Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| siderophores of bacillus anthracis, bacillus cereus, and bacillus thuringiensis. | three bacillus anthracis sterne strains (usamriid, 7702, and 34f2) and bacillus cereus atcc 14579 excrete two catecholate siderophores, petrobactin (which contains 3,4-dihydroxybenzoyl moieties) and bacillibactin (which contains 2,3-dihydroxybenzoyl moieties). however, the insecticidal organism bacillus thuringiensis atcc 33679 makes only bacillibactin. analyses of siderophore production by previously isolated [cendrowski et al., mol. microbiol. 52 (2004) 407-417] b. anthracis mutant strains rev ... | 2006 | 16875672 |
| [the influence of bt-melanin on the recovery of conditioned instrumental reflexes in rats surviving after ablation of the sensorimotor cortex]. | it has been shown the reinforcement of the corticofugal plasticity in adult rats after unilateral ablation of sensorimotor cortex accompanied by intramuscular injections of low concentrations of bt-melanin. in result the process of compensatory recovery in rats central nervous system is accelerated, confirmable by the rapid recovery of previously elaborated instrumental conditioned reflex in comparison with the control animals. it is assumed that the compensation of the motor deficit arised afte ... | 2006 | 16869274 |
| [environmental monitoring and control strategy of urban mosquito culicidae (diptera: culicidae) populations in wrocław]. | among dipterans of medical and veterinary importance, the mosquitoes (culicidae) play the most important role both as vectors and nuisance insects. mass occurrence of floodwater mosquito species in the flooded area in wrocław district (lower silesia, poland) in 1997 has enhanced the already existed problem of mosquito control. a successful model of control strategy for the city based on the currently recommended integrated methodologies with special emphasis on preventive treatment of aquatic la ... | 2004 | 16865970 |
| preparation and evaluation of spore-specific affinity-augmented bio-imprinted beads. | a novel, affinity-augmented, bacterial spore-imprinted, bead material was synthesized, based on a procedure developed for vegetative bacteria. the imprinted beads were intended as a front-end spore capture/concentration stage of an integrated biological detection system. our approach involved embedding bead surfaces with bacillus thuringiensis kurstaki (bt) spores (as a surrogate for bacillus anthracis) during synthesis. subsequent steps involved lithographic deactivation using a perfluoroether; ... | 2006 | 16865337 |
| a detection method of cryiac protein for identifying genetically modified rice using the lateral flow strip assay. | we examined the lateral flow strip assay for identifying unauthorized genetically modified (gm) rice. the gm rice expresses the bacillus thuringiensis (bt) toxin, cryiac protein, which confers tolerance to insects. the recombinant cryiac protein was prepared from the inclusion bodies of an e. coli. strain into which the cryiac gene had been inserted, using gel filtration chromatography. the lateral flow strip assay for the identification of gm cotton which also expresses cryiac protein, was appl ... | 2006 | 16862988 |
| feeding behavior of larval black flies (diptera: simuliidae) with and without exposure to bacillus thuringiensis var. israelensis. | behavioral time budgets were constructed for larval black flies of the simulium jenningsi and s. tuberosum groups in a recirculating flume. larvae spent the majority (54-80%) of time filter feeding. flick rates of the labral fans, which averaged 0.7-1.9 flicks/sec, did not differ significantly between regimens of 0 mg/l and 10 mg/l of food. larvae consistently flicked the fan nearest the water surface significantly more often than the lower fan. they also tended to flick the right fan more than ... | 2006 | 16859093 |
| ovipositional and ovicidal effects of the microbial agent bacillus thuringiensis israelensis on culex quinquefasciatus say (diptera: culicidae). | the magnitude of oviposition as well as the size, shape and the number of eggs per of egg rafts egg raft were determined after gravid culex quinquefasciatus say oviposited on water treated with water dispersible granules (wdg) of bacillus thuringiensis ssp. israelensis (bti) and on untreated water. the mean number of eggs/raft was lower in the treated than in the untreated water. bti concentrations from 0.5 to 2.0mg/l affected the shape of egg rafts and number of eggs in each raft. as the concen ... | 2006 | 16859087 |
| laboratory and field evaluations of rhodojaponin-iii against the imported cabbage worm pieris rapae (l.) (lepidoptera: pieridae). | the activity of rhodojaponin-iii (r-iii), a grayanoid diterpene compound isolated from rhododendron molle g. don flowers, was determined under laboratory and field conditions as an antifeedant, stomach poison, contact toxicant and insect growth inhibitor against pieris rapae (l.) larvae. the median antifeedant concentration (afc(50)) values in no-choice leaf disc tests were 1.16 and 15.85 mg l(-1) at 24 h after treatment when tested against third and fifth instars respectively. the median lethal ... | 2006 | 16856122 |
| characterization of bacillus anthracis-like bacteria isolated from wild great apes from cote d'ivoire and cameroon. | we present the microbiological and molecular characterization of bacteria isolated from four chimpanzees and one gorilla thought to have died of an anthrax-like disease in côte d'ivoire and cameroon. these isolates differed significantly from classic bacillus anthracis by the following criteria: motility, resistance to the gamma phage, and, for isolates from cameroon, resistance to penicillin g. a capsule was expressed not only after induction by co(2) and bicarbonate but also under normal growt ... | 2006 | 16855222 |
| pyrolysis mass spectrometry for distinguishing potential hoax materials from bioterror agents. | pyrolysis mass spectrometry (pyms) was investigated as a rapid tool to distinguish potential bioterror hoax materials from samples containing pathogenic bacteria. a pyrolysis time-of-flight (tof) mass spectrometer equipped with an alternative ionization technique, metastable atom bombardment (mab), was used to produce sample spectra. these spectra were analyzed by principal component and discriminant analysis for pattern recognition. materials investigated were two strains of vibrio parahaemolyt ... | 2006 | 16841357 |
| ecological risk assessment for bt crops. | 2006 | 16841050 | |
| restraining erwinia virulence by expression of n-acyl homoserine lactonase gene pro3a-aiia in bacillus thuringiensis subsp leesis. | to widen the biological control function of a genetically modified bacillus thuringiensis subsp leesis strain bmb-005, an acyl homoserine lactonase (ahl lactonase) gene aiia transcribed by the promoter of insecticidal crystal protein coding gene cry3a, was transformed into strain bmb-005. the amount of ahl lactonase protein produced by transformant bmb821a was 2.4-fold more than that produced by bmb-005. ahl-degradation assay showed that transformant bmb821a could degrade more ahls molecules tha ... | 2006 | 16838380 |
| activation process of the mosquitocidal delta-endotoxin cry39a produced by bacillus thuringiensis subsp. aizawai bun1-14 and binding property to anopheles stephensi bbmv. | most delta-endotoxins produced by bacillus thuringiensis require proteolytic processing in order to become active. the in vitro and in vivo activation processes of cry39a, a delta-endotoxin that is highly toxic to anopheles stephensi, were investigated. cry39a with a molecular mass of 72 kda was processed in vitro into a 60 kda fragment by trypsin and gut extract from a. stephensi larvae. n-terminal amino acid sequencing of the 60 kda fragment revealed that trypsin and the protease(s) in the gut ... | 2006 | 16837008 |
