Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| development and characterization of diamondback moth resistance to transgenic broccoli expressing high levels of cry1c. | a field-collected colony of the diamondback moth, plutella xylostella, had 31-fold resistance to cry1c protoxin of bacillus thuringiensis. after 24 generations of selection with cry1c protoxin and transgenic broccoli expressing a cry1c protein, the resistance that developed was high enough that neonates of the resistant strain could complete their entire life cycle on transgenic broccoli expressing high levels of cry1c. after 26 generations of selection, the resistance ratios of this strain to c ... | 2000 | 10966391 |
| [prevalence of microbiota in the digestive tract of wild females of lutzomyia longipalpis lutz & neiva, 1912) (diptera: psychodidae)]. | we dissected the digestive tract of 245 females in pools of 35 flies forming 7 groups. these flies were lutzomyia longipalpis originating from lapinha cave, lagoa santa, minas gerais. out of the 8 species of bacteria isolated there was a predominancy of gram negative bacterias (gnb) in the group of non-fermenters of sugar belonging to the following species: acinetobacter lwoffii, stenotrophomonas maltophilia, pseudomonas putida and flavimonas orizihabitans. the group of gnb fermenters were: ente ... | 2000 | 10967602 |
| molecular and insecticidal characterization of a bacillus thuringiensis strain isolated during a natural epizootic. | a new bacillus thuringiensis strain belonging to the serovar aizawai was isolated from a dead larva of the lepidopteran mythimna loreyi collected in a corn crop in spain during a natural epizootic. this strain, which was named leapi01, was compared with the kurstaki and aizawai strains isolated from dipel(r) and xentari(r), by electron microscopy, sds-page, plasmid pattern, pcr and insecticidal activity. this strain showed similar morphological and biochemical characteristics to the standard str ... | 2000 | 10971764 |
| improved shuttle vector for expression of chitinase gene in bacillus thuringiensis. | a 6.96-kbp plasmid vector pbcx was constructed from the plasmid pbc16 (4.4 kbp) and a 2.56-kbp fragment of pbluescript ii ks. the bifunctional plasmid pbcx conferred ampicillin and tetracycline resistance in escherichia coli but only tetracycline resistance in bacillus thuringiensis. it has unique sites for bamhi, smai, psti, hindiii, sali, xhoi, draii, apai and kpni derived from pbluescript ii ks and was lost at a low rate in b. thuringiensis subsp. israelensis when cultured in luria-bertani br ... | 2000 | 10972713 |
| withdrawn greenpeace bt suit enters spin cycle. | 2000 | 10973201 | |
| comparative study of the frequency, flagellar serotype, crystal shape, toxicity, and cry gene contents of bacillus thuringiensisfrom three environments. | a number of bacillus thuringiensis isolates from sericultural farm, soil, and granary samples in korea were found. b. thuringiensis isolates were predominant in granary (40%), followed by sericultural farm (33% and 25% in the spring and fall isolation), and soil (10%). in toxicity tests for three areas, lepidopteran-active isolates were rich in the spring of sericultural farm and granary, but the fall isolation of sericultural farm displayed that a large number of b. thuringiensis isolates havin ... | 2000 | 10977891 |
| correlation of the insecticidal activity of the bacillus thuringiensis a4 strain against bactrocera oleae (diptera) with the 140-kda crystal polypeptide. | the crystals of the soil-isolated bacillus thuringiensis (bt) strain a4 consist of two polypeptides with molecular mass of 140 kda and 32 kda that exhibit insecticidal activity against adult flies of bactrocera oleae (diptera). plasmid curing applied to this strain resulted in the isolation of several subclones exhibiting alterations in their crystal polypeptides as well as two acrystalliferous subclones. the crystals of subclone 1.1 lacked the 32-kda polypeptide and consisted uniquely of a 140- ... | 2000 | 10977893 |
| toxicity and receptor binding properties of bacillus thuringiensis delta-endotoxins to the midgut brush border membrane vesicles of the rice leaf folders, cnaphalocrocis medinalis and marasmia patnalis. | pesticidal activity and receptor-binding properties of bacillus thuringiensis toxins to rice leaf folders, cnaphalocrocis medinalis and marasmia patnalis, were investigated. saturation and competition binding experiments were done with iodine ((125)1)-labeled bt proteins and brush border membrane vesicles prepared from the midgut of c. medinalis and m. patnalis. the results show saturable, specific, and high-affinity binding of all toxins except cry2a toxin. cry1aa and cry2a toxins were bound wi ... | 2000 | 10977896 |
| common occurrence of enterotoxin genes and enterotoxicity in bacillus thuringiensis. | seventy-four strains of bacillus thuringiensis thuringiensis representing 24 serovars were examined for the presence of three enterotoxin genes/operons; the non-haemolytic enterotoxin nhe, the haemolytic enterotoxin hbl and the bacillus cereus toxin bcet using polymerase chain reaction. the nhebc genes were found in all strains examined, the hblcd genes in 65 of the 74 strains and bcet in 63 strains. there was little consistency of the distribution of enterotoxin loci among strains of the same s ... | 2000 | 10981706 |
| an in-field screen for early detection and monitoring of insect resistance to bacillus thuringiensis in transgenic crops. | we present a field-based approach to detect and monitor insects with resistance to insecticidal toxins produced by transgenic plants. our objective is to estimate the phenotypic frequency of resistance in a population by relating the densities of insects on genetically transformed plants to densities on nontransformed plants. we focus on european corn borer, ostrinia nubilalis (hübner), in sweet corn, zea mays l., expressing cry1ab from bacillus thuringiensis subsp. kurstaki berliner to illustra ... | 2000 | 10985012 |
| lack of toxicity to adults of the mexican fruit fly (diptera: tephritidae) of beta-exotoxin in bacillus thuringiensis endotoxin preparations. | beta-exotoxin (thuringiensin) was found in high titers in centrifugation supernatants and acetone/lactose powders produced from centrifugation pellets of strains guat 1 and hd 2 of bacillus thuringiensis (berliner). diets containing powders of either strain were toxic, diets containing guat 1 supernatant were not toxic, diets containing hd 2 supernatant were slightly toxic, and diets containing powders or supernatants from uninoculated culturing medium spiked with beta-exotoxin were not toxic. m ... | 2000 | 10985014 |
| comparative insecticidal properties of two nucleopolyhedrovirus vectors encoding a similar toxin gene chimer. | laboratory, greenhouse and field studies were conducted to characterize the insecticidal properties of genetically altered forms of autographa californica (speyer) nucleopolyhedrovirus (acnpv) and helicoverpa zea (boddie) npv (hznpv) against selected heliothine species. the altered viruses each contained a chimeric 0.8-kb fragment encoding the insect-specific, sodium channel neurotoxin from the algerian scorpion androctonus australis hector (aait, hence recombinant viruses designated ac-aait and ... | 2000 | 10985018 |
