-resistant bacteria did not alter in bt leaves, though slight increase was observed in pseudomo ... | 2009 | 19229489 |
| effect of bacillus thuringiensis naturally colonising brassica campestris var. chinensis leaves on neonate larvae of pieris brassicae. | the feeding of neonate larvae of pieris brassicae (order lepidoptera) on leaves of brassica plants that had been colonised by bacillus thuringiensis resulted in the death of 35% of the population within 72h. the bacteria multiplied in the cadavers, resulting in an increase of about 50-fold compared to the living insects. surviving insects showed no ill effects during the time of the study. there was negligible multiplication of b. thuringiensis in the frass. | 2009 | 19232351 |
| metabolic profiling of transgenic rice with cryiac and sck genes: an evaluation of unintended effects at metabolic level by using gc-fid and gc-ms. | the cryiac and sck genes were introduced to the rice for the purpose of improving the insect resistance. metabolic profiles of wild and transgenic rice were compared to assess the unintended effects related to gene modification. wild samples with different sowing dates or sites were also examined to determine the environmental effects on metabolites. the polar compounds of grains were extracted, trimethylsilylated and analyzed by gas chromatography-flame ionization detection (gc-fid). partial le ... | 2009 | 19233746 |
| proteomic identification of bacillus thuringiensis subsp. israelensis toxin cry4ba binding proteins in midgut membranes from aedes (stegomyia) aegypti linnaeus (diptera, culicidae) larvae. | novel bacillus thuringiensis subsp. israelensis (bti) cry4ba toxin-binding proteins have been identified in gut brush border membranes of the aedes (stegomyia) aegypti mosquito larvae by combining 2-dimensional gel electrophoresis (2de) and ligand blotting followed by protein identification using mass spectrometry and database searching. three alkaline phosphatase isoforms and aminopeptidase were identified. other cry4ba binding proteins identified include the putative lipid raft proteins flotil ... | 2009 | 19272330 |
| efficient constitutive expression of chitinase in the mother cell of bacillus thuringiensis and its potential to enhance the toxicity of cry1ac protoxin. | previous studies revealed that chitinase could enhance the insecticidal activity of bacillus thuringiensis and it has been used in combination with b. thuringiensis widely. however, the expression of b. thuringiensis chitinase is rather low and needs induction by chitin, which limits its field application. it would make sense to constitutively express the chitinase at a sufficiently high level to offer advantages in biological control of pests. in this study, a signal peptide-encoding sequence-d ... | 2009 | 19277644 |
| indian bt cotton varieties do not affect the performance of cotton aphids. | cotton varieties expressing cry proteins derived from the soil bacterium bacillus thuringiensis (bt) are grown worldwide for the management of pest lepidoptera. to prevent non-target pest outbreaks and to retain the biological control function provided by predators and parasitoids, the potential risk that bt crops may pose to non-target arthropods is addressed prior to their commercialization. aphids play an important role in agricultural systems since they serve as prey or host to a number of p ... | 2009 | 19279684 |
| an engineered bacillus thuringiensis strain with insecticidal activity against scarabaeidae (anomala corpulenta) and chrysomelidae (leptinotarsa decemlineata and colaphellus bowringi). | a genetically-engineered bacillus thuringiensis (bt) strain, 3a-hbf, with a broad insecticidal spectrum was constructed by introducing the recombinant plasmid pstk-3a containing cry3aa7 into the wild-type bt strain hbf-1 containing the cry8ca2 gene. the cry3aa7 protein produced by strain 3a-hbf was verified by sds-page and western blotting. flat rectangular crystals of cry3aa7 protein were observed besides spherical crystals (cry8ca2). the plasmid pstk-3a was stable when strain 3a-hbf was grown ... | 2009 | 19142586 |
| resistance of helicoverpa armigera to cry1ac toxin from bacillus thuringiensis is due to improper processing of the protoxin. | the bacterium bacillus thuringiensis produces icps (insecticidal crystal proteins) that are deposited in their spore mother cells. when susceptible lepidopteran larvae ingest these spore mother cells, the icps get solubilized in the alkaline gut environment. of approx. 140 insecticidal proteins described thus far, insecticidal protein cry1ac has been applied extensively as the main ingredient of spray formulation as well as the principal icp introduced into crops as transgene for agricultural cr ... | 2009 | 19146482 |
| potential-dependent permeabilization of plasma membrane by the peptide btm-p1 derived from the cry11bb1 protoxin. | the peptide btm-p1, which is derived from the amino acid sequence of the cry11bb1 protoxin, is able to permeabilize mitochondrial membranes and reveals antimicrobial activity. in this work we demonstrated that the permeabilizing activity of btm-p1 for the plasma membrane of rat red blood cells increased in a dose-dependent manner for the concentration range of 1-4 microg/ml. using osmotic protectants, the radius of pores formed at 4 microg/ml btm-p1 was determined as 0.8 nm for 5 min hemolysis d ... | 2009 | 19146823 |
| biopesticide production from bacillus thuringiensis: an environmentally friendly alternative. | since its discovery as a microbial insecticide, bacillus thuringiensis has been widely used to control insect pests important in agriculture, forestry, and medicine. the wide variety of formulations based on spore-crystal complexes intended for ingestion by target insects, are the result of many years of research. the development of a great variety of matrices for support of the spore-crystal complex enables many improvements, such as an increase in toxic activity, higher palatability to insects ... | 2009 | 19149720 |
| current patents related to bacillus thuringiensis insecticidal crystal proteins. | this work categorizes a number of patents related to bacillus thuringiensis insecticidal crystal proteins. the patents are classified into groups according to the type of toxins appearing in the claims. the purpose of the summary is to promote the application of b. thuringiensis insecticidal crystal proteins and the development of patentable technologies. | 2009 | 19149735 |
| construction of an escherichia coli to bacillus thuringiensis shuttle vector for large dna fragments. | shuttle vectors for bacillus thuringiensis or bacillus cereus usually cannot hold fragments larger than 20 kb. with the development of genome research, shuttle vectors with higher loading capacity are necessary. we constructed an escherichia coli to b. thuringiensis shuttle vector, pemb0557, with a large loading capacity. this vector incorporated the ori60 replicon from b. thuringiensis subsp. kurstaki ybt-1520, erythromycin resistance (b. thuringiensis), and chloromycetin resistance (e. coli) g ... | 2009 | 19153728 |