| genetically engineered plants, endangered species, and risk: a temporal and spatial exposure assessment for karner blue butterfly larvae and bt maize pollen. | genetically engineered maize (zea mays) containing insecticidal endotoxin proteins from bacillus thuringiensis (bt) delta-endotoxin proteins has been adopted widely in the midwestern united states. the proteins are toxic to several lepidopteran species and because a variety of maize tissues, including pollen, may express the endotoxins, the probability of exposure to nontarget species, including endangered species, needs to be understood. the objective of this study was to assess the potential t ... | 2006 | 16834638 |
| diversity of bacillus thuringiensis strains in the maize and bean phylloplane and their respective soils in colombia. | to evaluate the distribution of bacillus thuringiensis strains from maize and bean phylloplane and their respective soils. | 2006 | 16834598 |
| a metabonomic study of transgenic maize (zea mays) seeds revealed variations in osmolytes and branched amino acids. | the aim of the research was to investigate metabolic variations associated with genetic modifications in the grains of zea mays using metabonomic techniques. with this in mind, the non-targeted characteristic of the technique is useful to identify metabolites peculiar to the genetic modification and initially undefined. the results obtained showed that the genetic modification, introducing cry1ab gene expression, induces metabolic variations involving the primary nitrogen pathway. concerning the ... | 2006 | 16831843 |
| influence of the biophysical and biochemical environment on the kinetics of pore formation by cry toxins. | the effect of bacillus thuringiensis toxins on the permeability of the luminal membrane of manduca sexta midgut columnar epithelial cells is strongly influenced by several biophysical and biochemical factors, including ph, ionic strength, and divalent cations, suggesting an important role for electrostatic interactions. the influence of these factors can differ greatly, however, depending on the toxin being studied, even for closely related toxins such as cry1ac and cry1ca. in the present study, ... | 2006 | 16831627 |
| an ecological risk assessment of cry1f maize pollen impact to pale grass blue butterfly. | the intrinsic toxicity of lepidopteran-active bt proteins necessitates assessment of non-target risks associated with environmental release of transgenic crops expressing these proteins. principles of ecological risk assessment provide a means for assessing non-target risks when information regarding exposure to the toxin and species-specific effects are lacking. this is shown for the case of bt cry1f maize release in japan, where off-field pollen dissemination and effect on butterfly species is ... | 2006 | 16827552 |
| molecular and insecticidal characterization of a cry1i protein toxic to insects of the families noctuidae, tortricidae, plutellidae, and chrysomelidae. | the most notable characteristic of bacillus thuringiensis is its ability to produce insecticidal proteins. more than 300 different proteins have been described with specific activity against insect species. we report the molecular and insecticidal characterization of a novel cry gene encoding a protein of the cry1i group with toxic activity towards insects of the families noctuidae, tortricidae, plutellidae, and chrysomelidae. pcr analysis detected a dna sequence with an open reading frame of 2. ... | 2006 | 16820473 |
| sequence diversity of the bacillus thuringiensis and b. cereus sensu lato flagellin (h antigen) protein: comparison with h serotype diversity. | we set out to analyze the sequence diversity of the bacillus thuringiensis flagellin (h antigen [hag]) protein and compare it with h serotype diversity. some other bacillus cereus sensu lato species and strains were added for comparison. the internal sequences of the flagellin (hag) alleles from 80 bacillus thuringiensis strains and 16 strains from the b. cereus sensu lato group were amplified and cloned, and their nucleotide sequences were determined and translated into amino acids. the flagell ... | 2006 | 16820457 |
| effect of resistance to bacillus thuringiensis cotton on pink bollworm (lepidoptera: gelechiidae) response to sex pheromone. | fitness costs associated with resistance to transgenic crops producing toxins from bacillus thuringiensis (bt) could reduce male response to pheromone traps. such costs would cause underestimation of resistance frequency if monitoring was based on analysis of males caught in pheromone traps. to develop a dna-based resistance monitoring program for pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), we compared the response to pheromone traps of males with and without c ... | 2006 | 16813335 |
| differences in susceptibility and physiological fitness of mexican field trichoplusia ni strains exposed to bacillus thuringiensis. | the use of different commercial bacillus thuringiensis (bt) products in the bajio guanajuatense area in mexico began 12 yr ago, and resistance to bt in this area has been reported for plutella xylostella (l.) the current study provides a baseline response and resistance potential to bt in field and laboratory strains of bajio trichoplusia ni (hübner). differences in susceptibility to bt among t. ni populations were observed. t. ni neonates collected in romita, guanajuato, were more susceptible t ... | 2006 | 16813334 |
| effect of bacillus thuringiensis cry3bb1 protein on the feeding behavior and longevity of adult western corn rootworms (coleoptera: chrysomelidae). | the first transgenic corn hybrids expressing the bacillus thuringiensis (bt) cry3bb1 protein to control corn rootworm (diabrotica spp.) larvae were registered for commercial use in 2003. this study was conducted to investigate the effect of cry3bb1 protein in combination with a cucurbitacin bait on adult feeding and longevity of both organophosphate-resistant and -susceptible western corn rootworms, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae). in choice and no-choice tests ... | 2006 | 16813332 |
| effect of entomopathogenic nematodes on the fitness cost of resistance to bt toxin crylac in pink bollworm (lepidoptera: gelechiidae). | the widespread use of crop plants genetically engineered to produce toxins from the bacterium bacillus thuringiensis (bt) imposes selection on insect populations to evolve resistance. the pink bollworm, pectinophora gossypiella (saunders) (lepidoptera: gelechiidae), is a major pest of cotton in the southwestern united states that is currently controlled with transgenic cotton that produces bt toxin cry1ac. previously reported theoretical work suggests that, in conjunction with a high dose/refuge ... | 2006 | 16813331 |
| resistance monitoring of helicoverpa armigera (lepidoptera: noctuidae) to bt insecticidal protein during 2001-2004 in china. | susceptibility of helicoverpa armigera (hübner) (lepidoptera: noctuidae) field populations to the crylac toxin of bacillus thuringiensis berliner (bt) were monitored from 1997 to 2004 in china. during 2001-2004, 53 strains from the bt cotton planting region were sampled. the range of concentration producing 50% inhibition of larval development to third instar (ic50) values among different populations in 2001, 2002, 2003, and 2004 was 0.014-0.046, 0.010-0.062, 0.005-0.062, and 0.005-0.035 microg/ ... | 2006 | 16813327 |
