Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| unfolding events in the water-soluble monomeric cry1ab toxin during transition to oligomeric pre-pore and membrane-inserted pore channel. | the insecticidal crystal (cry) proteins produced by bacillus thuringiensis undergo several conformational changes from crystal inclusion protoxins to membrane-inserted channels in the midgut epithelial cells of the target insect. here we analyzed the stability of the different forms of cry1ab toxin, monomeric toxin, pre-pore complex, and membrane-inserted channel, after urea and thermal denaturation by monitoring intrinsic tryptophan fluorescence of the protein and 1-anilinonaphthalene-8-sulfoni ... | 2004 | 15498772 |
| the high-resolution architecture and structural dynamics of bacillus spores. | the capability to image single microbial cell surfaces at nanometer scale under native conditions would profoundly impact mechanistic and structural studies of pathogenesis, immunobiology, environmental resistance, and biotransformation. here, using in vitro atomic force microscopy, we have directly visualized high-resolution native structures of bacterial endospores, including the exosporium and spore coats of four bacillus species in air and water environments. our results demonstrate that the ... | 2005 | 15501940 |
| boiling and bacillus spores. | 2004 | 15515252 | |
| the hevcalp protein mediates binding specificity of the cry1a class of bacillus thuringiensis toxins in heliothis virescens. | retrotransposon-mediated disruption of the btr-4 gene encoding the heliothis virescens cadherin-like protein (hevcalp) is linked to high levels of resistance in the yhd2 strain to cry1ac toxin from bacillus thuringiensis. this suggests that hevcalp functions as a cry1ac toxin receptor on the surface of midgut cells in susceptible larvae and that the btr-4 gene disruption eliminates this protein in resistant larvae. however, cry1ac toxin binding to hevcalp is yet to be reported. we used the polym ... | 2004 | 15518581 |
| dna-based detection of bt resistance alleles in pink bollworm. | evolution of resistance by pests is the main threat to long-term insect control by transgenic crops that produce bacillus thuringiensis (bt) toxins. we previously identified three mutant alleles (r1, r2, r3) of a cadherin gene in pink bollworm (pectinophora gossypiella) linked with recessive resistance to bt toxin cry1ac and survival on transgenic bt cotton. here we describe a polymerase chain reaction (pcr)-based method that detects the mutation in genomic dna of each of the three resistant all ... | 2004 | 15522618 |
| antimicrobial effect of water extract of sumac (rhus coriaria l.) on the growth of some food borne bacteria including pathogens. | the antimicrobial effect of water extracts of sumac (rhus coriaria l.) at concentrations of 0.1%, 0.5%, 1.0%, 2.5% and 5.0% (w/v), non-neutralized and after neutralization to ph 7.2+/-0.1, was studied on the growth of 12 bacterial strains (six gram positive strains and six gram negative strains), mostly food borne including pathogens. it was found to be effective against all the test organisms with gram positive strains being more sensitive than gram negative strains. significant differences (p< ... | 2004 | 15527919 |
| display of biologically functional insecticidal toxin on the surface of lambda phage. | the successful use of bacillus thuringiensis insecticidal toxins to control agricultural pests could be undermined by the evolution of insect resistance. under selection pressure in the laboratory, a number of insects have gained resistance to the toxins, and several cases of resistance in the diamondback moth have been reported from the field. the use of protein engineering to develop novel toxins active against resistant insects could offer a solution to this problem. the display of proteins o ... | 2004 | 15528522 |
| capacity of bacillus thuringiensis s-layer protein displaying polyhistidine peptides on the cell surface. | s-layer protein of bacillus thuringiensis strain ctc was used as the carrier protein to display polyhistidine (poly[6his]) peptides on the cell surface. poly(6his)n was fused with s-layer protein at two different sites, inserting just downstream of the s-layer protein homologous domain (slh) and replacing the non-slh region of s-layer protein, respectively. the two series chimeric proteins were both expressed by crystal negative b. thuringiensis strain 4q7 and strain 171, respectively, as shown ... | 2004 | 15531784 |
| larvicidal persistence of formulations of bacillus thuringiensis var. israelensis to control larval aedes aegypti. | after detection of resistance to the organophosphate temephos in populations of aedes aegypti in brazil, corncob granule (cg) and water-dispersible granule (wdg) formulations of bacillus thuringiensis var. israelensis (bti) were introduced in routine focal treatments. larvicidal persistence and the influence of exposure to sunlight on vectobac formulations of bti were compared in 250-liter fiberglass water containers. production of pupal ae. aegypti in containers was used to indicate control. in ... | 2004 | 15532933 |
| oligomerization triggers binding of a bacillus thuringiensis cry1ab pore-forming toxin to aminopeptidase n receptor leading to insertion into membrane microdomains. | bacillus thuringiensis cry1a toxins, in contrast to other pore-forming toxins, bind two putative receptor molecules, aminopeptidase n (apn) and cadherin-like proteins. here we show that cry1ab toxin binding to these two receptors depends on the toxins' oligomeric structure. toxin monomeric structure binds to bt-r1, a cadherin-like protein, that induces proteolytic processing and oligomerization of the toxin (gomez, i., sanchez, j., miranda, r., bravo a., soberon, m., febs lett. (2002) 513, 242-2 ... | 2004 | 15533304 |
| cyt1a from bacillus thuringiensis restores toxicity of bacillus sphaericus against resistant culex quinquefasciatus (diptera: culicidae). | the 2362 strain of bacillus sphaericus, which produces a binary toxin highly active against culex mosquitoes, has been developed recently as a commercial larvicide. it is being used currently in operational mosquito control programs in several countries including brazil, france, india, and the united states. laboratory studies have shown that mosquitoes can develop resistance to b. sphaericus, and low levels of resistance have already been reported in field populations in brazil, france, and ind ... | 2000 | 15535584 |
| synergy between toxins of bacillus thuringiensis subsp. israelensis and bacillus sphaericus. | synergistic interactions among the multiple endotoxins of bacillus thuringiensis subsp. israelensis de barjac play an important role in its high toxicity to mosquito larvae and the absence of insecticide resistance in populations treated with this bacterium. a lack of toxin complexity and synergism are the apparent causes of resistance to bacillus sphaericus neide in particular culex field populations. to identify endotoxin combinations of the two bacillus species that might improve insecticidal ... | 2004 | 15535624 |
| insecticide resistance in alabama and florida mosquito strains of aedes albopictus. | the susceptibility of four strains of aedes albopictus (skuse) to permethrin, deltamethrin, resmethrin, chlorpyrifos, malathion, propoxur, fipronil, imidacloprid, spinosad, and bacillus thuringiensis variety israelensis (bti) was determined. the hamaal and mamaal strains were collected in 2002 and 2003, respectively, from huntsville and mobile, al, and the vbfmaal and sfmaal strains were collected in 1998 from vero beach and southern florida, respectively. the hamaal strain showed a 22-fold elev ... | 2004 | 15535626 |
