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a 52-week safety study in cynomolgus macaques for genetically modified rice expressing cry1ab/1ac protein.a 52-week feeding study in cynomolgus macaques was carried out to evaluate the safety of bt rice huahui 1 (hh1), a transgenic rice line expressing cry1ab/1ac protein. monkeys were fed a diet with 20% or 60% hh1 rice, 20% or 60% parental rice (minghui 63, mh63), normal diet, normal diet spiked with purified recombinant cry1ab/1ac fusion protein or bovine serum albumin (bsa) respectively. during the feeding trail, clinical observations were conducted daily, and multiple parameters, including body ...201627338709
rnai induced knockdown of a cadherin-like protein (ef531715) does not affect toxicity of cry34/35ab1 or cry3aa to diabrotica virgifera virgifera larvae (coleoptera: chrysomelidae).the western corn rootworm (wcr), diabrotica virgifera virgifera leconte, is an important maize pest throughout most of the u.s. corn belt. bacillus thuringiensis (bt) insecticidal proteins including modified cry3aa and cry34/35ab1 have been expressed in transgenic maize to protect against wcr feeding damage. to date, there is limited information regarding the wcr midgut target sites for these proteins. in this study, we examined whether a cadherin-like gene from diabrotica virgifera virgifera (d ...201627334721
sequencing, de novo assembly and annotation of a pink bollworm larval midgut transcriptome.the pink bollworm pectinophora gossypiella (saunders) (lepidoptera: gelechiidae) is one of the world's most important pests of cotton. insecticide sprays and transgenic cotton producing toxins of the bacterium bacillus thuringiensis (bt) are currently used to manage this pest. bt toxins kill susceptible insects by specifically binding to and destroying midgut cells, but they are not toxic to most other organisms. pink bollworm is useful as a model for understanding insect responses to bt toxins, ...201627333791
impact of lepidoptera (crambidae, noctuidae, and pyralidae) pests on corn containing pyramided bt traits and a blended refuge in the southern united states.blended refuge for transgenic plants expressing bacillus thuringiensis (bt) toxins has been approved in the northern united states as a resistance management strategy alternative to a structured refuge. a three-year study (2012-2014) was conducted with 54 trials across nine states in the southern united states to evaluate plant injury from lepidopteran pests of corn and yield in a corn hybrid expressing cry1f × cry1ab × vip3aa20 (pioneer brand optimum leptra) planted as a pure stand and in refug ...201627329627
field performance of bt eggplants (solanum melongena l.) in the philippines: cry1ac expression and control of the eggplant fruit and shoot borer (leucinodes orbonalis guenée).plants expressing cry proteins from the bacterium, bacillus thuringiensis (bt), have become a major tactic for controlling insect pests in maize and cotton globally. however, there are few bt vegetable crops. eggplant (solanum melongena) is a popular vegetable grown throughout asia that is heavily treated with insecticides to control the eggplant fruit and shoot borer, leucinodes orbonalis (efsb). herein we provide the first publicly available data on field performance in asia of eggplant engine ...201627322533
toxicity of bacillus thuringiensis (l.) cry proteins against summer fruit tortrix (adoxophyes orana - fischer von rösslerstamm).the activity of seven cry1, one cry9 and one hybrid cry1 protoxins against neonate larvae of summer fruit tortrix (adoxophyes orana - fischer von rösslerstamm) has been investigated. cry1ia is identified as the most toxic protein, followed by cry1aa and cry1ac. cry1ca, cry1cb, cry1da and cry1fa were less active, while sn19 (cry1 hybrid protein with domain composition 1ba/1ia/1ba) and cry9aa exhibited negligible toxicity against a. orana. in vitro trypsin-activated cry1ac is still less active tha ...201627311897
f2 screen for resistance to bacillus thuringiensis cry2ab2-maize in field populations of spodoptera frugiperda (lepidoptera: noctuidae) from the southern united states.the fall armyworm, spodoptera frugiperda (j. e. smith) (lepidoptera: noctuidae), is a target pest of transgenic maize and cotton expressing bacillus thuringiensis (bt) proteins in both north and south america. in 2013 and 2014, a total of 215 f2 two-parent families of s. frugiperda were established using single-pair mating of field individuals collected from seven locations in four states of the southern u.s.: texas, louisiana, georgia, and florida. the objective of the investigation was to dete ...201627311896
replicates, read numbers, and other important experimental design considerations for microbial rna-seq identified using bacillus thuringiensis datasets.rna-seq is being used increasingly for gene expression studies and it is revolutionizing the fields of genomics and transcriptomics. however, the field of rna-seq analysis is still evolving. therefore, we specifically designed this study to contain large numbers of reads and four biological replicates per condition so we could alter these parameters and assess their impact on differential expression results. bacillus thuringiensis strains atcc10792 and ct43 were grown in two luria broth medium l ...201627303383
comparative analysis of genomics and proteomics in the new isolated bacillus thuringiensis x022 revealed the metabolic regulation mechanism of carbon flux following cu(2+) treatment.bacillus thuringiensis (bt) x022 is a novel strain isolated from soil in china, and showed strong insecticidal activity against several lepidopteran pests. in this work, we performed whole genome sequencing of this bt strain using the next-generation sequencing technology, and further conducted a comparative analysis with the proteomics data of the specific spore-release period based on lc-ms/ms approach. the bt x022 genome consisted of one circular chromosomal dna and seven plasmids, which were ...201627303381
performance and cross-crop resistance of cry1f-maize selected spodoptera frugiperda on transgenic bt cotton: implications for resistance management.transgenic crops producing bacillus thuringiensis (bt) proteins have become a primary tool in pest management. due to the intensive use of bt crops, resistance of the fall armyworm, spodoptera frugiperda, to cry1f maize has occurred in puerto rico, brazil, and some areas of the southeastern u.s. the sustainability of bt crops faces a great challenge because the cry1f-maize resistant s. frugiperda may also infest other bt crops in multiple cropping ecosystems. here we examined the survival and pl ...201627301612
broad-spectrum resistance to bacillus thuringiensis toxins by western corn rootworm (diabrotica virgifera virgifera).the evolution of resistance and cross-resistance threaten the sustainability of genetically engineered crops that produce insecticidal toxins derived from the bacterium bacillus thuringiensis (bt). western corn rootworm, diabrotica virgifera virgifera leconte, is a serious pest of maize and has been managed with bt maize since 2003. we conducted laboratory bioassays with maize hybrids producing bt toxins cry3bb1, mcry3a, ecry3.1ab, and cry34/35ab1, which represent all commercialized bt toxins fo ...201627297953