| potential of selective insecticides for managing uraba lugens (lepidoptera: nolidae) on eucalypts. | the leaf skeletonizer uraba lugens walker (lepidoptera: nolidae), an australian species, locally known as "gumleaf skeletonizer", is well established in new zealand. this insect has the potential to become a serious pest of forestry and amenity eucalypts (eucalyptus spp.) and is the focus of a long-term management program. the use of synthetic chemical or biological insecticides is one possible control method within an integrated control program. a series of dose-response trials were conducted u ... | 2006 | 16813312 |
| cannibalism of helicoverpa zea (lepidoptera: noctuidae) from bacillus thuringiensis (bt) transgenic corn versus non-bt corn. | because of the importance of cannibalism in population regulation of helicoverpa zea (boddie) (lepidoptera: noctuidae) in corn, zea mays l., it is useful to understand the interactions between bacillus thuringiensis (bt) transgenic corn and cannibalism. to determine the effects of bt corn on cannibalism in h. zea, pairs of the same or different instars were taken from bt or non-bt corn and placed on artificial diet in proximity. cannibalism occurred in 91% of pairs and was approximately 7% great ... | 2006 | 16813305 |
| diabrotica virgifera virgifera (coleoptera: chrysomelidae) larval feeding behavior on transgenic maize (mon 863) and its isoline. | diabrotica species (coleoptera: chrysomelidae) larval behavior studies have posed a challenge to researchers because of the subterranean life cycle of this pest. to fully understand how the western corn rootworm, diabrotica virgifera virgifera leconte, injures the maize, zea mays l., root system, its behavior must be studied. for example, larvae that can detect an area of the root that has a lower amount of toxin, whether from an insecticide or a transgenic maize plant, have an increased chance ... | 2006 | 16813304 |
| cytocidal actions of parasporin-2, an anti-tumor crystal toxin from bacillus thuringiensis. | parasporin-2, a new crystal protein derived from noninsecticidal and nonhemolytic bacillus thuringiensis, recognizes and kills human liver and colon cancer cells as well as some classes of human cultured cells. here we report that a potent proteinase k-resistant parasporin-2 toxin shows specific binding to and a variety of cytocidal effects against human hepatocyte cancer cells. cleavage of the n-terminal region of parasporin-2 was essential for the toxin activity, whereas c-terminal digestion w ... | 2006 | 16809341 |
| pronase digestion of brush border membrane-bound cry1aa shows that almost the whole activated cry1aa molecule penetrates into the membrane. | bacillus thuringiensis insecticidal proteins, cry toxins, following ingestion by insect larvae, induce insecticidal effect by penetrating the brush border membranes (bbm) of midgut epithelial cells. purified, activated b. thuringiensis cry1aa bound to bombyx mori bbmv or unbound cry1aa were vigorously digested with pronase. both digests were compared by western blotting. free cry1aa was digested to alpha-helix and/or to amino acids at 1 mg pronase/ml within 2.4 h at 37 degrees c. whereas, bbmv-b ... | 2006 | 16807030 |
| chemical-induced autoexcision of selectable markers in elite tomato plants transformed with a gene conferring resistance to lepidopteran insects. | marker-free transgenic tomato plants harboring a synthetic bacillus thuringiensis endotoxin gene, cryiac, were obtained by using a chemically regulated, cre/loxp-mediated site-specific dna recombination system, in which the selectable marker neomycin phosphotransferase gene flanked by two directly oriented loxp sites was located between the cauliflower mosaic virus 35s promoter and a promoterless cryiac. upon induction by 2 microm beta-estradiol, sequences encoding the selectable marker and cre ... | 2006 | 16802102 |
| cry toxin mode of action in susceptible and resistant heliothis virescens larvae. | many pest insect species are effectively controlled by bacillus thuringiensis (bt) cry toxins delivered in plants and biopesticides. since the insect midgut epithelium contains receptors and other molecules that determine bt toxicity, characterization of these molecules is necessary for sustained usage of bt toxins. studies of bt susceptible and resistant strains of heliothis virescens have provided insights into resistance mechanisms and toxin receptors. for example, the first gene identified a ... | 2006 | 16797583 |
| expression of cry1ac cadherin receptors in insect midgut and cell lines. | cadherin-like proteins have been identified as putative receptors for the bacillus thuringiensis cry1a proteins in heliothis virescens and manduca sexta. immunohistochemistry showed the cadherin-like proteins are present in the insect midgut apical membrane, which is the target site of cry toxins. this subcellular localization is distinct from that of classical cadherins, which are usually present in cell-cell junctions. immunoreactivity of the cadherin-like protein in the insect midgut was enha ... | 2006 | 16797582 |
| antimicrobial activities of human beta-defensins against bacillus species. | natural defences in the human body function to protect us from numerous environmental toxins and exposure to potential harmful biological agents. an important frontline defence is antimicrobial peptides. these peptides occur at environmental interfaces and serve to limit bacterial invasion. there has been little work comparing specific peptides as potential antimicrobial compounds. in this study, we evaluated the antimicrobial activity of peptides from the human beta-defensin (hbd) family agains ... | 2006 | 16797165 |
| the enhancin-like metalloprotease from the bacillus cereus group is regulated by the pleiotropic transcriptional activator plcr but is not essential for larvicidal activity. | bacillus cereus group bacteria produce virulence factors. many of these are regulated by the pleiotropic transcriptional activator plcr, which is implicated in insect virulence. in silico analysis of the b. cereus strain atcc14579 genome showed an enhancin-like gene preceded by a typical plcr binding sequence. the gene is predicted to encode a polypeptide showing 23-25% identity with enhancins from several baculoviruses and 31% with that of yersinia pestis. viral enhancin acts after oral infecti ... | 2006 | 16790012 |
| a mechanism of cell death involving an adenylyl cyclase/pka signaling pathway is induced by the cry1ab toxin of bacillus thuringiensis. | many pathogenic organisms and their toxins target host cell receptors, the consequence of which is altered signaling events that lead to aberrant activity or cell death. a significant body of literature describes various molecular and cellular aspects of toxins associated with bacterial invasion, colonization, and host cell disruption. however, there is little information on the molecular and cellular mechanisms associated with the insecticidal action of bacillus thuringiensis (bt) cry toxins. r ... | 2006 | 16788061 |
| laboratory and field tests of spray-dried and granular formulations of a bacillus thuringiensis strain with insecticidal activity against the sugarcane borer. | formulations of bacillus thuringiensis berliner (bt) with insecticidal activity against the sugarcane borer, diatraea saccharalis fabricius (lepidoptera: pyralidae), were developed and tested under laboratory and field conditions. the formulations were prepared using biodegradable polymers such as modified corn starch as an encapsulating agent, gelatin as an adherent, powdered sugarcane as a feeding stimulant and a bt var. kurstaki gm-34 strain from a non-sugarcane region as the active ingredien ... | 2006 | 16786544 |
| effects of commercial microbial products on the immune system of elliptio complanata mussels. | 2006 | 16786456 | |