| baseline susceptibility of the corn earworm (lepidoptera: noctuidae) to the cry1ab toxin from bacillus thuringiensis. | susceptibility to cry1ab toxin from bacillus thuringiensis (bt) was determined for 12 field populations of neonate corn earworm, helicoverpa zea (boddie), from the united states. earworm larvae were exposed to artificial diet treated with increasing bt concentrations, and mortality and growth inhibition were evaluated after 7 d. the range of variation in bt susceptibility indicated by growth inhibition was very similar to that indicated by mortality. although interpopulation variation in suscept ... | 2000 | 10985041 |
| late-instar european corn borer (lepidoptera: crambidae) tunneling and survival in transgenic corn hybrids. | field studies were conducted in 1996 and 1997 to determine injury by and survival of late-instar european corn borer, ostrinia nubilalis (hübner), on genetically altered bacillus thuringiensis berliner corn, zea mays l. cry1ab events 176, bt11, mon810, and mon802; cry1ac event dbt418; and cry9c event cbh351 were evaluated. plants of each corn hybrid were manually infested with two third-, fourth-, or fifth-instar o. nubilalis. larvae were held in proximity to the internode of the plant above the ... | 2000 | 10985043 |
| plant-toxin interactions in transgenic bt cotton and their effect on mortality of helicoverpa armigera (lepidoptera: noctuidae). | in australia, transgenic cotton plants expressing the cry1ac gene from bacillus thuringiensis berliner variety kurstaki are less toxic to first-instar helicoverpa armigera (hübner) after the plant is producing fruit. we developed two bioassay methods (leaf mush, leaf disk) to test if the physiological state of the plants explained changes in toxicity and a third method (diet incorporation) was developed to quantify the toxicity of bt leaves when mixed in chickpea diet. cry1ac protein was less to ... | 2000 | 10985045 |
| feeding behavior of bollworm and tobacco budworm (lepidoptera: noctuidae) larvae in mixed stands of nontransgenic and transgenic cotton expressing an insecticidal protein. | feeding behavior of third-instar bollworm, helicoverpa zea (boddie), and tobacco budworm, heliothis virescens (f.), was observed in pure and mixed stands of nontransgenic and transgenic cotton (btk), gossypium hirsutum l., expressing an insecticidal protein cryia(c) from a bacterium, bacillus thuringiensis berliner subsp. kurstaki. five plant stands composed of btk and non-btk plants were evaluated; two pure stands and three mixed stands. percentage ratios of btk to non-btk plants in the stands ... | 2000 | 10985046 |
| trypsinogen-like cdnas and quantitative analysis of mrna levels from the indianmeal moth, plodia interpunctella. | two cdna fragments encoding full-length trypsinogen-like proteins were cloned from larvae of two strains (rc688s and hd198r) of the indianmeal moth, plodia interpunctella (hübner), which differed in their sensitivity to bacillus thuringiensis protoxins. one cdna fragment contained 874 nucleotides, including a 780-nucleotide open reading frame that encoded a trypsinogen-like protein (pit2b). another cdna fragment amplified from both p. interpunctella strains contained 864 nucleotides including a ... | 2000 | 10989289 |
| binding of bacillus thuringiensis delta-endotoxins cry1ac and cry1ba to a 120-kda aminopeptidase-n of epiphyas postvittana purified from both brush border membrane vesicles and baculovirus-infected sf9 cells. | a 120-kda protein was purified from brush border membrane vesicles of the tortricid moth epiphyas postvittana (walker) based both on its activity as an aminopeptidase and the ability to bind the bacillus thuringiensis delta-endotoxin cry1ac. the purified enzyme had a pi of 5.6 and was a leucine aminopeptidase, with some isoleucine, phenylalanine and tryptophan aminopeptidase activity. further characterisation showed that the protein was also able to bind cry1ba. during purification, the molecula ... | 2000 | 10989294 |
| proteolytic processing of the cyt1ab1 toxin produced by bacillus thuringiensis subsp. medellin. | bacillus thuringiensis produces d-endotoxins that require proteolytic processing to become active. the activation of the b. thuringiensis subsp. medellin 28 kda (cyt1ab1) cytolytic toxin by trypsin, chymotrypsin and gut extract from culex quinquefasciatus larvae was analyzed. the cyt1ab1 toxin of b. thuringiensis subsp. medellin was processed by all proteases tested to fragments between 23 and 25 kda, while processing of the cyt1aa1 toxin produce fragments between 22.5 and 24.5 kda. the cyt1ab1 ... | 2000 | 10998218 |
| molecular genetic manipulation of truncated cry1c protein synthesis in bacillus thuringiensis to improve stability and yield. | cry1 protoxins of bacillus thuringiensis are insecticidal 135-kda proteins synthesized and assembled into parasporal crystals during sporulation. after ingestion, these crystals dissolve in the midgut and active toxins with molecular masses of about 65-kda are released from the n-terminal half of the molecule by midgut proteases. direct synthesis of the toxin-containing n-terminal half of cry1 molecules using recombinant dna techniques results in a low level of unstable truncated proteins that d ... | 2000 | 11010897 |
| incorporation of protease k into larval insect membrane vesicles does not result in disruption of integrity or function of the pore-forming bacillus thuringiensis delta-endotoxin. | bacillus thuringiensis delta-endotoxins insert into the brush border membranes of insect larval cells to form ion channels. a possible interaction of these toxins with a cytoplasmic component was examined by preloading vesicles from insect larval cells with protease k followed by incubation with toxin. there was no evidence for toxin antigens smaller than the intact toxin in extracts of solubilized vesicles, nor was there an effect of the inclusion of protease k on either of two functional prope ... | 2000 | 11010919 |
| cross-resistance of pink bollworm (pectinophora gossypiella) to bacillus thuringiensis toxins. | two strains of pink bollworm (pectinophora gossypiella) selected in the laboratory for resistance to bacillus thuringiensis toxin cry1ac had substantial cross-resistance to cry1aa and cry1ab but not to cry1bb, cry1ca, cry1da, cry1ea, cry1ja, cry2aa, cry9ca, h04, or h205. the narrow spectrum of resistance and the cross-resistance to activated toxin cry1ab suggest that reduced binding of toxin to midgut target sites could be an important mechanism of resistance. | 2000 | 11010923 |
| apoptosis in cultured midgut cells from heliothis virescens larvae exposed to various conditions. | we exposed midgut cells from primary cultures of heliothis virescens larvae to cell-free previously used medium, the vaughn x and hyq sftrade mark media used for serum-free culture of insect cell lines which do not support h. virescens midgut cells, and to toxin from bacillus thuringiensis. a statistically significant increase in the percent of dying cells was counted in cell populations in vaughn x medium. use of the tunel method to detect apoptosis indicated a low rate (7.2%) of apoptosis in c ... | 2000 | 11015120 |
| premature polyadenylation contributes to the poor expression of the bacillus thuringiensis cry3ca1 gene in transgenic potato plants. | the cry genes that code for the insecticidal crystal proteins of bacillus thuringiensis (b.t.) have been widely used to develop insect-resistant transgenic plants. the cry3ca1 gene has been reported to code for a crystal protein which is particularly potent against the colorado potato beetle (cpb). to explore the biotechnological potential of cry3ca1, we introduced this gene into transgenic potato plants under the control of the camv 35s promoter. in the resulting transformants, the cry3-ca1 gen ... | 2000 | 11016836 |