assessment of bt trait purity in different generations of transgenic cottons.adequate expression of bt (bacillus thuringiensis) toxins and purity of seeds of bt-transgenic cottons are important for controlling bollworms, and thereby increasing the cotton productivity. therefore, we examined the variability in expression of bt toxin proteins in the seeds and in leaves of different cotton (gossypium hirsutum (l.) hybrids (jkch 226, jkch 1947, jkch durga, jkch ishwar, jkch varun kdchh 441 and kdchh 621) expressing bt toxins in f₁ and f₂ generations, using bioassays against ...201627295920
peptide isolated from cry1ab16 toxin present in bacillus thuringiensis: synthesis and morphology data for layer-by-layer films studied by atomic force microscopy.the peptide pcl342-354c was obtained from the cry1ab16 toxin present in bacillus thuringiensis ("computational modeling deduced three dimensional structure of cry1ab16 toxin from b. thuringiensis ac11" (kashyap, 2012) [1]). in this data article, we report the synthesis and characterization of the pcl342-354c peptide by maldi-tof/tof mass spectrometry. in addition, the preparation of layer-by-layer films is shown based on interspersion of this peptide with both polyethylenimine (pei) and poly(sod ...201627294178
preliminary report on the reduction of adult mosquitoes in housing compounds in western kenya using the provector flower and entobac bait pads containing bacillus thuringiensis israelensis with honey bait.reducing mosquito populations indoors and outdoors can have a significant impact on malaria and other mosquito-borne diseases. a new formulation and delivery system for bacillus thuringiensis israelensis (bti) was tested against adult mosquitoes. one entobac bait with 7% bti in a honey solution was placed within each provector flower applicator. the applicators were placed in nine housing compounds, one on the outside of each home in ahero and nyalenda, kenya, in june 2009. seven housing compoun ...201627282815
identification of an alkaline phosphatase as a putative cry1ac binding protein in ostrinia furnacalis (guenée).asian corn borer (acb), ostrinia furnacalis, is an important insect pest of maize susceptible to different cry1a toxins. based on amino acid sequence alignment of alp sequences from lepidopteran larvae an alp gene was cloned from acb, named ofalp. pull dawn assays using biotinylated cry1ac and brush border membrane vesicles isolated from second instar acb larvae showed that four proteins of 50, 65, 68 and 70kda precipitated with the cry1ac. the 65kda band cross-reacted with the anti-ofalp monocl ...201627265829
localization and in silico study of the vegetative insecticidal proteins vip2s-vip1s of bacillus thuringiensis.the bacillus thuringiensis s1/4 strain was previously found to harbour vip1s, vip2s, and vip3 genes. its plasmid curing led to the obtaining of four partially cured strains s1/4-2, s1/4-3, s1/4-7, and s1/4-9 (vip2s-vip1s (-), vip3 (+)), one strain s1/4-4 (vip2s-vip1s (+), vip3 (-)), and s1/4-0 strain lacking the three genes. using these derivative strains as templates, pcr amplification and southern blot assay revealed that vip2s-vip1s operon and vip3 gene were localized on two different large p ...201627264647
activation of bt protoxin cry1ac in resistant and susceptible cotton bollworm.crystalline (cry) proteins from bacillus thuringiensis (bt) are used extensively for insect control in sprays and transgenic plants, but their efficacy is reduced by evolution of resistance in pests. here we evaluated reduced activation of cry1ac protoxin as a potential mechanism of resistance in the invasive pest helicoverpa armigera. based on the concentration killing 50% of larvae (lc50) for a laboratory-selected resistant strain (lf120) divided by the lc50 for its susceptible parent strain ( ...201627257885
life-history traits of spodoptera frugiperda populations exposed to low-dose bt maize.exposure to bacillus thuringiensis (bt) toxins in low- and moderate-dose transgenic crops may induce sublethal effects and increase the rate of bt resistance evolution, potentially compromising control efficacy against target pests. we tested this hypothesis using the fall armyworm spodoptera frugiperda, a major polyphagous lepidopteran pest relatively tolerant to bt notorious for evolving field-relevant resistance to single-gene bt maize. late-instar larvae were collected from bt cry1ab and non ...201627243977
potential resistance management for the sustainable use of insect-resistant genetically modified corn and rice in china.many lines of insect-resistant genetically modified (irgm) corn and rice containing bacillus thuringiensis (bt) insecticidal genes have been developed and undergone different environmental biosafety assessments stages in china, showing robust application prospects. the potential of targeted pests to develop resistance to bt crops is widespread, which threatens the sustainable utility of irgm corn and rice. in this study, the potential risks of target pest complexes developing resistance to irgm ...201627436744
current situation of pests targeted by bt crops in latin america.transgenic crops producing bacillus thuringiensis- (bt) insecticidal proteins (bt crops) have provided useful pest management tools to growers for the past 20 years. planting bt crops has reduced the use of synthetic insecticides on cotton, maize and soybean fields in 11 countries throughout latin america. one of the threats that could jeopardize the sustainability of bt crops is the development of resistance by targeted pests. governments of many countries require vigilance in measuring changes ...201627436743
cry1f resistance among lepidopteran pests: a model for improved resistance management?the cry1fa protein from the bacterium bacillus thuringiensis (bt) is known for its potential to control lepidopteran pests, especially through transgenic expression in maize and cotton. the maize event tc1507 expressing the cry1fa toxin gene became commercially available in the united states in 2003 for the management of key lepidopteran pests including the european corn borer, ostrinia nubilalis, and the fall armyworm, spodoptera frugiperda. a high-dose/refuge strategy has been widely adopted t ...201627436741
resistance to bt maize by western corn rootworm: insights from the laboratory and the field.western corn rootworm is a serious pest of maize. beginning in 2003, management of western corn rootworm included transgenic maize that produces insecticidal toxins derived from the bacterium bacillus thuringiensis (bt). the first bt maize hybrids produced cry3bb1, but additional bt toxins have since been introduced, including ecry3.1ab, mcry3a and cry34/35ab1. laboratory selection experiments found that western corn rootworm could develop resistance to all types of bt maize following three to s ...201627436740
intestinal regeneration as an insect resistance mechanism to entomopathogenic bacteria.the intestinal epithelium of insects is exposed to xenobiotics and entomopathogens during the feeding developmental stages. in these conditions, an effective enterocyte turnover mechanism is highly desirable to maintain integrity of the gut epithelial wall. as in other insects, the gut of lepidopteran larvae have stem cells that are capable of proliferation, which occurs during molting and pathogenic episodes. while much is known on the regulation of gut stem cell division during molting, there ...201627436739
susceptibility, mechanisms of response and resistance to bacillus thuringiensis toxins in spodoptera spp.bioinsecticides based on bacillus thuringiensis have long been used as an alternative to synthetic insecticides to control insect pests. in this review, we focus on insects of the genus spodoptera, including relevant polyphagous species that are primary and secondary pests of many crops, and how b. thuringiensis toxins can be used for spodoptera spp. pest management. we summarize the main findings related to susceptibility, midgut binding specificity, mechanisms of response and resistance of thi ...201627436737