| bollgard ii cotton: compositional analysis and feeding studies of cottonseed from insect-protected cotton (gossypium hirsutum l.) producing the cry1ac and cry2ab2 proteins. | bollgard ii cotton event 15985 producing the cry1ac and cry2ab2 proteins has been developed by genetic modification to broaden the spectrum of insects to which the plant is tolerant and to provide an insect resistance management tool to impede the onset of resistance. the purpose of this study was to evaluate the composition and nutrition of bollgard ii cotton, relative to the use for food and animal feed, compared to that of conventional cotton varieties. compositional analyses were conducted t ... | 2004 | 15537305 |
| histopathological and ultrastructural effects of delta-endotoxins of bacillus thuringiensis serovar israelensis in the midgut of simulium pertinax larvae (diptera, simuliidae). | the bacterium bacillus thuringiensis (bt) produces parasporal crystals containing delta-endotoxins responsible for selective insecticidal activity on larvae. upon ingestion, these crystals are solubilized in the midgut lumen and converted into active toxins that bind to receptors present on the microvilli causing serious damage to the epithelial columnar cells. we investigated the effect of these endotoxins on larvae of the simulium pertinax, a common black fly in brazil, using several concentra ... | 2004 | 15543412 |
| population structure and evolution of the bacillus cereus group. | representative strains of the bacillus cereus group of bacteria, including bacillus anthracis (11 isolates), b. cereus (38 isolates), bacillus mycoides (1 isolate), bacillus thuringiensis (53 isolates from 17 serovars), and bacillus weihenstephanensis (2 isolates) were assigned to 59 sequence types (sts) derived from the nucleotide sequences of seven alleles, glpf, gmk, ilvd, pta, pur, pyca, and tpi. comparisons of the maximum likelihood (ml) tree of the concatenated sequences with individual ge ... | 2004 | 15547268 |
| detection and identification of bacteria in a juice matrix with fourier transform-near infrared spectroscopy and multivariiate analysis. | the use of fourier transform-near infrared (ft-nir) spectroscopy combined with multivariate pattern recognition techniques was evaluated to address the need for a fast and senisitive method for the detection of bacterial contamination in liquids. the complex cellular composition of bacteria produces ft-nir vibrational transitions (overtone and combination bands), forming the basis for identification and subtyping. a database including strains of escherichia coli, pseudomonas aeruginosa, bacillus ... | 2004 | 15553641 |
| identification, distribution pattern of is231 elements in bacillus thuringiensis and their phylogenetic analysis. | in order to better understand the fundamental biology of bacillus thuringiensis, a single oligonucleotide primer (5'-catssccatcaasytaavr-3') was used to investigate the distribution pattern of is231 elements in b. thuringiensis by pcr. the results indicated that is231 elements appeared in 20 standard strains and 107 of 111 china isolates. three novel is231, is231j, is231o and is231q, five variants and a mobile insertion cassette micbth4 were cloned from eight standard strains of b. thuringiensis ... | 2004 | 15556706 |
| plant-incorporated bacillus thuringiensis resistance for control of fall armyworm and corn earworm (lepidoptera: noctuidae) in corn. | fall armyworm, spodoptera frugiperda (j.e. smith), and corn earworm, helicoverpa zea (boddie), perennially cause leaf and ear damage to corn, zea mays l., in the southeastern united states. transgenic bacillus thuringiensis (bt) hybrids with the bt11, mon810, or 176 events expressing the cry1ab insecticidal endotoxin from were evaluated for control fall armyworm and corn earworm at seven locations in georgia during 1999 and 2000. corn was planted at the recommended time for each location and 1 a ... | 2004 | 15568349 |
| bacillus thuringiensis subsp. kurstaki aerial spray prescriptions for balsam fir stand protection against spruce budworm (lepidoptera: tortricidae). | although commercial formulations of bacillus thuringiensis subsp. kurstaki (btk) are being widely used in forest protection against lepidopteran defoliators, optimal application prescriptions have often yet to be worked out in detail. we conducted field experiments over a 6-yr period (1996-2001) in southwestern québec to determine application prescriptions for optimal protection of balsam fir, abies balsamea (l.), healthy stands against the spruce budworm, choristoneura fumiferana (clemens) (lep ... | 2004 | 15568352 |
| relative fitness of cry1a-resistant and -susceptible helicoverpa armigera (lepidoptera: noctuidae) on conventional and transgenic cotton. | glasshouse and laboratory experiments were conducted to evaluate the relative fitness of cry1a-susceptible and laboratory-selected resistant strains of helicoverpa armigera (hübner). life history parameters of h. armigera larvae feeding on young cotton plants showed a significant developmental delay of up to 7 d for the resistant strain compared with the susceptible strain on non-bacillus thuringiensis (bt) cotton. this fitness cost was not evident on artificial diet. there was no developmental ... | 2004 | 15568362 |
| effects of gossypol on fitness costs associated with resistance to bt cotton in pink bollworm. | fitness costs associated with insect resistance to bacillus thuringiensis (bt) crops may help to delay or prevent the spread of resistance alleles, especially when refuges of non-bt host plants are present. the potential for such delays increases as the magnitude and dominance of fitness costs increase. here, we examined the idea that plant secondary chemicals affect expression of fitness costs associated with resistance to bt cotton in pectinophora gossypiella (saunders). specifically, we teste ... | 2004 | 15568363 |
| comparative production of helicoverpa zea (lepidoptera: noctuidae) from transgenic cotton expressing either one or two bacillus thuringiensis proteins with and without insecticide oversprays. | transgenic cotton, gossypium hirsutum (l.), expressing either one or two bacillus thuringiensis ssp. kurstaki berliner (bt) proteins was compared with the conventional sister line in field experiments with regard to production of bollworm, helicoverpa zea (boddie), and bolls damaged by bollworm. the relative numbers of bollworms that developed on bollgard (monsanto co., st. louis, mo), bollgard ii (monsanto co.), and conventional cotton were estimated under nontreated conditions in 2000 and both ... | 2004 | 15568364 |
| relative concentration of cry1a in maize leaves and cotton bolls with diverse chlorophyll content and corresponding larval development of fall armyworm (lepidoptera: noctuidae) and southwestern corn borer (lepidoptera: crambidae) on maize whorl leaf profiles. | to manage insect resistance to transgenic crops that express insecticidal proteins from bacillus thuringiensis (bt) berliner, the u.s. environmental protection agency recommends a refuge-based insect resistance management strategy where a percentage of non-bt (refuge) crop is grown in proximity to a bt-expressing crop. an important requirement for this strategy is that the toxin exists at a high effective dose for control of the target pest(s), so that heterozygous individuals in the population ... | 2004 | 15568367 |
| flocculation of cellular suspensions by polyelectrolytes. | the regularities, kinetics and mechanisms of flocculation of escherichia coli and b. thuringiensis var. israelensis (bti) cellular suspensions by water-soluble polymers-and first of all cationic polyelectrolytes of different charge density and stiffness of the macromolecule chain have been investigated. the effect of the focculant dose and nature, its charge density, the hydrophobic-hydrophilic balance in macromolecule, the suspension concentration, the mode of adding the reagent, the ph and the ... | 2004 | 15571665 |