| field performance of transgenic elite commercial hybrid rice expressing bacillus thuringiensis delta-endotoxin. | here we describe development of transgenic elite rice lines expressing a bt fusion gene derived from cryia(b) and cryia(c) under the control of rice actini promoter. the lines used in the study were indica cms restorer line of minghui 63 and its derived hybrid rice shanyou 63. the level of bt fusion protein cryia(b)/cryia(c) detected in minghui 63 (t51-1) plants was 20 ng/mg soluble protein. the bt shanyou 63 was field-tested in natural and repeated heavy manual infestation of two lepidopteran i ... | 2000 | 11017051 |
| characterization of a bacillus thuringiensis delta-endotoxin which is toxic to insects in three orders. | we report here the first bacillus thuringiensis (bt) toxin which is toxic to insects from three insect orders (diptera, coleoptera, and lepidoptera). an oligonucleotide probe based on the delta-endotoxin n-terminal sequence was used to detect the gene. a 23-kb bamhi fragment containing the intact gene was identified and cloned from bt strain ybt-226 plasmid dna into the vector pbluescript ii. through a series of dna manipulations the size of this fragment was reduced and the gene sequenced. the ... | 2000 | 11023737 |
| whole-cell pcr of bacillus thuringiensis recovered from the phylloplane. | 2000 | 11023739 | |
| composition and ecological distribution of cry proteins and their genotypes of bacillus thuringiensis isolates from warehouses in china. | the composition and distribution of insecticidal crystal proteins (cry proteins) and their genotypes of bacillus thuringiensis isolates from warehouses were evaluated through sds-page and pcr techniques. the results showed that the electrophoretic patterns of delta-endotoxin crystal preparations were divided into five types. the isolates containing approximately 135 kda with a 65-kda protein or only a approximately 135-kda protein, which amounted to 55.74 and 35.25% of all isolates respectively, ... | 2000 | 11023747 |
| intestinal bacteria affect growth of bacillus thuringiensis in larvae of the oriental tea tortrix, homona magnanima diakonoff (lepidoptera: tortricidae). | spores and parasporal crystals of a bacillus thuringiensis serovar aizawai were fed to fifth instar larvae of the oriental tea tortrix, homona magnanima, that had been reared aseptically or that had been reared normally. viable cell numbers of b. thuringiensis and other bacteria in h. magnanima larvae were estimated by homogenization of samples and dilution plating on peptone-polymyxin agar medium for b. thuringiensis cells and on nutrient agar medium for the other bacterial cells. b. thuringien ... | 2000 | 11023751 |
| evidence for intermolecular interaction as a necessary step for pore-formation activity and toxicity of bacillus thuringiensis cry1ab toxin. | based on the observation of large conductance states formed by bacillus thuringiensis cry toxins in synthetic planar lipid bilayers and the estimation of a pore size of 10-20 a, it has been proposed that the pore could be formed by an oligomer containing four to six cry toxin monomers. however, there is a lack of information regarding the insertion of cry toxins into the membrane and oligomer formation. here we provide direct evidence showing that the intermolecular interaction between cry1ab to ... | 2000 | 11024267 |
| developmental expression and stress induction of glutathione s-transferase in the spruce budworm, choristoneura fumiferana. | developmental and stress-induced expression of choristoneura fumiferana glutathione s-transferase (cfgst) mrna and protein were examined using northern blots and western blots. high levels of cfgst mrna and protein were detected in 1st instar larvae and diapausing 2nd instar larvae. expression of cfgst gradually decreased during larval development from 3rd to 5th instar, after which the expression increased once again, reaching peak levels in 6th instar larvae. cfgst mrna and protein were undete ... | 2001 | 11033162 |
| deletion of apra and npra genes for alkaline protease a and neutral protease a from bacillus thuringiensis: effect on insecticidal crystal proteins. | the apra gene encoding alkaline protease a (apra) was cloned from bacillus thuringiensis subsp. kurstaki, and the cloned gene was used to construct apra-deleted (apra1) strains of b. thuringiensis. an apra1 strain of b. thuringiensis that contained the wild-type gene for neutral protease a (npra(+)) displayed levels of extracellular proteolytic activity that were similar to those of an apra(+)npra(+) strain. however, when edta was included in the protease assay to inhibit npra activity the apra1 ... | 2001 | 11035189 |
| the delta-endotoxin proteins accumulate in escherichia coli as a protein-dna complex that can be dissociated by hydrophobic interaction chromatography. | the insecticidal protein cryiac accumulated to form inclusion bodies in escherichia coli upon overexpression of the cloned gene. the solubilized inclusion bodies contained the delta-endotoxin in association with dna fragments of about 25 kb. the protein-dna complex could be dissociated and the delta-endotoxin purified by hydrophobic interaction chromatography on phenyl-sepharose. the dna was washed out in the high-salt buffer while the delta-endotoxin was bound to the matrix and was eluted at 4 ... | 2000 | 11035946 |
| [ribonuclease from bacillus thuringiensis var. subtoxicus. gene structure and biosynthesis regulation]. | the gene for extracellular guanyl-specific ribonuclease of bacillus thuringiensis var. subtoxicus (rnase bth), a close homologue of the b. intermedius rnase (binase), was completely sequenced. analysis of nucleotide sequences in the regions adjoining rnase genes revealed an identical organization of the chromosomal loci of rnase bth and binase. growth characteristics of the bacillus thuringiensis var. subtoxicus strain and its synthesis of rnase were studied. it was shown that the exogenous inor ... | 2000 | 11036526 |
| construction of chromosomal integrants of bacillus sphaericus 2362 by conjugation with escherichia coli. | incp-based plasmids conjugated between escherichia coli and mosquitocidal strains of bacillus sphaericus at frequencies of 10(-7) to 10(-9) per recipient. plasmid transfer was most efficient when a restriction-deficient strain of b. sphaericus 2362 (serotype 5a5b) was used as recipient and was least efficient with recipients from serotypes 1a and 2a2b. a deleted version of the cryptic locus 'gene 80' from strain 2362 was cloned into the suicide vector pmtl30, which could not replicate in b. spha ... | 2000 | 11037132 |
| construction of plant vectors with high level expression of b.t. toxin gene and studies on their expression behavior in transgenic tobaccos. | breeding pest-resistant plants using plant genetic engineering technique is an effective strategy in integrated pest management (ipm). increasing the expression level of foreign insecticidal protein by using a strong promoter is a useful method. in this work, a plant expression vector, pbinmobc, was constructed. it contained the cryia(c) gene under the control of a chimeric om promoter and the omega factor. as a control, another vector, pbinobc, was also constructed in this study. pbinobc carryi ... | 1999 | 11037944 |
| initial frequency of alleles for resistance to bacillus thuringiensis toxins in field populations of heliothis virescens. | the risk of rapid pest adaptation to an insecticide is highly dependent on the initial frequency of resistance alleles in field populations. because we have lacked empirical estimates of these frequencies, population-genetic models of resistance evolution have relied on a wide range of theoretical estimates. the recent commercialization of genetically engineered cotton that constitutively produces an insecticidal protein derived from the biocontrol agent, bacillus thuringiensis (bt) has raised c ... | 1997 | 11038613 |
