Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| the development and status of bt rice in china. | multiple lines of transgenic rice expressing insecticidal genes from the bacterium bacillus thuringiensis (bt) have been developed in china, posing the prospect of increases in production with decreased application of pesticides. we explore the issues facing adoption of bt rice for commercial production in china. a body of safety assessment work on bt rice has shown that bt rice poses a negligible risk to the environment and that bt rice products are as safe as non-bt control rice products as fo ... | 2016 | 26369652 |
| survival of corn earworm (lepidoptera: noctuidae) on bt maize and cross-pollinated refuge ears from seed blends. | refuge is mandated in the united states where genetically modified maize (zea mays l.) expressing insecticidal proteins derived from bacillus thuringiensis berliner (bt) are cultivated. currently, refuge is deployed in different ways including blocks, field strips, or seed blends containing bt and non-bt maize. seed blends provide practical advantages for refuge implementation. however, concerns related to the movement of insect larvae, potential differential survival of heterozygous resistant l ... | 2016 | 26357846 |
| adult exposure to bt toxin cry1ac reduces life span and reproduction of resistant and susceptible pink bollworm (lepidoptera: gelechiidae). | insecticidal proteins from bacillus thuringiensis (bt) are used widely in sprays and transgenic plants to control insect pests. although much research has elucidated the effects of bt toxins on larvae, relatively little is known about their effects on adults. here, we evaluated the effects of exposing adults to bt toxin cry1ac on the life span and reproduction of two strains of pink bollworm (pectinophora gossypiella (saunders)). in larval diet bioassays, the concentration of cry1ac killing 50% ... | 2016 | 27133579 |
| a promising hd133-like strain of bacillus thuringiensis with dual efficiency to the two lepidopteran pests: spodoptera littoralis (noctuidae) and ephestia kuehniella (pyralidae). | isolation and identification of new strains with wide variety of target pests is an ever growing field. in this paper, a screening of 260 strains from tunisian soil samples was conducted by dot-blot and pcr-sequencing analysis. the screening was done on the basis of the possession of cry1d-type genes and was followed by the evaluation of the insecticidal activity against spodoptera littoralis. blb250 strain showed an lc50 value (56.2 μg g(-1)) against s. littoralis lower than those of the two ba ... | 2016 | 27130040 |
| does bt maize expressing cry1ac protein have adverse effects on the parasitoid macrocentrus cingulum (hymenoptera: braconidae)? | the potential effects of insect-resistant, genetically engineered (ge) crops on non-target organisms, especially on predators and parasitoids, must be evaluated before their commercial cultivation. the effects of ge maize that produces cry1ac toxin on the parasitoid macrocentrus cingulum were assessed by direct bioassay and indirect bioassay. in the indirect bioassay, parasitism rate, cocoon weight and the number of m. cingulum progeny produced per host were significantly reduced when m. cingulu ... | 2016 | 27126195 |
| field-based assessment of resistance to bt corn by western corn rootworm (coleoptera: chrysomelidae). | western corn rootworm, diabrotica virgifera virgifera leconte, is a serious pest of corn and is managed with corn that produces insecticidal toxins derived from the bacterium bacillus thuringiensis (bt). beginning in 2009, resistance to cry3bb1 corn, and severe injury to cry3bb1 corn in the field, was observed in iowa. however, few data exist on how cry3bb1-resistant western corn rootworm interact with various management practices in the field. using a field experiment, we measured adult emergen ... | 2016 | 27122498 |
| bt toxin cry1ie causes no negative effects on survival, pollen consumption, or olfactory learning in worker honey bees (hymenoptera: apidae). | the honey bee (apis mellifera l.) is a key nontarget insect in environmental risk assessments of insect-resistant genetically modified crops. in controlled laboratory conditions, we evaluated the potential effects of cry1ie toxin on survival, pollen consumption, and olfactory learning of young adult honey bees. we exposed worker bees to syrup containing 20, 200, or 20,000 ng/ml cry1ie toxin, and also exposed some bees to 48 ng/ml imidacloprid as a positive control for exposure to a sublethal con ... | 2016 | 27122497 |
| continuous evolution of bacillus thuringiensis toxins overcomes insect resistance. | the bacillus thuringiensis δ-endotoxins (bt toxins) are widely used insecticidal proteins in engineered crops that provide agricultural, economic, and environmental benefits. the development of insect resistance to bt toxins endangers their long-term effectiveness. here we have developed a phage-assisted continuous evolution selection that rapidly evolves high-affinity protein-protein interactions, and applied this system to evolve variants of the bt toxin cry1ac that bind a cadherin-like recept ... | 2016 | 27120167 |
| frequency of cry1f non-recessive resistance alleles in north carolina field populations of spodoptera frugiperda (lepidoptera: noctuidae). | fall armyworm, spodoptera frugiperda (j.e. smith) (lepidoptera: noctuidae), is a target species of transgenic corn (zea mays l.) that expresses single and pyramided bacillus thuringiensis (bt) toxin. in 2014, s. frugiperda were collected from a light trap in north carolina, and a total of 212 f1/f2 isofemale lines of s. frugiperda were screened for resistance to bt and non-bt corn. all of the 212 isolines were susceptible to corn tissue expressing cry1a.105 + cry2ab, cry1f + cry1a.105 + cry2ab, ... | 2016 | 27119741 |
| experimental evolution in silico: a custom-designed mathematical model for virulence evolution of bacillus thuringiensis. | most mathematical models on the evolution of virulence are based on epidemiological models that assume parasite transmission follows the mass action principle. in experimental evolution, however, mass action is often violated due to controlled infection protocols. this "theory-experiment mismatch" raises the question whether there is a need for new mathematical models to accommodate the particular characteristics of experimental evolution. here, we explore the experimental evolution model system ... | 2016 | 27113405 |
| reproductive isolation between two populations of diatraea saccharalis (f.) (lepidoptera: crambidae) from different host plant species and regions in argentina. | the sugarcane borer, diatraea saccharalis (f.), has a widespread distribution throughout the western hemisphere and is a pest of many crop plants including sugarcane, corn, sorghum and rice. the use of bacillus thuringiensis (bt) corn has been the primary tool for managing this species in corn fields. sugarcane borer control has been recently threatened by observations of susceptibility and/or resistance to certain varieties of bt corn and the protein used in many newer varieties. this has led t ... | 2016 | 27112423 |
| biological activity of bacillus thuringiensis in drosophila suzukii (diptera: drosophilidae). | whole-culture extracts of bacillus thuringiensis berliner strains were assayed against larval and adult drosophila suzukii (matsumura), an important invasive pest of many thin-skinned soft fruit crops in north america. of the 22 serovars tested versus larval d. suzukii, strains of bacillus thuringiensis var. thuringiensis, kurstaki, thompsoni, bolivia, and pakistani caused high (75 to 100%) first-instar mortalities. pupal mortality, measured as a failure of adults to emerge, varied with serovar. ... | 2016 | 27106227 |