| single amino acid mutations in the cadherin receptor from heliothis virescens affect its toxin binding ability to cry1a toxins. | bacillus thuringiensis cry protein exerts its toxic effect through a receptor-mediated process. both aminopeptidases and cadherin proteins were identified as putative cry1a receptors from heliothis virescens and manduca sexta. the importance of cadherin was implied by its correlation with a cry1ac resistant h. virescens strain (gahan, l. j., gould, f., and heckel, d. g. (2001) science 293, 857-860). in this study, the cry1ac toxin-binding region in h. virescens cadherin was mapped to a 40-amino- ... | 2004 | 15572369 |
| genetic and biochemical characterization of field-evolved resistance to bacillus thuringiensis toxin cry1ac in the diamondback moth, plutella xylostella. | the long-term usefulness of bacillus thuringiensis cry toxins, either in sprays or in transgenic crops, may be compromised by the evolution of resistance in target insects. managing the evolution of resistance to b. thuringiensis toxins requires extensive knowledge about the mechanisms, genetics, and ecology of resistance genes. to date, laboratory-selected populations have provided information on the diverse genetics and mechanisms of resistance to b. thuringiensis, highly resistant field popul ... | 2004 | 15574894 |
| activity of gut proteinases from cry1ab-selected colonies of the european corn borer, ostrinia nubilalis (lepidoptera: crambidae). | susceptibility to the cry1ab protoxin and toxin from bacillus thuringiensis (berliner) and activity of gut proteinases were assessed in both susceptible and cry1ab-selected colonies of european corn borer, ostrinia nubilalis (hubner). resistance in two different selected colonies was at least 6- and 15-fold for the cry1ab protoxin and 108- and 484-fold for the cry1ab toxin. activities of trypsin-like, chymotrypsin-like and elastase-like proteinases were variable among the colonies tested and not ... | 2004 | 15578599 |
| the development of the endoparasitoid venturia canescens in bt-tolerant, immune induced larvae of the flour moth ephestia kuehniella. | we examined the survival and development of the endoparasitoid venturia canescens in a bt-tolerant laboratory strain of the flour moth ephestia kuehniella, in which bt-tolerance has been shown to be associated with an inducible elevation of the insect's immune response. the results indicate the elevated immune status associated with bt-tolerance does not confer cross-protection against parasitism by v. canescens. no significant difference was observed in the rate of emergent wasps from parasitis ... | 2004 | 15579322 |
| development of sludge based stable aqueous bacillus thuringiensis formulations. | this study focuses on development of aqueous flowable (suspension) formulations for bacillus thuringiensis (bt) based biopesticides from wastewater sludge. different inerts like sorbitol, sodium monophosphate, sodium metabisulphite, sorbic acid, propionic acid, tween-80, triton x-100 and glycerol were tested for formulations. five different formulations for non-hydrolyzed (nh) secondary sludges were tried and the best combination selected on the basis of various physical parameters like viscosit ... | 2004 | 15581017 |
| glycoconjugates for the recognition of bacillus spores. | carbohydrates act as ligands in many biological processes, including the folding and secretion of proteins, cell-cell recognition, adhesion, and sporulation in the bacillus genus. fluorescent-labeled disaccharide glycoconjugates have been applied to evaluate binding to bacterial spores assuming that the spore surface is covered with carbohydrates. this study has shown that specific recognition of bacterial spores is based on interactions between disaccharide glycoconjugates acting as ligands and ... | 2004 | 15582612 |
| crystallization of parasporin-2, a bacillus thuringiensis crystal protein with selective cytocidal activity against human cells. | bacillus thuringiensis is a valuable source of protein toxins that are specifically effective against certain insects and worms but harmless to mammals. in contrast, a protein toxin obtained from b. thuringiensis strain a1547, designated parasporin-2, is not insecticidal but has a strong cytocidal activity against human cells with markedly divergent target specificity. the 37 kda inactive protein is proteolytically activated to a 30 kda active form. the active form of the recombinant protein tox ... | 2004 | 15583389 |
| development of a hybrid delta-endotoxin and its expression in tobacco and cotton for control of a polyphagous pest spodoptera litura. | a hybrid delta-endotoxin protein was designed against a polyphagous lepidopteran insect pest spodoptera litura, which is tolerant to most of the known delta-endotoxins. the hybrid delta-endotoxin was created by replacing amino acid residues 530-587 in a poorly active natural cry1ea protein, with a highly homologous 70 amino acid region of cry1ca in domain iii. the truncated delta-endotoxins cry1ea, cry1ca and the hybrid protein cry1ec accumulated in escherichia coli to form inclusion bodies. the ... | 2004 | 15587265 |
| managing eastern tent caterpillars malacosoma americanum (f) on horse farms to reduce risk of mare reproductive loss syndrome. | an equine disease now known as mare reproductive loss syndrome (mrls) struck the ohio valley in 2001-2002 causing thousands of foal abortions and enormous economic loss. evidence that pregnant mares' exposure to eastern tent caterpillars malacosoma americanum (f) induces mrls created an urgent call for control measures suitable for use on horse farms. we surveyed egg mass distribution and monitored emergence in wild cherry trees, and evaluated reduced-risk treatment strategies including foliage ... | 2005 | 15593079 |
| cloning and localization of vip3a gene of bacillus thuringiensis. | an insecticidal protein gene, vip3a, was cloned from bacillus thuringiensis strain wb50. the nucleotide sequence of 2,460 bp (genbank acc. no. ay295778) showed 99% homology with the known vip3a genes. using specific primers for vip3a gene, pcr was performed to demonstrate that the gene was not located on the bacterial chromosome and this was confirmed by southern blotting using an internal fragment (486 bp) from vip3a gene as a probe. the gene was carried on a plasmid of 31.8 kb. | 2004 | 15604775 |
| cloning, characterization and expression of a new cry 1ab gene from bacillus thuringiensis wb9. | a new cry 1ab-type gene, cry 1ab17, was cloned from bacillus thuringiensis wb9 by pcr. nucleotide sequence indicated that the open reading frames (orfs) consists of 3471 bases and encodes a protein of 1156 residues with a calculated molecular weight of 130.5 kda and an pi value of 5.04. homology comparison revealed that the deduced amino acid sequence of cry1ab17 had 95.4% to 99.7% identity with those of the known cry1ab proteins. the cry1ab17 was one residue longer than the known cry1ab (except ... | 2004 | 15604796 |
| identification, cloning and expression of a cry1ab cadherin receptor from european corn borer, ostrinia nubilalis (hubner) (lepidoptera: crambidae). | transgenic corn expressing the cry1ab toxin from bacillus thuringiensis is highly toxic to european corn borer, ostrinia nubilalis, larvae. a putative cry1ab receptor (onbt-r(1)) molecule was cloned and sequenced from a cdna library prepared from midgut tissue of o. nubilalis larvae. the 5.6 kb gene is homologous with a number of cadherin genes identified as cry1 binding proteins in other lepidopterans. brush border membrane vesicles were prepared using dissected midguts from late instars. a 220 ... | 2005 | 15607653 |