| papr peptide maturation: role of the nprb protease in bacillus cereus 569 plcr/papr global gene regulation. | the global transcriptional regulator plcr controls gene expression in bacillus cereus and bacillus thuringiensis. activity of plcr is regulated by papr, the product of an orf located immediately downstream of plcr. to be active in b. cereus, papr must be secreted and then processed to the mature peptide by an unknown protease. this peptide is transported by an oligopeptide permease into the cell, where it activates plcr. in this study, we show that the neutral protease b (nprb) secreted by b. ce ... | 2009 | 19159431 |
| using an f(2) screen to monitor frequency of resistance alleles to bt cotton in field populations of helicoverpa armigera (hübner) (lepidoptera: noctuidae). | in an effort to control the most devastating cotton pest, helicoverpa armigera (hübner), in qiuxian county (hebei, china), bt cotton has been planted almost exclusively since 1998 in this area. owing to the high insecticidal selection pressures in this region, monitoring of bt resistance in h. armigera is necessary so that proactive actions can be implemented before field control measures fail. from 2003 to 2005, an f(2) screen was conducted in order to monitor bt resistance in h. armigera popul ... | 2009 | 19165746 |
| modified female calling behaviour in cry1ac-resistant helicoverpa armigera (lepidoptera: noctuidae). | the resistance risk in helicoverpa armigera (hübner) to transgenic cotton that expresses cry1ac from bacillus thuringiensis (bt) has raised concerns about the sustainable deployment of bt cotton. mating behaviour between resistant and susceptible individuals is an important factor that affects resistance evolution of the insect. the female calling behaviours of the cry1ac-resistant strain and its susceptible control were compared in the laboratory to understand the difference in mating biology. | 2009 | 19165761 |
| development of stable isotope and selenomethionine labeling methods for proteins expressed in pseudomonas fluorescens. | pseudomonas fluorescens is a robust protein expression system that is very well suited for high throughput protein expression for structural genomics studies. since nmr spectroscopy and x-ray crystallography are both used by various investigators in structure elucidation studies, the availability of target proteins labeled with stable isotopes or selenomethionine is essential for the determination of protein structures. a completely defined medium for the expression and stable isotope labeling o ... | 2009 | 19166940 |
| impact of transgenic oilseed rape expressing oryzacystatin-1 (oc-1) and of insecticidal proteins on longevity and digestive enzymes of the solitary bee osmia bicornis. | the risk that insect-resistant transgenic plants may pose for solitary bees was assessed by determining longevity of adult osmia bicornis (o. rufa) chronically exposed to transgenic oilseed rape expressing oryzacystatin-1 (oc-1) or to the purified insecticidal proteins recombinant roc-1, kunitz soybean trypsin inhibitor (sbti), galanthus nivalis agglutinin (gna), or bacillus thuringiensis toxin cry1ab dissolved in sugar solution (at 0.01 and 0.1%, w:v, cry1ab only at 0.01%). compared to control ... | 2009 | 19135058 |
| plasmid capture by the bacillus thuringiensis conjugative plasmid pxo16. | conjugation, mobilization, and retromobilization are three related mechanisms of horizontal gene transfer in bacteria. they have been extensively studied in gram-negative species, where retromobilization, the capture of dna from a recipient by a donor cell, was shown to result from two successive steps: the transfer of the conjugative plasmid from the donor to the recipient followed by the retrotransfer of the mobilizable plasmid to the donor. this successive model was established for gram-negat ... | 2009 | 19181805 |
| interaction of bacillus thuringiensis cry1 and vip3a proteins with spodoptera frugiperda midgut binding sites. | vip3aa, vip3af, cry1ab, and cry1fa were tested for their toxicities and binding interactions. vip3a proteins were more toxic than cry1 proteins. binding assays showed independent specific binding sites for cry1 and vip3a proteins. cry1ab and cry1fa competed for the same binding sites, whereas vip3aa competed for those of vip3af. | 2009 | 19181834 |
| evaluation of consortia of microorganisms for efficient removal of hexavalent chromium from industrial wastewater. | the chromium (cr) uptake ability of cr-resistant bacterium bacillus thuringiensis, yeast candida etschellsii, and a protozoan stylonychia mytilus, isolated from industrial waste water, was evaluated individually and in different combinations. it was found that the three types of microorganisms grown together in a culture medium could collectively uptake 90% of cr(6+) from the culture medium as against 82% by bacterium + protozoan or yeast + protozoan combined culture, each. consortium of bacteri ... | 2009 | 19183818 |
| characterization of a c-type lectin from the cotton bollworm, helicoverpa armigera. | c-type lectins can specifically recognize sugars on the surface of microorganisms and cause a series of immune responses to effectively resist pathogenic invasions. in previous work in our laboratory, we obtained a c-type lectin from helicoverpa armigera (ha-lectin). it has two different carbohydrate recognition domains (crds) crd1 and crd2 arranged in tandem. in this study, recombinant crd1 and crd2 were expressed separately in escherichia coli and purified. they have the ability to agglutinate ... | 2009 | 19185587 |
| differential cell surface properties of vegetative bacillus. | the genus bacillus encompasses a wide range of species which display varying pathogenic abilities. the hydrophobicity of a range of bacillus species was determined to evaluate the correlation between bacterial hydrophobicity and pathogenicity. | 2009 | 19187499 |
| the theoretical three-dimensional structure of bacillus thuringiensis cry5aa and its biological implications. | cry5aa is a crystal protein produced by bacillus thuringiensis serovar. damstadiensis during its stationary phase, this delta-endotoxin is active against nematodes and has great potential for nematodes control. the theoretical model of the three-dimensional structure of cry5aa was predicted by homology modeling on the structures of the cry1aa which is specific to lepidopteran insects. the structure of the cry5aa resembles previously reported cry toxin structures but shows the following distincti ... | 2009 | 19191014 |
| dna detection on ultrahigh-density optical fiber-based nanoarrays. | nanoarrays for dna detection were fabricated on etched nanofiber bundles based on recently developed techniques for microscale arrays. two different-sized nanoarrays were created: one with 700 nm feature sizes and a 1 microm center-to-center pitch (approximately 1x10(6) array elements/mm(2)) and one with 300 nm feature sizes and a 500 nm center-to-center pitch (4.6x10(6) array elements/mm(2)). a random, multiplexed array composed of oligonucleotide-functionalized nanospheres was constructed and ... | 2009 | 19195871 |