| human cell exposure assays of bacillus thuringiensis commercial insecticides: production of bacillus cereus-like cytolytic effects from outgrowth of spores. | most contemporary bioinsecticides are derived from scaled-up cultures of bacillus thuringiensis subspecies israelensis (bti) and kurstaki (btk), whose particulate fractions contain mostly b. thuringiensis spores (> 10(12)/l) and proteinaceous aggregates, including crystal-like parasporal inclusion bodies (pib). based on concerns over relatedness to b. cereus-group pathogens, we conducted extensive testing of b. thuringiensis (bt) products and their subfractions using seven human cell types. the ... | 2000 | 11049810 |
| [construction of b. thuringiensis shuttle vector and expression of the cry1c gene]. | we have constructed the e. coli-bt shuttle vector phv-1 by cloning the replicon (approximately 1.6 kb) of bt ken-ag and the aphi gene of puc4k into puc19. the rate of plasmid maintenance is more than 80% after 100 generations in e. coli, whereas 80% after 40 generations in bti 4q8. we have also constructed phv-cry1c through cloning the alpha-amylase promoter from b. licheniformis and the cry1c gene from bt 9510 into phv-1 and introduced it into bti 4q8 by means of electroporation. under the micr ... | 2000 | 11051727 |
| [construction and bioassay of secondary recombinant baculovirus with two foreign gene]. | plasmid pacleneo which bears neomycin gene derived by the baculovirus ie1 promotor was digested and the gene was harvested. a transfer vector pac34dz2 in which the polyhedrin envelope gene has been inactivated by insertion of expression cassette of pie1/neo was constructed by inserting the neo cassette into the saci site of plasmid pac34dz1. we have constructed the polyhedrin positive recombinant virus (i) vacphbtt which was able to express bt truncated endotoxin gene. in order to improve the in ... | 2000 | 11051817 |
| frequency of alleles conferring resistance to a bacillus thuringiensis toxin in a philippine population of scirpophaga incertulas (lepidoptera: pyralidae). | using the f2 screen methodology, we estimated the frequency of alleles conferring resistance to the cry1ab toxin of bacillus thuringiensis berliner in a philippine population of the stem borer scirpophaga incertulas (walker). evaluation of >450 isofemale lines for survival of f2 larvae on cry1ab plants did not detect the presence of an allele conferring a high level of resistance. the frequency of such an allele in the sampled population was conservatively estimated to be <3.6 x 10(-3) with 95% ... | 2000 | 11057726 |
| taco dispute underscores need for standardized tests. | 2000 | 11062423 | |
| super-infection by bacillus thuringiensis h34 or 3a3b can lead to death in mice infected with the influenza a virus. | bacterial super-infections are the main cause of complication and mortality after influenza virus (iav) infection. since bacillus thuringiensis (bt) is considered non-pathogenic for humans and is widely sprayed in urban areas, the aim of this work was to evaluate the potential pathogenicity of a combined infection bt-iav in a mouse model of pneumonia. bacteria used for super-infections were bt serotype h34 isolated from human infection and the insecticidal strain 3a3b obtained from a commercial ... | 2000 | 11064263 |
| the plcr regulon is involved in the opportunistic properties of bacillus thuringiensis and bacillus cereus in mice and insects. | bacillus thuringiensis has been widely used for 40 years as a safe biopesticide for controlling agricultural pests and mosquitoes because it produces insecticidal crystal proteins. however, spores have also been shown to contribute to overall entomopathogenicity. here, the opportunistic properties of acrystalliferous b. thuringiensis cry(-) and bacillus cereus strains were investigated in an insect species, galleria mellonella, and in a mammal, balb/c mice. in both animal models, the pathogenici ... | 2000 | 11065361 |
| safety and advantages of bacillus thuringiensis-protected plants to control insect pests. | plants modified to express insecticidal proteins from bacillus thuringiensis (referred to as bt-protected plants) provide a safe and highly effective method of insect control. bt-protected corn, cotton, and potato were introduced into the united states in 1995/1996 and grown on a total of approximately 10 million acres in 1997, 20 million acres in 1998, and 29 million acres globally in 1999. the extremely rapid adoption of these bt-protected crops demonstrates the outstanding grower satisfaction ... | 2000 | 11067772 |
| characterization of the anti-cancer-cell parasporal proteins of a bacillus thuringiensis isolate. | an unusual activity, associated with non-insecticidal and non-haemolytic parasporal inclusion proteins of a bacillus thuringiensis soil isolate, designated 89-t-26-17, was characterized. the parasporal inclusion of this isolate was bipyramidal, rounded at both ends, containing proteins of 180, 150, 120, 100, and 88 kda. no homologies with the cry and cyt proteins of b. thuringiensis were detected based on n-terminal sequences. proteolytic processing of the inclusion proteins by proteinase k, try ... | 2000 | 11068678 |
| role of two arginine residues in domain ii, loop 2 of cry1ab and cry1ac bacillus thuringiensis delta-endotoxin in toxicity and binding to manduca sexta and lymantria dispar aminopeptidase n. | two arginine residues (368-369) of cry1ab and cry1ac were mutated to alanine, glutamic acid and lysine by site-directed mutagenesis. insecticidal activities of the mutant toxins on manduca sexta and lymantria dispar larvae were examined. cry1ac mutant toxins (c)rr-aa and (c)rr-ee and cry1ab mutant toxins (b)rr-aa and (b)rr-ee showed great reductions in toxicity against both insects. in contrast, conservatively changed (c)rr-kk and (b)rr-kk mutants did not alter toxicity to either insect. binding ... | 2000 | 11069655 |
| characterization of inta 51-3, a new atypical strain of bacillus thuringiensis from argentina. | several isolates of bacillus thuringiensis native to argentina obtained in a nationwide screening program showed atypical crystal morphology. one of these strains, inta 51-3, was further characterized in order to determine other features like protein composition of its parasporal crystal, plasmid pattern, identification of cry genes and toxicological properties. b. thuringiensis inta 51-3 (serovar tohokuensis) had an amorphous inclusion containing a major protein component of ca. 130 kda. after ... | 2000 | 11080388 |
| pesticidal and receptor binding properties of bacillus thuringiensis cry1ab and cry1ac delta-endotoxin mutants to pectinophora gossypiella and helicoverpa zea. | bacillus thuringiensis produces several larvicidal crystalline inclusions during sporulation. an understanding of their mechanisms of action is commercially important. in this study, two toxins, cry1ab and cry1ac, were compared that showed 98% amino acid identity in domain i and ii, but differed significantly in domain iii. using site-directed mutagenesis techniques, two conserved loop 2 arg's ((368)rr(369)) of cry1ab and cry1ac toxins were replaced with ala ((368)ar(369), (368)ra(369), (368)aa( ... | 2000 | 11080394 |