| bt-transgenic oilseed rape hybridization with its weedy relative, brassica rapa. | the movement of transgenes from crops to weeds and the resulting consequences are concerns of modern agriculture. the possible generation of "superweeds" from the escape of fitness-enhancing transgenes into wild populations is a risk that is often discussed, but rarely studied. oilseed rape, brassica napus (l.), is a crop with sexually compatible weedy relatives, such as birdseed rape (brassica rapa (l.)). hybridization of this crop with weedy relatives is an extant risk and an excellent intersp ... | 2002 | 15612253 |
| ostrinia nubilalis parasitism and the field abundance of non-target insects in transgenic bacillus thuringiensis corn (zea mays). | in this study, we evaluated in field trials the effects on non-target species, of transgenic corn producing the cry1ab toxin of bacillus thuringiensis (bt). in 1998, we collected ostrinia nubilalis (hübner) larvae from transgenic bt corn (novartis hybrid 176) and non-bt corn at four geographical sites. we found a significant variation in parasitism by the tachinids lydella thompsoni (herting) and pseudoperichaeta nigrolineata (walker) among sites, and more parasitism in non-bt than in bt fields. ... | 2002 | 15612256 |
| selection of relevant non-target herbivores for monitoring the environmental effects of bt maize pollen. | genes of bacillus thuringiensis var. kurstaki (berliner) that encode lepidopteran-specific toxins were engineered into maize for protection against the european corn borer, ostrinia nubilalis (hbn.). recent data suggest that lepidoptera may be negatively affected, if maize pollen contains high amounts of bt toxin and is diposited on host plants near maize fields. monitoring the environmental effects of commercial bt maize fields requires effective use of limited financial and logistical resource ... | 2003 | 15612277 |
| bt crops: predicting effects of escaped transgenes on the fitness of wild plants and their herbivores. | one prominent concern about genetically modified crops is the possibility of environmental impacts from the movement of fitness-enhancing traits to wild plant populations. decisions to deregulate bt crops in the usa have relied strongly on arguments that these crops will not interbreed with wild relatives in the permitted growing regions. limited attention therefore has been directed to analyses of the consequences of gene flow. to provide a transparent evaluation process for risks associated wi ... | 2003 | 15612280 |
| enumerating lepidopteran species associated with maize as a first step in risk assessment in the usa. | pest management can have substantial impacts on non-target species both within and outside the units being managed. assessment of these impacts is hampered by the lack of even the most basic checklist of the species present in most systems. the maize agroecosytem is of particular interest because of the large area covered and the intensity of widely varying forms of pest management. in this study a database of lepidopteran species that occur within the maize agroecosystem in the united states wa ... | 2003 | 15612281 |
| transgenic bt-producing brassica napus: plutella xylostella selection pressure and fitness of weedy relatives. | release of transgenic insect-resistant crops creates the potential not only for the insect pest to evolve resistance but for the escape of transgenes that may confer novel or enhanced fitness-related traits through hybridization with their wild relatives. the differential response of diamondback moth (plutella xylostella) populations in eastern and western canada to bt-producing (gt) brassica napus and the potential for enhanced fitness of gt b. napus and weedy gt brassica rapa x b. napus hybrid ... | 2003 | 15612282 |
| inheritance of gfp-bt transgenes from brassica napus in backcrosses with three wild b. rapa accessions. | transgenes from transgenic oilseed rape, brassica napus (aacc genome), can introgress into populations of wild b. rapa (aa genome), but little is known about the long-term persistence of transgenes from different transformation events. for example, transgenes that are located on the crop's c chromosomes may be lost during the process of introgression. we investigated the genetic behavior of transgenes in backcross generations of wild b. rapa after nine gfp (green fluorescent protein)-bt (bacillu ... | 2004 | 15612354 |
| monitoring the impact of bt maize on butterflies in the field: estimation of required sample sizes. | the monitoring of genetically modified organisms (gmos) after deliberate release is important in order to assess and evaluate possible environmental effects. concerns have been raised that the transgenic crop, bt maize, may affect butterflies occurring in field margins. therefore, a monitoring of butterflies was suggested accompanying the commercial cultivation of bt maize. in this study, baseline data on the butterfly species and their abundance in maize field margins is presented together with ... | 2004 | 15612355 |
| effects of bacillus thuringiensis on non-target herbivore and natural enemy assemblages in tropical irrigated rice. | endotoxins from bacillus thuringiensis (bt) produced in transgenic pest-resistant bt crops are generally not toxic to predatory and parasitic arthropods. however, elimination of bt-susceptible prey and hosts in bt crops could reduce predator and parasitoid abundance and thereby disrupt biological control of other herbivorous pests. here we report results of a field study evaluating the effects of bt sprays on non-target terrestrial herbivore and natural enemy assemblages from three rice (oryza s ... | 2003 | 15612416 |
| hybridization and backcrossing between transgenic oilseed rape and two related weed species under field conditions. | determining the frequency of crop-wild transgene flow under field conditions is a necessity for the development of regulatory strategies to manage transgenic hybrids. gene flow of green fluorescent protein (gfp) and bacillus thuringiensis (bt) transgenes was quantified in three field experiments using eleven independent transformed brassica napus l. lines and the wild relatives, b. rapa l. and raphanus raphanistrum l. under a high crop to wild relative ratio (600:1), hybridization frequency with ... | 2004 | 15612504 |
| characterization of cry34ab1 and cry35ab1 insecticidal crystal proteins expressed in transgenic corn plants and pseudomonas fluorescens. | cry34ab1 and cry35ab1 proteins, identified from bacillus thuringiensis strain ps149b1, act together to control corn rootworms. transgenic corn lines coexpressing the two proteins were developed to protect corn against rootworm damage. large quantities of the two proteins were needed to conduct studies required for assessing the safety of this transgenic corn crop. because it was technically infeasible to obtain sufficient quantities of high purity cry34ab1 and cry35ab1 proteins from the transgen ... | 2004 | 15612796 |
| evaluation of broiler performance when fed insect-protected, control, or commercial varieties of dehulled soybean meal. | we evaluated the nutritional value of broiler diets containing approximately 35% soybean meal from insect-protected soybean containing crylac protein, or from a similar nontransgenic control, or from 7 reference commercial soybean varieties. the feeding trial lasted 41 d, and each treatment consisted of 10 replicates of 1-d-old ross 508 broilers (5 pens males and 5 pens females). each pen contained 12 birds, and at d 13, birds were randomly removed until 9 birds remained. body weight and feed in ... | 2004 | 15615017 |