| a new tunisian strain of bacillus thuringiensis kurstaki having high insecticidal activity and delta-endotoxin yield. | blb1 is a new bacillus thuringiensis kurstaki strain, isolated from a tunisian soil sample. assay of toxicity of blb1 crystal proteins resulted in an lc50 of 70.32 ng of toxin per mg of flour against third instar ephestia kuehniella with confidence limits of (31.6-109.04 ng). this lc50 is less than that of the commercial strains hd1 used as a reference. the characterization of this strain by scanning transmission electron microscopy, analysis of its cry genes content by pcr-sequencing, and analy ... | 2009 | 19214476 |
| restoration of the crystallization of altered delta-endotoxins cry1ac, by the promotion of their in vivo integration into the bacillus thuringiensis native crystals. | cry1ac is one of the most-studied bacillus thuringiensisdelta-endotoxins. structurally, it is divided into two domains: the n-terminal half corresponding to the toxic component and the c-terminal half corresponding to the region responsible for the crystal formation. we engineered cry1ac delta-endotoxins modified in their n-terminal part and studied the effect of such modifications on crystallization and delta-endotoxin production. when expressed in an acrystalliferous b. thuringiensis strain, c ... | 2009 | 19220475 |
| comparative flight performance of three important pest adelphocoris species of bt cotton in china. | the massive adoption of bt cotton throughout china has been accompanied by outbreaks of secondary pests such as adelphocoris spp. (heteroptera: miridae). the adelphocoris group primarily consists of three species: a. suturalis, a. fasciaticollis and a. lineolatus, which greatly differ in geographical distribution and seasonal dynamics. however, the underlying drivers of these differences remain to be understood. the study of flight behaviour of these three species can yield important insight int ... | 2009 | 19222869 |
| sensitive and highly specific quantitative real-time pcr and elisa for recording a potential transfer of novel dna and cry1ab protein from feed into bovine milk. | to address food safety concerns of the public regarding the potential transfer of recombinant dna (cry1ab) and protein (cry1ab) into the milk of cows fed genetically modified maize (mon810), a highly specific and sensitive quantitative real-time pcr (qpcr) and an elisa were developed for monitoring suspicious presence of novel dna and cry1ab protein in bovine milk. the developed assays were validated according to the assay validation criteria specified in the european commission decision 2002/65 ... | 2009 | 19225766 |
| identification of non-flagellar genes involved in swarm cell differentiation using a bacillus thuringiensis mini-tn10 mutant library. | swarming is a social phenomenon that enables motile bacteria to move co-ordinately over solid surfaces. the molecular basis regulating this process is not completely known and may vary among species. insertional mutagenesis of a swarming-proficient bacillus thuringiensis strain was performed, by use of the transposon mini-tn10, to identify novel genetic determinants of swarming that are dispensable for flagellation, swimming motility, chemotaxis and active growth. among the 67 non-swarming mutan ... | 2009 | 19246762 |
| design of a bacillus thuringiensis-based formulation that increases feeding preference on spodoptera exigua (lepidoptera: noctuidae) larvae. | a bacillus thuringiensis (bt)-based formulation intended to increase feeding response in spodoptera exigua (hübner) (lepidoptera: noctuidae) was developed. eight matrices were prepared from natural ingredients and confronted with fresh maize leaves to select one highly palatable to larvae. the selected matrix was combined with bt hd-125 strain at three different concentrations (30, 70, and 100 g/kg) of the spore-crystal complex to elaborate three insecticidal formulations. effects caused by the ... | 2009 | 19253618 |
| bacillus thuringiensis cry1ac resistance frequency in tobacco budworm (lepidoptera: noctuidae). | the tobacco budworm, heliothis virescens (f.) (lepidoptera: noctuidae), is one of the most important pests of cotton, gossypium hirsutum l, that has become resistant to a wide range of synthetic insecticides. crylac-expressing cotton has proven its effectiveness against this insect since its introduction in north america in 1996. however, the constant exposure of tobacco budworm to this protein toxin may result in the development of resistance to it. to estimate the frequency of alleles that con ... | 2009 | 19253658 |
| broad-spectrum cross-resistance in spodoptera exigua from selection with a marginally toxic cry protein. | spodoptera exigua (hübner) has developed resistance to a wide range of chemical insecticides. products based on bacillus thuringiensis cry toxins are used in integrated pest management as an ecologically friendly alternative for pest control. since there are few b. thuringiensis cry proteins highly active against s. exigua, it is desirable to apply appropriate resistance management strategies to prevent the evolution of resistance to these proteins. | 2009 | 19253909 |
| contributions of gut bacteria to bacillus thuringiensis-induced mortality vary across a range of lepidoptera. | gut microbiota contribute to the health of their hosts, and alterations in the composition of this microbiota can lead to disease. previously, we demonstrated that indigenous gut bacteria were required for the insecticidal toxin of bacillus thuringiensis to kill the gypsy moth, lymantria dispar. b. thuringiensis and its associated insecticidal toxins are commonly used for the control of lepidopteran pests. a variety of factors associated with the insect host, b. thuringiensis strain, and environ ... | 2009 | 19261175 |
| effects of bacillus thuringiensis toxin cry1ac and cytoplasmic polyhedrosis virus of helicoverpa armigera (hübner) (hacpv) on cotton bollworm (lepidoptera: noctuidae). | in this study, interactions on the mortality and debilitating effects between cry1ac, a toxic protein produced by bacillus thuringiensis (berliner) and hacpv (chinese strain) on first and third instars larvae of helicoverpa armigera were evaluated in laboratory. when first instar was exposed to combination of bt cotton leaf discs containing hacpv (6 x 10(6), 1 x 10(7), and 3 x 10(7) pib ml(-1)) the effect on mortality was additive, when such instar larvae exposed to combination of cry1ac (0.9, 2 ... | 2009 | 19269293 |
| insecticidal activity of bacillus thuringiensis crystal proteins. | published data on insecticidal activity of crystal proteins from bacillus thuringiensis are incorporated into the bt toxin specificity relational database. to date, 125 of the 174 holotype known toxins have been tested in approximately 1700 bioassays against 163 test species; 49 toxins have not been tested at all; 59 were tested against 71 lepidoptera species in 1182 bioassays; 53 toxins were tested against 23 diptera species in 233 bioassays; and 47 were tested against 39 coleoptera species in ... | 2009 | 19269294 |
