Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| proteomic analysis of cry2aa-binding proteins and their receptor function in spodoptera exigua. | the bacterium bacillus thuringiensis produces crystal (cry) proteins that are toxic to a diverse range of insects. transgenic crops that produce bt cry proteins are grown worldwide because of their improved resistance to insect pests. although bt "pyramid" cotton that produces both cry1a and cry2a is predicted to be more resistant to several lepidopteran pests, including spodoptera exigua, than plants that produce cry1ac alone, the mechanisms responsible for the toxicity of cry2aa in s. exigua a ... | 2017 | 28067269 |
| transgenic pigeonpea events expressing cry1ac and cry2aa exhibit resistance to helicoverpa armigera. | independent transgenic pigeonpea events were developed using two cry genes. transgenic cry2aa-pigeonpea was established for the first time. selected transgenic events demonstrated 100% mortality of helicoverpa armigera in successive generations. lepidopteran insect helicoverpa armigera is the major yield constraint of food legume pigeonpea. the present study was aimed to develop h. armigera-resistant transgenic pigeonpea, selected on the basis of transgene expression and phenotyping. agrobacteri ... | 2017 | 28352969 |
| dynamics of bacterial class bacilli in the deepest valley lake of kashmir-the manasbal lake. | in recognition of the importance of bacteria as ecological indicators of the aquatic systems a comprehensive and systematic analysis was carried out on manasbal lake, the deepest spring fed valley lake of kashmir. the main objective envisaged was to analyze bacterial community composition (bcc) and for this purpose systematic and regular sampling of waters from ten different sampling stations, predetermined in the lake according to differences in degree of human interference and also as zones of ... | 2017 | 28087491 |
| bacillus spp. isolated from puba as a source of biosurfactants and antimicrobial lipopeptides. | several products of industrial interest are produced by bacillus, including enzymes, antibiotics, amino acids, insecticides, biosurfactants and bacteriocins. this study aimed to investigate the potential of two bacterial isolates (p5 and c3) from puba, a regional fermentation product from cassava, to produce multiple substances with antimicrobial and surface active properties. phylogenetic analyses showed close relation of isolates p5 and c3 with bacillus amyloliquefaciens and bacillus thuringie ... | 2017 | 28197131 |
| combinatorial effect of bacillus amyloliquefaciens ag1 biosurfactant and bacillus thuringiensis vip3aa16 toxin on spodoptera littoralis larvae. | spodoptera littoralis, one of the most serious and destructive agricultural pests in the world, is very susceptible to vip3 toxin. in order to develop a new efficient bioinsecticide and to prevent the development of resistance by the target pest, insecticidal activity of biosurfactant produced by bacillus amyloliquefaciens ag1 was evaluated against s. littoralis. bioassays revealed the susceptibility of the first instar larvae of this pest to ag1 biosurfactant with an lc50 of 245ng/cm(2). moreov ... | 2017 | 28093209 |
| the detection and quantification of bacillus thuringiensis spores from soil and swabs using quantitative pcr as a model system for routine diagnostics of bacillus anthracis. | to optimize the dna isolation for the routine detection and quantification of bacillary spores in soil and swabs. the procedure is primarily intended for diagnostics of bacillus anthracis spores, but due to its high pathogenicity b. thuringiensis served as its surrogate organism. | 2017 | 28294483 |
| construction of bacillus thuringiensis simulant strains suitable for environmental release. | for a surrogate bacterium to be used in outdoor studies, it is important to consider environmental and human safety, and ease of detection. recently, bacillus thuringiensis, a popular bioinsecticide bacterium, is gaining attention as a surrogate bacterium for its use in biodefense. in this study, we constructed simulant strains of b. thuringiensis with enhanced characteristics for environmental studies. through transposon mutagenesis, pigment genes were inserted into the chromosome, producing ye ... | 2017 | 28258144 |
| re-aerosolization of bacillus thuringiensis spores from concrete and turf. | spores of bacillus anthracis deposited on surfaces can become airborne again as a result of air currents and mechanical forces. as such they are a potential source of infection by inhalation. spores of bacillus thuringiensis were used to quantify this phenomenon in a simulation of outdoor conditions. concrete and turf surfaces were inoculated by aerosol to produce high spore densities (greater than 1 x 10(9) cfu m(-2) ) which were then subjected to the passage of air at 10 ms(-1) with and withou ... | 2017 | 28256003 |
| comparison of sampling methods to recover germinated bacillus anthracis and bacillus thuringiensis endospores from surface coupons. | in an attempt to devise decontamination methods that are both effective and minimally detrimental to the environment, we evaluated germination induction as an enhancement to strategies for bacillus anthracis spore decontamination. to determine an optimal method for the recovery of germinating spores from different matrices, it was critical to ensure that the sampling procedures did not negatively impact the viability of the germinating spores possibly confounding the results and downstream analy ... | 2017 | 28191745 |
| resuspension of biological particles from indoor surfaces: effects of humidity and air swirl. | human exposure to airborne particles can lead to adverse health outcomes such as respiratory and allergic symptoms. understanding the transport mechanism of respirable particles in occupied spaces is a first step towards assessing inhalation exposure. several studies have contributed to the current knowledge of particle resuspension from indoor surfaces; however, few published studies are available on resuspension of biological particles from indoor surfaces. the objective of this study is to in ... | 2017 | 28117152 |
| characterization of yersinia species by protein profiling using automated microfluidic capillary electrophoresis. | yersinia pestis is a biological agent of high risk to national security due to its ability to be easily disseminated and transmitted among humans. if y. pestis was to be utilized in a deliberate disease outbreak it would be essential to rapidly and accurately identify the agent. current identification methods for yersinia species are limited by their reliance on cultivation, the time taken to achieve results and/or the use of protocols that are not amenable for field use. faster identification m ... | 2017 | 28019002 |
| killing the spores of bacillus species by molecular iodine. | to determine the responses of spores of bacillus subtilis and bacillus anthracis surrogate bacillus thuringiensis al hakam to i2 treatment. | 2017 | 27696602 |
| complete genome sequences of bacillus phages dirtybetty and kida. | we report here the genome sequences of two bacteriophages of the bacillus cereus group, dirtybetty and kida. these bacteriophages are double-stranded dna-containing myoviridae isolated from soil samples using bacillus thuringiensis subsp. kurstaki as their host bacteria. | 2017 | 28280018 |
| emergence of multi drug resistance among soil bacteria exposing to insecticides. | impacts of pesticide exposure on the soil microbial flora and cross resistance to antibiotics have not been well documented. development of antibiotic resistance is a common issue among soil bacteria which are exposing to pesticides continuously at sub-lethal concentration. the present study was focused to evaluate the correlation between pesticide exposures and evolution of multi drug resistance among isolates collected from soil applied with insecticides. twenty five insecticide (monochrotopho ... | 2017 | 28192223 |