| multiple assays indicate varying levels of cross resistance in cry3bb1-selected field populations of the western corn rootworm to mcry3a, ecry3.1ab, and cry34/35ab1. | minnesota populations of diabrotica virgifera virgifera leconte, the western corn rootworm, surviving cry3bb1-expressing corn in the field and western corn rootworm populations assumed to be susceptible to all bt proteins were evaluated for susceptibility to cry3bb1, mcry3a, ecry3.1ab, and cry34/35ab1 in diet assays and three different plant-based assays. rootworm populations originating from cry3bb1 fields and that consistently experienced greater than expected damage had increased survival and ... | 2016 | 27106225 |
| assessment of potential adjuvanticity of cry proteins. | genetically modified (gm) crops have achieved success in the marketplace and their benefits extend beyond the overall increase in harvest yields to include lowered use of insecticides and decreased carbon dioxide emissions. the most widely grown gm crops contain gene/s for targeted insect protection, herbicide tolerance, or both. plant expression of bacillus thuringiensis (bt) crystal (cry) insecticidal proteins have been the primary way to impart insect resistance in gm crops. although deemed s ... | 2016 | 27105772 |
| impact of violated high-dose refuge assumptions on evolution of bt resistance. | transgenic crops expressing bacillus thuringiensis (bt) toxins have been widely and successfully deployed for the control of target pests, while allowing a substantial reduction in insecticide use. the evolution of resistance (a heritable decrease in susceptibility to bt toxins) can pose a threat to sustained control of target pests, but a high-dose refuge (hdr) management strategy has been key to delaying countervailing evolution of bt resistance. the hdr strategy relies on the mating frequency ... | 2016 | 27099624 |
| application of a dense genetic map for assessment of genomic responses to selection and inbreeding in heliothis virescens. | adaptation of pest species to laboratory conditions and selection for resistance to toxins in the laboratory are expected to cause inbreeding and genetic bottlenecks that reduce genetic variation. heliothis virescens, a major cotton pest, has been colonized in the laboratory many times, and a few laboratory colonies have been selected for bacillus thuringiensis (bt) resistance. we developed 350-bp double-digest restriction-site associated dna-sequencing (ddrad-seq) molecular markers to examine a ... | 2016 | 27097739 |
| characterization of the resistance to vip3aa in helicoverpa armigera from australia and the role of midgut processing and receptor binding. | crops expressing genes from bacillus thuringiensis (bt crops) are among the most successful technologies developed for the control of pests but the evolution of resistance to them remains a challenge. insect resistant cotton and maize expressing the bt vip3aa protein were recently commercialized, though not yet in australia. we found that, although relatively high, the frequency of alleles for resistance to vip3aa in field populations of h. armigera in australia did not increase over the past fo ... | 2016 | 27095284 |
| use of redundant exclusion pcr to identify a novel bacillus thuringiensis cry8 toxin gene from pooled genomic dna. | with the aim of optimizing the cloning of novel genes from a genomic pool containing many previously identified homologous genes, we designed a redundant exclusion pcr (re-pcr) technique. in re-pcr, a pair of generic amplification primers are combined with additional primers that are designed to specifically bind to redundant, unwanted genes that are a subset of those copied by the amplification primers. during re-pcr, the specific primer blocks amplification of the full-length redundant gene. u ... | 2016 | 27084017 |
| contrasting invertebrate immune defense behaviors caused by a single gene, the caenorhabditis elegans neuropeptide receptor gene npr-1. | the invertebrate immune system comprises physiological mechanisms, physical barriers and also behavioral responses. it is generally related to the vertebrate innate immune system and widely believed to provide nonspecific defense against pathogens, whereby the response to different pathogen types is usually mediated by distinct signalling cascades. recent work suggests that invertebrate immune defense can be more specific at least at the phenotypic level. the underlying genetic mechanisms are as ... | 2016 | 27066825 |
| heritability of wing size and shape of the rice and corn strains of spodoptera frugiperda (j.e. smith) (lepidoptera: noctuidae). | spodoptera frugiperda (j.e. smith) (lepidoptera: noctuidae) represents a pest of economic importance in all western hemisphere. this polyphagous species has diverged into two populations that have been mainly recognized with various mitochondrial and nuclear molecular markers and named "the rice" and "the corn" strains. in colombia, both strains have evolved prezygotic and postzygotic isolation. they differ in tolerance to bacillus thuringiensis (cry1ac and cry1ab endotoxins) and the insecticide ... | 2016 | 27044394 |
| effects of illuminance and nutrients on bacterial photo-physiology of hydrocarbon degradation. | bacterial photophysiology was previously limited to photoautotrophs. the discovery of bacteriophytochromes in non-photoautotrophs raised a question whether these non-photoautotrophs are affected by the presence or absence of light? in this research work for the first time, bacterial hydrocarbon degradation and biomass production was studied under the influence of nutrients, illuminance (light flux) and time. an experimental model was designed, with six isolated bacterial strains (pseudomonas poa ... | 2016 | 27039061 |
| heme sensing in bacillus thuringiensis: a supplementary hssrs-regulated heme resistance system. | several gram-positive pathogens scavenge host-derived heme to satisfy their nutritional iron requirement. however, heme is a toxic molecule capable of damaging the bacterial cell. gram-positive pathogens within the phylum firmicutes overcome heme toxicity by sensing heme through hssrs, a two-component system that regulates the heme detoxification transporter hrtab. here we show that heme sensing by hssrs and heme detoxification by hrtab occur in the insect pathogen bacillus thuringiensis we find ... | 2016 | 27030728 |
| immuno-physiological adaptations confer wax moth galleria mellonella resistance to bacillus thuringiensis. | microevolutionary mechanisms of resistance to a bacterial pathogen were explored in a population of the greater wax moth, galleria mellonella, selected for an 8.8-fold increased resistance against the entomopathogenic bacterium bacillus thuringiensis (bt) compared with a non-selected (suspectible) line. defense strategies of the resistant and susceptible insect lines were compared to uncover mechanisms underpinning resistance, and the possible cost of those survival strategies. in the uninfected ... | 2016 | 27029421 |
| a role for weak electrostatic interactions in peripheral membrane protein binding. | bacillus thuringiensis phosphatidylinositol-specific phospholipase c (btpi-plc) is a secreted virulence factor that binds specifically to phosphatidylcholine (pc) bilayers containing negatively charged phospholipids. btpi-plc carries a negative net charge and its interfacial binding site has no obvious cluster of basic residues. continuum electrostatic calculations show that, as expected, nonspecific electrostatic interactions between btpi-plc and membranes vary as a function of the fraction of ... | 2016 | 27028646 |
| transcriptional profiling analysis of spodoptera litura larvae challenged with vip3aa toxin and possible involvement of trypsin in the toxin activation. | vip proteins, a new group of insecticidal toxins produced by bacillus thuringiensis, are effective against specific pests including spodoptera litura. here, we report construction of a transcriptome database of s. litura by de novo assembly along with detection of the transcriptional response of s. litura larvae to vip3aa toxin. in total, 56,498 unigenes with an n50 value of 1,853 bp were obtained. results of transcriptome abundance showed that vip3aa toxin provoked a wide transcriptional respon ... | 2016 | 27025647 |