| mycotoxin reduction in bt corn: potential economic, health, and regulatory impacts. | genetically modified (gm) bt corn, through the pest protection that it confers, has lower levels of mycotoxins: toxic and carcinogenic chemicals produced as secondary metabolites of fungi that colonize crops. in some cases, the reduction of mycotoxins afforded by bt corn is significant enough to have an economic impact, both in terms of domestic markets and international trade. in less developed countries where certain mycotoxins are significant contaminants of food, bt corn adoption, by virtue ... | 2006 | 16779644 |
| vip3a is responsible for the potency of bacillus thuringiensis 9816c culture supernatant against helicoverpa armigera and spodoptera exigua. | culture supernatant of bacillus thuringiensis 9816c had high toxicity against helicoverpa armigera and spodoptera exigua. however, it lost insecticidal activities after being bathed in boiling water for 5 min. acrystalliferous mutants of bt9816c (bt9816c-np1 and bt9816c-np2) cured of its endogenous plasmids no longer possessed vip3a gene and toxicity. the 89 kd protein which existed in bt9816c supernatant disappeared in the two mutants' supernatant; nevertheless, the two mutants still exhibited ... | 2006 | 16778351 |
| pathogenicity of intrathoracically administrated bacillus thuringiensis spores in blatta orientalis. | the ability of bacillus thuringiensis to produce septicaemia in periplaneta americana and blatta orientalis has been investigated. spores and crystals from several wild-type strains as well as spores of a b. thuringiensis crystal-deficient mutant, were first orally administrated at high doses, and no significant mortality was recorded. intrathoracic injection of spore suspensions in p. americana revealed that this species is not very susceptible to b. thuringiensis spores. b. orientalis, by cont ... | 2006 | 16777139 |
| structural and functional analysis of the pre-pore and membrane-inserted pore of cry1ab toxin. | bacillus thuringiensis produces insecticidal cry proteins that are active against different insect species. the primary action of cry toxins is to lyse midgut epithelial cells in the target insect by forming lytic pores on the apical membrane. after interaction with cadherin receptor, cry proteins undergo conformational changes from a monomeric structure to a pre-pore-oligomeric form that is able to interact with a second gpi-anchored aminopeptidase-n receptor and then insert into lipid membrane ... | 2006 | 16777138 |
| cry1aa lacks stability elements at its 5'-utr but integrity of its transcription terminator is critical to prevent decay of its transcript. | we analyzed the influence of the 5' and 3' untranslated regions of the bacillus thuringiensis cry1aa on its mrna stability. although the cry1aa gene has a stable transcript (8 min), its 5' utr did not provide stability to the reporter gene uida. stability of cry1aa could be increased to 40 min by addition of an sp82 stability element at the 5' utr, suggesting that once the 5' and 3' ends were protected initiation of decay could be effectively blocked. we generated mutations in the transcription ... | 2006 | 16775783 |
| characterization of bacillus thuringiensis strain bt185 toxic to the asian cockchafer: holotrichia parallela. | a new bacillus thuringiensis strain, bt185, was isolated from hebei soil samples in china. observations after transmission electron microscopy found that the strain produced spherical parasporal inclusions similar to that of the b. thuringiensis subsp. japonensis buibui strain, which showed toxicity to both anomala corpulenta and popillia japonica. the plasmid profile seen on an agarose gel revealed that bt185 contained six large bands of 191 kb, 161 kb, 104 kb, 84 kb, 56 kb, and 37 kb. sodium d ... | 2006 | 16775781 |
| malaysian mosquitocidal soil bacterium (bacillus thuringiensis) strains with selective hemolytic and lectin activity against human and rat erythrocytes. | the objective of this study is to determine the role of carbohydrates on the toxic effect of parasporal inclusion proteins isolated from malaysian mosquitocidal bacillus thuringiensis (bt) strains on erythrocytes (human and rat). dose response analyses on the effect of these parasporal inclusions on human and rat erythrocytes suggest that toxin action is selective depending on bacterial strains and source of erythrocytes. results from this study suggest bt toxin is a lectin which recognizes spec ... | 2006 | 16771215 |
| laboratory and semi-field evaluation of mosquito dunks against aedes aegypti and aedes albopictus larvae (diptera: culicidae). | laboratory bioassays and semi-field studies were conducted on the efficacy and longevity of mosquito dunks (7,000 itu/mg bti) in order to determine the concentration-response relationship and the effectiveness on the potency of the bti product against aedes mosquito species based on the who protocol standard methods and to determine the longevity of release for this product against ae. aegypti mosquito larvae in water storage containers. this bio-potency study with the late 3rd instar larvae of ... | 2006 | 16771214 |
| effects of cry1ac toxin of bacillus thuringiensis and nuclear polyhedrosis virus of helicoverpa armigera (hübner) (lepidoptera: noctuidae) on larval mortality and pupation. | in the laboratory, the percentage mortality and pupation of helicoverpa armigera (hübner) were investigated when larvae were exposed to cry1ac of bacillus thuringiensis berliner, nuclear polyhedrosis virus of h. armigera (hanpv) or cry1ac and hanpv together. the results revealed that interactions between cry1ac and hanpv varied with bioassay method and concentration of the suspension. when larvae were infected using a suspension containing both hanpv and cry1ac, most combinations of cry1ac (62.5 ... | 2006 | 16770833 |
| invasion of pests resistant to bt toxins can lead to inherent non-uniqueness in genetically modified bt-plant dynamics: mathematical modeling. | genetically modified crops are effective pest management tools for worldwide growers. however, there is a concern that pests may develop resistance to bt-toxins produced by genetically modified bt-plants. we study the impact of the bt-resistant pests on bt-crops. furthermore, the dynamics of the bt-plant-bt-susceptible insects-bt-resistant insects system is analysed and it is shown that throughout the insect reproduction period the plant biomass dynamics resulting from invasion of bt-resistant i ... | 2006 | 16757001 |
| novel preparation and characterization of the alpha4-loop-alpha5 membrane-perturbing peptide from the bacillus thuringiensis cry4ba delta-endotoxin. | helices 4 and 5 of the bacillus thuringiensis cry4ba delta-endotoxin have been shown to be important determinants for mosquito-larvicidal activity, likely being involved in membrane-pore formation. in this study, the cry4ba mutant protein containing an additional engineered tryptic cleavage site was used to produce the alpha4-alpha5 hairpin peptide by an efficient alternative strategy. upon solubilization of toxin inclusions expressed in escherichia coli and subsequent digestion with trypsin, th ... | 2006 | 16756755 |
| acrylic acid removal by acrylic acid utilizing bacteria from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system. | the aim of this study is to isolate the acrylic acid utilizing bacteria from the abs resin manufactured wastewater treatment system. the bacteria should have the ability to remove acrylic acid and tolerate the acrylonitrile and acrylamide toxicity. the aim is also to understand the performance of isolated pure strain for treating different initial acrylic acid concentrations from synthetic wastewater. the results are: twenty strains were isolated from the abs resin manufactured wastewater treatm ... | 2006 | 16749456 |