| the thnr gene is a negative transcription regulator of the thurincin h genetic cassette in bacillus thuringiensis subsp. morrisoni. | thurincin h is a bacteriocin synthesized by some strains of bacillus thuringiensis. in this study, the thurincin h genetic cassette, which contains ten genes, from a mexican strain of b. thuringiensis subsp. morrisoni (btm) was cloned and sequenced. to study the function of the thnr gene component in the cassette, we generated various constructs with or without thnr for expression in btm. all transformants harboring thnr in recombinant plasmids showed a decrease of ~15 to ~90 % in inhibitory act ... | 2017 | 27699438 |
| role of ni-tolerant bacillus spp. and althea rosea l. in the phytoremediation of ni-contaminated soils. | in our current study, four nickel-tolerant (ni-tolerant) bacterial species viz, bacillus thuringiensis 002, bacillus fortis 162, bacillus subtilis 174, and bacillus farraginis 354, were screened using ni-contaminated media. the screened microbes exhibited positive results for synthesis of indole acetic acid (iaa), siderophore production, and phosphate solubilization. the effects of these screened microbes on ni mobility in the soil, root elongation, plant biomass, and ni uptake in althea rosea p ... | 2017 | 27739873 |
| no adverse effects of transgenic maize on population dynamics of endophytic bacillus subtilis strain b916-gfp. | endophytic bacterial communities play a key role in promoting plant growth and combating plant diseases. however, little is known about their population dynamics in plant tissues and bulk soil, especially in transgenic crops. this study investigated the colonization of transgenic maize harboring the bacillus thuringiensis (bt) cry1ah gene by bacillus subtilis strain b916-gfp present in plant tissues and soil. bt and nontransgenic maize were inoculated with b916-gfp by seed soaking, or root irrig ... | 2017 | 27666942 |
| baseline susceptibility of field populations of helicoverpa armigera to bacillus thuringiensis vip3aa toxin and lack of cross-resistance between vip3aa and cry toxins. | the cotton bollworm helicoverpa armigera (hübner) is one of the most damaging cotton pests worldwide. in china, control of this pest has been dependent on transgenic cotton producing a single bacillus thuringiensis (bt) protein cry1ac since 1997. a small, but significant, increase in h. armigera resistance to cry1ac was detected in field populations from northern china. since vip3aa has a different structure and mode of action than cry proteins, bt cotton pyramids containing vip3aa are considere ... | 2017 | 28379206 |
| role of the c-terminal and chitin insertion domains on enzymatic activity of endochitinase chia74 of bacillus thuringiensis. | chia74 has modular structure that includes a secretion signal peptide (sp) sequence, and catalytic (cd), chitin insertion (cid), fibronectin type-iii (fniii) and chitin binding (cbd) domains. we described for the first time the existence of a putative cid in chia74. mature chia74 lacking its sp sequence (rchia74δsp, ∼70kda) and two truncated versions, rchia74δsp-60, rchia74δsp-50 lacking, respectively, cbd and cdb-fniii were produced. rchia74δsp and rchia74δsp-60 are unstable and were processed ... | 2017 | 28377239 |
| transfer of cry1ac and cry2a proteins from genetically engineered bt cotton to herbivores and predators. | with the cultivation of bt cotton, the produced insecticidal cry proteins are ingested by herbivores and potentially transferred along the food chain to natural enemies, such as predators. in laboratory experiments with bollgard ii cotton, concentrations of cry1ac and cry2ab were measured in lepidoptera larvae (spodoptera littoralis, heliothis virescens), plant bugs (euschistus heros), aphids (aphis gossypii), whiteflies (bemisia tabaci), thrips (thrips tabaci, frankliniella occidentalis), and s ... | 2017 | 28374515 |
| predator preference for bt-fed spodoptera frugiperda (lepidoptera: noctuidae) prey: implications for insect resistance management in bt maize seed blends. | understanding indirect, trophic-level effects of genetically engineered plants, expressing insecticidal proteins derived from the bacterium, bacillus thuringiensis (bt), is essential to the ecological risk assessment process. in this study, we examine potential indirect, trophic-level effects of bt-sensitive prey using the predator, harmonia axyridis (pallas), feeding upon spodoptera frugiperda (j.e. smith) larvae, which had delayed development (lower body mass) following ingestion of cry1ab mai ... | 2017 | 28369505 |
| nitrogen rate effects on cry3bb1 and cry3bb1 + cry34/35ab1 expression in transgenic corn roots, resulting root injury, and corn rootworm beetle emergence. | nitrogen (n) application rates have been recommended historically for maximum economic yield of corn (zea mays l.), but not for optimal expression or impacts of bt (bacillus thuringiensis berliner) cry protein(s) on target insects. this study explored the need to adjust n rates to optimize expression of corn rootworm-active bt (bt-rw) protein(s) in a single and a pyramided trait hybrid and resulting impacts on beetle emergence and root injury, under field conditions. the experiment featured a fa ... | 2017 | 28369407 |
| influence of ephestia kuehniella stage larvae on the potency of bacillus thuringiensis cry1aa delta-endotoxin. | the economically important crop pest ephestia kuehniella was tested at two stages of larval development for susceptibility to bacillus thuringiensis cry1aa toxin. bioassays showed that toxicity decreased during the development of larvae stage. in fact, cry1aa toxins from bns3-cry(-) (pht-cry1aa) showed low toxicity against the first-instar larvae (l1) with a lc50 value of about 421.02μg/g of diet and was not toxic against the fifth-instar (l5), comparing to the blb1 toxins used as positive contr ... | 2017 | 28364809 |
| toxicity and binding studies of bacillus thuringiensis cry1ac, cry1f, cry1c and cry2a proteins in the soybean pests anticarsia gemmatalis and chrysodeixis (pseudoplusia) includens. | anticarsia gemmatalis (velvetbean caterpillar) and chrysodeixis includens (soybean looper, formerly named pseudoplusia includens) are two important defoliating insects of soybean. both lepidopteran pests are controlled mainly with synthetic insecticides. alternative control strategies such as biopesticides based on the bacillus thuringiensis (bt) toxins or transgenic plants expressing bt toxins can be used and are increasingly being adopted. studies on the insect susceptibility and mode of actio ... | 2017 | 28363958 |
| draft genome sequence of bacillus thuringiensis inta fr7-4. | we report here the complete annotated 6,035,547-bp draft genome sequence of bacillus thuringiensis inta fr7-4. this strain contains three cry8 and two vip1 and vip2 insecticidal toxin genes. | 2017 | 28360155 |
| patterns of gene expression in western corn rootworm (diabrotica virgifera virgifera) neonates, challenged with cry34ab1, cry35ab1 and cry34/35ab1, based on next-generation sequencing. | with next generation sequencing technologies, high-throughput rna sequencing (rnaseq) was conducted to examine gene expression in neonates of diabrotica virgifera virgifera (leconte) (western corn rootworm, wcr) challenged with individual proteins of the binary bacillus thuringiensis insecticidal proteins, cry34ab1 and cry35ab1, and the combination of cry34/cry35ab1, which together are active against rootworm larvae. integrated results of three different statistical comparisons identified 114 an ... | 2017 | 28358336 |