| a mixture of bacillus thuringiensis subsp. israelensis with xenorhabdus nematophila-cultured broth enhances toxicity against mosquitoes aedes albopictus and culex pipiens pallens (diptera: culicidae). | xenorhabdusandphotorhabdusspp. (enterobacteriaceae) can synthesize and release secondary metabolites that play crucial roles in their pathogenicity by suppressing the immunity of target insects. the insect immunity contributes to defense against the pathogenicity ofbacillus thuringiensis(bt). this study tested a hypothesis that bacterial immunosuppresants could enhance the susceptibility of mosquitoes (aedes albopictusandculex pipiens pallens) to bt. three symbiotic bacteria [x. nematophila(xn), ... | 2016 | 27018440 |
| ipm use with the deployment of a non-high dose bt pyramid and mitigation of resistance for western corn rootworm (diabrotica virgifera virgifera). | recent detection of western corn rootworm resistance to bt (bacillus thuringiensis) corn prompted recommendations for the use of integrated pest management (ipm) with planting refuges to prolong the durability of bt technologies. we conducted a simulation experiment exploring the effectiveness of various ipm tools at extending durability of pyramided bt traits. results indicate that some ipm practices have greater merits than others. crop rotation was the most effective strategy, followed by inc ... | 2016 | 27018423 |
| a black (white) hole in the global spread of gm cotton. | bt (bacillus thuringiensis) cotton has been widely adopted, notably by smallholder farmers in developing countries. however, it has not been used in central asia, an important cotton-producing region. we discuss possible reasons and hypothesize that the most likely explanation is limited local demand for bt owing to low levels of pest infestation. this would imply that global bt cotton adoption rates may already be close to 100% when considering real demand for insect-resistant varieties. | 2016 | 27017312 |
| transgenic rice expressing the cry2ax1 gene confers resistance to multiple lepidopteran pests. | a chimeric bacillus thuringiensis toxin (bt) gene, cry2ax1was cloned in a bi-selectable marker free binary vector construct. the cry2ax1 gene, driven by the chrysanthemum rbcs1 promoter, was introduced into jk1044r, the restorer line (oryza sativa l. ssp. indica) of a notified commercially grown rice hybrid in india, by agrobacterium-mediated transformation. its effect against two major lepidopteran insect pests viz., yellow stem borer (ysb) scirpophaga incertulas, rice leaf folder (rlf) cnaphal ... | 2016 | 27017220 |
| ingestion of bt corn pollen containing cry1ab/2aj or cry1ac does not harm propylea japonica larvae. | propylea japonica (thunberg) (coleoptera: coccinellidae) is a prevalent pollen consumer in corn fields and is therefore exposed to insecticidal proteins contained in the pollen of insect-resistant transgenic corn cultivars expressing cry proteins derived from bacillus thuringiensis (bt). in the present study, the potential effect of cry1ab/2aj- or cry1ac-containing transgenic bt corn pollen on the fitness of p. japonica larvae was evaluated. the results show that the larval developmental time wa ... | 2016 | 27005950 |
| a novel metalloproteinase virulence factor is involved in bacillus thuringiensis pathogenesis in nematodes and insects. | the gram-positive soil bacterium bacillus thuringiensis has been developed as the leading microbial insecticide for years. the pathogenesis of b. thuringiensis requires common extracellular factors that depend on the plcr regulon, which regulates a large number of virulence factors; however, the precise role of many of these proteins is not known. in this study, we describe the complete lifecycle of a nematicidal b. thuringiensis strain in the free living nematode caenorhabditis elegans using in ... | 2016 | 26995589 |
| comparison of susceptibility of chilo suppressalis and bombyx mori to five bacillus thuringiensis proteins. | transformation of rice with genes encoding insecticidal cry proteins from bacillus thuringiensis (bt) should confer high resistance to target lepidopteran pests, such as chilo suppressalis, and low toxicity to non-target organisms, such as silkworm bombyx mori. five purified cry proteins that have been used for plant transformation were tested using dietary exposure assays. the susceptibility of c. suppressalis larvae to the five insecticidal proteins in the decreasing order was: cry1ca>cry1ab>c ... | 2016 | 26994840 |
| daphnia magna negatively affected by chronic exposure to purified cry-toxins. | cry-toxin genes originating from bacillus thuringiensis are inserted into genetically modified (gm) plants, often called bt-plants, to provide insect resistance to pests. significant amounts of bt-plant residues, and thus cry-toxins, will be shed to soil and aquatic environments. we exposed daphnia magna to purified cry1ab and cry2aa toxins for the full life-span of the animals. we used single toxins in different doses and combinations of toxins and roundup(®), another potential stressor on the ... | 2016 | 26993955 |
| characterization of trypsin-like and chymotrypsin-like serine proteases from midgut of mythimna separata walker. | two cdna sequences encoding a trypsin-like and a chymotrypsin-like serine protease (mst and msct, genbank accession nos. kp730443 and kp730444, respectively) were cloned from midgut of oriental armyworm, mythimna separata walker. multiple alignments revealed that the deduced amino acid sequences of mst and msct contained a serine protease catalytic motif gdsggpl and catalytic triads (his, asp, and ser). analyses of tissue and developmental expression of mst and msct showed that they were mainly ... | 2016 | 26988941 |
| bacterial vegetative insecticidal proteins (vip) from entomopathogenic bacteria. | entomopathogenic bacteria produce insecticidal proteins that accumulate in inclusion bodies or parasporal crystals (such as the cry and cyt proteins) as well as insecticidal proteins that are secreted into the culture medium. among the latter are the vip proteins, which are divided into four families according to their amino acid identity. the vip1 and vip2 proteins act as binary toxins and are toxic to some members of the coleoptera and hemiptera. the vip1 component is thought to bind to recept ... | 2016 | 26935135 |
| no association between the use of bti for mosquito control and the dynamics of non-target aquatic invertebrates in french coastal and continental wetlands. | the environmental safety of bacillus thuringiensis subsp. israelensis (bti) is still controversial, mainly because most of the previous field studies on its undesired effects were spatially limited and did not address the relationship between community similarity and application time and frequency. no general statement can therefore be drawn on the usage conditions of bti that insure protection of non-target organisms. the present study was conducted in eight sites distributed over the main geog ... | 2016 | 26930319 |
| single amino acid insertions in extracellular loop 2 of bombyx mori abcc2 disrupt its receptor function for bacillus thuringiensis cry1ab and cry1ac but not cry1aa toxins. | in a previous report, seven cry1ab-resistant strains were identified in the silkworm, bombyx mori; these strains were shown to have a tyrosine insertion at position 234 in extracellular loop 2 of the abc transporter c2 (bmabcc2). this insertion was confirmed to destroy the receptor function of bmabcc2 and confer the strains resistance against cry1ab and cry1ac. however, these strains were susceptible to cry1aa. in this report, we examined the mechanisms of the loss of receptor function of the tr ... | 2016 | 26928903 |