| molecular methods to evaluate biodiversity in bacillus cereus and bacillus thuringiensis strains from different origins. | the spore-forming genus bacillus includes species of industrial, clinical and environmental significance. the possibility of differentiating between bacillus cereus and bacillus thuringiensis, toxin producers associated with illness, is a real need in monitoring potentially contaminated foods to understand the real distribution of b. cereus/b. thuringiensis in different outbreak cases. as the use of dna comparison obtains clearer results than classical microbiological methods in distinguishing b ... | 2009 | 19269566 |
| sk66-his, a novel glycine-rich peptide derived from drosophila with antibacterial activity. | sk(66)-his, a novel glycine-rich peptide derived from the cg13551 gene of drosophila, was directly expressed in escherichia coli with the help of the glucose effect of the lac repressor and efficiently purified in high yield (10.063 mg/l). it showed significant activity against gram-positive bacteria. we determined a mic value of 9 microg ml(-1) with bacillus thuringiensis. | 2009 | 19270403 |
| screening and identification of vip genes in bacillus thuringiensis strains. | to identify known vip genes and to detect potentially novel vip genes in a collection of 507 strains of bacillus thuringiensis. | 2009 | 19302326 |
| distribution, diversity, and potential mobility of extrachromosomal elements related to the bacillus anthracis pxo1 and pxo2 virulence plasmids. | the presence of a pxo1- and/or pxo2-like plasmid(s) in clinical isolates of bacillus cereus sensu stricto and in strains of the biopesticide bacillus thuringiensis has been reported recently, and the pxo2-like plasmid pbt9727 and another pxo2-like plasmid, paw63, were found to be conjugative. in this study, a total of 1,000 b. cereus group isolates were analyzed for the presence of pxo1- and pxo2-like replicons and for the presence of pxo2-related conjugative modules. pxo1- and pxo2-like replico ... | 2009 | 19304837 |
| a conserved 3' extension in unusual group ii introns is important for efficient second-step splicing. | the b.c.i4 group ii intron from bacillus cereus atcc 10987 harbors an unusual 3' extension. here, we report the discovery of four additional group ii introns with a similar 3' extension in bacillus thuringiensis kurstaki 4d1 that splice at analogous positions 53/56 nt downstream of domain vi in vivo. phylogenetic analyses revealed that the introns are only 47-61% identical to each other. strikingly, they do not form a single evolutionary lineage even though they belong to the same bacterial b cl ... | 2009 | 19304998 |
| peritrophic membrane contribution to bt cry delta-endotoxin susceptibility in lepidoptera and the effect of calcofluor. | in an effort to determine a reason for differing susceptibilities to bacillus thuringiensis (bt) cry delta-endotoxins amongst lepidopteran species, the peritrophic membrane (pm), and a number of agents that target the pm, were investigated to determine their effect on the efficacy of bt toxins. in particular calcofluor is able to disrupt the pm that acts as a barrier to microorganisms. although bt toxins have been shown to traverse the pm in some lepidopteran species, new data shows that toxins ... | 2009 | 19320042 |
| protease activities in the midgut of western corn rootworm (diabrotica virgifera virgifera leconte). | the western corn rootworm is one of the most economically important pests in corn. one possibility for controlling this pest is the cultivation of transgenic corn expressing bacillus thuringiensis (bt) toxins, such as cry3a, cry34ab1/cry35ab1, and cry3bb1. however, widespread cultivation of the resulting bt corn may result in the development of resistant pest populations. the bt toxins are processed by proteases in the midgut of susceptible insects. thus, protease activity studies were conducted ... | 2009 | 19320044 |
| rapid decomposition of maize detritus in agricultural headwater streams. | headwater streams draining agricultural landscapes receive maize leaves (zea mays l.) via wind and surface runoff, yet the contribution of maize detritus to organic-matter processing in agricultural streams is largely unknown. we quantified decomposition and microbial respiration rates on conventional (non-bt) and genetically engineered (bt) maize in three low-order agricultural streams in northwestern indiana, usa. we also examined how substrate quality and in-stream nutrient concentrations inf ... | 2009 | 19323178 |
| acute and repeated dose (28 day) mouse oral toxicology studies with cry34ab1 and cry35ab1 bt proteins used in coleopteran resistant das-59122-7 corn. | expression of the cry34ab1 and cry35ab1 proteins from bacillus thuringiensis (bt) berliner strain ps149b1 in genetically modified maize (event das-59122-7) protects the crop from damage due to feeding by diabrotica larvae including the western corn rootworm (diabrotica virgifera virgifera). as part of the safety assessment of this maize, mammalian toxicology studies were conducted with heterologously produced cry34ab1 and cry35ab1 proteins. no evidence of acute toxicity was observed in mice foll ... | 2009 | 19328831 |
| enhancement of bacillus thuringiensis cry3aa and cry3bb toxicities to coleopteran larvae by a toxin-binding fragment of an insect cadherin. | the cry3aa and cry3bb insecticidal proteins of bacillus thuringiensis are used in biopesticides and transgenic crops to control larvae of leaf-feeding beetles and rootworms. cadherins localized in the midgut epithelium are identified as receptors for cry toxins in lepidopteran and dipteran larvae. previously, we discovered that a peptide of a toxin-binding cadherin expressed in escherichia coli functions as a synergist for cry1a toxicity against lepidopteran larvae and cry4 toxicity against dipt ... | 2009 | 19329664 |
| parasporin, a new anticancer protein group from bacillus thuringiensis. | parasporin (ps) is a collection of genealogically heterogeneous cry proteins synthesized in bacillus thuringiensis. a prominent feature commonly associated with ps proteins is the strong cytocidal activity preferential for human cancer cells of various origins. the proteins exhibit cytocidal activities only when digested with proteases. currently, this protein group is classified into four families: ps1, ps2, ps3 and ps4. marked differences are evident in cytotoxicity spectra and activity levels ... | 2009 | 19331182 |
| microbial larvicide application by a large-scale, community-based program reduces malaria infection prevalence in urban dar es salaam, tanzania. | malaria control in africa is most tractable in urban settlements yet most research has focused on rural settings. elimination of malaria transmission from urban areas may require larval control strategies that complement adult mosquito control using insecticide-treated nets or houses, particularly where vectors feed outdoors. | 2009 | 19333402 |
| correlation of vesicle binding and phospholipid dynamics with phospholipase c activity: insights into phosphatidylcholine activation and surface dilution inhibition. | the enzymatic activity of the peripheral membrane protein, phosphatidylinositol-specific phospholipase c (pi-plc), is increased by nonsubstrate phospholipids with the extent of enhancement tuned by the membrane lipid composition. for bacillus thuringiensis pi-plc, a small amount of phosphatidylcholine (pc) activates the enzyme toward its substrate pi; above 0.5 mol fraction pc (xpc), enzyme activity decreases substantially. to provide a molecular basis for this pc-dependent behavior, we used flu ... | 2009 | 19336401 |