| a general approach to test for interaction among mixtures of insecticidal proteins which target different orders of insect pests. | a shift toward transgenic crops which produce combinations of insecticidal proteins has increased the interest (syngenta seeds, inc., minnetonka, mn) in studying the potential for interactions amongst those proteins. we present a general testing method which accommodates proteins with nonoverlapping spectrums of activity. our sequential testing approach first investigates groups of the proteins with overlapping activity; e.g., proteins active against lepidoptera or coleoptera, respectively. the ... | 2017 | 28355479 |
| therapeutic use of bacillus thuringiensis in the treatment of psoroptic mange in naturally infested new zealand rabbits. | bacillus thuringiensis is a bacteria known for its bioinsecticidal toxins and it has been proposed as an alternative in the treatment of several parasites that infect domestic animals (helminths, ticks, mites). in this work, we evaluated the clinical efficiency of the bacillus thuringiensis gp532 strain in the treatment of six rabbits naturally infested with the p. cuniculi mite. gp532 extract (10mg/ml) was applied by aspersion in both pinna, with a second application after seven days, and the t ... | 2017 | 28342673 |
| metagenomic analyses of bacterial endophytes associated with the phyllosphere of a bt maize cultivar and its isogenic parental line from south africa. | genetic modification of maize with bacillus thuringiensis (bt) cry proteins may predispose shifts in the bacterial endophytes' community associated with maize shoots. in this study, the diversity of bacterial endophytes associated with a bt maize genotype (mon810) and its isogenic non-transgenic parental line were investigated at pre-flowering (50 days) and post-flowering (90 days) developmental stages. pcr-dgge and high throughput sequencing on the illumina miseq sequencer were used to characte ... | 2017 | 28341909 |
| the human cancer cell active toxin cry41aa from bacillus thuringiensis acts like its insecticidal counterparts. | understanding how certain protein toxins from the normally insecticidal bacterium bacillus thuringiensis target human cell lines has implications for both the risk assessment of products containing these toxins and potentially for cancer therapy. this understanding requires knowledge of whether the human cell active toxins work by the same mechanism as their insecticidal counterparts or by alternative ones. the b. thuringiensis cry41aa (also known as parasporin3) toxin is structurally related to ... | 2017 | 28341807 |
| effectiveness of microbial and chemical insecticides for supplemental control of bollworm on bt and non-bt cottons. | laboratory and field experiments were conducted to determine the effectiveness of microbial and chemical insecticides for supplemental control of bollworm, helicoverpa zea (boddie) (lepidoptera: noctuidae), on non-bt (dp1441rf) and bt (dp1321b2rf) cottons. neonate and 3rd instar larvae survival was evaluated on leaf tissue treated with microbial and chemical insecticides including a commercial formulation of bacillus thuringiensis (dipel), a heliothis (helicoverpa) nuclear polyhedrosis virus (np ... | 2017 | 28334359 |
| large-scale evaluation of association between pheromone trap captures and cotton boll infestation for pink bollworm (lepidoptera: gelechiidae). | although transgenic cotton producing insecticidal proteins from bacillus thuringiensis (bt) is a cornerstone for pink bollworm control in some countries, integrated pest management remains important for bolstering sustainability of bt cotton and is critical for controlling pink bollworm where bt cotton is not available or where this pest has evolved resistance to bt cotton. here, we used data on moth captures in gossyplure-baited pheromone traps and boll infestations for 163 bt and 152 non-bt co ... | 2017 | 28334341 |
| lethal and sublethal effects of some chemical and biological insecticides on tuta absoluta (lepidoptera: gelechiidae) eggs and neonates. | tuta absoluta (meyrick) is one of the serious pests of tomatoes. this study was conducted to evaluate the effects of some chemical and biological insecticides on t. absoluta . the insecticides tested were diazinon, dichlorvos, chlorantraniliprole, deltamethrin, acetamiprid, imidacloprid, spinosad, abamectin, indoxacarb, bacillus thuringiensis berliner, beauveria bassiana (balsamo) vuillemin, and metarhizium anisopliae (metschnikoff) sorokin. sublethal effects for the most effective insecticides ... | 2017 | 28334249 |
| aminopeptidase n1 is involved in bacillus thuringiensis cry1ac toxicity in the beet armyworm, spodoptera exigua. | understanding how insecticidal proteins from the bacterium bacillus thuringiensis (bt) interact with their hosts is crucial to fully explain the molecular bases of bt specificity and insecticidal activity. previous studies support atp binding cassette transporters (abcc2/3) and one cadherin-like protein are cry1ac functional receptors in the beet armyworm (spodoptera exigua). in this study, a combined one-dimensional gel electrophoresis and immunoblotting approach identified aminopeptidase n (ap ... | 2017 | 28327568 |
| influence of calcareous soil on cry3bb1 expression and efficacy in the field. | greater than expected injury by western corn rootworm (wcr) (diabrotica virgifera virgifera leconte) to cry3bb1 expressing maize hybrids (zea mays l.) has been reported in southwestern nebraska. affected areas of some fields are often associated with high ph calcareous soils where maize growth is poor and iron chlorosis is common. as part of a comprehensive study to understand potential causes of unexpected injury, experiments were conducted during 2013 and 2014 to ascertain whether the calcareo ... | 2017 | 28326506 |
| effects of site-mutations within the 22 kda no-core fragment of the vip3aa11 insecticidal toxin of bacillus thuringiensis. | bacillus thuringiensis vegetative insecticidal proteins (vips) are not homologous to other known cry proteins, and they act against lepidopteran larvae via a unique process. all reported studies on the mode of action of vip3 proteins have been performed on the vip3a family, mostly on the vip3aa subfamily. vip3aa proteins are activated by midgut proteases, and they cross the peritrophic membrane and bind specific proteins in apical membrane epithelial midgut cells, which results in pore formation ... | 2017 | 28321527 |
| influence of environmental factors on biodegradation of quinalphos by bacillus thuringiensis. | the extensive and intensive uses of organophosphorus insecticide-quinalphos in agriculture, pose a health hazard to animals, humans, and environment because of its persistence in the soil and crops. however, there is no much information available on the biodegradation of quinalphos by the soil micro-organisms, which play a significant role in detoxifying pesticides in the environment; so research is initiated in biodegradation of quinalphos. | 2017 | 28316900 |
| cry1a(b)16 toxin from bacillus thuringiensis: theoretical refinement of three-dimensional structure and prediction of peptides as molecular markers for detection of genetically modified organisms. | transgenic maize produced by the insertion of the cry transgene into its genome became the second most cultivated crop worldwide. cry gene from bacillus thuringiensis kurstaki expresses protein derivatives of crystalline endotoxins which confer insect resistance onto the maize crop. mandatory labeling of processed food containing or made by genetically modified organisms is in force in many countries, so, it is very urgent to develop fast and practical methods for gmo identification, e.g., biose ... | 2017 | 28316108 |