| expression of an engineered synthetic cry2aa (d42/k63f/k64p) gene of bacillus thuringiensis in marker free transgenic tobacco facilitated full-protection from cotton leaf worm (s. littoralis) at very low concentration. | emergence of resistant insects limits the sustainability of bacillus thuringiensis (bt) transgenic crop plants for insect management. beside this, the presence of unwanted marker gene(s) in the transgenic crops is also a major environmental and health concern. thus, development of marker free transgenic crop plants expressing a new class of toxin having a different mortality mechanism is necessary for resistance management. in a previous study, we generated an engineered cry2aa (d42/k63f/k64p) t ... | 2016 | 26925624 |
| bacillus thuringiensis peptidoglycan hydrolase sleb171 involved in daughter cell separation during cell division. | whole-genome analyses have revealed a putative cell wall hydrolase gene (sleb171) that constitutes an operon with two other genes (ypebandyhcn) of unknown function inbacillus thuringiensisbmb171. the putative sleb171 protein consists of 259 amino acids and has a molecular weight of 28.3 kda. gene disruption ofsleb171in the bmb171 genome causes the formation of long cell chains during the vegetative growth phase and delays spore formation and spore release, although it has no significant effect o ... | 2016 | 26922318 |
| the use of aedes aegypti larvae attractants to enhance the effectiveness of larvicides. | aedes aegypti (l.) is an important dengue, chikungunya, and yellow fever vector. immature stages of this species inhabit human-made containers placed in residential landscapes, and the application of larvicides inside containers that cannot be eliminated is still considered a priority in control programs. larvicidal efficacy is influenced by several factors, including the formulation used, the water quality, and the susceptibility of larvae, among others. if an attractant can be incorporated int ... | 2016 | 26922177 |
| diffusible signal factor family signals provide a fitness advantage to xanthomonas campestris pv. campestris in interspecies competition. | diffusible signal factor (dsf) represents a new class of widely conserved quorum sensing signals, which regulates various biological functions through intra- or interspecies signaling. the previous studies identified that there is an antagonistic interaction between xanthomonas and bacillus species bacteria in natural ecosystem, but the detailed molecular mechanism of interspecies competition is not clear. this study showed that xanthomonas campestris pv. campestris (xcc) interfered with morphol ... | 2016 | 26913592 |
| cloning, characterization and expression of a novel haplotype cry2a-type gene from bacillus thuringiensis strain swk1, native to himalayan valley kashmir. | bacillus thuringiensis (bt) is a gram positive bacterium which is effectively being used in pest management strategies as an eco-friendly bioinsecticide. in the present study a new cry2a gene was cloned from a promising indigenous b. thuringiensis swk1 strain previously characterized for its toxicity against spodoptera litura and helicoverpa armigera larvae. the nucleotide sequence of the cloned cry2a gene pointed out that the open reading frame has 1902 bases encoding a polypeptide of 634 amino ... | 2016 | 26906447 |
| investigation of larvae digestive β-glucosidase and proteases of the tomato pest tuta absoluta for inhibiting the insect development. | the tomato leaf miner tuta absoluta is one of the most devastating pests for tomato crops. digestive proteases and β-glucosidase enzymes were investigated using general and specific substrates and inhibitors. maximal β-glucosidase and proteolytic activities occurred at temperature and ph optima of 30 and 40°c, 5 and 10-11 unit of ph, respectively. zymogram analysis showed the presence of distinguished β-glucosidase exhibiting a specific activity of about 183 ± 15 µmol min-1 mg-1. in vitro inhibi ... | 2016 | 26898349 |
| effect of adding amino acids residues in n- and c-terminus of vip3aa16 (l121i) toxin. | to study the importance of n- and c-terminus of bacillus thuringiensis vip3aa16 (l121i) toxin (88 kda), a number of mutants were generated. the addition of two (2r: rs) or eleven (11r: rsrpghhhhhh) amino acid residues at the vip3aa16 (l121i) c-terminus allowed to an unappropriated folding illustrated by the abundant presence of the 62 kda proteolytic form. the produced vip3aa16 (l121i) full length form was less detected when increasing the number of amino acids residues in the c-terminus. bioass ... | 2016 | 26876111 |
| novel actin filaments from bacillus thuringiensis form nanotubules for plasmid dna segregation. | here we report the discovery of a bacterial dna-segregating actin-like protein (btparm) from bacillus thuringiensis, which forms novel antiparallel, two-stranded, supercoiled, nonpolar helical filaments, as determined by electron microscopy. the btparm filament features of supercoiling and forming antiparallel double-strands are unique within the actin fold superfamily, and entirely different to the straight, double-stranded, polar helical filaments of all other known parms and of eukaryotic f-a ... | 2016 | 26873105 |
| resistance to bacillus thuringiensis mediated by an abc transporter mutation increases susceptibility to toxins from other bacteria in an invasive insect. | evolution of pest resistance reduces the efficacy of insecticidal proteins from the gram-positive bacterium bacillus thuringiensis (bt) used widely in sprays and transgenic crops. recent efforts to delay pest adaptation to bt crops focus primarily on combinations of two or more bt toxins that kill the same pest, but this approach is often compromised because resistance to one bt toxin causes cross-resistance to others. thus, integration of bt toxins with alternative controls that do not exhibit ... | 2016 | 26872031 |
| effect of crop plants on fitness costs associated with resistance to bacillus thuringiensis toxins cry1ac and cry2ab in cabbage loopers. | fitness costs associated with resistance to bacillus thuringiensis (bt) toxins critically impact the development of resistance in insect populations. in this study, the fitness costs in trichoplusia ni strains associated with two genetically independent resistance mechanisms to bt toxins cry1ac and cry2ab, individually and in combination, on four crop plants (cabbage, cotton, tobacco and tomato) were analyzed, in comparison with their near-isogenic susceptible strain. the net reproductive rate ( ... | 2016 | 26868936 |
| development of leaffolder resistant transgenic rice expressing cry2ax1 gene driven by green tissue-specific rbcs promoter. | the insecticidal cry genes of bacillus thuringiensis (bt) have been successfully used for development of insect resistant transgenic rice plants. in this study, a novel cry2ax1 gene consisting a sequence of cry2aa and cry2ac gene driven by rice rbcs promoter was introduced into a rice cultivar, asd16. among 27 putative rice transformants, 20 plants were found to be positive for cry2ax1 gene. the expression of cry2ax1 protein in transgenic rice plants ranged from 5.95 to 122.40 ng/g of fresh leaf ... | 2016 | 26867598 |
| chronic toxicity and physiological changes induced in the honey bee by the exposure to fipronil and bacillus thuringiensis spores alone or combined. | in the agricultural environment, honey bees may be exposed to combinations of pesticides. until now, the effects of these combinations on honey bee health have been poorly investigated. in this study, we assessed the impacts of biological and chemical insecticides, combining low dietary concentrations of bacillus thuringiensis (bt) spores (100 and 1000µg/l) with the chemical insecticide fipronil (1µg/l). in order to assess the possible effects of cry toxins, the bt kurstaki strain (btk) was comp ... | 2016 | 26866756 |