| effectiveness of aerial- and ground-applied bacillus formulations against anopheles quadrimaculatus larvae in arkansas rice plots. | experimental bacillus larvicides designed to float on or near the water surface were compared to labeled standard bacillus corn-cob-based larvicides using sentinel anopheles quadrimaculatus larvae in arkansas rice plots during the 1998 growing season. experimental floating formulations of bacillus thuringiensis israelensis applied at 5.58 and 11.18 kg/ha provided up to 100% control of 3rd- and 4th-stage anopheles larvae within 24-48 h, whereas the water-dispersible granule formulations containin ... | 2000 | 11081651 |
| kurstakins: a new class of lipopeptides isolated from bacillus thuringiensis. | a novel class of lipopeptides was isolated from bacillus thuringiensis kurstaki hd-1. four compounds (1-4) were separated by high-performance liquid chromatography and their primary structures determined using a combination of chemical reactions and mass spectrometry. the four lipopeptides were found to have the same amino acid sequence, thr-gly-ala-ser-his-gln-gln, but different fatty acids. the fatty acyl chain is linked to the n-terminal amino acid residue via an amide bond. each lipopeptide ... | 2000 | 11087590 |
| frequency of resistance to bacillus thuringiensis in field populations of pink bollworm. | strategies for delaying pest resistance to genetically modified crops that produce bacillus thuringiensis (bt) toxins are based primarily on theoretical models. one key assumption of such models is that genes conferring resistance are rare. previous estimates for lepidopteran pests targeted by bt crops seem to meet this assumption. we report here that the estimated frequency of a recessive allele conferring resistance to bt toxin cry1ac was 0.16 (95% confidence interval = 0.05-0.26) in strains o ... | 2000 | 11087854 |
| role of proteolysis in determining potency of bacillus thuringiensis cry1ac delta-endotoxin. | bacillus thuringiensis protein delta-endotoxins are toxic to a variety of different insect species. larvicidal potency depends on the completion of a number of steps in the mode of action of the toxin. here, we investigated the role of proteolytic processing in determining the potency of the b. thuringiensis cry1ac delta-endotoxin towards pieris brassicae (family: pieridae) and mamestra brassicae (family: noctuidae). in bioassays, cry1ac was over 2,000 times more active against p. brassicae than ... | 2000 | 11097886 |
| homoduplex and heteroduplex polymorphisms of the amplified ribosomal 16s-23s internal transcribed spacers describe genetic relationships in the "bacillus cereus group". | bacillus anthracis, bacillus cereus, bacillus mycoides, bacillus pseudomycoides, bacillus thuringiensis, and bacillus weihenstephanensis are closely related in phenotype and genotype, and their genetic relationship is still open to debate. the present work uses amplified 16s-23s internal transcribed spacers (its) to discriminate between the strains and species and to describe the genetic relationships within the "b. cereus group," advantage being taken of homoduplex-heteroduplex polymorphisms (h ... | 2000 | 11097928 |
| aventis gets short shrift over release of modified corn. | 2000 | 11100697 | |
| regulation of toxin and virulence gene transcription in bacillus thuringiensis. | bacillus thuringiensis is a spore-forming bacterium well known for its insecticidal properties and its ability to produce a crystal inclusion during sporulation. the specific activity of b. thuringiensis against insect larvae is due to the crystal proteins (cry proteins). two different transcriptional mechanisms (dependent and independent of sporulation) are responsible for cry gene transcription during the stationary phase. in addition to these specific insecticidal toxins, b. thuringiensis pro ... | 2000 | 11111901 |
| bacillus thuringiensis and its use in transgenic insect control technologies. | the insecticidal activity of bacillus thuringiensis (bt) is mainly due to the production of crystals containing insecticidal crystal proteins (icps). these proteins are very selectively active against certain insect species, including some agronomically important pest species. some icp genes have been used for bioengineered crop protection, resulting in transgenic crop plants with excellent insect protection. | 2000 | 11111927 |
| toxicity of chitinase-producing bacillus thuringiensis ssp. kurstaki hd-1 (g) toward plutella xylostella. | one-hundred fifty isolates of bacillus thuringiensis were tested for their ability to produce chitinase using colloidal chitin agar as the primary plating medium. of 14 strains that produced chitinase, b. thuringiensis ssp. kurstaki hd-1(g) was identified as the highest chitinase producer and selected for further study. this bacterium produced the highest amount of chitinase (19.3 mu/ml) when it was cultivated in nutrient broth supplemented with 0.3% colloidal chitin on a rotary shaker (200 rpm) ... | 2000 | 11112372 |
| recombinant cry3aa has insecticidal activity against the andean potato weevil, premnotrypes vorax. | the andean potato weevil, premnotrypes vorax, an insect of the order coleoptera, is a major cause of damage to potato crops in the andean regions of south america. the insecticidal cry proteins from bacillus thuringiensis are useful biological pesticides, and some are toxic to coleopteran insects. we overexpressed recombinant, histidine-tagged cry3aa protein in escherichia coli host cells. the recombinant protein was solubilized at high ph with urea, purified using ni(2+)-nitrilo-triacetic acid ... | 2000 | 11118340 |
| are there pros as well as cons to being parasitized? | the diversity of ways in which parasites reduce the fitness of their hosts has been documented during the past decades, and clearly indicates that parasites can often be considered as direct agents of selection. in natural systems, however, the outcome of a host-parasite interaction might be strongly determined by other ecological factors. parasites can be detrimental to host fitness in one environment, whereas they can be beneficial to it in another. from an evolutionary perspective, this pheno ... | 2000 | 11121851 |
| domain i plays an important role in the crystallization of cry3a in bacillus thuringiensis. | the insecticidal bacterium bacillus thuringiensis synthesizes endotoxin cry proteins of two size classes, 135 and 70 kda, and both form crystalline inclusions in cells after synthesis. crystallization of 135-kda proteins is due to intermolecular attraction of regions in the c-terminal half of the molecule, and the n-terminal half fails to crystallize when synthesized in vivo. alternatively, endotoxins of the 70-kda class such as cry2a and cry3a, which correspond to the n-terminal half of 135-kda ... | 2000 | 11131976 |
| [the characteristics of bacillus thuringiensis strain ybt833 and its transformants that containing different icp genes]. | four different transformants were selected by transferring cry1c into bacillus thuringiensis strain ybt833. southern blot and plasmid profiles results all proved that cry1c was transferred into strain ybt833. however, it was found by pcr analysis that transformant ybt833-1 kept all indigenous icp(insecticidal crystal protein) genes of strain ybt833 while transformant ybt833-2 lost cry1ab, and transformant ybt833-3 lost all icp genes. sds-page showed that transformants of ybt833-1, ybt833-2 and y ... | 2000 | 11132501 |