| identification of a chitinase-producing bacterium c4 and histopathologic study on locusts. | in order to develop the potential of chitinase-producing micro-organisms as biocontrol agents for insect pests, five chitinase-producing bacterial strains (c1, c2, c3, c4 and c5) previously isolated from soil samples were chosen to infect grassland locusts. the data showed that the mortality rate of locusts fed with strain c4 was significantly higher than that of other groups, and its pathogenicity was confirmed by koch's law. midgut tissues of locusts infected with c4 were examined with a light ... | 2005 | 15619732 |
| targeted mutagenesis of loop residues in the receptor-binding domain of the bacillus thuringiensis cry4ba toxin affects larvicidal activity. | loop residues in domain ii of bacillus thuringiensis cry delta-endotoxins have been demonstrated to be involved in insecticidal specificity. in this study, selected residues in loops beta6-beta7 (s(387)sps(390)), beta8-beta9 (s(410), n(411), t(413), t(415), e(417) and g(418)) and beta10-beta11 (d(454)yns(457)) in domain ii of the cry4ba mosquito-larvicidal protein were changed individually to alanine by pcr-based directed mutagenesis. all mutant toxins were expressed in escherichia coli jm109 ce ... | 2005 | 15621455 |
| [control of chironomids in water by immobilized bacillus thuringiensis var. israelensis de barjac]. | a strain from bacillus thuringiensis var. israelensis de barjac (b. t. i), having a fatal toxicity to chironomids, was immobilized in the pva-h3bo3 gel beads confected with a bit of sodium alginate and activated carbon. the result showed that optimal weight ratios were 10% pva, 1% sodium alginate and 20% activated carbon, respectively. when 4% calcium chloride saturated boric acid solution (ph=6.7) was used as gelatin agent for gelating 24 h, the produced gel beads had good performance in mechan ... | 2004 | 15623035 |
| [expression and root exudation of cry1ab toxin protein in cry1ab transgenic rice and its residue in rhizosphere soil]. | the expression and root exudation of cry1ab toxin protein in cry1ab transgenic rice (kmd) and its residue in rhizosphere soil were investigated. the results showed that content of cry1ab toxin protein in the shoot and root of kmd were 3.23-8.22 and 0.68-0.89 microg/g from early tillering to maturing stage, respectively. the content of the cry1ab toxin proteins via root exudation were 1.66-48.02 ng/(individual x d) at that phase. the results also demonstrated that the residue of the cry1ab toxin ... | 2004 | 15623037 |
| comparison of broiler chicken performance when fed diets containing meals of bollgard ii hybrid cotton containing cry-x gene (cry1ac and cry2ab gene), parental line or commercial cotton. | (1) total and free gossypol contents were 6.2 and 0.8, 5.4 and 0.5, and 6.1 and 0.7 g/kg in meals processed (solvent extracted) from bollgard (bg) ii, non-bg ii or commercial cottonseeds, respectively. (2) broiler chicks were given one of 7 dietary treatments (iso-nitrogenous, 220 and 195 g crude protein/ kg diet at 0 to 21 and 21 to 42 d, respectively, at a metabolisable energy concentration of 12.15 mj/kg). the treatments were: d1 (control, soybean meal [sbm] based), d2 and d3 (commercial csm ... | 2004 | 15623220 |
| [photosynthetic characters and bt toxin content of different transgenic bt cottons]. | the study on the photosynthetic characters and bt toxin content of different bt cottons (zk, gk) and non-bt cotton (cz) indicated that bt cottons gk and zk had different total expressed amount of bt toxin and its distribution in different tissues. the bt cottons had obviously different chlorophyll contents, responses of photosynthetic rate to photosynthetic active radiation, and diurnal changes of photosynthetic rate and transpiration rate, but the diurnal change of leaf temperature, co2 concent ... | 2004 | 15624827 |
| insect resistance management in gm crops: past, present and future. | transgenic plants expressing insecticidal proteins from the bacterium bacillus thuringiensis (bt) were first commercialized in 1996 amid concern from some scientists, regulators and environmentalists that the widespread use of bt crops would inevitably lead to resistance and the loss of a 'public good,' specifically, the susceptibility of insect pests to bt proteins. eight years later, bt corn and cotton have been grown on a cumulative area >80 million ha worldwide. despite dire predictions to t ... | 2005 | 15637622 |
| [miniscale preparation for large plasmid dna from bacillus thuringiensis]. | miniprep of low copy number and large plasmid was done from three subspecies of bacillus thuringiensis. the plasmid was purified using peg 6000 instead of phenol and chloroform. experiments demonstrate that consequences from this protocol were stable, the quality and yield of plasmid dna produced from it have met the standard for many molecular biology experiments. | 2003 | 15639824 |
| cyt1a of bacillus thuringiensis delays evolution of resistance to cry11a in the mosquito culex quinquefasciatus. | insecticides based on bacillus thuringiensis subsp. israelensis have been used for mosquito and blackfly control for more than 20 years, yet no resistance to this bacterium has been reported. moreover, in contrast to b. thuringiensis subspecies toxic to coleopteran or lepidopteran larvae, only low levels of resistance to b. thuringiensis subsp. israelensis have been obtained in laboratory experiments where mosquito larvae were placed under heavy selection pressure for more than 30 generations. s ... | 2005 | 15640186 |
| a detergent-like mechanism of action of the cytolytic toxin cyt1a from bacillus thuringiensis var. israelensis. | the cytolytic delta-endotoxin cyt1a from bacillus thuringiensis var. israelensis is used in commercial preparations of environmentally safe insecticides. the current hypothesis on its mode of action is that the toxin self-assembles into well-defined cation-selective channels or pores, which results in colloid-osmotic lysis of the cell. recently, a new hypothesis has been put forward suggesting that cyt1a rather nonspecifically aggregates on the membrane surface and acts in a detergent-like manne ... | 2005 | 15641784 |
| regional reversion of insecticide resistance in helicoverpa armigera (lepidoptera: noctuidae) is associated with the use of bt cotton in northern china. | a continuous programme for monitoring resistance of helicoverpa armigera (hubner) to commonly used insecticides was undertaken for assessing the impact of bt cotton planting on the evolution of the pest resistance from 1994 to 2002 in china. the bioassay results showed that the resistance levels per year in field populations of h armigera to lambda-cyhalothrin, phoxim and endosulfan decreased, respectively, to 9-15-fold, 11-14-fold and 6-8-fold in 2001-2002 from 197-262-fold, 52-74-fold and 18-3 ... | 2005 | 15643649 |
| the clonal structure of bacillus thuringiensis isolates from north-east poland does not correlate with their cry gene diversity. | the genetic relationship among 103 natural bacillus thuringiensis isolates was investigated on the basis of polymerase chain reaction amplification of their specific crystal (cry) protein type genes and chromosomal dna profiling by pulsed-field gel electrophoresis (pfge). the strains were recovered from the intestines of small wild rodents and insectivores from the biebrza national park and the lomza landscape park of the narew river valley in north-east poland. the percentage of b. thuringiensi ... | 2005 | 15643933 |
| fate of bacillus thuringiensis strains in different insect larvae. | in favorable conditions bacillus thuringiensis spores germinate and vegetative cells multiply, whereas in unfavorable conditions bacillus thuringiensis sporulates and produces insecticidal crystal proteins. the development of b. thuringiensis strains was investigated in the larvae of insects belonging to the orders lepidoptera and diptera. bacillus thuringiensis strains able to kill the insects did not always multiply in cadavers. strains with no specificity to kill the insect sometimes multipli ... | 2004 | 15644915 |