| risk assessment of bt crops on the non-target plant-associated insects and soil organisms. | transgenic plants containing bacillus thuringiensis (bt) genes are being cultivated worldwide to express toxic insecticidal proteins. however, the commercial utilisation of bt crops greatly highlights biosafety issues worldwide. therefore, assessing the risks caused by genetically modified crops prior to their commercial cultivation is a critical issue to be addressed. in agricultural biotechnology, the goal of safety assessment is not just to identify the safety of a genetically modified (gm) p ... | 2016 | 26857894 |
| immunity of the greater wax moth galleria mellonella. | investigation of insect immune mechanisms provides important information concerning innate immunity, which in many aspects is conserved in animals. this is one of the reasons why insects serve as model organisms to study virulence mechanisms of human pathogens. from the evolutionary point of view, we also learn a lot about host-pathogen interaction and adaptation of organisms to conditions of life. additionally, insect-derived antibacterial and antifungal peptides and proteins are considered for ... | 2016 | 26847724 |
| from qutn to bt cotton: development, adoption and prospects. a review. | cotton has unique history of domestication, diversification, and utilization. globally it is an important cash crop that provides raw material for textile industry. the story of cotton started from human civilization and the climax arrived with the efforts of developing transgenic cotton for various traits. though conventional breeding brought steady improvement in developing resistance against biotic stresses but recent success story of gene transferfrom bacillus thuringiensis into cotton showe ... | 2016 | 26841496 |
| mode of inheritance for biochemical traits in genetically engineered cotton under water stress. | drought is an abiotic environmental stress that can significantly reduce crop productivity. we examined the mode of inheritance for different biochemical traits including total soluble proteins, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, total phenolic contents and enzymatic antioxidants (superoxide dismutase, peroxidase and catalase), and their relationship with bacillus thuringiensis (bt) toxin under control and drought conditions. eight genetically diverse cotton genotypes ... | 2016 | 26839284 |
| layer-by-layer films containing peptides of the cry1ab16 toxin from bacillus thuringiensis for potential biotechnological applications. | cry1ab16 is a toxin of crystalline insecticidal proteins that has been widely used in genetically modified organisms (gmos) to gain resistance to pests. for the first time, in this study, peptides derived from the immunogenic cry1ab16 toxin (from bacillus thuringiensis) were immobilized as layer-by-layer (lbl) films. given the concern about food and environmental safety, a peptide with immunogenic potential, pcl342-354c, was selected for characterization of the electrochemical, optical, and morp ... | 2016 | 26838914 |
| curing of plasmid pbmb28 from bacillus thuringiensis ybt-020 using an unstable replication region. | bacillus thuringiensis serovar finitimus strain ybt-020 is the well-studied spore-crystal association (sca) phenotypic strain, whose parasporal crystals adhere to spore after lysis of the mother cell. its endogenous plasmids pbmb26 and pbmb28 were proved essential for this sca phenotype. in our previous study, using conventional methods, pbmb26 cured derivative and both pbmb26 and pbmb28 cured derivative of ybt-020 were obtained. however, ybt-020 solely cured of pbmb28 could not be obtained. in ... | 2016 | 26837065 |
| loop replacements with gut-binding peptides in cry1ab domain ii enhanced toxicity against the brown planthopper, nilaparvata lugens (stål). | bacillus thuringiensis (bt) cry toxins have been used widely in pest managements. however, cry toxins are not effective against sap-sucking insects (hemiptera), which limits the application of bt for pest management. in order to extend the insecticidal spectrum of bt toxins to the rice brown planthopper (bph), nilaparvata lugens, we modified cry1ab putative receptor binding domains with selected bph gut-binding peptides (gbps). three surface exposed loops in the domain ii of cry1ab were replaced ... | 2016 | 26830331 |
| bt proteins cry1ah and cry2ab do not affect cotton aphid aphis gossypii and ladybeetle propylea japonica. | plant varieties expressing the bt (bacillus thuringiensis) insecticidal proteins cry1ah and cry2ab have potential commercialization prospects in china. however, their potential effects on non-target arthropods (ntas) remain uncharacterized. the cotton aphid aphis gossypii is a worldwide pest that damages various important crops. the ladybeetle propylea japonica is a common and abundant natural enemy in many cropping systems in east asia. in the present study, the effects of cry1ah and cry2ab pro ... | 2016 | 26829252 |
| involvement of the processing step in the susceptibility/tolerance of two lepidopteran larvae to bacillus thuringiensis cry1aa toxin. | bacillus thuringiensis (bt) cry1a toxins are known for their effectiveness against lepidopteran insects. in this study, the entomopathogenic activity of cry1aa was investigated against two lepidopteran larvae causing serious threat to various crops, spodoptera littoralis and tuta absoluta. contrarily to s. littoralis, which showed low susceptibility to cry1aa (40% mortality with 1μg/cm(2)), t. absoluta was very sensitive to this delta-endotoxin (lc50 of 95.8ng/cm(2)). the different steps in the ... | 2016 | 26821657 |
| long-term toxicity study on genetically modified corn with cry1ac gene in a wuzhishan miniature pig model. | the objective of the present study was to investigate the chronic effect of transgenic maize lines by the insertion of the cry1ac gene from bacillus thuringiensis (bt) on the growth performance, immune response and health using a wuzhishan miniature pig model through a 196-day feeding study. | 2016 | 26777397 |
| can pyramids and seed mixtures delay resistance to bt crops? | the primary strategy for delaying the evolution of pest resistance to transgenic crops that produce insecticidal proteins from bacillus thuringiensis (bt) entails refuges of plants that do not produce bt toxins and thus allow survival of susceptible pests. recent advances include using refuges together with bt crop 'pyramids' that make two or more bt toxins effective against the same pest, and planting seed mixtures yielding random distributions of pyramided bt and non-bt corn plants within fiel ... | 2016 | 26774592 |
| construction of an environmental safe bacillus thuringiensis engineered strain against coleoptera. | cloning of new toxic genes from bacillus thuringiensis (bt) and construction of bt engineered strains are two key strategies for bio-control of coleopteran pests in agriculture and forestry. in this study, we cloned a new cry3aa-type gene, cry3aa8, from wild bt strain yc-03 against coleopteran, and constructed a bt engineered strain, ace-38, containing insecticidal protein-encoding gene cry3aa8. the engineered strain, with almost four times of cry3aa yield compared with strain yc-03, was an anti ... | 2016 | 26767987 |
| native plant growth promoting bacteria bacillus thuringiensis and mixed or individual mycorrhizal species improved drought tolerance and oxidative metabolism in lavandula dentata plants. | this study evaluates the responses of lavandula dentata under drought conditions to the inoculation with single autochthonous arbuscular mycorrhizal (am) fungus (five fungal strains) or with their mixture and the effects of these inocula with a native bacillus thuringiensis (endophytic bacteria). these microorganisms were drought tolerant and in general, increased plant growth and nutrition. particularly, the am fungal mixture and b. thuringiensis maximized plant biomass and compensated drought ... | 2016 | 26796423 |