| expression of the cry1ec gene in castor (ricinus communis l.) confers field resistance to tobacco caterpillar (spodoptera litura fabr) and castor semilooper (achoea janata l.). | castor (cv. dcs-9) has been transformed through agrobacterium-mediated and particle gun bombardment methods using appropriate vectors containing the bt chimeric gene cry1ec driven by enhanced 35s promoter. about 81 and 12 putative transformants were regenerated following selection on hygromycin and kanamycin, respectively. southern analysis of dna extracted from t(0) plants confirmed integration of the introduced gene in castor genome. the integration and inheritance of the introduced genes was ... | 2009 | 19337736 |
| efficient screening and breeding of bacillus thuringiensis subsp. kurstaki for high toxicity against spodoptera exigua and heliothis armigera. | spodoptera exigua is one of the most renowned agricultural pest insects and relatively insensitive to bacillus thuringiensis subsp. kurstaki strains which are widely used commercial products to control lepidopterans such as heliothis armigera. in the current study, we have developed a new and efficient approach to screen and breed a b. thuringiensis subsp. kurstaki strain exhibiting high toxicity against s. exigua while retaining its high toxicity against h. armigera. uv and diethyl sulfate meth ... | 2009 | 19337765 |
| hyperproduction of chitinase influences crystal toxin synthesis and sporulation of bacillus thuringiensis. | bacillus thuringiensis hd-73 was transformed with the endochitinase gene chia74 under the control of a strong promoter (pcyta) and a 5' mrna stabilizing (stab-sd) sequence (hd-73-pebchia74). expression levels were compared with those observed from the wild type strain (hd-73) and the recombinant hd-73 strain expressing chia74 under the control of its native promoter (hd-73-pehchia74). the chitinolytic activity of hd-73-pebchia74 was markedly elevated, being ~58- and 362-fold higher than, respect ... | 2009 | 19337851 |
| safety assessment of cry1ab/ac fusion protein. | cry1ab/ac gene was fused by both the cry1ab gene (genbank accession no. x54939) and the cry1ac gene (genbank accession no. y09787), which was widely used in genetically modified (gm) rice, cotton, maize and so on. in order to support the safety assessment of gm food or feed products containing cry1ab/ac protein, sufficient quantities of cry1ab/ac protein were produced in escherichia coli for in vitro evaluation and animal studies. the cry1ab/ac protein does not possess the characteristics associ ... | 2009 | 19341779 |
| agrobacterium-mediated transformation of fraxinus pennsylvanica hypocotyls and plant regeneration. | a genetic transformation protocol for green ash (fraxinus pennsylvanica) hypocotyl explants was developed. green ash hypocotyls were transformed using agrobacterium tumefaciens strain eha105 harboring binary vector pq35gr containing the neomycin phosphotransferase (nptii) and beta-glucuronidase (gus) fusion gene, and an enhanced green fluorescent protein gene. pre-cultured hypocotyl explants were transformed in the presence of 100 microm acetosyringone using 90 s sonication plus 10 min vacuum-in ... | 2009 | 19343350 |
| entomopathogenic bacteria as a source of secondary metabolites. | insects are not only the most diverse group of animals on our planet, but also a huge reservoir for unusual microorganism which are a rich source of pharmaceutically interesting natural products. this review focuses on recent advances in the understanding of secondary metabolism of bacillus thuringiensis, pseudomonas entomophila, and xenorhabdus and photorhabdus bacteria all of which are entomopathogenic. genome-sequencing projects revealed the capacity of these bacteria to produce several diffe ... | 2009 | 19345136 |
| identification of an entomopathogenic bacterium, serratia sp. anu101, and its hemolytic activity. | four different bacterial colonies were isolated from an old stock of an entomopathogenic nematode, steinernema monticolum. they all showed entomopathogenicity to final instar larvae of beet armyworm, spodoptera exigua, by hemocoelic injection. however, they varied in colony form, susceptibility to antibiotics, and postmortem change of the infected host insects. biolog microbial identification and 16s rdna sequence analyses indicate that these are four different species classified into different ... | 2009 | 19349758 |
| expression of cry1ac in transgenic tobacco plants under the control of a wound-inducible promoter (aopr1) isolated from asparagus officinalis to control heliothis virescens and manduca sexta. | expression of cry1ac gene from bacillus thuringiensis (bt) was evaluated under the control of a wound-inducible aopr1 promoter from asparagus officinalis in transgenic tobacco plants. the leaves of transgenic plants were mechanically wounded to evaluate the activity of the aopr1 promoter in driving the expression of cry1ac protein at the wound site. our results indicate that mechanical wounding of transgenic plants was effective in inducing the expression of cry1ac protein. as a result of this i ... | 2009 | 19353306 |
| setting the record straight: a rebuttal to an erroneous analysis on transgenic insecticidal crops and natural enemies. | 2009 | 19357987 | |
| an improved bioassay for the detection of bacillus thuringiensis beta-exotoxin. | some bacillus thuringiensis strains secrete beta-exotoxin, which is an insecticidal, thermostable adenine nucleotide analogue. discrepancies between detection of beta-exotoxin by high-performance liquid chromatography and insect bioassays have shown the importance of bioassays in the determination of beta-exotoxin production. with the aim of improving the fly beta-exotoxin bioassay, a range of fly diets were evaluated and the best performing diet was incorporated into a novel beta-exotoxin bioas ... | 2009 | 19358852 |
| activity of bacteriocins synthesized by bacillus thuringiensis against staphylococcus aureus isolates associated to bovine mastitis. | antimicrobial therapy is a useful tool to control bovine mastitis caused by staphylococcus aureus, as consequence an increase in staphylococci resistant cases has been registered. alternative strategies are desirable and bacteriocins represent attractive control agents to prevent bovine mastitis. the aim of this work was to evaluate the activity of five bacteriocins synthesized by bacillus thuringiensis against s. aureus isolates associated to bovine mastitis. fifty s. aureus isolates were recov ... | 2009 | 19359107 |
| validity assessment of the detection method of maize event bt10 through investigation of its molecular structure. | in march 2005, u.s. authorities informed the european commission of the inadvertent release of unauthorized maize gm event bt10 in their market and subsequently the grain channel. in the united states measures were taken to eliminate bt10 from seed and grain supplies; in the european union an embargo for maize gluten and brewer's grain import was implemented unless certified of bt10 absence with a bt10-specific pcr detection method. with the aim of assessing the validity of the bt10 detection me ... | 2009 | 19368351 |