| occurrence, leaching, and degradation of cry1ab protein from transgenic maize detritus in agricultural streams. | the insecticidal cry1ab protein expressed by transgenic (bt) maize can enter adjacent water bodies via multiple pathways, but its fate in stream ecosystems is not as well studied as in terrestrial systems. in this study, we used a combination of field sampling and laboratory experiments to examine the occurrence, leaching, and degradation of soluble cry1ab protein derived from bt maize in agricultural streams. we surveyed 11 agricultural streams in northwestern indiana, usa, on 6 dates that enco ... | 2017 | 28314135 |
| microbial pest control agents: are they a specific and safe tool for insect pest management? | microorganisms (viruses, bacteria and fungi) or their bioactive agents can be used as active substances and therefore are referred as microbial pest control agents (mpca). they are used as alternative strategies to chemical insecticides to counteract the development of resistances and to reduce adverse effects on both environment and human health. these natural entomopathogenic agents, which have specific modes of action, are generally considered safer as compared to conventional chemical insect ... | 2017 | 28292241 |
| in vivo crystallization of three-domain cry toxins. | bacillus thuringiensis (bt) is the most successful, environmentally-friendly, and intensively studied microbial insecticide. the major characteristic of bt is the production of proteinaceous crystals containing toxins with specific activity against many pests including dipteran, lepidopteran, and coleopteran insects, as well as nematodes, protozoa, flukes, and mites. these crystals allow large quantities of the protein toxins to remain stable in the environment until ingested by a susceptible ho ... | 2017 | 28282927 |
| the within-host dynamics of infection in trans-generationally primed flour beetles. | many taxa exhibit plastic immune responses initiated after primary microbial exposure that provide increased protection against disease-induced mortality and the fitness costs of infection. in several arthropod species, this protection can even be passed from parents to offspring through a phenomenon called trans-generational immune priming. here, we first demonstrate that trans-generational priming is a repeatable phenomenon in flour beetles (tribolium castaneum) primed and infected with bacill ... | 2017 | 28277618 |
| rna interference knockdown of aminopeptidase n genes decrease the susceptibility of chilo suppressalis larvae to cry1ab/cry1ac and cry1ca-expressing transgenic rice. | transgenic rice expressing bacillus thuringiensis (bt) cry toxins are resistant to lepidopteran pests, such as chilo suppressalis, a major insect pest of rice in asia. understanding how these toxins interact with their hosts is crucial to understanding their insecticidal action. in this study, knockdown of two aminopeptidase n genes (apn1 and apn2) by rna interference resulted in decreased susceptibility of c. suppressalis larvae to the bt rice varieties tt51 (cry1ab and cry1ac fusion genes) and ... | 2017 | 28274717 |
| fitness of bt-resistant cabbage loopers on bt-cotton plants. | development of resistance to the insecticidal toxins from bacillus thuringiensis (bt) in insects is the major threat to the continued success of transgenic bt-crops in agriculture. the fitness of bt-resistant insects on bt- and non-bt-plants is a key parameter that determines the development of bt-resistance in insect populations. in this study, a comprehensive analysis of the fitness of bt-resistant trichoplusia ni strains on bt-cotton leaves was conducted. the bt-resistant t. ni strains carrie ... | 2017 | 28273400 |
| fusarium verticillioides and fumonisin contamination in bt and non-bt maize cultivated in brazil. | fusarium verticillioides is one of the main pathogens of maize, causing ear and stalk rots. this fungus is also able to produce high levels of fumonisins, which have been linked to various illnesses in humans and animals. previous studies have shown that maize hybrids genetically modified with the cry genes from the bacterium bacillus thuringiensis (bt) presented lower incidence of f. verticillioides and fumonisin levels, presumably through the reduction of insects, which could act as vectors of ... | 2017 | 28265970 |
| knockdown of the mapk p38 pathway increases the susceptibility of chilo suppressalis larvae to bacillus thuringiensis cry1ca toxin. | the bacterium bacillus thuringiensis (bt) produces a wide range of toxins that are effective against a number of insect pests. identifying the mechanisms responsible for resistance to bt toxin will improve both our ability to control important insect pests and our understanding of bacterial toxicology. in this study, we investigated the role of mapk pathways in resistance against cry1ca toxin in chilo suppressalis, an important lepidopteran pest of rice crops. we first cloned the full-length of ... | 2017 | 28262736 |
| quantification of bacillus thuringiensis vip3aa16 entomopathogenic toxin using its hemolytic activity. | vegetative insecticidal proteins produced by some bacillus thuringiensis strains are specifically toxic to different agricultural pests such as the polyphagous spodoptera and several other lepidopteran insects, but one of the major problems found in the use of these biopesticides was the lack of an easy and credible method of quantification of such secreted toxins. heterologous expression of b. thuringiensis vip3aa16 toxin was performed in escherichia coli then the protein was purified by chroma ... | 2017 | 28260117 |
| characterization of a bacillus thuringiensis chitinase that binds to cellulose and chitin. | bacillus thuringiensis is a gram-positive soil bacterium that is known to be a bacterial biopesticide that produces insecticidal proteins called crystal proteins (cry). in the insecticidal process, chitinases are suggested to perforate the peritrophic membrane barrier to facilitate the invasion of the cry proteins into epithelial membranes. a chitinase gene from b. thuringiensis was successfully expressed in a soluble form in escherichia coli, and the gene product was purified and characterized. ... | 2017 | 28244030 |
| bacillus thuringiensis: a successful insecticide with new environmental features and tidings. | bacillus thuringiensis (bt) is known as the most successful microbial insecticide against different orders of insect pests in agriculture and medicine. moreover, bt toxin genes also have been efficiently used to enhance resistance to insect pests in genetically modified crops. in light of the scientific advantages of new molecular biology technologies, recently, some other new potentials of bt have been explored. these new environmental features include the toxicity against nematodes, mites, and ... | 2017 | 28235989 |
| possible insecticidal mechanisms mediated by immune-response-related cry-binding proteins in the midgut juice of plutella xylostella and spodoptera exigua. | cry toxins are insecticidal toxin proteins produced by a spore-forming gram-positive bacterium bacillus thuringiensis. interactions between the cry toxins and the receptors from midgut brush border membrane vesicles (bbmvs), such as cadherin, alkaline phosphatase, and aminopeptidase, are key steps for the specificity and insecticidal activity of cry proteins. however, little is known about the midgut juice proteins that may interfere with cry binding to the receptors. to validate the hypothesis ... | 2017 | 28231709 |