bacillus thuringiensis resistance in plutella - too many trees?plutella xylostella was the first insect for which resistance to bacillus thuringiensis was reported in the field, yet despite many studies on the nature of this resistance phenotype its genetic and molecular basis remains elusive. many different factors have been proposed as contributing to resistance, although in many cases it has not been possible to establish a causal link. indeed, there are so many studies published that it has become very difficult to 'see the wood for the trees'. this art ...201627436736
bacillus thuringiensis toxin resistance mechanisms among lepidoptera: progress on genomic approaches to uncover causal mutations in the european corn borer, ostrinia nubilalis.transgenic plants that express bacillus thuringiensis (bt) crystal (cry) protein toxins (bt crops) effectively control feeding by the european corn borer, ostrinia nubilalis, although documented resistance evolution among a number of species in both the laboratory and field has heightened concerns about the durability of this technology. research has provided major insights into the mutations that alter bt toxin binding receptor structure and function within the midgut of lepidoptera that direct ...201627436734
receptors are affected by selection with each bacillus thuringiensis israelensis cry toxin but not with the full bti mixture in aedes aegypti.bacillus thuringiensis israelensis (bti) toxins are increasingly used for mosquito control, but little is known about the precise mode of action of each of these toxins, and how they interact to kill mosquito larvae. by using rna sequencing, we investigated change in gene transcription level and polymorphism variations associated with resistance to each bti cry toxin and to the full bti toxin mixture in the dengue vector aedes aegypti. the up-regulation of genes related to chitin metabolism in a ...201627418233
three toxins, two receptors, one mechanism: mode of action of cry1a toxins from bacillus thuringiensis in heliothis virescens.insecticidal crystal (cry) proteins from bacillus thuringiensis (bt) are highly active against lepidoptera. however, field-evolved resistance to bt toxins is on the rise. the 12-cadherin domain protein hevcalp and the abc transporter hevabcc2 are both genetically linked to cry toxin resistance in heliothis virescens. we investigated their interaction using stably expressing non-lytic clonal sf9 cell lines expressing either protein or both together. untransfected sf9 cells are innately sensitive ...201627456115
cry1ac toxicity enhancement towards lepidopteran pest ephestia kuehniella through its protection against excessive proteolysis.bacillus thuringiensis has been extensively used in agroecosystems for four decades due to its high specific toxicity. strategies based on b. thuringiensis proteins combinations for the improvement of its activity present an important focus for biopesticides development. however, the widespread use of b. thuringiensis δ-endotoxins has often been challenged by a lack of understanding of the target insect physiology as well as its midgut biochemistry. in the present investigation, we have evidence ...201627452929
cry1ab-expressing rice did not influence expression of fecundity-related genes in the wolf spider pardosa pseudoannulata.the impact of bacillus thuringiensis (bt) toxin proteins on non-target predatory arthropods is not well understood at the cellular and molecular levels. here, we investigated the potential effects of cry1ab expressing rice on fecundity of the wolf spider, pardosa pseudoannulata, and some of the underlying molecular mechanisms. the results indicated that brown planthoppers (bphs) reared on cry1ab-expressing rice accumulated the cry toxin and that reproductive parameters (pre-oviposition period, p ...201627452121
routine implementation costs of larviciding with bacillus thuringiensis israelensis against malaria vectors in a district in rural burkina faso.the key tools in malaria control are early diagnosis and treatment of cases as well as vector control. current strategies for malaria vector control in sub-saharan africa are largely based on long-lasting insecticide-treated nets (llins) and to a much smaller extent on indoor residual spraying (irs). an additional tool in the fight against malaria vectors, larval source management (lsm), has not been used in sub-saharan africa on a wider scale since the abandonment of environmental spraying of d ...201627449023
silver nanoparticles production by two soil isolated bacteria, bacillus thuringiensis and enterobacter cloacae, and assessment of their cytotoxicity and wound healing effect in rats.production of silver nanoparticles by bacillus thuringiensis and enterobacter cloacae was performed and confirmed through uv-visible spectrophotometry, transmission electron microscopy (tem), and x-ray diffraction (xrd) analyses. the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (mtt) assay using mouse fibroblast cell line nih-3t3 d4 was carried out and ic50s of agnps were obtained. the nontoxic dose of each agnps solution was selected for wound healing assay. thirty-two rats were ...201627448276
vip3aa induces apoptosis in cultured spodoptera frugiperda (sf9) cells.the vegetative insecticidal proteins (vip) secreted by many bacillus thuringiensis strains during their vegetative growth stage are regarded as second generation insecticidal proteins, as they share no sequence or structural homology with known crystal insecticidal proteins (cry) and have a broad insecticidal spectrum. compared with insecticidal crystal proteins (icps), the insecticidal mechanisms of vips have been little studied. here we investigated the mechanism responsible for vip3aa toxicit ...201627476462
coprinopsis cinerea intracellular lactonases hydrolyze quorum sensing molecules of gram-negative bacteria.biofilm formation on fungal hyphae and production of antifungal molecules are strategies of bacteria in their competition with fungi for nutrients. since these strategies are often coordinated and under control of quorum sensing by the bacteria, interference with this bacterial communication system can be used as a counter-strategy by the fungi in this competition. hydrolysis of n-acyl-homoserine lactones (hsl), a quorum sensing molecule used by gram-negative bacteria, by fungal cultures has bee ...201627475110
effects of field history on corn root injury and adult abundance of northern and western corn rootworm (coleoptera: chrysomelidae).western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), and northern corn rootworm, diabrotica barberi smith & lawrence, are major pests of corn (zea mays l.). corn producing bacillus thuringiensis (bt) toxins are widely used to manage diabrotica spp.; however, bt resistance by d. v. virgifera has led to high levels of feeding injury in the field. we tested whether field history affected root injury and abundance of adult diabrotica spp. in 2013 and 2014, four ...201627498115