| modulation of bacillus thuringiensis phosphatidylinositol-specific phospholipase c activity by mutations in the putative dimerization interface. | cleavage of phosphatidylinositol (pi) to inositol 1,2-(cyclic)-phosphate (cip) and cip hydrolysis to inositol 1-phosphate by bacillus thuringiensis phosphatidylinositol-specific phospholipase c are activated by the enzyme binding to phosphatidylcholine (pc) surfaces. part of this reflects improved binding of the protein to interfaces. however, crystallographic analysis of an interfacially impaired phosphatidylinositol-specific phospholipase (w47a/w242a) suggested protein dimerization might occur ... | 2009 | 19369255 |
| construction of a recombinant intergenus multidomain chimeric protein for simultaneous expression of haemolysin bl of bacillus cereus, listeriolysin o of listeria monocytogenes and enterotoxin b of staphylococcus aureus. | haemolysin bl (hbl) of bacillus cereus, listeriolysin o (llo) of listeria monocytogenes and enterotoxin b (seb) of staphylococcus aureus are among the major toxin components contributing to the pathogenicity of these organisms in foodborne illnesses. in this study, an intergenus non-toxic multidomain fusion protein (r-hle) was generated with specificity for hbl, llo and seb. the fusion gene (r-hle) comprising the conserved regions of hbld and the hly and entb genes was codon-optimized for expres ... | 2009 | 19369518 |
| mutation of an aminopeptidase n gene is associated with helicoverpa armigera resistance to bacillus thuringiensis cry1ac toxin. | a cry1ac-resistant strain (bt-r) of helicoverpa armigera, with 2971-fold resistance, was derived by selection with cry1ac toxin for 75 generations. we used cdna-amplified fragment length polymorphism analysis to identify those genes differentially expressed in the cry1ac-resistant and -susceptible strains, which revealed 212 differentially expressed transcripts among 2000 screened cdnas. among these transcript-derived fragments (tdfs), 37 showed some homology to known sequences, including aminop ... | 2009 | 19376227 |
| mutations in domain i interhelical loops affect the rate of pore formation by the bacillus thuringiensis cry1aa toxin in insect midgut brush border membrane vesicles. | pore formation in the apical membrane of the midgut epithelial cells of susceptible insects constitutes a key step in the mode of action of bacillus thuringiensis insecticidal toxins. in order to study the mechanism of toxin insertion into the membrane, at least one residue in each of the pore-forming-domain (domain i) interhelical loops of cry1aa was replaced individually by cysteine, an amino acid which is normally absent from the activated cry1aa toxin, using site-directed mutagenesis. the to ... | 2009 | 19376918 |
| susceptibility of diabrotica virgifera virgifera (coleoptera: chrysomelidae) to the entomopathogenic fungus metarhizium anisopliae when feeding on bacillus thuringiensis cry3bb1-expressing maize. | genetically engineered maize producing the insecticidal protein cry3bb1 from bacillus thuringiensis (bt maize) is protected against corn rootworms (diabrotica spp.), which are serious maize pests in north america and europe. the aim of the present study was to investigate the interaction of bt maize (event mon88017) and the entomopathogenic fungus metarhizium anisopliae for controlling the western corn rootworm, diabrotica virgifera virgifera. exposure to cry3bb1 expressed in bt maize seedlings ... | 2009 | 19376921 |
| bacillus thuringiensis var. tenebrionis control of synanthropic mites (acari: acaridida) under laboratory conditions. | bacillus thuringiensis (bt) toxins present a potential for control of pest mites. information concerning the effect of bt and its possible application to the biocontrol of synathropic mites is rare. the toxic effect of bacillus thuringiensis var. tenebrionis producing cry3a toxin was tested on the mites acarus siro l., tyrophagus putrescentiae (schrank), dermatophagoides farinae hughes, and lepidoglyphus destructor (schrank) via feeding tests. fifty mites were reared on bt additive diets in conc ... | 2009 | 19381844 |
| [identification and cloning of vip3a genes from isolates of bacillus thuringiensis and their bioactivity analysis]. | to survey the distribution of vip3a-type genes from isolates of bacillus thuringiensis in china and to clone novel vip3a genes encoding vip3a proteins with high insecticidal activity against lepidopteran insect larvae. | 2009 | 19388273 |
| transgenic insecticidal crops and natural enemies: a detailed review of laboratory studies. | this review uses a data-driven, quantitative method to summarize the published, peer-reviewed literature about the impact of genetically modified (gm) plants on arthropod natural enemies in laboratory experiments. the method is similar to meta-analysis, and, in contrast to a simple author-vote counting method used by several earlier reviews, gives an objective, data-driven summary of existing knowledge about these effects. significantly more non-neutral responses were observed than expected at r ... | 2009 | 19389277 |
| characterization of a novel cry8 gene specific to melolonthidae pests: holotrichia oblita and holotrichia parallela. | a new polymerase chain reaction-restriction fragment length polymorphism method for the identification of cry8-type genes from bacillus thuringiensis has been established by designing a pair of new universal primers. by this method, a novel gene, cry8ga1, encoding a polypeptide of 1,157 amino acids with a deduced molecular mass of 131.2 kda was identified and cloned from b. thuringiensis hbf-18. recombinant b. thuringiensis strain hd8g, harboring cry8ga1, has insecticidal activity against larvae ... | 2009 | 19399496 |
| [structural changes in wild-type cry3a delta-endotoxin and its mutants in ethyl alcohol solutions at ph 2-2.5]. | the methods of circular dichroism, scanning microcalorimetry, electron microscopy, and proteolysis were used to study the ability of wild-type cry3a-delta-endotoxin and three mutant toxins with cysteine substitutions in helices alpha3 and alpha4 (domain i) to form oligomeric structures in acidic alcohol solutions that reproduce the premembrane environment. at ph 2-2.2 and 20% ethanol, the mutant toxins with single substitutions e132c (alpha3) and e160c (alpha4), as well as the double mutant e132 ... | 2009 | 19402530 |
| does distant homology with evf reveal a lipid binding site in bacillus thuringiensis cytolytic toxins? | the cry and cyt classes of insecticidal toxins derived from the sporulating bacterium bacillus thuringiensis are valuable substitutes for synthetic pesticides in agricultural contexts. crystal structures and many biochemical data have provided insights into their molecular mechanisms, generally thought to involve oligomerization and pore formation, but have not localised the site on cyt toxins responsible for selective binding of phospholipids containing unsaturated fatty acids. here, distant ho ... | 2009 | 19409387 |