| vegetative insecticidal protein of bacillus thuringiensis blb459 and its efficiency against lepidoptera. | bacillus thuringiensis strain blb459 supernatant showed a promising activity against lepidopteran pests with extremely damages in the larvae midgut. investigations of the genes that encode secreted toxin demonstrated that this strain harbored a vip3-type gene named vip3(459). based on its original nucleotide and amino acid sequences, this gene was cloned into pet-14b vector and overexpressed in escherichia coli. the expressed protein was purified and tested against different insects and interest ... | 2017 | 28223048 |
| cloning and expression of cry2aa from native bacillus thuringiensis strain sy49-1 and its insecticidal activity against culex pipiens (diptera: culicidae). | bacillus thuringiensis (berliner) (bt) is well known for having toxicity against pest insects because of their ability to form endospores and broad-range activity of their parasporal inclusions. in this study, a new member of cry2a gene from previously characterized native b. thuringiensis sy49-1 strain was cloned, expressed and used for its activity against culex pipiens (diptera: culicidae) larvae. the sequence analysis of the cloned cry2a gene revealed that it encodes a polypeptide of 633 aa ... | 2017 | 28215855 |
| laboratory selection and characterization of resistance to the bacillus thuringiensis vip3aa toxin in heliothis virescens (lepidoptera: noctuidae). | laboratory selection with vip3aa of a field-derived population of heliothis virescens produced >2040-fold resistance in 12 generations of selection. the vip-sel resistant population showed little cross-resistance to cry1ab and no cross-resistance to cry1ac. resistance was unstable after 15 generations without exposure to the toxin. f1 reciprocal crosses between vip-unsel and vip-sel indicated a strong paternal influence on the inheritance of resistance. resistance ranged from almost completely r ... | 2017 | 28213547 |
| review: biosafety assessment of bt rice and other bt crops using spiders as example for non-target arthropods in china. | since the birth of transgenic crops expressing bacillus thuringiensis (bt) toxin for pest control, the public debate regarding ecological and environmental risks as well as benefits of bt crops has continued unabated. the impact of bt crops, especially on non-target invertebrates, has received particular attention. in this review, we summarize and analyze evidences for non-target effects of bt rice on spiders, major predators in rice fields. bt rice has been genetically modified to express the b ... | 2017 | 28210764 |
| impact of routine bacillus thuringiensis israelensis (bti) treatment on the availability of flying insects as prey for aerial feeding predators. | since 1980, mosquito breeding habitats in the upper rhine valley were routinely treated with bacillus thuringiensis var. israelensis (bti). bti is considered to significantly reduce the number of mosquitoes, and - especially when used in higher dosages - to be toxic to other nematocera species, e.g. chironomidae, which could be food sources for aerial feeding predators. to investigate direct and indirect effects of routine bti treatment on food sources for aerial feeding predators, the availabil ... | 2017 | 28202094 |
| next-generation transgenic cotton: pyramiding rnai and bt counters insect resistance. | transgenic crops producing insecticidal proteins from the bacterium bacillus thuringiensis (bt) are extensively cultivated worldwide. to counter rapidly increasing pest resistance to crops that produce single bt toxins, transgenic plant 'pyramids' producing two or more bt toxins that kill the same pest have been widely adopted. however, cross-resistance and antagonism between bt toxins limit the sustainability of this approach. here we describe development and testing of the first pyramids of co ... | 2017 | 28199783 |
| a large scale biorational approach using bacillus thuringiensis israeliensis (strain am65-52) for managing aedes aegypti populations to prevent dengue, chikungunya and zika transmission. | aedes aegypti is a container-inhabiting mosquito and a vector of dengue, chikungunya, and zika viruses. in 2009 several cases of autochthonous dengue transmission were reported in key west, florida, usa prompting a comprehensive response to control a. aegypti. in key west, larvae of this mosquito develop in containers around human habitations which can be numerous and labor intensive to find and treat. aerial applications of larvicide covering large areas in a short time can be an efficient and ... | 2017 | 28199323 |
| expression of bacillus thuringiensis cytolytic toxin (cyt2ca1) in citrus roots to control diaprepes abbreviatus larvae. | diaprepes abbreviatus (l.) is an important pest of citrus in the usa. currently, no effective management strategies of d. abbreviatus exist in citriculture, and new methods of control are desperately sought. to protect citrus against d. abbreviatus a transgenic citrus rootstock expressing bacillus thuringiensis cyt2ca1, an insect toxin protein, was developed using agrobacterium-mediated transformation of 'carrizo' citrange [citrus sinensis (l) osbeck poncirus trifoliate (l) raf]. the transgenic ... | 2017 | 28187824 |
| levels of insecticide resistance to deltamethrin, malathion, and temephos, and associated mechanisms in aedes aegypti mosquitoes from the guadeloupe and saint martin islands (french west indies). | in the guadeloupe and saint martin islands, aedes aegypti mosquitoes are the only recognized vectors of dengue, chikungunya, and zika viruses. for around 40 years, malathion was used as a mosquito adulticide and temephos as a larvicide. since the european union banned the use of these two insecticide molecules in the first decade of the 21st century, deltamethrin and bacillus thuringiensis var. israelensis are the remaining adulticide and larvicide, respectively, used in guadeloupe. in order to ... | 2017 | 28187780 |
| environmental safety review of methoprene and bacterially-derived pesticides commonly used for sustained mosquito control. | some pesticides are applied directly to aquatic systems to reduce numbers of mosquito larvae (larvicides) and thereby reduce transmission of pathogens that mosquitoes vector to humans and wildlife. sustained, environmentally-safe control of larval mosquitoes is particularly needed for highly productive waters (e.g., catchment basins, water treatment facilities, septic systems), but also for other habitats to maintain control and reduce inspection costs. common biorational pesticides include the ... | 2017 | 28187397 |
| responses of the cutworm spodoptera litura (lepidoptera: noctuidae) to two bt corn hybrids expressing cry1ab. | to examine the responses of the secondary lepidopteran pest spodoptera litura to two bacillus thuringiensis (bt) corn hybrids [5422bt1 (event bt11), 5422cbcl (mon810)] expressing cry1ab, larval bioassays with cry1ab toxin, corn leaves or kernels and bagging on corn plants were conducted. the results showed that larvae displayed a similar performance when fed kernels, but not leaves of 5422bt1, 5422cbcl and their near-isogenic non-bt corn (5422). significantly higher cry1ab amounts were detected ... | 2017 | 28186125 |
| recombinant bacillus thuringiensis subsp. kurstaki hd73 strain that synthesizes cry1ac and chimeric chia74∆sp chitinase inclusions. | in this study, the endochitinase chia74 gene lacking its secretion signal peptide sequence (chia74∆sp) was fused in frame with the sequence coding for the c-terminal crystallization domain and transcription terminator of cry1ac. the chimeric gene was expressed under the strong pcyta-p/stab-sd promoter system in an acrystalliferous cry(-)b strain of bacillus thuringiensis and b. thuringiensis subsp. kurstaki hd73. we showed that the chimeric chia74∆sp produced amorphous inclusions in both cry(-)b ... | 2017 | 28184966 |