one-pot biogenic fabrication of silver nanocrystals using quisqualis indica: effectiveness on malaria and zika virus mosquito vectors, and impact on non-target aquatic organisms.currently, mosquito vector control is facing a number of key challenges, including the rapid development of resistance to synthetic pesticides and the recent spread of aggressive arbovirus outbreaks. the biosynthesis of silver nanoparticles (agnps) is currently considered an environmental friendly alternative to the employ of pyrethroids, carbamates and microbial agents (e.g. bacillus thuringiensis var. israelensis), since agnps are easy to produce, effective and stable in the aquatic environmen ...201627491031
how quorum sensing connects sporulation to necrotrophism in bacillus thuringiensis.bacteria use quorum sensing to coordinate adaptation properties, cell fate or commitment to sporulation. the infectious cycle of bacillus thuringiensis in the insect host is a powerful model to investigate the role of quorum sensing in natural conditions. it is tuned by communication systems regulators belonging to the rnpp family and directly regulated by re-internalized signaling peptides. one such rnpp regulator, nprr, acts in the presence of its cognate signaling peptide nprx as a transcript ...201627483473
midgut microbiota and host immunocompetence underlie bacillus thuringiensis killing mechanism.bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. surprisingly, the killing mechanism of b. thuringiensis remains controversial. in particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. here this key issue is addressed by rn ...201627506800
insecticidal activity and histopathological effects of vip3aa protein from bacillus thuringiensis on spodoptera litura.vegetative insecticidal proteins (vips) are insecticidal proteins synthesized by bacillus thuringiensis during the vegetative stage of growth. in this study, vip3aa protein, obtained by in vitro expression of the vip3aa gene from b. thuringiensis wb5, displayed high insecticidal activity against spodoptera litura aside from spodoptera exigua and helicoverpa armigera. bioassay results showed that the toxicity of vip3aa protein against s. litura larvae statistically decreased along with the increa ...201627435544
spatio-temporal evolution of sporulation in bacillus thuringiensis biofilm.bacillus thuringiensis can produce a floating biofilm which includes two parts: a ring and a pellicle. the ring is a thick structure which sticks to the culture container, while the pellicle extends over the whole liquid surface and joins the ring. we have followed over time, from 16 to 96 h, sporulation in the two biofilm parts. sporulation was followed in situ in 48-wells polystyrene microtiterplates with a fluorescence binocular stereomicroscope and a spoiid-yfp transcriptional fusion. sporul ...201627536298
characterization of a highly toxic strain of bacillus thuringiensis serovar kurstaki very similar to the hd-73 strain.the lbit-1200 strain of bacillus thuringiensis was recently isolated from soil, and showed a 6.4 and 9.5 increase in toxicity, against manduca sexta and trichoplusia ni, respectively, compared to hd-73. however, lbit-1200 was still highly similar to hd-73, including the production of bipyramidal crystals containing only one protein of ∼130 000 kda, its flagellin gene sequence related to the kurstaki serotype, plasmid and reppcr patterns similar to hd-73, no production of β-exotoxin and no presen ...201627535648
interactions between bt crops and aquatic ecosystems: a review.the term bt crops collectively refers to crops that have been genetically modified to include a gene (or genes) sourced from bacillus thuringiensis (bt) bacteria. these genes confer the ability to produce proteins toxic to certain insect pests. the interaction between bt crops and adjacent aquatic ecosystems has received limited attention in research and risk assessment, despite the fact that some bt crops have been in commercial use for 20 yr. reports of effects on aquatic organisms such as dap ...201627530353
proteomics-based identification of midgut proteins correlated with cry1ac resistance in plutella xylostella (l.).the diamondback moth, plutella xylostella (l.), is a worldwide pest of cruciferous crops and can rapidly develop resistance to many chemical insecticides. although insecticidal crystal proteins (i.e., cry and cyt toxins) derived from bacillus thuringiensis (bt) have been useful alternatives to chemical insecticides for the control of p. xylostella, resistance to bt in field populations of p. xylostella has already been reported. a better understanding of the resistance mechanisms to bt should be ...201627521921
complete genome sequence of bacillus thuringiensis bacteriophage smudge.smudge, a bacteriophage enriched from soil using bacillus thuringiensis dsm-350 as the host, had its complete genome sequenced. smudge is a myovirus with a genome consisting of 292 genes and was identified as belonging to the c1 cluster of bacillus phages.201627540049
bacterial cross-contamination potential associated with contaminated currency.previous studies have shown a significant amount of contaminants on paper currencies. it is important to study the transfer of microorganisms between paper currencies to determine whether it meets the level of a human health threat. this cross-contamination potential was analyzed by seeding new us 1-dollar bills with bacillus thuringiensis, and pressing or rubbing them against clean currency to determine the amount of bacteria transfer to the unseeded currency. the transferred amount of bacteria ...201627539663
nematicidal spore-forming bacilli share similar virulence factors and mechanisms.in the soil environment, bacilli can affect nematode development, fecundity and survival. however, although many bacillus species can kill nematodes, the virulence mechanisms bacilli utilize remain unknown. in this study, we collected 120 strains comprising 30 species across the bacillaceae and paenibacillaceae families of the bacillales order and measured their nematicidal activities in vitro. comparison of these strains' nematicidal capacities revealed that nine species, including bacillus thu ...201627539267
inheritance of field-relevant resistance to the bacillus thuringiensis protein cry1ac in pectinophora gossypiella (lepidoptera: gelechiidae) collected from india.the inheritance and phenotypic expression of resistance to bacillus thuringiensis cry1ac insecticidal protein were studied in selected populations of pink bollworm, pectinophora gossypiella (saunders), that were collected from bollgard cotton in india. the individual populations in the pool were cry1ac resistant and sourced from cry1ac-containing bt cotton (bollgard) hybrids in 2010.201625864528
high resistance of transgenic cabbage plants with a synthetic cry1ia8 gene from bacillus thuringiensis against two lepidopteran species under field conditions.plutella xylostella (linnaeus) has become the most destructive pest in cabbage throughout the world. cry1ia8 cabbage has been developed to reduce pest attacks. to gain a better understanding of the efficacy of cry1ia8 cabbage, a homozygous cry1ia8 cabbage line a14-5 was produced, and its resistance to p. xylostella, pieris rapae (linnaeus) and other lepidopteran pests was evaluated in the field in 2011, 2012 and 2013.201625721816
enhancement of bacillus thuringiensis insecticidal activity by combining cry1ac and bi-functional toxin hwtx-xi from spider.in order to assess the potency of bi-functional hwtx-xi toxin from spider ornithoctonus huwena in improving the insecticidal activity of bacillus thuringiensis, a fusion gene of cry1ac and hwtx-xi was constructed and expressed in an acrystalliferous b. thuringiensis strain cry(-)b. western blot analysis and microscopic observation revealed that the recombinant strain could express 140-kda cry1ac-hwtx-xi fusion protein and produce parasporal inclusions during sporulation. bioassay using the larva ...201625721170