| n546 in beta18-beta19 loop is important for binding and toxicity of the bacillus thuringiensis cry1ac toxin. | our previous mutagenic analysis showed that the unique residue n546 in the apex of beta18-beta19 loop of bacillus thuringiensis cry1ac toxin is important for its toxicity. in this study, trypsin digestion susceptibility, binding to bbmv and oligomer formation activity was therefore analyzed to determine the mechanism of toxicity change of these mutant toxins. the results showed that residue n546 was not involved in toxin oligomerisation and maintaining the stability of toxin, the enhanced toxici ... | 2009 | 19416731 |
| a novel tenebrio molitor cadherin is a functional receptor for bacillus thuringiensis cry3aa toxin. | cry toxins produced by the bacterium bacillus thuringiensis are effective biological insecticides. cadherin-like proteins have been reported as functional cry1a toxin receptors in lepidoptera. here we present data that demonstrate that a coleopteran cadherin is a functional cry3aa toxin receptor. the cry3aa receptor cadherin was cloned from tenebrio molitor larval midgut mrna, and the predicted protein, tmcad1, has domain structure and a putative toxin binding region similar to those in lepidopt ... | 2009 | 19416969 |
| plant fitness assessment for wild relatives of insect resistant crops. | risk assessments of new insect-resistant crops will need to estimate the potential for increased weediness of wild crop relatives as a consequence of gene flow. when field experiments are precluded by containment concerns, simulation experiments can identify hazards or measure expected differences between gmos and parental plants. to measure plant fitness consequences of wild plant protection from bt-susceptible herbivores, we used topical sprays of bacterial bacillus thuringiensis larvacide (bt ... | 2009 | 19419653 |
| generation of mini-tn10 transposon insertion mutant library of bacillus thuringiensis for the investigation of genes required for its bacteriocin production. | bacillus thuringiensis strain bupm4 is known for its ability to produce a bacteriocin, called bacthuricin f4 (bf4), which inhibits the growth of several gram-positive bacteria and particularly bacillaceae. this study aimed to use the insertional transposon mutagenesis approach for disrupting and thus identifying genes associated with bf4 synthesis. here, the mini-tn10 transposon was used to generate a library of b. thuringiensis mutants. twenty thousand clones were screened for the search of mut ... | 2009 | 19431236 |
| laboratory and field investigations of pestiferous chironomidae (diptera) in some man-made wetlands in central florida, usa. | a 1-year larval and adult population survey of pestiferous chironomids was conducted in 4 man-made wetlands in a resort area of central florida, usa. benthic samples were randomly collected from each wetland at least once every month. geocoordinates, water depth, and physical composition of substrates at each larval sample location were noted. adult midge populations were sampled weekly around the wetlands by employing 10 new jersey light traps permanently placed in the area. chironominae and ta ... | 2009 | 19432073 |
| initial and residual activity of vectobac 12 as, vectobac wdg, and vectolex wdg for control of mosquitoes in ararat valley, turkey. | two formulations, vectobac 12 as and vectobac wdg, of bacillus thuringiensis israelensis (bti) and one formulation, vectolex wdg, of bacillus sphaericus were tested against anopheles maculipennis, culex pipiens, culex theileri, aedes caspius, and aedes dorsalis larvae in drainage canals, a flooded plain, and a drainage well in the igdir plain of arafat valley, turkey. vectobac 12 as applied at 0.5 and 1 liter/ha to a drainage canal provided complete control of cx. theileri and 80% to 98% control ... | 2009 | 19432078 |
| investigation of the unfolding pathway of bacillus thuringiensis cyt2aa2 toxin reveals an unfolding intermediate. | cyt2aa2 is a cytolytic toxin from bacillus thuringiensis subsp. darmstadiensis. its active form has a lethal activity against specific mosquito larvae. we characterized an unfolding pathway of cyt2aa2 using a guanidinium hydrochloride denaturation. the results revealed three-state transition with a detectable intermediate in a condition with 3-4m of guhcl. the conformational free energies for native and intermediate state unfolding were 5.82+/-0.47 and 16.85+/-1.47kcal/mol, respectively. kinetic ... | 2009 | 19433217 |
| prays oleae midgut putative receptor of bacillus thuringiensis vegetative insecticidal protein vip3lb differs from that of cry1ac toxin. | vegetative insecticidal protein (vip) is a class of insecticidal proteins produced by many bacillus thuringiensis strains during their vegetative growth stage. the vip3lb gene of b. thuringiensis strain bupm95, which encodes a protein active against the lepidoptera olive tree pathogenic insect prays oleae, was cloned into pet-14b vector and overexpressed in escherichia coli. the expressed vip3lb protein, found in the e. coli cytoplasmic fraction, was purified and used to produce anti-vip3lb anti ... | 2009 | 19434523 |
| dominant negative mutants of bacillus thuringiensis cry1ab toxin function as anti-toxins: demonstration of the role of oligomerization in toxicity. | bacillus thuringiensis cry toxins, that are used worldwide in insect control, kill insects by a mechanism that depends on their ability to form oligomeric pores that insert into the insect-midgut cells. these toxins are being used worldwide in transgenic plants or spray to control insect pests in agriculture. however, a major concern has been the possible effects of these insecticidal proteins on non-target organisms mainly in ecosystems adjacent to agricultural fields. | 2009 | 19440244 |
| nosocomial bacteremia caused by biofilm-forming bacillus cereus and bacillus thuringiensis. | bacterial biofilms cause serious problems, such as antibiotic resistance and medical device-related infections. recent reports indicate that bacillus species potentially form biofilms and cause nosocomial bacteremia via catheter infection. our objective was to investigate the relationship between nosocomial bacteremia caused by bacillus species and biofilm formations. | 2009 | 19443973 |
| is the cry1ab protein from bacillus thuringiensis (bt) taken up by plants from soils previously planted with bt corn and by carrot from hydroponic culture? | the uptake of the insecticidal cry1ab protein from bacillus thuringiensis (bt) by various crops from soils on which bt corn had previously grown was determined. in 2005, the cry1ab protein was detected by western blot in tissues (leaves plus stems) of basil, carrot, kale, lettuce, okra, parsnip, radish, snap bean, and soybean but not in tissues of beet and spinach and was estimated by enzyme-linked immunosorbent assay (elisa) to be 0.05 +/- 0.003 ng g(-1) of fresh plant tissue in basil, 0.02 +/- ... | 2009 | 19444360 |