| prevention and control of pests and diseases. | a well-controlled growth environment with plants that are not unduly stressed is essential for arabidopsis molecular biology research. even if they do not kill the plants outright, insect pests and microbial pathogens can cause subtle changes in gene expression or plant metabolism that affect experimental results. therefore, regular scouting for infestations, frequent cleaning of plant growth areas, proper disposal of dead or diseased plant material, and controlled access to the greenhouses or g ... | 2006 | 16739564 |
| impact of transgenic bt maize residues on the mycotoxigenic plant pathogen fusarium graminearum and the biocontrol agent trichoderma atroviride. | transformation of maize with genes encoding for insecticidal crystal (cry) proteins from bacillus thuringiensis (bt) could have an impact on the saprophytic survival of plant pathogens and their antagonists on crop residues. we assessed potential effects on the mycotoxin deoxynivalenol (don)-producing wheat and maize pathogen fusarium graminearum and on the biocontrol agent trichoderma atroviride. purified cry1ab protein caused no growth inhibition of these fungi on agar plates. cry1ab concentra ... | 2006 | 16738384 |
| lactobacillus plantarum gene clusters encoding putative cell-surface protein complexes for carbohydrate utilization are conserved in specific gram-positive bacteria. | genomes of gram-positive bacteria encode many putative cell-surface proteins, of which the majority has no known function. from the rapidly increasing number of available genome sequences it has become apparent that many cell-surface proteins are conserved, and frequently encoded in gene clusters or operons, suggesting common functions, and interactions of multiple components. | 2006 | 16723015 |
| resistance evolution to bt crops: predispersal mating of european corn borers. | over the past decade, the high-dose refuge (hdr) strategy, aimed at delaying the evolution of pest resistance to bacillus thuringiensis (bt) toxins produced by transgenic crops, became mandatory in the united states and is being discussed for europe. however, precopulatory dispersal and the mating rate between resident and immigrant individuals, two features influencing the efficiency of this strategy, have seldom been quantified in pests targeted by these toxins. we combined mark-recapture and ... | 2006 | 16719560 |
| effects of genetic modification on herbivore-induced volatiles from maize. | large-scale implementation of transgenic crop varieties raises concerns about possible nontarget effects on other organisms. this study examines the effects of genetic modification on plant volatile production and its potential impact on arthropod population dynamics. we compared herbivore-induced volatile emissions from bacillus thuringiensis berliner (bt) maize plants to those from a nontransformed isoline following exposure to various types of leaf damage. when equal numbers of helicoverpa ze ... | 2006 | 16718567 |
| identification of a bacillus thuringiensis cry11ba toxin-binding aminopeptidase from the mosquito, anopheles quadrimaculatus. | aminopeptidase n (apn) type proteins isolated from several species of lepidopteran insects have been implicated as bacillus thuringiensis (bt) toxin-binding proteins (receptors) for cry toxins. we examined brush border membrane vesicle (bbmv) proteins from the mosquito anopheles quadrimaculatus to determine if apns from this organism would bind mosquitocidal cry toxins that are active to it. | 2006 | 16716213 |
| identification and characterization of a germination operon from bacillus thuringiensis. | spore cortex-lytic enzymes are essential for germination in bacillus. a homologue of the cwlj gene involved in spore germination was isolated from bacillus thuringiensis. the deduced product of this gene exhibits striking sequence similarity to cwlj of bacillus subtilis. another open reading frame (orf) was found 27 bp downstream of cwlj and its deduced product shows high similarity to ywdl of b. subtilis. reverse transcription polymerase chain reaction analysis indicated that cwlj and ywdl form ... | 2006 | 16710636 |
| frequency and fitness cost of resistance to bacillus thuringiensis in chrysomela tremulae (coleoptera: chrysomelidae). | the "high dose-refuge" (hdr) strategy is commonly recommended and currently used for delaying or preventing pest adaptation to transgenic plants producing bacillus thuringiensis (bt) toxins. the efficiency of this strategy depends, among other factors, on the initial frequency of bt resistance alleles and on the fitness costs associated with these alleles. two years ago, an allele conferring resistance to bt poplar was detected in a french population of the poplar pest chrysomela tremulae f. alt ... | 2006 | 16705321 |
| occurrence of parasporin-producing bacillus thuringiensis in vietnam. | a total of 63 bacillus thuringiensis isolates were recovered from urban soils of hanoi, vietnam. of these, 34 were identified to 12 h serogroups. none of the isolates showed larvicidal activities against three lepidopterous insects. three isolates belonging to the two serovars, colmeri (h21) and konkukian (h34), were highly toxic to larvae of the mosquito aedes aegypti. parasporal inclusion proteins of four isolates exhibited cytocidal activities against hela cells. immunologically, proteins of ... | 2006 | 16699587 |
| detection of antibiotic-related genes from bacterial biocontrol agents with polymerase chain reaction. | pseudomonas chlororaphis pa23, pseudomonas spp. strain df41, and bacillus amyloliquefaciens bs6 consistently inhibit infection of canola petals by sclerotinia sclerotiorum in both greenhouse and field experiments. bacillus thuringiensis bs8, bacillus cereus l, and bacillus mycoides s have shown significant inhibition against s. sclerotiorum on plate assays. the presence of antibiotic biosynthetic or self-resistance genes in these strains was investigated with polymerase chain reaction and, in on ... | 2006 | 16699573 |
| adhesion and cytotoxicity of bacillus cereus and bacillus thuringiensis to epithelial cells are flha and plcr dependent, respectively. | some bacteria of the bacillus cereus group are enteropathogens. the first cells encountered by bacteria following oral contamination of the host are epithelial cells. we studied the capacity of these bacteria to adhere to epithelial cells and the consequences of this interaction. we found that cell adhesion is strain dependent and that a strain mutated in flha, which encodes a component of flagellum-apparatus formation, is impaired in adhesion, suggesting that flagella are important virulence fa ... | 2006 | 16697234 |
| composition of bacillus species in aerosols from 11 u.s. cities. | a pcr-based heteroduplex assay was used to determine the presence and composition of bacillus species in 11,059 environmental protection agency pm2.5 aerosol samples from 11 u.s. cities. the assay differentiated three groups: type a containing bacillus anthracis and very closely related, often pathogenic, bacillus cereus and bacillus thuringiensis strains; type b containing other b. cereus and b. thuringiensis strains; and a third group of more-distantly related bacillus species. eight of the 11 ... | 2006 | 16696702 |
| recent developments and future prospects in insect pest control in transgenic crops. | the adoption of insect-resistant transgenic crops has been increasing annually at double-digit rates since the commercial release of first-generation maize and cotton expressing a single modified bacillus thuringiensis toxin (bt) nine years ago. studies have shown that these bt crops can be successfully deployed in agriculture, which has led to a decrease in pesticide usage, and that they are environmentally benign. however, the sustainability and durability of pest resistance continues to be di ... | 2006 | 16690346 |