effects of refuges on the evolution of resistance to transgenic corn by the western corn rootworm, diabrotica virgifera virgifera leconte.diabrotica virgifera virgifera leconte is a major pest of corn and causes over a billion dollars of economic loss annually through yield reductions and management costs. corn producing toxins derived from bacillus thuringiensis (bt) has been developed to help manage d. v. virgifera. however, previous studies have demonstrated the ability of this species to evolve resistance to bt toxins in both laboratory and field settings.201625652190
lack of fitness costs and inheritance of resistance to bacillus thuringiensis cry1ac toxin in a near-isogenic strain of plutella xylostella (lepidoptera: plutellidae).resistance to bacillus thuringiensis (bt) formulations in insects may be associated with fitness costs. a lack of costs enables resistance alleles to persist, which may contribute to the rapid development and spread of resistance in populations.201625684167
hematotoxicity and genotoxicity evaluations in swiss mice intraperitoneally exposed to bacillus thuringiensis (var kurstaki) spore crystals genetically modified to express individually cry1aa, cry1ab, cry1ac, or cry2aa.bacillus thuringiensis (bt) has been widely used in foliar sprays as part of integrated pest management strategies against insect pests of agricultural crops. since the advent of genetically modified plants expressing bt δ-endotoxins, the bioavailability of cry proteins has increased, and therefore for biosafety reasons their adverse effects should be studied, mainly for nontarget organisms. we evaluated, in swiss mice, the hematotoxicity and genotoxicity of the genetically modified strains of b ...201625899034
expression of recombinant and mosaic cry1ac receptors from helicoverpa armigera and their influences on the cytotoxicity of activated cry1ac to spodoptera litura sl-hp cells.bacillus thuringiensis (bt) toxin receptors play important roles in the killing of pests, and investigation on characterization of the receptors is essential for utilization of bt and management of insect resistance. here, recombinant and mosaic receptors of bt cry1ac toxin from helicoverpa armigera were expressed in spodoptera litura sl-hp cells and their influences on cytotoxicity of activated cry1ac toxin were investigated. when h. armigera aminopeptidase n1 (apn1), alkaline phosphatase 2 (al ...201625412589
bacillus thuringiensis: mechanism of action, resistance, and new applications: a review.since the first report by ishiwata in 1902 of a bombyx mori infection, followed by the description by berliner, bacillus thuringiensis (bt) has become the main microorganism used in biological control. the application of bt to combat invertebrates of human interest gained momentum with the growing demand for food free of chemical pesticides and with the implementation of agriculture methods that were less damaging to the environment. however, the mechanisms of action of these products have not b ...201625264571
complete genome sequence of bacillus phage belinda from grand cayman island.soil from george town, grand cayman island, yielded the bacteriophage belinda, isolated on bacillus thuringiensis dsm 350. we present here the analysis of the complete genome sequence of 162,308 bp, with 298 predicted genes. the genome also contains three trna genes. belinda belongs to the c1 cluster of bacillus phages.201627738022
effective dominance of resistance of spodoptera frugiperda to bt maize and cotton varieties: implications for resistance management.the resistance of fall armyworm (faw), spodoptera frugiperda, has been characterized to some cry and vip3a proteins of bacillus thuringiensis (bt) expressed in transgenic maize in brazil. here we evaluated the effective dominance of resistance based on the survival of neonates from selected bt-resistant, heterozygous, and susceptible (sus) strains of faw on different bt maize and cotton varieties. high survival of strains resistant to the cry1f (hx-r), cry1a.105/cry2ab (vt-r) and cry1a.105/cry2a ...201627721425
no effect of bt-transgenic rice litter on the meiobenthos community in field ditches.the non-target effect of bacillus thuringiensis (bt) toxins in aquatic ecosystems is crucial to improve the present assessment of bt-transgenic plants, particularly where crops are cultivated near aquatic ecosystems. we conducted decomposition experiments during two growing seasons to determine the effects of bt-transgenic rice litter with and without insecticide application on the meiobenthos communities in a field ditch.201627717164
identification of a bacillus thuringiensis surface-layer-protein with cytotoxic activity against mda-mb-231 breast cancer cells.in this work we isolated a surface-layer-protein (slp) from a bacillus thuringiensis (bt) strain to evaluate it cytotoxic effects against mda-mb-231 human breast cancer cells. ap11 was selected from a group of bt strains using slp oligonucleotides developed from bacillus conserved regions. ap11 strain was grown in luria bertani (lb) medium until late exponential phase; an 86 kda protein was extracted using 5 m licl and identified by liquid chromatography-tandem mass spectrometry (lc-ms/ms). it c ...201627713207
type of fitness cost influences the rate of evolution of resistance to transgenic bt crops.the evolution of resistance to pesticides by insect pests is a significant challenge for sustainable agriculture. for transgenic crops expressing bacillus thuringiensis (bt), crystalline (cry) toxins resistance evolution may be delayed by the high-dose/refuge strategy in which a non-toxic refuge is planted to promote the survival of susceptible insects. the high-dose/refuge strategy may interact with fitness costs associated with resistance alleles to further delay resistance. however, while a d ...201627708457
edible safety assessment of genetically modified rice t1c-1 for sprague dawley rats through horizontal gene transfer, allergenicity and intestinal microbiota.in this study, assessment of the safety of transgenic rice t1c-1 expressing cry1c was carried out by: (1) studying horizontal gene transfer (hgt) in sprague dawley rats fed transgenic rice for 90 d; (2) examining the effect of cry1c protein in vitro on digestibility and allergenicity; and (3) studying the changes of intestinal microbiota in rats fed with transgenic rice t1c-1 in acute and subchronic toxicity tests. sprague dawley rats were fed a diet containing either 60% gm bacillus thuringiens ...201627706188
the response of soybean to nod factors and a bacteriocin.microbe-to-plant signals can enhance the growth of a wide range of crops. the responses by soybean (glycine max var. 91m01) to 2 signal molecules were investigated: bradyrhizobium japonicum 532c lipo-chitooligosaccharide (nod bj v [c:18, mefuc]) (lco); and bacillus thuringiensis strain neb17 bacteriocin thuricin 17 (th17). the objective was to assess and quantify the response by soybean, in terms of factors that contribute to yield, to the experimental signal molecules in germination experiments ...201627700227
challenges of implementing a large scale larviciding campaign against malaria in rural burkina faso - lessons learned and recommendations derived from the emira project.recent malaria control and elimination attempts show remarkable success in several parts of sub-saharan africa. vector control via larval source management represents a new and to date underrepresented approach in low income countries to further reduce malaria transmission. although the positive impact of such campaigns on malaria incidence has been researched, there is a lack of data on which prerequisites are needed for implementing such programs on a routine basis on large scale. our objectiv ...201627686125