| the cry3aa gene of bacillus thuringiensis bt886 encodes a toxin against long-horned beetles. | this report describes the identification of a new toxigenic strain of bacillus thuringiensis specific for long-horned beetles. b. thuringiensis bt866 encodes a cry3aa-like gene (bt886cry3aa) that is 1,956 bp in length and is predicted to encode an 85.78-kda protein. the gene is highly similar to cry3aa1, differing in only six nucleotides and four amino acids. the four disparate amino acids occur within the conserved domains of the cry3aa toxin. the expression of bt866cry3a in escherichia coli ce ... | 2005 | 15647932 |
| expression of a recombinant cry1ac crystal protein fused with a green fluorescent protein in bacillus thuringiensis subsp. kurstaki cry-b. | to investigate the co-expression and crystallization of a fusion gene between the bacillus thuringiensis crystal protein and a foreign protein in b. thuringiensis, the expression of the cry1ac fused with green fluorescent protein (gfp) genes in a b. thuringiensis cry(-)b strain was examined. the cry1ac gene was cloned in the b. thuringiensis-e. coli shuttle vector, pht3101, under the control of the native cry1ac gene promoter, while the gfp gene was inserted into the xhoi site upstream of the pr ... | 2004 | 15650692 |
| scale-up of biopesticide production processes using wastewater sludge as a raw material. | studies were conducted on the production of bacillus thuringiensis (bt)-based biopesticides to ascertain the performance of the process in shake flasks, and in two geometrically similar fermentors (15 and 150 l) utilizing wastewater sludge as a raw material. the results showed that it was possible to achieve better oxygen transfer in the larger capacity fermentor. viable cell counts increased by 38-55% in the bioreactor compared to shake flasks. as for spore counts, an increase of 25% was observ ... | 2004 | 15662544 |
| efficacy of native and recombinant cry1b protein against experimentally induced and naturally acquired ovine myiasis (fly strike) in sheep. | several hundred strains of bacillus thuringiensis (bt), isolated in new zealand from samples of soil and sheep fleece, were tested for toxicity to larvae of the blowfly lucilia cuprina wiedemann. characterization of the bt strains revealed that three of the more active strains produced cry1ba (an insecticidal protein present in bt mother cell crystal inclusion) that was toxic to blowflies. these strains were evaluated for the ability to prevent experimentally induced fly strike in a bioassay by ... | 2004 | 15666730 |
| a strategy for shuffling numerous bacillus thuringiensis crystal protein domains. | bacillus thuringiensis that produce cry1ba are toxic to lucilia cuprina wiedemann blow fly maggots in vivo, and when applied in quantity to sheep fleece, provide up to 6 wk protection against flystrike in the field. these strains also are toxic to epiphyas postvittana (walker) light brown apple moth caterpillars. b. thuringiensis expressing cry1db are toxic only to e. postvittana. when cry1ba and cry1db proteins are expressed within escherichia coli, the recombinant bacteria have the same toxici ... | 2004 | 15666731 |
| bacillus thuringiensis variety kurstaki x aizawai applied to spruce flowers reduced dioryctria abietella (lepidoptera: pyralidae) infestation without affecting seed quality. | we investigated the effects of bacillus thuringiensis variety kurstaki x aizawai (bt) on infestation levels of two lepidopteran insects as well as on seed quality in norway spruce, picea abies l. (karst.) in central sweden. spruce flowers (female strobili) were sprayed with a 0.2% suspension (wt:wt) of the bt preparation turex 50 wp, 25,000 iu/mg in water. to expose even those lepidopteran larvae that feed exclusively embedded within the cone tissue, the bt treatment was applied to open flowers, ... | 2004 | 15666734 |
| fipronil resistance in the diamondback moth (lepidoptera: plutellidae): inheritance and number of genes involved. | bioassays (at generation 1, g1) using fipronil, spinosad, indoxacarb, and bacillus thuringiensis toxins cry1ac and cry1ca with a newly collected field population of plutella xylostella (l.) from farmers fields in the cameron highlands, malaysia, indicated a resistance ratio of approximately 400-, 1,170-, 330-, 2,840-, and 1,410-fold, respectively, compared with a laboratory-susceptible population of p. xylostella (roth). at g3, the field-derived population was divided into two subpopulations, on ... | 2004 | 15666763 |
| inheritance of resistance to bacillus thuringiensis cry1ac toxin in a greenhouse-derived strain of cabbage looper (lepidoptera: noctuidae). | a population of cabbage looper, trichoplusia ni (hübner), collected from commercial greenhouses in the lower mainland of british columbia, canada, in 2001 showed a resistance level of 24-fold to dipel, a product of bacillus thuringiensis (bt) subspecies kurstaki. this population was selected with cry1ac, the major bt cry toxin in dipel, to obtain a homogenous population resistant to cry1ac. the resulting strain of t. ni, named glen-cry1ac, was highly resistant to cry1ac with a resistance ratio o ... | 2004 | 15666767 |
| management of feeding damage and survival of southwestern corn borer and sugarcane borer (lepidoptera: crambidae) with bacillus thuringiensis transgenic field corn. | the efficacy of transgenic corn hybrids expressing an insecticidal bacillus thuringiensis (bt) delta-endotoxin from different transformation events was evaluated in field corn, zea mays l., against the southwestern corn borer, diatraea grandiosella dyar, and sugarcane borer, diatraea saccharalis (f.). susceptibilities of neonates and third instars were determined on bt and non-bt corn plants (v6 and r1 stages) in field plots and corn leaf tissue feeding exposure in laboratory bioassays. bt corn ... | 2004 | 15666772 |
| insect-resistant transgenic pinus radiata. | transgenic radiata pine (pinus radiata d. don) plants containing a bacillus thuringiensis (bt) toxin gene, crylac, were produced by means of biolistic transformation of embryogenic tissue. using the selectable marker gene nptii and corresponding geneticin selection, 20 independent transgenic lines from five genotypes were established. over 200 plants regenerated from ten transgenic lines were successfully transferred to soil. the integration and expression of the introduced genes in transgenic t ... | 2005 | 15668791 |
| two self-splicing group i introns interrupt two late transcribed genes of prolate-headed lactobacillus delbrueckii phage jcl1032. | two group i introns were detected from the late gene region of the prolate-headed phage jcl1032 of lactobacillus delbrueckii. introns jcl-i1 and jcl-i2 interrupt orf602 and orf1868 encoding a phage terminase large subunit (terl, 69.7 kda) and a putative tape measure protein (tmp, 202 kda), respectively. the introns jcl-i1 (226 bp) and jcl-i2 (322 bp) were efficiently self-spliced in vivo. both introns were classified to the subgroup ia1 having all the conserved structures necessary for splicing, ... | 2004 | 15669111 |
| documentation of high-level bacillus sphaericus 2362 resistance in field populations of culex quinquefasciatus breeding in polluted water in thailand. | bacillus sphaericus (bsph) neide has been recognized as an effective mosquito larvicide since its discovery 20 years ago. various strains of this agent, such as 2362, 2297, 1593, and c3-41, have been developed, formulated, and field-evaluated against mosquito larvae in different countries. their high efficacy in controlling mosquitoes breeding in various habitats, especially those in polluted water, has been documented. however, resistance to bsph has been reported in culex pipiens complex in bo ... | 2004 | 15669382 |