| insecticidal activity of avidin combined with genetically engineered and traditional host plant resistance against colorado potato beetle (coleoptera: chrysomelidae) larvae. | colorado potato beetle, leptinotarsa decemlineata (say), is a destructive pest of potato, solanum tuberosum (l.), in north america. it is renowned for adapting to insecticides. with the arsenal of effective insecticides decreasing, it is important to consider alternative forms of control. biotin is an essential coenzyme for insect growth and development. avidin is a protein found in chicken egg that sequesters biotin and has shown insecticidal properties against a range of insect. we assessed th ... | 2006 | 16686156 |
| is resistance to bacillus thuringiensis endotoxin cry1ac associated with a change in the behavior of light brown apple moth larvae (lepidoptera: tortricidae)? | bacillus thuringiensis (bt)-resistant light brown apple moth, epiphyas postvittana (walker) (lepidoptera: tortricidae), created by selection of a laboratory colony with artificial diets containing the bt endotoxin cry1ac, were used to explore relationships between larval behavior and resistance to toxins. our hypothesis was that behavioral responses during the first days of exposure to diet are directly related to the toxicity of the diet, as measured by subsequent mortality. we tested two predi ... | 2006 | 16686154 |
| frequency of resistance to bacillus thuringiensis toxin cry1ab in southern united states corn belt population of european corn borer (lepidoptera: crambidae). | the high-dose refuge resistance management strategy is the main approach used to delay resistance in targeted pests to bacillus thuringiensis (bt) toxins in transgenic crops. we used an f2 screen to test a critical assumption of the high-dose refuge strategy, which is that resistance allele (r) frequencies are initially rare (<10(-3)) in ostrinia nubilalis (hübner) (lepidoptera: crambidae) from the southern corn belt. we expanded the methodological scope of the f2 screen so that both males and f ... | 2006 | 16686153 |
| inheritance of resistance to the cry1ab bacillus thuringiensis toxin in ostrinia nubilalis (lepidoptera: crambidae). | laboratory selection with cry1ab, the predominant bacillus thuringiensis (bt) toxin in transgenic corn, zea mays l., produced >1000-fold resistance in two laboratory strains of european corn borer, ostrinia nubilalis (hübner). we tested the offspring of various crosses to determine the mode of inheritance of resistance to cry1ab. patterns of inheritance of resistance were similar in the two resistant strains. the progeny of reciprocal f1 crosses (resistant male x susceptible female and vice vers ... | 2006 | 16686152 |
| inactivation of biological agents using neutral oxone-chloride solutions. | bleach solutions containing the active ingredient hypochlorite (ocl-) serve as powerful biological disinfectants but are highly caustic and present a significant compatibility issue when applied to contaminated equipment or terrain. a neutral, bicarbonate-buffered aqueous solution of oxone (2k2hso5.khso4.k2so4) and sodium chloride that rapidly generates hypochlorite and hypochlorous acid (hocl) in situ was evaluated as a new alternative to bleach for the inactivation of biological agents. the so ... | 2006 | 16683620 |
| farm-scale evaluation of the impacts of transgenic cotton on biodiversity, pesticide use, and yield. | higher yields and reduced pesticide impacts are needed to mitigate the effects of agricultural intensification. a 2-year farm-scale evaluation of 81 commercial fields in arizona show that use of transgenic bacillus thuringiensis (bt) cotton reduced insecticide use, whereas transgenic cotton with bt protein and herbicide resistance (bthr) did not affect herbicide use. transgenic cotton had higher yield than nontransgenic cotton for any given number of insecticide applications. however, nontransge ... | 2006 | 16675554 |
| the international bacillus anthracis, b. cereus, and b. thuringiensis conference, "bacillus-act05". | 2006 | 16672596 | |
| occurrence of natural bacillus thuringiensis contaminants and residues of bacillus thuringiensis-based insecticides on fresh fruits and vegetables. | a total of 128 bacillus cereus-like strains isolated from fresh fruits and vegetables for sale in retail shops in denmark were characterized. of these strains, 39% (50/128) were classified as bacillus thuringiensis on the basis of their content of cry genes determined by pcr or crystal proteins visualized by microscopy. random amplified polymorphic dna analysis and plasmid profiling indicated that 23 of the 50 b. thuringiensis strains were of the same subtype as b. thuringiensis strains used as ... | 2006 | 16672488 |
| bacillus thuringiensis section sign-endotoxin expressed in transgenic nicotiana tabacum provides resistance to lepidopteran insects. | the crystal proteins, or section sign-endotoxins, of bacillus thuringiensis are specifically lethal to lepidopteran insects. we utilized a truncated and modified portion of a cloned crystal protein gene to construct a chimeric gene capable of expression in plant cells. using an agrobacterium tumefaciens binary vector system, we then transferred the chimeric toxin gene into tobacco (nicotiana tabacum cv havana 425) cells and regenerated recombinant plants. one to several copies per cell of the to ... | 1987 | 16665812 |
| susceptibility of adult coccinella septempunctata (coleoptera: coccinellidae) to insecticides with different modes of action. | five insecticides (pyriproxifen, imidacloprid, deltamethrin + heptenophos, lambda-cyhalothrin and bacillus thuringiensis berliner subsp. tenebrionis) were examined in the laboratory for their acute detrimental side-effects at field rates on adult seven-spot ladybird beetle, coccinella septempunctata l. the toxicity of the preparations was determined by measuring the acute surface contact effects (dried spray on leaves of philadelphus coronarius l.), except for b. thuringiensis where mixed pollen ... | 2006 | 16649191 |
| mitigating the effects of the green alga scenedesmus quadricauda on the efficacy of bacillus thuringiensis var. israelensis against larval black flies. | the green alga scenedesmus quadricauda has been shown to decrease the efficacy of bacillus thuringiensis var. israelensis (bti) to black fly larvae in laboratory experiments. in this study, 2 approaches to mitigating the effects of s. quadricauda were tested, increasing the dose of bti exposed to the larval black flies and increasing the length of the exposure period. results showed that increasing the dose as well as increasing the exposure time were effective methods for mitigating the effects ... | 2006 | 16646337 |
| susceptibility of laboratory and field-collected aedes aegypti and aedes albopictus to bacillus thuringiensis israelensis h-14. | susceptibility levels of a few laboratory-cultured and dengue-endemic area field-collected strains of aedes aegypti and aedes albopictus to bacillus thuringiensis israelensis (bti) at different storage ages were studied. the susceptibility of laboratory-cultured world health organization (who) bora bora reference, vector control research unit (vcru), and fumakilla malaysia berhad (fmb) strains of ae. aegypti to bti was examined. the sensitivity to bti decreased with storage age. the median letha ... | 2006 | 16646329 |