| detection of enterotoxic bacillus cereus and bacillus thuringiensis strains by pcr analysis. | many strains of bacillus cereus cause gastrointestinal diseases, and the closely related insect pathogen b. thuringiensis has also been involved in outbreaks of diarrhea. the diarrheal types of diseases are attributed to enterotoxins. two different enterotoxic protein complexes, hemolysin bl (hbl) and nonhemolytic enterotoxin (nhe), and an enterotoxic protein, enterotoxin t, have been characterized, and the genes have been sequenced. pcr primers for the detection of these genes were deduced and ... | 2001 | 11133444 |
| importance of cry1 delta-endotoxin domain ii loops for binding specificity in heliothis virescens (l.). | we constructed a model for bacillus thuringiensis cry1 toxin binding to midgut membrane vesicles from heliothis virescens. brush border membrane vesicle binding assays were performed with five cry1 toxins that share homologies in domain ii loops. cry1ab, cry1ac, cry1ja, and cry1fa competed with (125)i-cry1aa, evidence that each toxin binds to the cry1aa binding site in h. virescens. cry1ac competed with high affinity (competition constant [k(com)] = 1.1 nm) for (125)i-cry1ab binding sites. cry1a ... | 2001 | 11133462 |
| plasmid transfer between bacillus thuringiensis subsp. israelensis strains in laboratory culture, river water, and dipteran larvae. | plasmid transfer between strains of bacillus thuringiensis subsp. israelensis was studied under a range of environmentally relevant laboratory conditions in vitro, in river water, and in mosquito larvae. mobilization of pbc16 was detected in vitro at a range of temperatures, ph values, and available water conditions, and the maximum transfer ratio was 10(-3) transconjugant per recipient under optimal conditions. transfer of conjugative plasmid pxo16::tn5401 was also detected under this range of ... | 2001 | 11133463 |
| cyt1a from bacillus thuringiensis lacks toxicity to susceptible and resistant larvae of diamondback moth (plutella xylostella) and pink bollworm (pectinophora gossypiella). | we tested cyt1aa, a cytolytic endotoxin of bacillus thuringiensis, against susceptible and cry1a-resistant larvae of two lepidopteran pests, diamondback moth (plutella xylostella) and pink bollworm (pectinophora gossypiella). unlike previous results obtained with mosquito and beetle larvae, cyt1aa alone or in combination with cry toxins was not highly toxic to the lepidopteran larvae that we examined. | 2001 | 11133481 |
| overexpression of the bt cry2aa2 operon in chloroplasts leads to formation of insecticidal crystals. | in nuclear transgenic plants, expression of multiple genes requires introduction of individual genes and time-consuming subsequent backcrosses to reconstitute multi-subunit proteins or pathways, a problem that is compounded by variable expression levels. in order to accomplish expression of multiple genes in a single transformation event, we have introduced several genes into the chromoplast genome. we confirmed stable integration of the cry2aa2 operon by pcr and southern blot analyses in t(0) a ... | 2001 | 11135556 |
| pcr analysis of cry7 genes in bacillus thuringiensis by the five conserved blocks of toxins. | an alternative pcr analysis to screen for cry7 genes is proposed, based on the five conserved blocks of amino acids of bacillus thuringiensis toxins and their encoding dna sequences. a complete set of five primers was constructed, four direct and one reverse, yielding four specific amplicons. modified profiles can identify new cry genes. | 2001 | 11136129 |
| two delta-endotoxin genes, cry9da and a novel related gene, commonly occurring in lepidoptera-specific bacillus thuringiensis japanese isolates that produce spherical parasporal inclusions. | six lepidoptera-specific bacillus thuringiensis isolates, which belong to the four h serovars (sotto, fukuokaensis, canadensis, and galleriae) and produce spherical parasporal inclusions, were examined for assignment of the classes of the delta-endotoxin genes. gene analysis was conducted by pcr technique with primers designed to probe the genes cry9ca and cry9da. the data revealed that the delta-endotoxin of a serovar canadensis isolate is encoded by the gene cry9da, while those of the five oth ... | 2001 | 11136135 |
| extreme resistance to potato leafroll virus in potato cv. russet burbank mediated by the viral replicase gene. | high levels of field resistance to potato leafroll virus (plrv; genus: polerovirus; family: luteoviridae) were achieved by expression of the unmodified, full-length plrv replicase gene in potato plants cv. russet burbank. a high degree of resistance was also achieved, but less frequently, by expression of a truncated construct of the replicase gene. in limited testing, neither miss-frame nor antisense constructs of the replicase gene conferred resistance. the degree of resistance expressed among ... | 2000 | 11137161 |
| insecticide resistance and dominance levels. | dominance has been assessed in different ways in insecticide resistance studies, based on three phenotypic traits: the insecticide concentration required to give a particular mortality (dlc), mortality at a particular insecticide dose (dml), and fitness in treated areas (dwt). we propose a general formula for estimating dominance on a scale of 0 to 1 (0 = complete recessivity and 1 = complete dominance). dlc, dml, and dwt are not directly related and their values depend on genetic background and ... | 2000 | 11142285 |
| biological control of bactocera oleae (diptera: tephritidae) using a greek bacillus thuringiensis isolate. | bacillus thuringiensis, isolate 114a, was used in toxicity experiments against the wild population ofthe olive pest bactroceria oleae (gmelin). in laboratory experiments, spores and crystals of the b.t. were delivered to the insects with the food. longevity, oviposition period, number of eggs produced, and percent hatch were recorded. olive fruits from the oviposition test were dipped into a suspension containing spores and crystals of b. thuringiensis 114a after the eggs were deposited. in fiel ... | 2000 | 11142295 |
| indirect reduction of ear molds and associated mycotoxins in bacillus thuringiensis corn under controlled and open field conditions: utility and limitations. | in 1995, ears of a experimental inbred (cg59-2) containing a synthetic bacillus thuringiensis cry ia (b) gene driven by pepc, pith and pollen promoters and artificially infested with ostrinia nubilalis (hübner) larvae in small plot studies were free from insect damage, whereas 40-50% of the corresponding non-bt inbred ears were damaged. bt inbred ears that were inoculated with aspergillus flavus link and fusarium proliferatum t. matsushima (nirenberg) or exposed to natural mold inoculum after in ... | 2000 | 11142297 |
| efficacy tests and determination of optimal spray timing values to control nantucket pine tip moth (lepidoptera: tortricidae) infestations. | the nantucket pine tip moth, rhyaciona frustrana (comstock), a common regeneration pest of loblolly pine, pinus taeda l., has been shown to reduce tree volume yields through larval feeding. chemical applications can be effective in protecting trees from the growth losses associated with this feeding, and optimum spray timing values are commonly used to reduce the number of necessary applications and to increase insecticide efficacy. optimal spray timing values for the georgia piedmont were obtai ... | 2000 | 11142302 |