| cry-like genes, in an uncommon gene configuration, produce a crystal that localizes within the exosporium when expressed in an acrystalliferous strain of bacillus thuringiensis. | cry proteins are pesticidal toxins produced by the bacterium bacillus thuringiensis (bt), which aggregate in sporulating cells to form a crystal. except in a relatively few cases, these crystals are located outside the exosporium that surrounds the spore. bt2-56 is a strain of bt that has the relatively uncommon characteristic of locating its cry protein-containing crystal within the exosporium, and in association with a long, multifiber filament. with the ultimate goal of both understanding and ... | 2016 | 26781916 |
| dissecting the self-assembly kinetics of multimeric pore-forming toxins. | pore-forming toxins are ubiquitous cytotoxins that are exploited by both bacteria and the immune response of eukaryotes. these toxins kill cells by assembling large multimeric pores on the cell membrane. however, a quantitative understanding of the mechanism and kinetics of this self-assembly process is lacking. we propose an analytically solvable kinetic model for stepwise, reversible oligomerization. in biologically relevant limits, we obtain simple algebraic expressions for the rate of pore f ... | 2016 | 26763328 |
| molecular and insecticidal characterization of vip3a protein producing bacillus thuringiensis strains toxic against helicoverpa armigera (lepidoptera: noctuidae). | vegetative insecticidal proteins (vip) represent the second generation of insecticidal proteins produced by bacillus thuringiensis (bt) during the vegetative growth stage of growth. bt-based biopesticides are recognized as viable alternatives to chemical insecticides; the latter cause environmental pollution and lead to the emergence of pest resistance. to perform a systematic study of vip genes encoding toxic proteins, a total of 30 soil samples were collected from diverse locations of kashmir ... | 2016 | 26751639 |
| monitoring susceptibility of western bean cutworm (lepidoptera: noctuidae) field populations to bacillus thuringiensis cry1f protein. | zea mays l. (maize) hybrids producing the cry1f protein from bacillus thuringiensis were first commercialized in the united states in 2003. these products demonstrated varying levels of moderate control, but not immunity to striacosta albicosta (smith) (lepidoptera: noctuidae) (western bean cutworm). susceptibility of western bean cutworm to cry1f protein was assessed in field populations collected in the mid- and western united states in 2003, 2004, 2013, and 2014 using diet bioassay. a meta-an ... | 2016 | 26748981 |
| selection and characterization of resistance to the vip3aa20 protein from bacillus thuringiensis in spodoptera frugiperda. | spodoptera frugiperda is one the main target pests of maize events expressing vip3aa20 protein from bacillus thuringiensis (bt) in brazil. in this study, we selected a resistant strain of s. frugiperda on bt maize expressing vip3aa20 protein and characterized the inheritance and fitness costs of the resistance. | 2016 | 26733182 |
| determining the drift potential of venturi nozzles compared with standard nozzles across three insecticide spray solutions in a wind tunnel. | previous research has sought to adopt the use of drift-reducing technologies (drts) for use in field trials to control diamondback moth (dbm) plutella xylostella (l.) (lepidoptera: plutellidae) in canola (brassica napus l.). previous studies observed no difference in canopy penetration from fine to coarse sprays, but the coverage was higher for fine sprays. dbm has a strong propensity to avoid sprayed plant material, putting further pressure on selecting technologies that maximise coverage, but ... | 2016 | 26732308 |
| valorization of soy waste through ssf for the production of compost enriched with bacillus thuringiensis with biopesticide properties. | there is a growing generation of biodegradable wastes from different human activities from industrial to agricultural including home and recreational activities. on the other hand, agricultural and horticultural activities require significant amounts of organic amendments and pesticides. in this framework, the present study evaluates the viability of soy fiber residue valorization as organic soil amendment with biopesticide properties through aerobic solid-state fermentation (ssf) in the presenc ... | 2016 | 26731311 |
| transgenic bt cotton driven by the green tissue-specific promoter shows strong toxicity to lepidopteran pests and lower bt toxin accumulation in seeds. | a promoter of the pnzip (pharbitis nil leucine zipper) gene (1.459 kb) was cloned from pharbitis nil and fused to the gus (β-glucuronidase) and bacillus thuringiensis endotoxin (cry9c) genes. several transgenic pnzip::gus and pnzip::cry9c cotton lines were developed by agrobacterium-mediated transformation. strong gus staining was detected in the green tissues of the transgenic pnzip::gus cotton plants. in contrast, gus staining in the reproductive structures such as petals, anther, and immature ... | 2016 | 26728504 |
| complete genome sequence of bacillus thuringiensis ctc-a typical strain with high production of s-layer proteins. | bacillus thuringiensis ctc, which is identified as serotype h2, serovar. finitimus, is high production of s-layer protein. due to the property of forming isoporous lattices on the whole cell surface, s-layer protein has been widely used in (nano) biotechnology, biomimetics, biomedicine, especially been employed for displaying many important active proteins. here, we report the complete genome of strain ctc, which contains one circular chromosome and one linear plasmid. | 2016 | 26718563 |
| differential expression and characterization of cypermethrin-degrading potential proteins in bacillus thuringiensis strain, sg4. | a cypermethrin-degrading bacterium (sg4) was isolated from the pesticide-contaminated soil in the agricultural field of the crop research centre of the university, and characterized as bacillus thuringiensis strain, sg4. the bacterium degraded 78.9 % of cypermethrin (50 ppm) in 15 days when grown in a minimal medium. to understand the functional proteins of cypermethrin degradation in bacillus thuringiensis strain sg4, a comparative proteomic analysis was performed in the presence/absence of cyp ... | 2016 | 28330297 |
| classical and bayesian predictions applied to bacillus toxin production. | bacillus thuringiensis is a bacterium with unusual properties that make it useful for pest control in ecoagriculture. it can form a parasporal crystal containing polypeptides (also called delta-endotoxins). these entomopathogenic toxins are made during the stationary phase of the bacterial growth cycle and were initially characterized as an insect pathogen. nowadays, the use of saturated two-level designs is very popular. this method is especially used in industrial applications where the cost o ... | 2016 | 28330277 |
| transgenic rice plants expressing synthetic cry2ax1 gene exhibits resistance to rice leaffolder (cnaphalocrosis medinalis). | bacillus thuringiensis is a major source of insecticidal genes imparting insect resistance in transgenic plants. level of expression of transgenes in transgenic plants is important to achieve desirable level of resistance against target insects. in order to achieve desirable level of expression, rice chloroplast transit peptide sequence was fused with synthetic cry2ax1 gene to target its protein in chloroplasts. sixteen pcr positive lines of rice were generated by agrobacterium mediated transfor ... | 2016 | 28330080 |
| the complete genome sequence of bacillus thuringiensis serovar hailuosis ywc2-8. | bacillus thuringiensis, a typical aerobic, gram-positive, spore-forming bacterium, is an important microbial insecticide widely used in the control of agricultural pests. b. thuringiensis serovar hailuosis ywc2-8 with high insecticidal activity against diptera and lepidoptera insects has three insecticidal crystal protein genes, such as cry4cb2, cry30ea2, and cry56aa1. in this study, the complete genome sequence of b. thuringiensis ywc2-8 was analyzed, which contains one circular gapless chromos ... | 2016 | 26707806 |