| discovery of a significant optical chromatographic difference between spores of bacillus anthracis and its close relative, bacillus thuringiensis. | a significant difference between two closely related bacillus spores has been discovered using optical chromatography. this difference can be harnessed for the separation of microscopic particles using opposing laser and fluid flow forces. particles of different size, composition, and shape experience different optical and fluid forces and come to rest at unique equilibrium positions where the two forces balance. separations in excess of 600 mum have been observed between bacillus anthracis ster ... | 2006 | 16643018 |
| relationship between poly-beta-hydroxybutyrate production and delta-endotoxin for bacillus thuringiensis var. kurstaki. | a linear relationship between total solid concentration (tsc), delta-endotoxin production [cry = 0.2795(tsc)-0.2472, r2 = 0.8644] and poly-beta-hydroxybutyrate (phb) accumulation [phb = 0.1327(tsc) + 0.3974, r2 = 0.9877] in bacillus thuringiensis var. kurstaki hd-73 was observed. a similar correlation between delta-endotoxin and phb accumulation [cry = 2.1573(phb)-1.1248, r2 = 0.9181] was found. a minimum phb accumulation of 0.52 mg l(-1) was required before the onset of delta-endotoxin producti ... | 2006 | 16642302 |
| simple and rapid method for detection of bacterial spores in powder useful for first responders. | the need for a rapid method by which first responders can screen for the presence of spores in powder samples has been increased since the anthrax attack of 2001. the majority of powders that were sampled in the context of that attack were hoaxes and did not contain bacillus anthracis. the large number of samples overwhelmed the analysis capacity of public health laboratories. a rapid screening method for determining the presence of viable spores would eliminate much laboratory work and expedite ... | 2006 | 16637561 |
| carboxy-terminal extension effects on crystal formation and insecticidal properties of colorado potato beetle-active bacillus thuringiensis delta-endotoxins. | many bacillus thuringiensis crystal proteins, particularly those active against lepidopteran insects, have carboxy-terminal extensions that mediate bipyramidal crystal formation. these crystals are only soluble at high (>10.0) ph in reducing conditions such as generally found in the lepidopteran midgut. most of the colorado potato beetle (cpb)-active toxins lack such an extension, yet some toxins with a carboxy-terminal extension have cryptic activity against this insect, revealed only after in ... | 2006 | 16632885 |
| cloning, characterization, and expression of a new cry2ab gene from bacillus thuringiensis strain 14-1. | bacillus thuringiensis is the major source for transfer of genes to impart insect resistance in transgenic plants. cry2a proteins of b. thuringiensis are promising candidates for management of resistance development in insects owing to their difference from the currently used cry1a proteins, in structure and insecticidal mechanism. the cry2ab gene was found to lack a functional promoter and, hence, is cryptic in nature. the cry2ab7 gene was cloned from a new indigenous b. thuringiensis strain, 1 ... | 2006 | 16632879 |
| cyt2ba of bacillus thuringiensis israelensis: activation by putative endogenous protease. | the gene cyt2ba of bacillus thuringiensis subsp. israelensis was cloned for expression, together with p20, in an acrystalliferous strain. the large hexagonal crystals formed were composed of cyt2ba, which facilitated its purification. crystal solubilization in the presence of endogenous proteases (with spores and cell debris) enabled quick and simple procedure to obtain rather pure and active toxin species by cleavage between amino acid residues 34 and 35, most likely by a camelysin-like proteas ... | 2006 | 16630537 |
| structure of the functional form of the mosquito larvicidal cry4aa toxin from bacillus thuringiensis at a 2.8-angstrom resolution. | the cry4aa delta-endotoxin from bacillus thuringiensis is toxic to larvae of culex, anopheles, and aedes mosquitoes, which are vectors of important human tropical diseases. with the objective of designing modified toxins with improved potency that could be used as biopesticides, we determined the structure of this toxin in its functional form at a resolution of 2.8 angstroms. like other cry delta-endotoxins, the activated cry4aa toxin consists of three globular domains, a seven-alpha-helix bundl ... | 2006 | 16621834 |
| pathogenomic sequence analysis of bacillus cereus and bacillus thuringiensis isolates closely related to bacillus anthracis. | bacillus anthracis, bacillus cereus, and bacillus thuringiensis are closely related gram-positive, spore-forming bacteria of the b. cereus sensu lato group. while independently derived strains of b. anthracis reveal conspicuous sequence homogeneity, environmental isolates of b. cereus and b. thuringiensis exhibit extensive genetic diversity. here we report the sequencing and comparative analysis of the genomes of two members of the b. cereus group, b. thuringiensis 97-27 subsp. konkukian serotyp ... | 2006 | 16621833 |
| bacillus thuringiensis insecticidal cry1ab toxin does not affect the membrane integrity of the mammalian intestinal epithelial cells: an in vitro study. | the mammalian intestinal epithelium has been found, based on in vivo experiments, to be resistant to insecticidal cry toxins, which are derived from bacillus thuringiensis and fatally damage insect midgut cells. thus, the toxins are commonly used as a genetic resource in insect-resistant transgenic plants for feed. however, cry toxins bind to the cellular brush border membrane vesicle (bbmv) of mammalian intestinal cells. in this study, we investigated the affinity of cry1ab toxin, a lepidoptera ... | 2006 | 16618212 |
| improvement of bacillus thuringiensis delta-endotoxins synthesis yields through acquisition of erythromycin resistance. | the acquisition of the erythromycin resistance by bacillus thuringiensis kurstaki improved yields of delta-endotoxins in sporulating cells ranging from 134 to 215%. resistance to erythromycin decreased the final spore count by at least 50%. consequently, erythromycin resistance is an efficient tool for the improvement of bioinsecticides yields with a high ratio of delta-endotoxins to spores. | 2006 | 16614918 |
| co-expression of alpha(1,3)galactosyltransferase and bacillus thuringiensis piplc enhances hyperacute rejection of tumor cells. | the use of alpha(1,3)galactosyltransferase (alphagt) as a method of inducing hyperacute rejection of tumors has been gaining interest recently. however, the approach is based in part on the sensitivity of each tumor line to the effects of complement lysis. tumors expressing complement resistance factors such as membrane cofactor (cd46), decay accelerating factor (cd55) and protectin (cd59) have been shown to be more resistant to complement mediated lysis. anchored to the membrane by a glycosylph ... | 2007 | 16612594 |
| functional display of bacillus thuringiensis cry1ac toxin on t7 phage. | the cry1ac toxin from bacillus thuringiensis was displayed on the surface of t7 phage. the cry1ac gene was fused to the c-terminal end of t7-10b capsid protein and displayed on the surface of t7 phage as revealed by western blot analysis of the purified phage particles. the t7-cry1ac phages retained toxicity against manduca sexta larvae. we demonstrated that the t7-cry1ac phage interacts with cry1ac receptors present in m. sexta bbmv either in solution or in overlay binding assays. | 2006 | 16603180 |