| variation among conventional cultivars could be used as a criterion for environmental safety assessment of bt rice on nontarget arthropods. | the current difficulty facing risk evaluations of bacillus thuringiensis (bt) crops on nontarget arthropods (ntas) is the lack of criteria for determining what represents unacceptable risk. in this study, we investigated the biological parameters in the laboratory and field population abundance of nilaparvata lugens (hemiptera: delphacidae) on two bt rice lines and the non-bt parent, together with 14 other conventional rice cultivars. significant difference were found in nymphal duration and fec ... | 2017 | 28167821 |
| regulation by gut bacteria of immune response, bacillus thuringiensis susceptibility and hemolin expression in plodia interpunctella. | plodia interpunctella (hübner) is an important stored grain insect pest worldwide, and the first lepidopteran with reported resistance to bacillus thuringiensis (bt) toxins. since gut bacteria may affect bt insecticidal activity, we evaluated whether p. interpunctella lacking gut bacteria had differences in immune responses and susceptibility to the bt formulation, bactospeine. in order to clear gut bacteria, third instar larvae were reared on artificial diet containing antibiotics, or were obta ... | 2017 | 28167070 |
| genome sequences of bacillus thuringiensis serovar kurstaki strain bp865 and b. thuringiensis serovar aizawai strain hd-133. | we report the draft genome sequences of two insecticidal strains against lepidopteran pests, bacillus thuringiensis serovar kurstaki strain bp865, an isolate from the south korean phylloplane, and strain hd-133, a reference strain of b. thuringiensis serovar aizawai. | 2017 | 28153898 |
| comparisons of transcriptional profiles of gut genes between cry1ab-resistant and susceptible strains of ostrinia nubilalis revealed genes possibly related to the adaptation of resistant larvae to transgenic cry1ab corn. | a microarray developed on the basis of 2895 unique transcripts from larval gut was used to compare gut gene expression profiles between a laboratory-selected cry1ab-resistant (r) strain and its isoline susceptible (s) strain of the european corn borer (ostrinia nubilalis) after the larvae were fed the leaves of transgenic corn (mon810) expressing cry1ab or its non-transgenic isoline for 6 h. we revealed 398 gut genes differentially expressed (i.e., either up- or down-regulated genes with express ... | 2017 | 28146087 |
| pest management through bacillus thuringiensis (bt) in a tea-silkworm ecosystem: status and potential prospects. | bacillus thuringiensis (bt) is a soil bacterium that forms spores containing crystals comprising one or more cry or cyt proteins having potential and specific insecticidal activity. different strains of bt produce different types of toxins, affecting a narrow taxonomic group of insects. therefore, it is used in non-chemical pest management, including inherent pest resistance through gm crops. the specificity of action of bt toxins reduces the concern of adverse effects on non-target species, a c ... | 2017 | 28144706 |
| no effect of bt cry1ie toxin on bacterial diversity in the midgut of the chinese honey bees, apis cerana cerana (hymenoptera, apidae). | cry1ie protein derived from bacillus thuringiensis (bt) has been proposed as a promising candidate for the development of a new bt-maize variety to control maize pests in china. we studied the response of the midgut bacterial community of apis cerana cerana to cry1ie toxin under laboratory conditions. newly emerged bees were fed one of the following treatments for 15 and 30 days: three concentrations of cry1ie toxin (20 ng/ml, 200 ng/ml, and 20 μg/ml) in sugar syrup, pure sugar syrup as a negati ... | 2017 | 28139751 |
| translocation of bacillus thuringiensis in phaseolus vulgaris tissues and vertical transmission in arabidopsis thaliana. | to demonstrate the ability of bacillus thuringiensis to penetrate as spore-crystal complex to the internal tissues of bean plants, and keep its insecticidal activity. to test the vertical transmission of the spore-crystal complex in arabidopsis thaliana. | 2017 | 28129468 |
| resistance to bacillus thuringiensis toxin cry2ab and survival on single-toxin and pyramided cotton in cotton bollworm from china. | evolution of helicoverpa armigera resistance to bacillus thuringiensis (bt) cotton producing cry1ac is progressing in northern china, and replacement of cry1ac cotton by pyramided bt cotton has been considered to counter such resistance. here, we investigated four of the eight conditions underlying success of the refuge strategy for delaying resistance to cry1ac+cry2ab cotton, a pyramid that has been used extensively against h. armigera outside china. laboratory bioassays of a cry2ab-selected st ... | 2017 | 28127393 |
| cry1ac and vip3aa proteins from bacillus thuringiensis targeting cry toxin resistance in diatraea flavipennella and elasmopalpus lignosellus from sugarcane. | the biological potential of vip and cry proteins from bacillus is well known and widely established. thus, it is important to look for new genes showing different modes of action, selecting those with differentiated entomotoxic activity against diatraea flavipennella and elasmopalpus lignosellus, which are secondary pests of sugarcane. therefore, cry1 and vip3 proteins were expressed in escherichia coli, and their toxicities were evaluated based on bioassays using neonate larvae. of those, the m ... | 2017 | 28123906 |
| toxicity and biodegradation of ibuprofen by bacillus thuringiensis b1(2015b). | in recent years, the increased intake of ibuprofen has resulted in the presence of the drug in the environment. this work presents results of a study on degradation of ibuprofen at 25 mg l(-1) in the presence of glucose, as an additional carbon source by bacillus thuringiensis b1(2015b). in the cometabolic system, the maximum specific growth rate of the bacterial strain was 0.07 ± 0.01 mg ml(-1) h(-1) and k sμ 0.27 ± 0.15 mg l(-1). the maximum specific ibuprofen removal rate and the value of the ... | 2017 | 28116629 |
| first mass development of aedes albopictus (diptera: culicidae)-its surveillance and control in germany. | the asian tiger mosquito aedes albopictus has undergone a dramatic expansion of its range in the last few decades. since its first detection in 2007 in germany at the motorway a5 coming from italy via switzerland to germany, it has been continuously introduced by vehicles, most probably from italy. after a hint from an alert gardener in an allotment garden area in freiburg, southwest germany, in 2015, a surveillance programme was started focusing on the garden area and adjacent areas as well as ... | 2017 | 28116530 |
| does bt rice pose risks to non-target arthropods? results of a meta-analysis in china. | transgenic bt rice expressing the insecticidal proteins derived from bacillus thuringiensis berliner (bt) has been developed since 1989. their ecological risks towards non-target organisms have been investigated; however, these studies were conducted individually, yielding uncertainty regarding potential agroecological risks associated with large-scale deployment of bt rice lines. here, we developed a meta-analysis of the existing literature to synthesize current knowledge of the impacts of bt r ... | 2017 | 28111920 |