| importance of thr(328) and thr(369) for functional maintenance of two receptor-binding β-hairpins of the bacillus thuringiensis cry4ba toxin: implications for synergistic interactions with cyt2aa2. | bacillus thuringiensis cry4ba mosquito-active toxin was previously shown to utilize two critical loop-residues, tyr(332) and phe(364) which are respectively located in β2-β3 and β4-β5 loops, for synergistic interactions with its alternative receptor-cyt2aa2. here, structural analysis of the cry4ba-receptor-binding domain revealed that its n-terminal subdomain encompasses β2-β3 and β4-β5 hairpins which are stabilized by inter-hairpin hydrogen bonding between thr(328) in β2 and thr(369) in β5. fun ... | 2016 | 26692482 |
| bioinsecticide and leaf litter combination increases oviposition and reduces adult recruitment to create an effective ovitrap for culex mosquitoes. | mosquito egg traps, aquatic habitats baited with oviposition attractant and insecticide, are important tools for surveillance and control efforts in integrated vector management programs. the bioinsecticide bacillus thuringiensis subsp. israelensis (bti) is increasingly used as an environmentally friendly alternative to chemical insecticides and the combination of bti with a simple oviposition attractant like leaf litter to create an effective egg trap seems appealing. however, previous research ... | 2016 | 27232134 |
| effects of bt-transgenic rice cultivation on planktonic communities in paddy fields and adjacent ditches. | the non-target effects of transgenic plants are issues of concern; however, their impacts in cultivated agricultural fields and adjacent natural aquatic ecosystems are poorly understood. we conducted field experiments during two growing seasons to determine the effects of cultivating bacillus thuringiensis (bt)-transgenic rice on the phytoplankton and zooplankton communities in a paddy field and an adjacent ditch. bt toxin was detected in soil but not in water. water quality was not significantl ... | 2016 | 27219503 |
| synthetic predator cues impair immune function and make the biological pesticide bti more lethal for vector mosquitoes. | the control of vector mosquitoes is one of the biggest challenges facing humankind with the use of chemical pesticides often leading to environmental impact and the evolution of resistance. although to a lesser extent, this also holds for bacillus thuringiensis israelensis (bti), the most widely used biological pesticide to control mosquito populations. this raises the need for the development of integrated pest management strategies that allow the reduction of bti concentrations without loss of ... | 2016 | 27209779 |
| molecular cloning, expression, and identification of bre genes involved in glycosphingolipids synthesis in helicoverpa armigera (lepidoptera: noctuidae). | glycosphingolipids (gsls) play important roles in the cellular biology of vertebrate and invertebrate organisms, such as cell differentiation, tumor metastasis, and cell coordination. gsls also serve as receptors for different bacterial toxins. for example, in the nematode caenorhabditis elegans, gsls function as receptors of the insecticidal cry toxins produced by bacillus thuringiensis (bt), and mutations in bre genes involved in gsls synthesis resulted in resistance to cry5 toxin in this orga ... | 2016 | 27190043 |
| western corn rootworm (coleoptera: chrysomelidae) larval movement in ecry3.1ab+mcry3a seed blend scenarios. | corn fields planted with plant-incorporated bacillus thuringiensis (bt) proteins must have a portion of the field planted with non-bt, isoline, plants that serve as a refuge for susceptible insects. in the corn belt, refuge seeds are now blended in the bag with bt seeds for corn hybrids containing two or more toxins targeted toward the western corn rootworm, diabrotica virgifera virgifera leconte. syngenta's corn hybrid, agrisure duracade, containing the ecry3.1ab (event 5307) and mcry3a (event ... | 2016 | 27190042 |
| genetic transformation and expression of transgenic lines of populus x euramericana with insect-resistance and salt-tolerance genes. | we characterized new transgenic varieties of poplar with multiple insect-resistant and salt stress tolerant genes. two insect-resistant bacillus thuringiensis (bt) genes, cry1ac and cry3a, and a salt-tolerant gene, betaine aldehyde dehydrogenase (badh) were inserted into a vector, p209-cry1ac-cry3a-badh. the clone of populus x euramericana was transformed by the vector using the agrobacterium-mediated method. three transgenic lines were assessed using genetic detection and resistance expression ... | 2016 | 27173305 |
| cloning, expression, purification, and insecticidal activity of a novel cry1na3 toxin from bacillus thuringiensis brc-zyr2. | bacillus thuringiensis produces a variety of insecticidal crystal proteins (icps). genome sequencing is a promising strategy for detecting and identifying b. thuringiensis icps, which are of great interest to the biocontrol field. in this study, a novel icp gene was cloned from b. thuringiensis brc-zyr2 based on genomic data from 454 gs-flx titanium sequencing and an analysis of the results using the b. thuringiensis toxin_scanner (http://bcam.hzaubmb.net/bttoxin_scanner/index.php). cry1na3 desi ... | 2016 | 27170729 |
| marker-free transgenic rice expressing the vegetative insecticidal protein (vip) of bacillus thuringiensis shows broad insecticidal properties. | genetically engineered rice lines with broad insecticidal properties against major lepidopteran pests were generated using a synthetic, truncated form of vegetative insecticidal protein (syn vip3br) from bacillus thuringiensis. the selectable marker gene and the redundant transgene(s) were eliminated through cre/ lox mediated recombination and genetic segregation to make consumer friendly bt -rice. for sustainable resistance against lepidopteran insect pests, chloroplast targeted synthetic versi ... | 2016 | 27165311 |
| evaluation of potential fitness costs associated with ecry3.1ab resistance in diabrotica virgifera virgifera (coleoptera: chrysomelidae). | both an ecry3.1ab-selected and paired control western corn rootworm, diabrotica virgifera virgifera leconte, colony were tested for adult longevity, egg oviposition, egg viability, and larval development in order to evaluate the potential fitness costs associated with ecry3.1ab resistance. adult longevity experiments were conducted by pairing virgin males and females together in plastic boxes supplied with food, water, and ovipositional medium and observed for survival time. eggs were also colle ... | 2016 | 27151470 |
| 4-hydroxyisoleucine: a potential new treatment for type 2 diabetes mellitus. | 4-hydroxyisoleucine (4-hil) is a compound found in trigonella foenum-graecum (fenugreek) seeds, which have been used as part of traditional medicine to treat diabetes mellitus. the synthesis of 4-hil on a large scale is possible using fermentation methods (artificial synthesis) involving the isolation of the l-isoleucine dioxygenase gene from bacillus thuringiensis, which can yield a greater quantity of 4-hil than that produced with conventional methods (82 % attained with fermentation methods v ... | 2016 | 27151154 |
| sox transcription in sarcosine utilization is controlled by sigma(54) and soxr in bacillus thuringiensis hd73. | sarcosine oxidase catalyzes the oxidative demethylation of sarcosine to yield glycine, formaldehyde, and hydrogen peroxide. in this study, we analyzed the transcription and regulation of the sox locus, including the sarcosine oxidase-encoding genes in bacillus thuringiensis (bt). rt-pcr analysis revealed that the sox locus forms two opposing transcriptional units: soxb (soxb/e/f/g/h/i) and soxr (soxr/c/d/a). the typical -12/-24 consensus sequence was located 15 bp and 12 bp from the transcriptio ... | 2016 | 27404799 |