| differentiated pattern of protein composition of crystalline inclusions of newly isolated bacillus thuringiensis strains from silesia in poland. | protein profiles of crystal delta-endotoxins were determined in twenty nine bacillus thuringiensis strains-soil and phylloplane isolates--from poland. electrophoretic analysis revealed quantatively and qualitatively different patterns of delta-endotoxin crystal preparations of these b. thuringiensis strains. the crystalline parasporal inclusions of b. thuringiensis isolates were composed of two, three, four or five proteins. molecular weights of these polypeptides varied from 23.4 kda to 142 kda ... | 2005 | 16599296 |
| evaluation of the present dengue situation and control strategies against aedes aegypti in cebu city, philippines. | the present dengue situation and methods to control aedes aegypti larvae in cebu city, philippines, were evaluated for the development of an integrated community-based dengue control program. the study included the detection of dengue infection among filipino patients, surveying mosquito breeding sites to determine larval population density of aedes aegypti, an evaluation of public knowledge, attitude, and personal protection practices against dengue, and an evaluation of the efficacy of vectoba ... | 2005 | 16599163 |
| bacillus thuringiensis and bacillus sphaericus biopesticides production. | the long residual action and toxicity of the chemical insecticides have brought about serious environmental problems such as the emergence and spread of insecticide resistance in many species of vectors, mammalian toxicity, and accumulation of pesticide residues in the food chain. all these problems have highlighted the need for alternative biological control agents. entomo-pathogenic bacillus thuringiensis (bt) and bacillus sphaericus (bs) are two safe biological control agents. they have attra ... | 2006 | 16598830 |
| toxicity and mode of action of bacillus thuringiensis cry proteins in the mediterranean corn borer, sesamia nonagrioides (lefebvre). | sesamia nonagrioides is one of the most damaging pests of corn in spain and other mediterranean countries. bt corn expressing the bacillus thuringiensis cry1ab toxin is being grown on about 58,000 ha in spain. here we studied the mode of action of this cry protein on s. nonagrioides (binding to specific receptors, stability of binding, and pore formation) and the modes of action of other cry proteins that were found to be active in this work (cry1ac, cry1ca, and cry1fa). binding assays were perf ... | 2006 | 16597962 |
| some bacillus thuringiensis strains share rpob nucleotide polymorphisms also present in bacillus anthracis. | 2006 | 16597912 | |
| differential effects of ionic strength, divalent cations and ph on the pore-forming activity of bacillus thuringiensis insecticidal toxins. | the combined effects of ionic strength, divalent cations, ph and toxin concentration on the pore-forming activity of cry1ac and cry1ca were studied using membrane potential measurements in isolated midguts of manduca sexta and a brush border membrane vesicle osmotic swelling assay. the effects of ionic strength and divalent cations were more pronounced at ph 10.5 than at ph 7.5. at the higher ph, lowering ionic strength in isolated midguts enhanced cry1ac activity but decreased considerably that ... | 2005 | 16596448 |
| assessing the effects of bt maize on the predatory mite neoseiulus cucumeris. | the investigation of neoseiulus cucumeris in the context of the ecological risk assessment of insect resistant transgenic plants is of particular interest as this omnivorous predatory mite species is commercially available and considered important for biological control. in a multitrophic feeding experiment we assessed the impact of bt maize on the performance of n. cucumeris when offered spider mites (tetranychus urticae) reared on bt (bt11, syngenta) or non-bt maize (near isogenic line) and bt ... | 2006 | 16596347 |
| molecular cloning and characterization of the insecticidal crystal protein gene of bacillus thuringiensis var. tenebrionis. | the insecticidal crystal protein gene of the coleopteran-toxic bacillus thuringiensis var. tenebrionis has been isolated, and the nucleotide sequence has been determined. a total dna library from var. tenebrionis was made in the plasmid vector puc12. by using a synthetic 27-base oligonucleotide corresponding to a stretch of nine n-terminal amino acids of a tryptic fragment of purified crystal protein of var. tenebrionis as a probe, recombinant colonies were screened by in situ hybridization for ... | 1987 | 16593878 |
| [effects of helper protein p20 from bacillus thuringiensis on vip3a expression]. | insecticidal crystal proteins (icps) produced in bacillus thuringiensis accumulate as crystalline inclusions that represent up to 30% of total dry weight the cell produces. the mechanisms of in vivo crystallization of these insecticidal proteins remain interests, yet unclear. a 20-kda protein (p20), the product of the third open reading frame of cry11a operon in b. thuringiensis subsp. israelensis has been defined to be an important molecular chaperone (helper protein) for forming cyt1a crystal ... | 2006 | 16579471 |
| do herbicide treatments reduce the sensitivity of mosquito larvae to insecticides? | invasive mosquitoes are economic and sanitary concerns especially in europe and america. most work has emphasized the role of resistance [berrada, s., fournier, d., cuany, a., nguyen, t.x., 1994. identification of resistance mechanisms in a selected laboratory strain of cacopsylla pyri (homoptera: psyllidae): altered acetylcholinesterases and detoxifying oxidases. pesticide biochemistry and physiology 48, 41-47; hemingway, j., hawkes, n.j., mccarroll, l., ranson, h., 2004. the molecular basis of ... | 2006 | 16574189 |
| comparative susceptibility of european corn borer, southwestern corn borer, and sugarcane borer (lepidoptera: crambidae) to cry1ab protein in a commercial bacillus thuringiensis corn hybrid. | one field strain each of the european corn borer, ostrinia nubilalis (hübner); southwestern corn borer, diatraea grandiosella dyar; and sugarcane borer, diatraea saccharalis (f.); were collected from cornfields in northeastern louisiana. susceptibilities of the field strain and a corresponding laboratory strain of the three borer species to cry1ab protein in dk69-70 bacillus thuringiensis (bt) corn hybrid were determined by exposing neonates to intact leaf tissues from whorl stage plants or by f ... | 2006 | 16573340 |
| susceptibilities of helicoverpa zea and heliothis virescens (lepidoptera: noctuidae) populations to cry1ac insecticidal protein. | susceptibilities of bollworm, helicoverpa zea (boddie) and tobacco budworm, heliothis virescens (f.) to cry1ac were measured via a diet-incorporated assay with mpv ii at the university of arkansas during 2002-2004. lethal concentration-mortality (lc50) estimates of five laboratory, seven laboratory-cross, and 10 field populations of h. virescens varied 12-fold. pooled susceptibilities of h. virescens across all laboratory and field populations varied five-fold. the lc50 estimates for h. virescen ... | 2006 | 16573337 |
| management of cottonwood leaf beetle (coleoptera: chrysomelidae) with a novel transplant soak and biorational insecticides to conserve coccinellid beetles. | biorational foliar sprays and a novel application method of soaking transplants in imidacloprid were evaluated for control of adult and larval cottonwood leaf beetle, chrysomela scripta f., on hybrid poplar, with emphasis on conservation of coccinellid predators. foliar sprays of four biorational insecticides killed adult and larval c. scripta: bacillus thuringiensis (b.t.) variety tenebrionis (novodor), b.t. variety kurstaki (raven), spinosad (conserve sc), and azadirachtin (azatin xl) (larvae ... | 2006 | 16573329 |