| variation in performance on cry1ab-transformed and nontransgenic rice varieties among populations of scirpophaga incertulas (lepidoptera: pyralidae) from luzon island, philippines. | we quantified variation in performance under greenhouse conditions among seven populations of scirpophaga incertulas (walker) from luzon island, philippines, on three rice varieties: 'ir58' transformed with the cry1ab gene from bacillus thuringiensis berliner, and nontransgenic ir58 and ir62. on ir62, s. incertutas performance did not differ among provinces for any of the 10 parameters measured, but there was a significant effect of town within province for one parameter, 20-d-old larval weight. ... | 2000 | 11142312 |
| mosquitocidal bacterial toxins: diversity, mode of action and resistance phenomena. | bacteria active against dipteran larvae (mosquitoes and black flies) include a wide variety of bacillus thuringiensis and b. sphaericus strains, as well as isolates of brevibacillus laterosporus and clostridium bifermentans. all display different spectra and levels of activity correlated with the nature of the toxins, mainly produced during the sporulation process. this paper describes the structure and mode of action of the main mosquitocidal toxins, in relationship with their potential use in ... | 2000 | 11142715 |
| the use of bacterial larvicides in mosquito and black fly control programmes in brazil. | bacillus spp. based larvicides are increasingly replacing, with numerous advantages, chemical insecticides in programmes for controlling black fly and mosquito populations. brazil was among the pioneers in adopting bacillus thuringiensis israelensis (b.t.i) to control black flies. however, the major current mosquito control programme in brazil, the programme for eradication of aedes aegypti launched in 1997, only recently decided to replace temephos by b.t.i based larvicides, in the state of rio ... | 2000 | 11142716 |
| simulium spp. control program in rio grande do sul, brazil. | insects of the simuliidae family have been the object of control in rio grande do sul since the 70s. their constant attacks became a social-economical problem as well as a problem of public health, with serious consequences to men and to the economy of the areas in which the insects develop. at first, the control was done with a chemical larvicide themephos abate 500 e, but an imperfect measuring of outflow to determine the quantity of the product made simulium spp. resistant to it. from 1983 on ... | 2000 | 11142717 |
| cultivation of bacillus thuringiensis in an airlift reactor with wire mesh draft tubes. | an aeration strategy was proposed for foam control in an airlift reactor with double wire mesh draft tubes. the airlift reactor was employed in the cultivation of bacillus thuringiensis for thuringiensin production. the aeration strategy involved two situations. if the foam rose and touched the foam probe, the air flow rate was dropped to a low value for a certain period. however, if the do value was already below 10% of the saturation when the air flow rate was dropped, the conventional foam co ... | 2001 | 11150794 |
| phylogenetic analysis of bacillus thuringiensis serovars based on 16s rrna gene restriction fragment length polymorphisms. | to determine the 16s rrna gene fingerprints of bacillus thuringiensis strains to reveal phylogenetic relationships among them. | 2001 | 11155130 |
| temperature influences induction of a j7w-1-related phage in bacillus thuringiensis serovar indiana. | induction of a plasmid-integrative j7w-1-related phage in bacillus thuringiensis serovar indiana by ethidium bromide was influenced by the temperature at which the host cells were cultured. under optimal growth conditions, the maximum titer of the phage produced by the serovar indiana reached 1.2 x 10(6) pfu/ml at 37 degrees c while at 27 degrees c it was lower by an order of magnitude (1.3 x 10(5) pfu/ml). the temperature-sensitive period was estimated to occur early during the phage induction. ... | 2000 | 11155363 |
| mating in bacillus thuringiensis can induce plasmid integrative prophage j7w-1. | bacillus thuringiensis serovar israelensis, a bacterium which possesses plasmid transfer ability after mating, has been lysogenized by plasmid integrative phage j7w-1. the induction of phage in this j7w-1 lysogen was observed after mating with phage-insensitive strains, such as b. thuringiensis serovar thuringiensis, b. cereus and b. subtilis, as well as the phage-sensitive strain serovar israelensis. the phage induction was not observed after mating with b. thuringiensis strains af101, serovar ... | 2000 | 11155364 |
| binding analyses of bacillus thuringiensis cry delta-endotoxins using brush border membrane vesicles of ostrinia nubilalis. | transgenic corn expressing the bacillus thuringiensis cry1ab gene is highly insecticidal to ostrinia nubilalis (european corn borer) larvae. we ascertained whether cry1f, cry9c, or cry9e recognizes the cry1ab binding site on the o. nubilalis brush border by three approaches. an optical biosensor technology based on surface plasmon resonance measured binding of brush border membrane vesicles (bbmv) injected over a surface of immobilized cry toxin. preincubation with cry1ab reduced bbmv binding to ... | 2001 | 11157257 |
| portable system for microbial sample preparation and oligonucleotide microarray analysis. | we have developed a three-component system for microbial identification that consists of (i) a universal syringe-operated silica minicolumn for successive dna and rna isolation, fractionation, fragmentation, fluorescent labeling, and removal of excess free label and short oligonucleotides; (ii) microarrays of immobilized oligonucleotide probes for 16s rrna identification; and (iii) a portable battery-powered device for imaging the hybridization of fluorescently labeled rna fragments with the arr ... | 2001 | 11157263 |
| mannose phosphate isomerase isoenzymes in plutella xylostella support common genetic bases of resistance to bacillus thuringiensis toxins in llpidopteran species. | a strong correlation between two mannose phosphate isomerase (mpi) isoenzymes and resistance to cry1a toxins from bacillus thuringiensis has been found in a plutella xylostella population. mpi linkage to cry1a resistance had previously been reported for a heliothis virescens population. the fact that the two populations share similar biochemical, genetic, and cross-resistance profiles of resistance suggests the occurrence of homologous resistance loci in both species. | 2001 | 11157273 |
| the mammalian safety of bacillus thuringiensis-based insecticides. | the united states environmental protection agency between the years 1961 and 1995 registered 177 products containing viable bacillus thuringiensis (bt). numerous laboratory studies have demonstrated that bt and bt products are noninfectious and are toxic to mammals only at a dose > or =10(8) colony forming units (cfu) per mouse (a human equivalent based on the weight of >10(11) cfu). in contrast, as few as three vegetative cells of bacillus anthracis can kill mice (a human equivalent of >10(3) c ... | 2001 | 11161988 |
| why bacillus thuringiensis insecticidal toxins are so effective: unique features of their mode of action. | the spore-forming bacterium bacillus thuringiensis produces intracellular inclusions comprised of protoxins active on several orders of insects. these highly effective and specific toxins have great potential in agriculture and for the control of disease-related insect vectors. inclusions ingested by larvae are solubilized and converted to active toxins in the midgut. there are two major classes, the cytolytic toxins and the delta-endotoxins. the former are produced by b. thuringiensis subspecie ... | 2001 | 11166987 |