| purification, characterization and functional analysis of the immune molecule lectin from the haemolymph of blue swimmer crab portunus pelagicus and their antibiofilm properties. | the present study reveals purification and characterization of immune molecule lectin from the haemolymph of blue swimmer crab portunus pelagicus (pp-lec). the pp-lec was purified by affinity chromatography with mannose coupled sepharose cl-4b column and it exhibits single band with a molecular weight of 155 kda in sds-page. the surface morphology of purified pp-lec displays the homogeneous nature of protein. a distinct peak with a retention time of 3.3 min was appeared in high performance liqui ... | 2017 | 28110033 |
| identification of aminopeptidase-n2 as a cry2ab binding protein in manduca sexta. | bacillus thuringiensis cry2ab toxin has been used in combination with cry1ac for resistance management on the bt-cotton that is widely planted worldwide. however, little is known regarding cry2ab mode of action. particularly, there is a gap of knowledge on the identification of insect midgut proteins that bind cry2ab and mediate toxicity. in the case of cry1ab toxin, a transmembrane cadherin protein and glycosyl-phosphatidylinositol (gpi) anchored proteins like aminopeptidase-n1 (apn1) or alkali ... | 2017 | 28108197 |
| characterization of the synergistic interaction between beauveria bassiana strain gha and bacillus thuringiensis morrisoni strain tenebrionis applied against colorado potato beetle larvae. | studies were undertaken to further characterize the previously identified synergistic activity of bacillus thuringiensis- and beauveria bassiana-based biopesticides against colorado potato beetle (cpb). a flowable concentrate of b. thuringiensis morrisoni strain tenebrionis (bt) (novodor® fc) and a wettable powder of b. bassiana strain gha (bb) (mycotrol® 22wp) were applied against cpb larval populations infesting potato in field plots. novodor fc and an oil-dispersion formulation of bb (mycotro ... | 2017 | 28108175 |
| bacillus thuringiensis-based biopesticides, are they as effective as they should be? | 2017 | 28108052 | |
| is the insect world overcoming the efficacy of bacillus thuringiensis? | the use of chemical pesticides revolutionized agriculture with the introduction of ddt (dichlorodiphenyltrichloroethane) as the first modern chemical insecticide. however, the effectiveness of ddt and other synthetic pesticides, together with their low cost and ease of use, have led to the generation of undesirable side effects, such as pollution of water and food sources, harm to non-target organisms and the generation of insect resistance. the alternative comes from biological control agents, ... | 2017 | 28106770 |
| effects of cry1ab bt maize straw return on bacterial community of earthworm eisenia fetida. | the eco-toxicological effects of bacillus thuringiensis (bt) maize on earthworm life-history traits were widely studied and the results were controversial, while their effects on earthworm bacterial community have been rarely studied. here, effects of two hybrids of bt maize [5422bt1 (event bt11) and 5422cbcl (mon810)] straw return on eisenia fetida bacterial community were investigated by the terminal restriction fragment length polymorphism (t-rflp) and polymerase chain reaction-denaturing gra ... | 2017 | 28104475 |
| corrigendum: purification and characterization of a novel cold shock protein-like bacteriocin synthesized by bacillus thuringiensis. | 2017 | 28102369 | |
| transcriptomic response of wolf spider, pardosa pseudoannulata, to transgenic rice expressing bacillus thuringiensis cry1ab protein. | bacillum thuringiensis (bt) toxin produced in cry1-expressing genetically modified rice (bt rice) is highly effective to control lepidopteran pests, which reduces the needs for synthetic insecticides. non-target organisms can be exposed to bt toxins through direct feeding or trophic interactions in the field. the wolf spider pardosa pseudoannulata, one of the dominant predators in south china, plays a crucial role in the rice agroecosystem. in this study, we investigated transcriptome responses ... | 2017 | 28100213 |
| effects of soil salinity on the expression of bt toxin (cry1ac) and the control efficiency of helicoverpa armigera in field-grown transgenic bt cotton. | an increasing area of transgenic bacillus thuringiensis (bt) cotton is being planted in saline-alkaline soil in china. the bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. however, how soil salinity affects the expression of bt protein, thus influencing the control efficiency of bt cotton against the cotton bollworm (cbw) helicoverpa armigera (hübner) in the field, is poorly ... | 2017 | 28099508 |
| assessing environmental impacts of genetically modified plants on non-target organisms: the relevance of in planta studies. | in legal frameworks worldwide, genetically modified plants (gmps) are subjected to pre-market environmental risk assessment (era) with the aim of identifying potential effects on the environment. in the european union, the efsa guidance document introduces the rationale that gmps, as well as their newly produced metabolites, represent the potential stressor to be evaluated during era. as a consequence, during several phases of era for cultivation purposes, it is considered necessary to use whole ... | 2017 | 28095991 |
| complete sequence and organization of pfr260, the bacillus thuringiensis inta fr7-4 plasmid harboring insecticidal genes. | we report the complete sequence and analysis of pfr260, a novel megaplasmid of 260,595 bp from the bacillus thuringiensis strain inta fr7-4 isolated in argentina. it carries 7 insecticidal genes: 3 cry8 copies previously reported, 2 vip1, and 2 vip2. also, it carries a gene encoding a putative atypical cry protein. these genes are arranged in a region of approximately 105 kbp in size with characteristics of a pathogenicity island with a potential coleopteran-specific insecticide profile. dna str ... | 2017 | 28092918 |
| genetic and biochemical characterization of a gene operon for trans-aconitic acid, a novel nematicide from bacillus thuringiensis. | trans-aconitic acid (taa) is an isomer of cis-aconitic acid (caa), an intermediate of the tricarboxylic acid cycle that is synthesized by aconitase. although taa production has been detected in bacteria and plants for many years and is known to be a potent inhibitor of aconitase, its biosynthetic origins and the physiological relevance of its activity have remained unclear. we have serendipitously uncovered key information relevant to both of these questions. specifically, in a search for novel ... | 2017 | 28087696 |
| an empirical assessment of transgene flow from a bt transgenic poplar plantation. | to assess the possible impact of transgenic poplar plantations on the ecosystem, we analyzed the frequency and distance of gene flow from a mature male transgenic populus nigra plantation carrying the bacillus thuringiensis toxin gene (bt poplar) and the survival of bt poplar seeds. the resultant bt poplar seeds occurred at a frequency of ~0.15% at 0 m to ~0.02% at 500 m from the bt poplar plantation. the germination of bt poplar seeds diminished within three weeks in the field (germination rate ... | 2017 | 28085955 |
| a single point mutation resulting in cadherin mislocalization underpins resistance against bacillus thuringiensis toxin in cotton bollworm. | transgenic plants that produce bacillus thuringiensis (bt) crystalline (cry) toxins are cultivated worldwide to control insect pests. resistance to b. thuringiensis toxins threatens this technology, and although different resistance mechanisms have been identified, some have not been completely elucidated. to gain new insights into these mechanisms, we performed multiple back-crossing from a 3000-fold cry1ac-resistant btr strain from cotton bollworm (helicoverpa armigera), isolating a 516-fold c ... | 2017 | 28082675 |