| effects of sublethal concentrations of vectobac on biological parameters of aedes aegypti. | the effect of sublethal concentrations (30% lethal concentration [lc30] = 0.41 ppm, lc50 = 1.04 ppm, and lc70 = 2.60 ppm) of vectobac 12 aqueous suspension (as, bacillus thuringiensis var. israelensis h-14, 600 itu/mg) on life parameters of aedes aegypti and its f1 progeny (not exposed) was assessed in laboratory tests. based on the data, it was clear that concentrations of 0.41 ppm of vectobac significantly shortened the duration of the developmental cycle of the exposed mosquitoes, but not tha ... | 2004 | 15669383 |
| efficacy studies of vectobac 12as and teknar hp-d larvicides against 3rd-instar ochlerotatus taeniorhynchus and culex quinquefasciatus in small plot field studies. | efficacy studies were conducted with vectobac 12as and teknar hp-d larvicides against 3rd-instar ochlerotatus taeniorhynchus and culex quinquefasciatus in small field test plots. the products were obtained off the shelf from distributors and had different lot numbers. they were evaluated over a 2-year period in spring 2002 and 2003. application rates were 0.29, 0.58, and 1.10 liter/ha and evaluations were made 24 and 48 h after treatment. both products performed well in these studies, with vecto ... | 2004 | 15669386 |
| detoxification of distillery effluent through bacillus thuringiensis (mtcc 4714) enhanced phytoremediation potential of spirodela polyrrhiza (l.) schliden. | 2004 | 15669736 | |
| field evaluation of biolarvicides in surat city, india. | two bacterial larvicide (bio-larvicide) formulations--bacticide and vectobac containing viable endospores and delta endotoxin of bacillus thuringiensis var israelensis h-14 were evaluated in 2001 for their mosquito larvicidal efficacy under the operational conditions of urban malaria control programme in surat city, india. | 2004 | 15672558 |
| potentiation and cellular phenotypes of the insecticidal toxin complexes of photorhabdus bacteria. | the toxin complex (tc) genes of bacteria comprise a large and growing family whose mode of action remains obscure. in the insect pathogen photorhabdus, tc genes encode high molecular weight insecticidal toxins with oral activity against caterpillar pests. one protein, tcda, has recently been expressed in transgenic plants and shown to confer insect resistance. these toxins therefore represent alternatives to toxins from bacillus thuringiensis (bt) for deployment in transgenic crops. levels of tc ... | 2005 | 15679840 |
| sequence variation in the cadherin gene of ostrinia nubilalis: a tool for field monitoring. | toxin-binding proteins of insect midgut epithelial cells are associated with insect resistance to bacillus thuringiensis (bt) cry toxins. a 5378 nt cdna encoding a 1717 amino acid putative midgut cadherin-like glycoprotein and candidate cry1ab toxin-binding protein was characterized from ostrinia nubilalis. intraspecific alignment of partial o. nubilalis cadherin gene sequences identified variance within proposed cry1a toxin binding region 2 (tbr2), 1328iplqtsilvvt[i/v] n1340, and flanking cry1a ... | 2005 | 15681223 |
| cellular fatty-acid analysis of bacillus thuringiensis var. kurstaki commercial preparations. | cellular fatty acid (cfa) composition of bacillus thuringiensis var. kurstaki (btk) preparations was determined by use of the midi sherlock microbial identification system on a hewlett-packard 5890 gas chromatograph. four commercial preparations--one btk sample obtained from the u.s. forest service, one btk sample obtained from dugway proving ground, and btk and bacillus thuringiensis var. israelensis (bti) preparations obtained from american type culture collection (atcc)--were analyzed and eva ... | 2005 | 15686395 |
| isolation, characterization and expression of a novel vegetative insecticidal protein gene of bacillus thuringiensis. | twenty-four serovars of bacillus thuringiensis (bt) were screened by polymerase chain reaction to detect the presence of vegetative insecticidal protein gene (vip)-like sequences by using vip3aa1-specific primers. vip-like gene sequences were identified in eight serovars. these genes were cloned and sequenced. the deduced amino acid sequence of the vip3aa14 gene from bacillus thuringiensis tolworthi showed considerable differences as compared to those of vips reported so far. the vip3aa14 gene f ... | 2005 | 15686851 |
| [testing the efficiency of bacillus thuringien israelesis against mosquito larvae in uzbekistan]. | experiments were conducted in the potential and neighboring malarious areas in the flood plains of the tupalang river in the sarias district, surkhandarya region, uzbekistan. they have indicated that the numbers of larvae of pp. culex and aedes within the first 24 hours after treatment with bti drastically reduced with all test doses (0.01-5.0 g/m2) and 92.3-100% larval deaths were recorded. at the same time the efficacy of the drugs retained for more than 7 days (100% death), i.e. throughout th ... | 2004 | 15689133 |
| new strategy for identification of novel cry-type genes from bacillus thuringiensis strains. | we designed five degenerate primers for detection of novel cry genes from bacillus thuringiensis strains. an efficient strategy was developed based on a two-step pcr approach with these primers in five pair combinations. in the first step, only one of the primer pairs is used in the pcr, which allows amplification of dna fragments encoding protein regions that include consensus domains of representative proteins belonging to different cry groups. a second pcr is performed by using the first-step ... | 2005 | 15691928 |
| disruption of a cadherin gene associated with resistance to cry1ac {delta}-endotoxin of bacillus thuringiensis in helicoverpa armigera. | a laboratory strain (gy) of helicoverpa armigera (hubner) was established from surviving larvae collected from transgenic cotton expressing a bacillus thuringiensis var. kurstaki insecticidal protein (bt cotton) in gaoyang county, hebei province, people's republic of china, in 2001. the gybt strain was derived from the gy strain through 28 generations of selection with activated cry1ac delivered by diet surface contamination. when resistance to cry1ac in the gybt strain increased to 564-fold aft ... | 2005 | 15691952 |
| indian bt gene monoculture, potential time bomb. | 2005 | 15696133 | |
| efficient transformation of cellulomonas flavigena by electroporation and conjugation with bacillus thuringiensis. | the conjugative self-transmissible plasmid pht73, harbored in bacillus thuringiensis var. kurstaki, was demonstrated to be transferred to cellulomonas flavigena, a cellulolytic bacterium. both conjugation and transformation procedures yielded resistant colonies; however, chromosomal integration was observed only when bacterial conjugation occurred. the efficiency of conjugation was 10% of recipient strain, which is considered a very efficient process. when the plasmid pht73 was introduced by tra ... | 2004 | 15696619 |
| enhancement of pathogenicity of bacillus thuringiensis by gamma rays. | studies were conducted on the enhancement of pathogenicity of bacillus thuringiensis by gamma rays on various species of termites. the results showed that the 72 hrs old and 60 or 70 kr irradiated culture of b. thuringiensis were more pathogenic than the non-irradiated ones. 168 hrs old and 150 kr (1.5 kgy) irradiated b. thuringiensis caused quicker mortality rate than the non-irradiated one as it shows maximum enhancement ratio (1.32). | 2004 | 15702915 |