local mosquito-borne transmission of zika virus - miami-dade and broward counties, florida, june-august 2016.during the first 6 months of 2016, large outbreaks of zika virus disease caused by local mosquito-borne transmission occurred in puerto rico and other u.s. territories, but local mosquito-borne transmission was not identified in the continental united states (1,2). as of july 22, 2016, the florida department of health had identified 321 zika virus disease cases among florida residents and visitors, all occurring in either travelers from other countries or territories with ongoing zika virus tran ...201627684886
interaction of pseudostellaria heterophylla with quorum sensing and quorum quenching bacteria mediated by root exudates in a consecutive monoculture system.many plant-pathogenic bacteria are dependent on quorum sensing (qs) to evoke disease. in this study, the population of qs and quorum quenching (qq) bacteria was analyzed in a consecutive monoculture system of pseudostellaria heterophylla. the isolated qs strains were identified as serratia marcescens with swrir-type qs system and exhibited a significant increase over the years of monoculture. only one qq strain was isolated from newly planted soil sample and was identified as bacillus thuringien ...201627666992
effects of bacillus thuringiensis var. israelensis on nonstandard microcrustacean species isolated from field zooplankton communities.the toxicity of bacillus thuringiensis var. israelensis on zooplanktonic microcrustaceans was evaluated using individuals collected in coastal wetlands where this larvicide has been used for mosquito control over the last decades. we tested five zooplankton species that coexist with mosquito larvae: two copepods (both nauplii and adults of tropocyclops prasinus and acantocyclops americanus), and three cladocerans (ceriodaphnia reticulata, chydorus sphaericus, and daphnia cf. pulex). our experime ...201627640016
individual and combined effects of bacillus thuringiensis and azadirachtin on plodia interpunctella hübner (lepidoptera: pyralidae).the indianmeal moth, plodia interpunctella hübner (lepidoptera: pyralidae), is a major stored product pest that is found throughout the world. in this study, the effect of oral exposure to bacillus thuringiensis (berliner) subsp. kurstaki (bacillales: bacillaceae) and azadirachtin was evaluated in third instar p. interpunctella under laboratory conditions. the median lethal concentration (lc50) of bt and azadirachtin on third instars was 490 and 241 μg a.i./ml, respectively. the median lethal ti ...201627638953
effects and mechanisms of bacillus thuringiensis crystal toxins for mosquito larvae.bacillus thuringiensis is a gram-positive aerobic bacterium that produces insecticidal crystalline inclusions during sporulation phases of the mother cell. the virulence factor, known as parasporal crystals, is composed of cry and cyt toxins. most cry toxins display a common 3-domain topology. cry toxins exert intoxication through toxin activation, receptor binding and pore formation in a suitable larval gut environment. the mosquitocidal toxins of bt subsp. israelensis (bti) were found to be hi ...201627628909
occupational hazards and health cost of women cotton pickers in pakistani punjab.farm workers and female cotton pickers are exposed to residual impacts of pesticide use in cotton production, in addition to dust, ultraviolet radiation, etc. cotton picking causes various health hazards among cotton pickers with varied health cost. a soil bacterium known as bacillus thuringiensis (bt) is incorporated in cotton seed through genetic modification and it has resistance against certain bollworms of cotton. so it is considered that bt cotton fields have less pesticide exposure compar ...201627618928
highly selective and sensitive electrochemical immunoassay of cry1c using nanobody and π-π stacked graphene oxide/thionine assembly.cry1c is one of the emerging toxin proteins produced by the bacillus thuringiensis in the genetically modified crops for pest control in agriculture; thus, it is vital to measure the cry1c level in crops for the healthy and environmental concerns. current detections of cry1c mainly rely on instrumental analysis such as high-performance liquid chromatography, which are time-consuming and are generally cost-prohibitive. herein, a simple nanobodies (nbs)-based electrochemical immunosensor has been ...201627617345
role of the sulfur to α-carbon thioether bridges in thurincin h.thurincin h is a small protein produced by bacillus thuringiensis sf361 with gram-positive antimicrobial properties. the toxins produced by b. thuringiensis are widely used in the agriculture as, e.g. natural preservatives in dairy products. the structure of thurincin h possesses four covalent sulfur to [formula: see text]-carbon bonds that involve the cysteine side-chains; these bonds are probably responsible for the shape and stability of the protein and, thereby, for its antimicrobial propert ...201627615507
proteolytic activation of bacillus thuringiensis cry2ab through a belt-and-braces approach.proteolytic processing of bacillus thuringiensis (bt) crystal toxins by insect midgut proteases plays an essential role in their insecticidal toxicities against target insects. in the present study, proteolysis of bt crystal toxin cry2ab by plutella xylostella l. midgut proteases (pxmj) was evaluated. both trypsin and chymotrypsin were identified involving the proteolytic activation of cry2ab and cleaving cry2ab at arg(139) and leu(144), respectively. three cry2ab mutants (r139a, l144a, and r139 ...201627598769
larvicidal activity of bacillus thuringiensis var. israelensis cry11aa toxin against haemonchus contortus.effective control of gastrointestinal parasites is necessary in sheep production. the development of anthelmintics resistance is causing the available chemically based anthelmintics to become less effective. biological control strategies present an alternative to this problem. in the current study, we tested the larvicidal effects of bacillus thuringiensis var. israelensis cry11aa toxin against haemonchus contortus larvae. bacterial suspensions [2 × 108 colony-forming units (cfu) g-1 of the fece ...201627573677
effect of genetically modified corn on the jejunal mucosa of adult male albino rat.genetically modified (gm) plants expressing insecticidal traits offer a new strategy for crop protection. gm-corn contains bacillus thuringiensis (bt) genes producing delta endotoxins in the whole plant. diet can influence the characteristics of the gastrointestinal tract altering its function and structure. the aim of this study was to evaluate the effect of gm-corn on the histological structure of jejunal mucosa of adult male albino rat using different histological, immunohistochemical and mor ...201627769625
complete genome sequence of bacillus thuringiensis serovar alesti bgsc 4c1, a typical strain with toxicity to lepidoptera insects.bacillus thuringiensis serovar alesti was used to control caterpillars from 1970s. here we reported the complete genome of bgsc 4c1, the type strain of this serovar. it has a circular chromosome and six plasmids. the largest plasmid pbmb267 contains five insecticidal crystal protein genes (two copies of cry1ae, cry1gb, cry2ab, and a novel cry1m-type gene) and three vegetative insecticidal protein genes (a novel binary toxin gene operon vip1-vip2 and vip3aa). besides, the strain also has many gen ...201627693093