| efficacy of soybean's event das-81419-2 expressing cry1f and cry1ac to manage key tropical lepidopteran pests under field conditions in brazil. | bacillus thuringiensis (bt) event das-81419-2 (conkesta technology) in soybean, glycine max (l.) merrill, expresses cry1f and cry1ac proteins to provide protection from feeding by several lepidopteran pests. a total of 27 field experiments across nine locations were conducted from 2011 to 2015 in southern and central brazil to characterize the efficacy of das-81419-2 soybean infested with anticarsia gemmatalis hübner (lepidoptera: erebidae), chrysodeixis includens (walker) (lepidoptera: noctuida ... | 2016 | 27401112 |
| distribution and metabolism of bt-cry1ac toxin in tissues and organs of the cotton bollworm, helicoverpa armigera. | crystal (cry) proteins derived from bacillus thuringiensis (bt) have been widely used in transgenic crops due to their toxicity against insect pests. however, the distribution and metabolism of these toxins in insect tissues and organs have remained obscure because the target insects do not ingest much toxin. in this study, several cry1ac-resistant strains of helicoverpa armigera, fed artificial diets containing high doses of cry1ac toxin, were used to investigate the distribution and metabolism ... | 2016 | 27399776 |
| cry1ac toxin induces macrophage activation via erk1/2, jnk and p38 mitogen-activated protein kinases. | the cry1ac toxin from bacillus thuringiensis is used commercially as a bio-insecticide and is expressed in transgenic plants that are used for human and animal consumption. although it was originally considered innocuous for mammals, the cry1ac toxin is not inert and has the ability to induce mucosal and systemic immunogenicity. herein, we examined whether the cry1ac toxin promotes macrophage activation and explored the signalling pathways that may mediate this effect. treatment of primary and r ... | 2016 | 27394658 |
| high expression of cry1ac protein in cotton (gossypium hirsutum) by combining independent transgenic events that target the protein to cytoplasm and plastids. | transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1ac gene (1,848 bp), which was originally characterized from bacillus thuringiensis subspecies kurstaki strain hd73 that encodes a toxin highly effective against many lepidopteran pests. in construct i, the cry1ac gene was cloned under fmvde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. in construct ii, the encoded protein was directed to the plastids ... | 2016 | 27391960 |
| effects of transgenic bt rice on nontarget rhopalosiphum maidis (homoptera: aphididae). | the effects of three transgenic bacillus thuringiensis (bt) rice lines, kmd1, kmd2, and g8-7, on biological parameters and population dynamics of nontarget insect, rhopalosiphum maidis (fitch) (homoptera: aphididae), were investigated in the laboratory and field. no significant differences were found between bt and non-bt rice lines for aphid survival. the developmental time of r. maidis that fed on kmd1 and kmd2 did not differ significantly from those of the individuals feeding on the parental ... | 2016 | 27389683 |
| [the analysis of major metabolic pathways in bacillus thuringiensis under alkaline stress]. | the study aimed to determine the appropriate stage for exploring the responseof bacillus thuringiensis to the alkaline stress, to profile the metabolic pathways under this stress. | 2016 | 27382791 |
| crystal structure of cry6aa: a novel nematicidal clya-type α-pore-forming toxin from bacillus thuringiensis. | crystal (cry) proteins from bacillus thuringiensis (bt) are globally used in agriculture as proteinaceous insecticides. numerous crystal structures have been determined, and most exhibit conserved three-dimensional architectures. recently, we have identified a novel nematicidal mechanism by which cry6aa triggers cell death through a necrosis-signaling pathway via an interaction with the host protease asp-1. however, we found little sequence conservation of cry6aa in our functional study. here, w ... | 2016 | 27381865 |
| cyclic di-gmp contributes to adaption and virulence of bacillus thuringiensis through a riboswitch-regulated collagen adhesion protein. | cyclic di-gmp is a ubiquitous second messenger that regulates diverse cellular processes in bacteria by binding to various protein or riboswitch effectors. in bacillus thuringiensis bmb171, a c-di-gmp riboswitch termed bc2 rna resides in the 5'-untranslated region (5'-utr) of an mrna that encodes a collagen adhesion protein (cap). the expression of cap was strongly repressed in parent strain bmb171 because of the presence of bc2 rna but was significantly promoted in the bc2 rna markerless deleti ... | 2016 | 27381437 |
| toxicity of bacillus thuringiensis crystal proteins against eri silkworm, samia cynthia ricini (lepidoptera: saturniidae). | ten purified crystal proteins of bacillus thuringiensis (bt) were tested at concentrations ranging from 2.93 to 3000ng/cm(2) for their toxicity to eri silkworm through protein paint bioassays using castor leaves. based on lc50 values, cry1aa (2.6ng/cm(2)) was highly toxic followed by cry1ac (29.3ng/cm(2)) and cry1ab (68.7ng/cm(2)). the cry1ca and cry1ea proteins were moderately toxic to eri silkworm larvae and resulted in 23% and 28% mortality, respectively at the highest concentration tested (3 ... | 2016 | 27377590 |
| histochemical effects of some biological agents on culex pipiens larvae. | the histochemical effects of the lethal concentration that kills 50% of larvae (lc50) of three biological agents, abamectin, bacillus thuringiensis and spinosad on the carbohydrates (polysaccharides), proteins, nucleic acids and lipids content of the midgut and fat bodies of culex pipiens 2nd instar larvae were studied. the results showed that the three tested compounds reduced the carbohydrates (polysaccharides), proteins, rna synthesis and lipids content after 72 hours of treatment where abame ... | 2016 | 27363043 |
| diversity and toxicity of bacillus thuringiensis from shifting cultivation (jhum) habitat. | bacillus thuringiensis (bt) strains were isolated from jhum-agriculture, jhum-forest, aquatic and fallow soil samples from mizoram by acetate selection method. isolates were characterized for biochemical typing, cry gene and protein profiling, growth curve study and toxicity against culex tritaeniorhynchus. bt frequency was high in jhum-agriculture land (69.56%) whereas low in jhum-forest soils (31.57%). bt was found to be abundant in jhum shifting cultivation soil with an index ranging between ... | 2016 | 27350428 |
| effects of transgenic cry1ie maize on non-lepidopteran pest abundance, diversity and community composition. | non-lepidopteran pests are exposed to, and may be influenced by, bt toxins when feeding on bt maize that express insecticidal cry proteins derived from bacillus thuringiensis (bt). in order to assess the potential effects of transgenic cry1ie maize on non-lepidopteran pest species and ecological communities, a 2-year field study was conducted to compare the non-lepidopteran pest abundance, diversity and community composition between transgenic cry1ie maize (event ie09s034, bt maize) and its near ... | 2016 | 27344564 |
| functional validation of cadherin as a receptor of bt toxin cry1ac in helicoverpa armigera utilizing the crispr/cas9 system. | cadherins have been identified as receptors of bacillus thuringiensis (bt) cry1a toxins in several lepidopteran insects including the cotton bollworm, helicoverpa armigera. disruption of the cadherin gene hacad has been genetically linked to resistance to bt toxin cry1ac in h. armigera. by using the crispr/cas9 genome editing system (clustered regularly interspaced short palindromic repeats/crispr-associated protein 9), hacad from the cry1ac-susceptible scd strain of h. armigera was successfully ... | 2016 | 27343383 |