| glycolipids as receptors for bacillus thuringiensis crystal toxin. | the development of pest resistance threatens the effectiveness of bacillus thuringiensis (bt) toxins used in transgenic and organic farming. here, we demonstrate that (i) the major mechanism for bt toxin resistance in caenorhabditis elegans entails a loss of glycolipid carbohydrates; (ii) bt toxin directly and specifically binds glycolipids; and (iii) this binding is carbohydrate-dependent and relevant for toxin action in vivo. these carbohydrates contain the arthroseries core conserved in insec ... | 2005 | 15705852 |
| combination of mesocyclops thermocyclopoides and bacillus thuringiensis var. israelensis: a better approach for the control of aedes aegypti larvae in water containers. | the efficacy of a local thai-strain of the copepod, mesocyclops thermocyclopoides and the larvicide, bacillus thuringiensis var. israelensis (bti), used jointly and singly, was studied against aedes aegypti in water containers. in a laboratory test, copepods alone produced mortality of 98-100% in 1st instar larvae of ae. aegypti at copepod:larvae ratios ranging from 1:1 to 1:4. in an outdoor field simulated experiment that ran for 16 wk, after a single inoculation, the treatment of copepods and ... | 2004 | 15707281 |
| isolation and toxicity of bacillus thuringiensis from potato-growing areas in bolivia. | bacillus thuringiensis was isolated from 116 samples collected in high altitude potato-growing areas in bolivia. in these regions, main potato pests are the potato tuberworm phthorimaea operculella, and the andean weevils premnotrypes latithorax and rhigopsidius tucumanus. b. thuringiensis was found in 60% of the samples. the main percentage of samples with b. thuringiensis was found in larvae of r. tucumanus (78%). bioassays were performed with 112 isolates. none resulted toxic to either larvae ... | 2005 | 15707864 |
| response of larval chironomus tepperi (diptera: chironomidae) to individual bacillus thuringiensis var. israelensis toxins and toxin mixtures. | the biopesticide bacillus thuringiensis israelensis (b.t.i.) is highly toxic to the larvae of chironomus tepperi, an important pest of aerially sown rice in southern australia. in this study, all of the known cry genes and the cyt1a gene from b.t.i. were expressed and tested for individual toxicity against fourth instar c. tepperi larvae. possible synergism between toxins in two component mixtures involving all toxins except cry10a was also evaluated. of the cry toxins, only cry11a and cry4b dis ... | 2004 | 15707867 |
| plant codon optimized cry genes of bacillus thuringiensis can be expressed as soluble proteins in escherichia coli bl21 codon plus strain as nusa-cry protein fusions. | for optimal expression of delta-endotoxins from bacillus thuringiensis in plants, preferential changes in the codon sequences, and reduction in overall at content in the nucleotide sequence of the genes is important. reports suggest that sequences with such modifications cannot be overexpressed in bacteria. we report here that the modified genes can be overexpressed in a strain of escherichia coli carrying extra trna genes for some of the codons occurring at high frequency in plant genes and les ... | 2005 | 15707873 |
| inheritance of resistance and cross-resistance to deltamethrin in plutella xylostella (lepidoptera: plutellidae) from pakistan. | a field population of plutella xylostella (l) from pakistan was found to be highly resistant to deltamethrin (>500-fold) but had little or no resistance to spinosad, fipronil, indoxacarb, abamectin, bacillus thuringiensis (bt) var kurstaki, bt var aizawai or cry1ac when compared with a susceptible laboratory population, lab-uk. a sub-population was selected for six generations (laboratory g3-g8) with deltamethrin (delta-sel), while a second sub-population was left unselected (unsel). bioassays a ... | 2005 | 15712350 |
| mitochondria permeabilization by a novel polycation peptide btm-p1. | bacillus thuringiensis subsp. medellin is known to produce the cry11bb protein of 94 kda, which is toxic for mosquito larvae due to permeabilization of the plasma membrane of midgut epithelial cells. earlier we found that a 2.8-kda novel peptide btm-p1, which was artificially synthesized taking into account the primary structure of cry11bb endotoxin, is active against several species of bacteria. in this work we show that btm-p1 induces cyclosporin a-insensitive swelling of rat liver mitochondri ... | 2005 | 15713682 |
| parasporin-1, a novel cytotoxic protein to human cells from non-insecticidal parasporal inclusions of bacillus thuringiensis. | pro-parasporin-1 is a parasporal inclusion protein of the non-insecticidal bacillus thuringiensis strain a1190. cytotoxic fragments, named parasporin-1, were generated from pro-parasporin-1 by trypsin digestion. parasporin-1 was purified by a combination of chromatography procedures based on the cytotoxic activity to hela cells. two different fragments of 15-kda and 56-kda were detected in the purified parasporin-1 fraction. these fragments were tightly associated with each other and could not b ... | 2005 | 15713879 |
| long-term evaluation of compliance with refuge requirements for bt cotton. | the success of the refuge strategy for delaying pest resistance to bt crops depends on compliance by farmers. however, the accuracy of previous estimates of compliance has been questioned. we have applied a novel approach based on the use of geographical information system (gis) technology to measure compliance with refuge requirements for bt cotton in six arizona regions from 1998 to 2003. although compliance varied among regions, overall compliance was above 88% in five of six years. with the ... | 2005 | 15714465 |
| validation of a cotton-specific gene, sad1, used as an endogenous reference gene in qualitative and real-time quantitative pcr detection of transgenic cottons. | genetically modified (gm) cotton lines have been approved for commercialization and widely cultivated in many countries, especially in china. as a step towards the development of reliable qualitative and quantitative pcr methods for detecting gm cottons, we report here the validation of the cotton (gossypium hirsutum) endogenous reference control gene, sad1, using conventional and real-time (rt)-pcr methods. both methods were tested on 15 different g. hirsutum cultivars, and identical amplicons ... | 2005 | 15726375 |
| persistence of vectobac wdg and metoprag s-2g against aedes aegypti larvae using a semi-field bioassay in rio de janeiro, brazil. | persistence of bacillus thuringiensis var. israelensis (vectobac wdg) and methoprene (metoprag s-2g) was evaluated against aedes aegypti late third instar larvae of the rockefeller strain in a semi-field bioassay. tests were performed in rio de janeiro, using containers made of plastic, iron, concrete and asbestos, placed in a shaded area. the formulations used were 0.2 g of vectobac-wdg and 1 g of metoprag s-2g per 100 liters of water in house storage containers. vectobac wdg was tested twice, ... | 2005 | 15729468 |
| degradation of cry1ab protein from genetically modified maize in the bovine gastrointestinal tract. | immunoblotting assays using commercial antibodies were established to investigate the unexpected persistence of the immunoactive cry1ab protein in the bovine gastrointestinal tract (git) previously suggested by enzyme-linked immunosorbent assay (elisa). samples of two different feeding experiments in cattle were analyzed with both elisa and immunoblotting methods. whereas results obtained by elisa suggested that the concentration of the cry1ab protein increased during the git passage, the immuno ... | 2005 | 15740023 |