| [chitinase b from bacillus thuringiensis enhancing potential and its antagonism and insecticidal]. | we studied the characteristics of chitinase b (chib) from bacillus thuringiensis subsp. colmeri 15a3 (bt 15a3) and evaluated its antagonism and insecticidal potential. | 2009 | 19445172 |
| reduction of bacillus thuringiensis cry1ac toxicity against helicoverpa armigera by a soluble toxin-binding cadherin fragment. | a cadherin-like protein has been identified as a putative receptor for bacillus thuringiensis (bt) cry1ac toxin in helicoverpa armigera and plays a key role in bt insecticidal action. in this study, we produced a fragment from this h. armigera cry1ac toxin-binding cadherin that included the predicted toxin-binding region. binding of cry1ac toxin to this cadherin fragment facilitated the formation of a 250-kda toxin oligomer. the cadherin fragment was evaluated for its effect on cry1ac toxin-bind ... | 2009 | 19446559 |
| entomotoxicity, protease and chitinase activity of bacillus thuringiensis fermented wastewater sludge with a high solids content. | this study investigated the production of biopesticides, protease and chitinase activity by bacillus thuringiensis grown in raw wastewater sludge at high solids concentration (30 g/l). the rheology of wastewater sludge was modified with addition of tween-80 (0.2% v/v). this addition resulted in 1.6 and 1.3-fold increase in cell and spore count, respectively. the maximum specific growth rate (micro(max)) augmented from 0.17 to 0.22 h(-1) and entomotoxicity (tx) increased by 29.7%. meanwhile, volu ... | 2009 | 19447031 |
| effects of bacillus thuringiensis delta-endotoxins on the pea aphid (acyrthosiphon pisum). | four bacillus thuringiensis delta-endotoxins, cry3a, cry4aa, cry11aa, and cyt1aa, were found to exhibit low to moderate toxicity on the pea aphid, acyrthosiphon pisum, in terms both of mortality and growth rate. cry1ab was essentially nontoxic except at high rates. to demonstrate these effects, we had to use exhaustive buffer-based controls. | 2009 | 19447954 |
| quality assurance of aerial applications of larvicides for mosquito control: effects of granule and catch tray size on field monitoring programs. | aerial applications of granular insecticides are preferable because they can effectively penetrate vegetation, there is less drift, and no loss of product due to evaporation. we aimed to 1) assess the field efficacy ofvectobac g to control aedes vigilax (skuse) in saltmarsh pools, 2) develop a stochastic-modeling procedure to monitor application quality, and 3) assess the distribution of vectobac g after an aerial application. because ground-based studies with ae. vigilax immatures found that ve ... | 2009 | 19449629 |
| technique to assess effectiveness of control tactics against ostrinia nubilalis (lepidoptera: crambidae) in whorl-stage corn. | ostrinia nubilalis (hübner) (lepidoptera: crambidae) is one of the most damaging insect pests of corn. studies were conducted to determine whether live larval counts obtained from corn whorls were predictive of the amount of larval tunneling that would result in the stalk of the plant 40 d later at the end of larval development. whorls from plants treated with dipel 10g (6,400 iu per whorl) and untreated controls, both infested with o. nubilalis neonates, were evaluated for the number of live la ... | 2009 | 19449642 |
| limited survival of a cry2ab-resistant strain of helicoverpa armigera (lepidoptera: noctuidae) on bollgard ii. | bollgard ii cotton (which expresses two bt insecticidal genes cry1ac/cry2ab) and conventional cotton, grown in the laboratory or field and sampled at different stages, was exposed to helicoverpa armigera (hübner) larvae of three genotypes: homozygous for resistance to cry2ab; homozygous for susceptibility to cry2ab, and heterozygous for resistance. survival of all genotypes was limited on bollgard ii but increased as plants aged. this was particularly the case for homozygous resistant individual ... | 2009 | 19449653 |
| combining pest control and resistance management: synergy of engineered insects with bt crops. | transgenic crops producing insecticidal toxins are widely used to control insect pests. their benefits would be lost if resistance to the toxins became widespread in pest populations. the most widely used resistance management method is the high-dose/refuge strategy. this requires toxin-free host plants as refuges near insecticidal crops, and toxin doses intended to be sufficiently high to kill insects heterozygous for a resistant allele, thereby rendering resistance functionally recessive. we h ... | 2009 | 19449654 |
| frequency of alleles conferring resistance to the bacillus thuringiensis toxins cry1ac and cry2ab in australian populations of helicoverpa punctigera (lepidoptera: noctuidae) from 2002 to 2006. | helicoverpa punctigera and helicoverpa armigera (hübner) (lepidoptera: noctuidae) are important pests of field and horticultural crops in australia. the former is endemic to the continent, whereas the latter is also distributed in africa and asia. although h. armigera rapidly developed resistance to virtually every group of insecticide used against it, there is only one report of resistance to an insecticide in h. punctigera. in 1996 the australian cotton industry adopted ingard, which expresses ... | 2009 | 19449655 |
| bacillus thuringiensis resistance influences european corn borer (lepidoptera: crambidae) larval behavior after exposure to cry1ab. | the behavior of pests targeted by bacillus thuringiensis (bt) crops has been recognized as an important factor to define resistance management plans. however, most data do not include the possible impact resistance may have on the behavior of pests. to examine whether resistance influences behavior of european corn borer, ostrinia nubilalis (hübner) (lepidoptera: crambidae), neonates after exposure to dietary bt, the responses of cry1ab-resistant, -susceptible, and hybrid (f1) lines from two pop ... | 2009 | 19449661 |
| loop residues of the receptor binding domain of bacillus thuringiensis cry11ba toxin are important for mosquitocidal activity. | using a cry11ba toxin model, predicted loops in domain ii were analyzed for their role in receptor binding and toxicity. peptides corresponding to loops alpha8, 1 and 3, but not loop 2, competed with toxin binding to aedes midgut membranes. mutagenesis data reveal loops alpha8, 1 and 3 are involved in toxicity. loops 1 and 3 are of greater significance in toxicity to aedes and culex larvae than to anopheles. cry11ba binds the apical membrane of larval caecae and posterior midgut, and binding can ... | 2009 | 19450583 |
| mutagenic analysis of putative domain ii and surface residues in mosquitocidal bacillus thuringiensis cry19aa toxin. | the mosquitocidal crystal protein, cry19aa, from bacillus thuringiensis ssp. jegathesan, has high toxicity to anopheles stephensi and culex pipiens but is less toxic to aedes aegypti. to study the functional role of putative domain ii and surface residues in mosquito toxicity, 16 alanine substitution mutations were introduced into cry19aa. all mutant constructs were expressed as 65-kda protoxins and subsequently digested by trypsin to produce further fragmented polypeptides of 40 and 25 kda. wit ... | 2009 | 19456870 |