| the ptsh gene from bacillus thuringiensis israelensis. characterization of a new phosphorylation site on the protein hpr. | the ptsh gene from bacillus thuringiensis israelensis (bti), coding for the phosphocarrier protein hpr of the phosphotransferase system has been cloned and overexpressed in escherichia coli. comparison of its primary sequence with other hpr sequences revealed that the conserved his15 and ser46 residues were shifted by one amino acid and located at positions 14 and 45, respectively. the biological activity of the protein was not affected by this change. when expressed in a bacillus subtilis ptsh ... | 2001 | 11168390 |
| spatial and temporal distribution of airborne bacillus thuringiensis var. kurstaki during an aerial spray program for gypsy moth eradication. | we measured airborne exposures to the biological insecticide bacillus thuringiensis var. kurstaki (btk) during an aerial spray program to eradicate gypsy moths on the west coast of canada. we aimed to determine whether staying indoors during spraying reduced exposures, to determine the rate of temporal decay of airborne concentrations, and to determine whether drift occurred outside the spray zone. during spraying, the average culturable airborne btk concentration measured outdoors within the sp ... | 2001 | 11171524 |
| the role of a proline-induced broken-helix motif in alpha-helix 2 of bacillus thuringiensis delta-endotoxins. | bacillus thuringiensis delta-endotoxins (cry proteins), are widely used for insect control and plant protection. they are water-soluble proteins that insert into membranes forming ion channels. in most cry toxins alpha-helix 2 is broken by a highly conserved proline residue (pro70 in cry1ab), generating a broken-helix motif. the flexibility of the motif was altered through site-directed mutagenesis. it was found that increasing the flexibility of the motif decreased the stability, the ion transp ... | 2001 | 11172813 |
| toxicology. panel urges further study of biotech corn. | 2000 | 11187032 | |
| [transfer of cry1c gene into bacillus thuringiensis by electroporation to construct strain with broader insecticidal activity]. | three transformants were selected by transferring cry1c into bacillus thuringiensis strain ybt1535. plasmid profiles, pcr and southern blot result all proved that cry1c had been transferred into strain ybt1535. bioassay results showed that the transformants of strain ybt1535 displayed significantly higher toxicity against spodoptera exigua than strain ybt1535, but the toxicities against heliothis armigera and plutella xylostella did not rise except transformant ybt1535-2. | 2000 | 11191763 |
| [research on improving rice resistance to the pest by b.t. and sbti genes]. | b.t. gene alone or and sbti gene together were introduced into two elite indica rice varieties grown in south china by bombardment. and 21 independent transgenic lines containing b.t. gene and 4 independent transgenic lines containing b.t. gene and sbti gene were obtained. molecular and genetics analysis for r1 plants showed integration of multiple transgenes occurred at one genetic locus. northern blot result proved b.t. gene expressed in r2 transgenic plants stably. bioassays using r2 transgen ... | 2000 | 11191767 |
| [cloning of plasmid pbmb2062 in bacillus thuringiensis strain ybt-1520 and construction of plasmid vector with genetic stability]. | a small plasmid pbmb2062 in bacillus thuringiensis strain ybt-1520 was cloned and sequenced. its 2,062 bp sequence contains two potential open reading frames (orfs). the orf1 and orf2 encode a tentative replication initial protein consisting of 289 amino acid residues and a tentative replication protein consisting of 80 amino acid residues, respectively. two homological plasmids were found by blast searching. there are 23 nucleotides difference occurring among three of the plasmids. the differen ... | 2000 | 11192439 |
| the measurement of volatile constituents in foray 48b, an insecticide prepared from bacillus thuringiensis var. kurstaki. | foray 48b, an insecticide prepared from bacillus thuringiensis var. kurstaki (btk), has been used for many years to combat infestations of gypsy moths. foray 48b also contains a large number of 'inert ingredients' which are not disclosed by the manufacturer. gypsy moths usually enter the country through marine- and airports in close proximity to urban areas, which consequently need to be sprayed. the population affected often demands more detailed information than what is available including the ... | 2000 | 11194149 |
| [characterization of a new strain of bacillus thuringiensis, a producer of an endotoxin against coleoptera]. | a new strain of bacillus thuringiensis 2-7 was found to belong to the serotype h8. cells of this strain contained irregular and flat crystalline inclusions and two large plasmids. the gene responsible for crystal formation is most likely located on the large plasmid greater than 105 mda in size. comparison of the cry gene of b. thuringiensis 2-7 and the cryiiia gene of b. thuringiensis subsp. tenebrionis showed that their nucleotide sequences are identical. | 2000 | 11195579 |
| control of aedes aegypti breeding in desert coolers and tires by use of bacillus thuringiensis var. israelensis formulation. | three different formulations of bacillus thuringiensis var. israelensis (bti) were evaluated for their efficacy against immature aedes aegypti in desert coolers and tires. three formulations, viz., vectobac tablets, vectobac granules, and bacticide powder, at the application rate of 0.75, 2, and 1 g per cooler, respectively, and vectobac tablets at 0.75 and 0.375 g per tire, were evaluated. in coolers and tires, 100% reduction in the abundance of late larval instars of ae. aegypti was observed f ... | 2000 | 11198918 |
| evaluation of methylated soy oil and water-based formulations of bacillus thuringiensis var. israelensis and golden bear oil (gb-1111) against anopheles quadrimaculatus larvae in small rice plots. | the efficacy of formulations containing methylated soybean oil (mso) alone and with technical-grade bacillus thuringiensis var. israelensis (bti) were compared to golden bear oil (gb-1111) and a water-based bti formulation against 3rd- to 4th-stage anopheles quadrimaculatus larvae confined to sentinel cages in small rice plots. three replicates each of mso with 2% pyroter added as a surfactant (mso + pyr), mso with 2% pyroter and 4 g of bti technical powder (mso + pyr + bti), gb-1111, a water-ba ... | 2000 | 11198923 |
| diversity of bacillus thuringiensis in different habitats of northern jordan. | a survey of bacillus thuringiensis was conducted for 17 locations in northern jordan representing 12 different habitats. eighty isolates were identified as b. thuringiensis in the majority of the tested samples. results showed that soils contaminated with the slaughterhouses waste materials had the highest content of spore-forming bacteria [(4.05-2.2) 10(7) cfu/g)] and b. thuringiensis [(4.05-7.9) 10(7) cfu/g)] with a (5.5%-14.9%) and (5.2%-7.7%) of the total viable bacterial count, respectively ... | 2000 | 11199499 |
| a battery-powered notebook thermal cycler for rapid multiplex real-time pcr analysis. | a compact, real-time pcr instrument was developed for rapid, multiplex analysis of nucleic acids in an inexpensive, portable format. the instrument consists of a notebook computer, two reaction modules with integrated optics for four-color fluorescence detection, batteries, and a battery-charging system. the instrument weighs 3.3 kg, measures 26 x 22 x 7.5 cm, and can run continuously on the internal batteries for 4 h. independent control of the modules allows differing temperature profiles and ... | 2001 | 11199979 |