isolation and characterization of gut bacterial proteases involved in inducing pathogenicity of bacillus thuringiensis toxin in cotton bollworm, helicoverpa armigera.bacillus thuringiensis toxin proteins are deployed in transgenic plants for pest management. the present studies were aimed at characterization of gut bacterial proteases involved in activation of inactive cry1ac protoxin (pro-cry1ac) to active toxin in helicoverpa armigera. bacterial strains were isolated from h. armigera midgut and screened for their proteolytic activation toward pro-cry1ac. among 12 gut bacterial isolates seven isolates showed proteolytic activity, and proteases from three is ...201627766093
susceptibility of grapholita molesta (busck, 1916) to formulations of bacillus thuringiensis, individual toxins and their mixtures.the oriental fruit moth, grapholita molesta (lepidoptera: tortricidae), is a major pest of fruit trees worldwide, such as peach and apple. bacillus thuringiensis has been shown to be an efficient alternative to synthetic insecticides in the control of many agricultural pests. the objective of this study was to evaluate the effectiveness of b. thuringiensis individual toxins and their mixtures for the control of g. molesta. bioassays were performed with cry1aa, cry1ac, cry1ca, vip3aa, vip3af and ...201627686262
development of monoclonal antibody-based sensitive elisa for the determination of cry1ie protein in transgenic plant.cry1ie is a kind of bacillus thuringiensis (bt) toxin protein which has a different action model than the cry1ab and cry1ac protein. the transgenic maize expressing cry1ie might be commercially used in the near future and it is urgent to develop a method to detect cry1ie protein in transgenic plants and their products. to develop an elisa method, cry1ie protein was expressed in escherichia coli strain transetta de3, purified with the ni-nta spin columns, and then validated by sequencing. bioassa ...201627659816
development of bt rice and bt maize in china and their efficacy in target pest control.rice and maize are important cereal crops that serve as staple foods, feed, and industrial material in china. multiple factors constrain the production of both crops, among which insect pests are an important one. lepidopteran pests cause enormous yield losses for the crops annually. in order to control these pests, china plays an active role in development and application of genetic engineering (ge) to crops, and dozens of ge rice and ge maize lines expressing insecticidal proteins from the soi ...201627763554
controlled-release of bacillus thurigiensis formulations encapsulated in light-resistant colloidosomal microcapsules for the management of lepidopteran pests of brassica crops.bacillus thuringiensis (b. t.) based formulations have been widely used to control lepidopteran pests in agriculture and forestry. one of their weaknesses is their short residual activity when sprayed in the field. using pickering emulsions, mixtures of spores and crystals from three b. t. serovars were successfully encapsulated in colloïdosomal microparticles (50 μm) using innocuous chemicals (acrylic particles, sunflower oil, iron oxide nanoparticles, ethanol and water). a ph trigger mechanism ...201627761325
a selective insecticidal protein from pseudomonas for controlling corn rootworms.the coleopteran insect western corn rootworm (wcr) (diabrotica virgifera virgifera leconte) is a devastating crop pest in north america and europe. although crop plants that produce bacillus thuringiensis (bt) proteins can limit insect infestation, some insect populations have evolved resistance to bt proteins. here we describe an insecticidal protein, designated ipd072aa, that is isolated from pseudomonas chlororaphis. transgenic corn plants expressing ipd072aa show protection from wcr insect i ...201627708055
prevalence of cry2-type genes in bacillus thuringiensis isolates recovered from diverse habitats in india and isolation of a novel cry2af2 gene toxic to helicoverpa armigera (cotton boll worm).insecticidal cry and vip genes from bacillus thuringiensis (bt) have been used for control of lepidopteran insects in transgenic crops. however, novel genes are required for gene pyramiding to delay evolution of resistance to the currently deployed genes. two pcr-based techniques were employed for screening of cry2-type genes in 129 bt isolates from diverse habitats in india and 27 known bt strains. cry2ab-type genes were more prevalent than cry2aa- and cry2ac-type genes. correlation between sou ...201627805417
correction: how quorum sensing connects sporulation to necrotrophism in bacillus thuringiensis.[this corrects the article doi: 10.1371/journal.ppat.1005779.].201627798684
pyramiding and evaluation of both a foreign bacillus thuringiensis and a lysine-rich protein gene in the elite indica rice 9311.gene pyramiding is an efficient approach for the genetic improvement of multiple agronomic traits simultaneously. in this study, we pyramided two foreign genes, cry1ac driven by the rice actin i promoter, and lysine-rich protein (lrp), driven by the endosperm-specific glutelin1 (gt1) promoter, into the elite indica cultivar 9311. these two genes were chosen in an attempt to enhance insect-resistance and lysine (lys) content. in the pyramided line, the foreign gene cry1ac was efficiently expresse ...201627795684
perturbation and delayed recovery of the reed invertebrate assemblage in camargue marshes sprayed with bacillus thuringiensis israelensis.bacillus thuringiensis var. israelensis (bti) is the most commonly used larvicide to control mosquitoes worldwide. considered as nontoxic to most organisms, bti can nevertheless cause trophic perturbations to natural communities by reducing the abundance of chironomidae, which are a key element of wetland food webs. since august 2006, up to 8400 of the 33 000 ha of mosquito larval biotopes in the camargue (rhône delta, in southern france), are monitored by a public agency and bti-sprayed (aqueou ...201627794203
detection of the cryptic prophage-like molecule pbtic235 in bacillus thuringiensis subsp. israelensis.bacillus thuringiensis has long been recognized to carry numerous extrachromosomal molecules. of particular interest are the strains belonging to the b. thuringiensis subsp. israelensis lineage, as they can harbor at least seven extrachromosomal molecules. one of these elements seems to be a cryptic molecule that may have been disregarded in strains considered plasmid-less. therefore, this work focused on this cryptic molecule, named pbtic235. using different approaches that included transpositi ...201627793675
unshared binding sites for bacillus thuringiensis cry3aa and cry3ca proteins in the weevil cylas puncticollis (brentidae).bacillus thuringiensis cry3aa and cry3ca proteins have been reported to be toxic against the african sweetpotato pest cylas puncticollis. in the present work, the binding sites of these proteins in c. puncticollis brush border vesicles suggest the occurrence of different binding sites, but only one of them is shared. our results suggest that pest resistance mediated by alteration of the shared cry-receptor binding site might not render both cry proteins ineffective.201627662801