| a laboratory assessment of the potential effect of cry1ab/cry2aj-containing bt maize pollen on folsomia candida by toxicological and biochemical analyses. | the common soil arthropod folsomia candida can survive well when fed only maize pollen and thus may be exposed to insecticidal proteins by ingesting insect-resistant genetically engineered maize pollen containing bacillus thuringiensis (bt) proteins when being released into the soil. laboratory experiments were conducted to assess the potential effects of cry1ab/cry2aj-producing transgenic bt maize (shuangkang 12-5) pollen on f. candida fitness. survival, development, and the reproduction were n ... | 2017 | 28082132 |
| transgenic cotton expressing cry10aa toxin confers high resistance to the cotton boll weevil. | genetically modified (gm) cotton plants that effectively control cotton boll weevil (cbw), which is the most destructive cotton insect pest in south america, are reported here for the first time. this work presents the successful development of a new gm cotton with high resistance to cbw conferred by cry10aa toxin, a protein encoded by entomopathogenic bacillus thuringiensis (bt) gene. the plant transformation vector harbouring cry10aa gene driven by the cotton ubiquitination-related promoter uc ... | 2017 | 28081289 |
| establishment of a sandwich enzyme-linked immunosorbent assay for specific detection of bacillus thuringiensis (bt) cry1ab toxin utilizing a monoclonal antibody produced with a novel hapten designed with molecular model. | cry1ab toxin is commonly expressed in genetically modified crops in order to control chewing pests. at present, the detection method with enzyme-linked immunosorbent assay (elisa) based on monoclonal antibody cannot specifically detect cry1ab toxin for cry1ab's amino acid sequence and spatial structure are highly similar to cry1ac toxin. in this study, based on molecular design, a novel hapten polypeptide was synthesized and conjugated to keyhole limpet hemocyanin (klh). then, through animal imm ... | 2017 | 28078413 |
| effects of carriers, emulsifiers, and biopesticides for direct silk treatments on caterpillar feeding damage and ear development in sweet corn. | in the northeastern united states, control of lepidopteran pests of sweet corn, particularly corn earworm [helicoverpa zea (boddie)], is difficult using organic methods. the direct application of corn oil and bacillus thuringiensis (bt) to corn silk has been shown to reduce ear damage from corn earworm in past studies; these studies sought to optimize this method by evaluating additional carrier and biopesticide mixtures that comply with the united states federal insecticide, fungicide, and rode ... | 2017 | 28073976 |
| cry3bb1-resistant western corn rootworm, diabrotica virgifera virgifera (leconte) does not exhibit cross-resistance to dvsnf7 dsrna. | there is a continuing need to express new insect control compounds in transgenic maize against western corn rootworm, diabrotica virgifera virgifera (leconte) (wcr). in this study three experiments were conducted to determine cross-resistance between the new insecticidal dvsnf7 dsrna, and bacillus thuringiensis (bt) cry3bb1; used to control wcr since 2003, with field-evolved resistance being reported. laboratory susceptible and cry3bb1-resistant wcr were evaluated against dvsnf7 dsrna in larval ... | 2017 | 28060922 |
| biopolymer microencapsulations of bacillus thuringiensis crystal preparations for increased stability and resistance to environmental stress. | parasporal crystals synthesized by bacillus thuringiensis (bt) have been widely used as microbial pesticides because of their toxicity to the larval stages of specific insects. however, parasporal crystals can be damaged by environmental stresses, such as high temperature, ultraviolet radiation, and desiccation. to reduce environmental susceptibility of parasporal crystals and extend the duration of their activity, we developed a new type of protection by making microcapsules of crystals (mcs). ... | 2017 | 28050633 |
| spatio-temporal variation in landscape composition may speed resistance evolution of pests to bt crops. | transgenic crops that express insecticide genes from bacillus thuringiensis (bt) are used worldwide against moth and beetle pests. because these engineered plants can kill over 95% of susceptible larvae, they can rapidly select for resistance. here, we use a model for a pyramid two-toxin bt crop to explore the consequences of spatio-temporal variation in the area of bt crop and non-bt refuge habitat. we show that variability over time in the proportion of suitable non-bt breeding habitat, q, or ... | 2017 | 28046073 |
| incidental mutations occur frequently during transposon mutagenesis. | transposon mutagenesis and subsequent phenotype-driven screening have been extensively used to annotate gene function and uncover the mechanisms of biological phenomena. during this process, the resulting phenotypic differences are specifically attributable to the disrupted genes. in this study, the complementation of the mini-tn10 transposon-disrupted gene gntp did not restore the germination ability of the bacillus thuringiensis mt1518-1 mutant to the wild-type level. genome sequencing identif ... | 2017 | 28011697 |
| activity of selected formulated biorational and synthetic insecticides against larvae of helicoverpa armigera (lepidoptera: noctuidae). | this work studied 17 insecticides belonging to nucleopolyhedrovirus (npv), bacillus thuringiensis (bt kurstaki and bt aizawai), benzoylureas (insect growth regulators [igrs]), carbamates, organophosphates, spinosyns, and diamides against larvae of helicoverpa armigera (hübner), invasive species in the south american continent. larvae of different instars were fed for 7 d with untreated or insecticide-treated diets. mortality was recorded daily for 7 d, and surviving larvae were individually weig ... | 2017 | 28011685 |
| low-dose effects: nonmonotonic responses for the toxicity of a bacillus thuringiensis biocide to daphnia magna. | currently, there is a trend toward an increasing use of biopesticides assumed to be environmentally friendly, such as bacillus thuringiensis (bt). studies of the bt toxicity to nontarget organisms have reported low effects at high exposure levels, which is interpreted as indicating negligible risk to nontarget organisms. we investigated the response of the nontarget organism daphnia magna to waterborne dipel es, a globally used bt formulation. neonates and adults were exposed for 48 h to a wide ... | 2017 | 28001053 |
| insecticidal specificity of cry1ah to helicoverpa armigera is determined by binding of apn1 via domain ii loops 2 and 3. | bacillus thuringiensis cry1ah protein is highly toxic against helicoverpa armigera but shows no toxicity against bombyx mori larvae. in contrast, the closely related cry1ai toxin showed the opposite phenotype: high activity against b. mori but no toxicity against h. armigera. analysis of binding of cry1ah to brush border membrane vesicle (bbmv) proteins from h. armigera and b. mori by surface plasmon resonance revealed association of toxin binding with insect specificity. pulldown experiments id ... | 2017 | 27940541 |
| validation of adam10 metalloprotease as a bacillus thuringiensis cry3aa toxin functional receptor in colorado potato beetle (leptinotarsa decemlineata). | bacillus thuringiensis parasporal crystal proteins (cry proteins) are insecticidal pore-forming toxins that bind to specific receptor molecules on the brush border membrane of susceptible insect midgut cells to exert their toxic action. in the colorado potato beetle (cpb), a coleopteran pest, we previously proposed that interaction of cry3aa toxin with a cpb adam10 metalloprotease is an essential part of the mode of action of this toxin. here, we annotated the gene sequence encoding an adam10 me ... | 2017 | 27918112 |