frequency of cry1f resistance alleles in spodoptera frugiperda (lepidoptera: noctuidae) in brazil.the frequency of resistance alleles is a major factor influencing the rate of resistance evolution. here, we adapted the f2 screen procedure for spodoptera frugiperda (j. e. smith) with a discriminating concentration assay, and extended associated statistical methods to estimate the frequency of resistance to cry1f protein in s. frugiperda in brazil when resistance was not rare.201626990201
fate of insecticidal bacillus thuringiensis cry protein in soil: differences between purified toxin and biopesticide formulation.bacillus thuringiensis produces insecticidal proteins known as cry, and its efficiency and absence of side effects make it the most widely used biopesticide. there is little information on the role of soils in the fate of cry proteins from commercial biopesticide formulations, unlike toxins from genetically modified crops, which have been intensively studied in recent years. the persistence of cry in soil was followed under field and laboratory conditions.201626910634
toxin stability improvement and toxicity increase against dipteran and lepidopteran larvae of bacillus thuringiensis crystal protein cry2aa.bacillus thuringiensis δ-endotoxins are the most widely used biopesticides for controlling economically important crop pests and disease vectors. improving their efficacy is of great benefit. here, an improvement in cry2aa δ-endotoxin toxicity was attempted via a cry gene over expression system using p20 from b. thuringiensis israelensis.201626910489
comparative genomics of extrachromosomal elements in bacillus thuringiensis subsp. israelensis.bacillus thuringiensis subsp. israelensis is one of the most important microorganisms used against mosquitoes. it was intensively studied following its discovery and became a model bacterium of the b. thuringiensis species. those studies focused on toxin genes, aggregation-associated conjugation, linear genome phages, etc. recent announcements of genomic sequences of different strains have not been explicitly related to the biological properties studied. we report data on plasmid content analysi ...201627810477
functional characterization of bacillus thuringiensis cry toxin receptors explains resistance in insects.bacillus thuringiensis produces cry toxins, which are used as insecticides in sprays and in transgenic crops. however, little is known about the function of cry toxin receptors and the mechanisms that determine their binding specificity and activity. in this study, the crnas of bombyx mori abc transporter c2 (bmabcc2), the toxin-binding region of cadherin-like receptor (btr175-tbr), or aminopeptidase n1 (bmapn1) were injected into xenopus oocytes, and the cry1aa-dependent cation-selective pore f ...201627813251
an entomopathogenic bacterium strain, bacillus thuringiensis, as a biological control agent against the red palm weevil, rhynchophorus ferrugineus (coleoptera: curculionidae).the red palm weevil (rpw), rhynchophorus ferrugineus, is an invasive wood-boring insect that damages palms and sugarcane. bacillus thuringiensis (bt) is an entomopathogenic bacterium which has been modified into various strains and widely used in pest management. the aim of this study was to evaluate the susceptibility of rpw to the ha strain of bt.201627862867
possibly similar genetic basis of resistance to bacillus thuringiensis cry1ab protein in 3 resistant colonies of the sugarcane borer collected from louisiana, usa.the sugarcane borer, diatraea saccharalis (f.), is a major maize borer pest and a target of transgenic maize expressing bacillus thuringiensis (bt) proteins in south america and the mid-southern region of the united states. evolution of resistance in target pest populations is a great threat to the long-term efficacy of bt crops. in this study, we compared the genetic basis of resistance to cry1ab protein in 3 resistant colonies of sugarcane borer established from field populations in louisiana, ...201627860288
transgenic bt cotton does not disrupt the top-down forces regulating the cotton aphid in central china.top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. in the context of prevalent adoption of transgenic bt crops that produce insecticidal cry proteins derived from bacillus thuringiensis (bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the bt crops. we explored how bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-t ...201627870914
correction: necrotrophism is a quorum-sensing-regulated lifestyle in bacillus thuringiensis.[this corrects the article doi: 10.1371/journal.ppat.1002629.].201627898733
a p-glycoprotein is linked to resistance to the bacillus thuringiensis cry3aa toxin in a leaf beetle.chrysomela tremula is a polyvoltine oligophagous leaf beetle responsible for massive attacks on poplar trees. this beetle is an important model for understanding mechanisms of resistance to bacillus thuringiensis (bt) insecticidal toxins, because a resistant c. tremula strain has been found that can survive and reproduce on transgenic poplar trees expressing high levels of the cry3aa bt toxin. resistance to cry3aa in this strain is recessive and is controlled by a single autosomal locus. we used ...201627929397
microbial degradation of total petroleum hydrocarbons in crude oil: a field-scale study at the low-land rainforest of ecuador.a field-level feasibility study was conducted to determine total petroleum hydrocarbon (tph)-degrading potential of two bacterial strains, bacillus thuringiensis b3 and b. cereus b6, and two fungi, geomyces pannorum hr and geomyces sp. strain hv, all soil isolates obtained from an oil field located in north-east region of ecuador. crude oil-treated soil samples contained in wooden boxes received a mixture of all the four microorganisms and were incubated for 90 days in an open low-land area of a ...201627928937
field effectiveness of microbial larvicides on mosquito larvae in malaria areas of botswana and zimbabwe.the successful control of malaria vectors requires the control of both the larval and adult stages. the adult control methods through indoor residual spraying (irs) and use of long-lasting insecticidal nets (llins) continue to be widely used with some high measure of success. larval control methods are also being used by a number of national malaria control programmes (nmcps) with limited understanding of its contribution. larval control might be needed in some areas to move from malaria control ...201627923385
a return to the pore - dissecting bacillus thuringiensis toxin mode of action via voltage clamp experiments.pore-forming toxins from bacillus thuringiensis are increasingly used in crop protection, but evolution of resistance in crop pests threatens their continued deployment. a study by tanaka et al. shows how voltage clamp experiments that quantify pore formation can be used to dissect toxin mode of action, thereby revealing unexpected complexities that could be exploited to counter resistance.201627995777
reproductive cost associated with juvenile hormone in bt-resistant strains of helicoverpa armigera (lepidoptera: noctuidae).transgenic bacillus thuringiensis (bt) crops are increasingly significant in pest control, but resistance development of target pests is a major issue in the sustainable deployment of bt crops. the fitness cost of resistance in target pests is regarded as one of the main factors delaying resistance when adopting the refuge strategy. in this study, we compared the life-history traits of three independent sets of helicoverpa armigera (hübner, 1809) adults, of each there were a susceptible populati ...201627986942
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