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heterologous expression and biochemical characterisation of fourteen esterases from helicoverpa armigera.esterases have recurrently been implicated in insecticide resistance in helicoverpa armigera but little is known about the underlying molecular mechanisms. we used a baculovirus system to express 14 of 30 full-length esterase genes so far identified from midgut cdna libraries of this species. all 14 produced esterase isozymes after native page and the isozymes for seven of them migrated to two regions of the gel previously associated with both organophosphate and pyrethroid resistance in various ...201323799064
bacillus thuringiensis insecticidal crystal proteins affect lifespan and reproductive performance of helicoverpa armigera and spodoptera exigua adults.being delivered as sprays or expressed in plant, bacillus thuringiensis (bt) crystalline proteins (cry toxins) display insecticidal activities against numerous lepidopteran, dipteran, and coleopteran larvae. comparative study of toxicities of bt cry toxins between larvae and adults may afford important new insights into the interactions of the toxins with receptor proteins in host insect, and represent intriguing targets for the control of insect pests. however, the effectiveness of bt cry toxin ...201323786046
use of a pooled clone method to isolate a novel bacillus thuringiensis cry2a toxin with activity against ostrinia furnacalis.a pooled clone method was developed to screen for cry2a genes. this metagenomic method avoids the need to analyse isolated bacillus thuringiensis strains by performing gene specific pcr on plasmid-enriched dna prepared from a pooled soil sample. using this approach the novel holotype gene cry2ah1 was cloned and characterized. the toxin gene was over-expressed in escherichia coli rosetta (de3) and the expressed toxin accumulated in both the soluble and insoluble fractions. the soluble cry2ah1 was ...201323711413
constructing bacillus thuringiensis strain that co-expresses cry2aa and chitinase.a triple recombineering technique was used with plasmid pht315 to produce phtec, a construct carrying chitinase and cry2aa genes from bacillus thuringiensis subsp. kurstaki 4.0718. transformation of wild-type b. thuringiensis strain hd73 and the acrystalliferous strain cry-b with phtec resulted in the recovery of recombinant strains that expressed cry2aa as cubic crystals in the cell pellet and soluble chitinase protein. the toxicity of hd73 (phtec) against helicoverpa armigera larvae increased ...201323515891
characterization of cry9da4, cry9eb2, and cry9ee1 genes from bacillus thuringiensis strain t03b001.three cry9 genes, cry9da4, cry9eb2, and cry9ee1, were cloned from bacillus thuringiensis strain t03b001 using a high-resolution melting analysis method. all three cry9 genes were overexpressed in escherichia coli rosetta (de3), and the expressed products cry9eb2 and cry9ee1 were shown to be toxic to plutella xylostella and ostrinia furnacalis, but not to helicoverpa armigera or colaphellus bowringi. the bioassay of cry9eb2 and cry9ee1 against cry1ac-resistant p. xylostella strains indicated that ...201323455566
influence of oxalic and malic acids in chickpea leaf exudates on the biological activity of cryiac towards helicoverpa armigera.efforts are being made to express toxin genes from the bacterium, bacillus thuringiensis (bt) in chickpea for minimizing the losses due to the pod borer, helicoverpa armigera. however, there is an apprehension that acidic exudates in chickpea leaves may influence the protoxin-toxin conversion in the insect midgut, and thus, reduce the efficacy of bt toxins. therefore, we studied the influence of organic acids (oxalic acid and malic acid) present in the trichome exudates of chickpea on the biolog ...201323391855
providence virus (family: carmotetraviridae) replicates vrna in association with the golgi apparatus and secretory vesicles.providence virus (prv) is the sole member of the family carmotetraviridae (formerly tetraviridae) sharing the characteristic t=4 capsid architecture with other tetravirus families. despite significant structural similarities, prv differs from other tetraviruses in terms of genome organization, non-structural protein sequence and regulation of gene expression. in addition, it is the only tetravirus that infects tissue culture cells. previous studies showed that in persistently infected helicoverp ...201323343628
dna-based screening for an intracellular cadherin mutation conferring non-recessive cry1ac resistance in field populations of helicoverpa armigera.a number of cadherin mutants conferring resistance to bt toxin cry1ac have been reported in three major lepidopteran pests, including helicoverpa armigera. unlike most of the cadherin mutants conferring recessive resistance, an allele (r15) with a 55aa deletion in the intracellular domain of cadherin (hacad) was previously identified to cause non-recessive resistance to cry1ac in h. armigera. in the present study, a dna-based pcr method was developed to screen the r15 allele from field populatio ...201325149249
molecular cloning and recombinant expression of cytochrome p450 cyp6b6 from helicoverpa armigera in escherichia coli.the cytochrome p450 s play a significant role in the detoxification of plant allelochemicals and synthetic insecticides in lepidoptera. in the cotton bollworm helicoverpa armigera, 2-tridecanone and quercetin can induce p450-dependent monooxygenase activity increased, to further the characterization of p450, the cyp6b6 of cotton bollworm (h. armigera) was cloned, sequenced and expressed in pmal-p2x vector and expressed in escherichia coli. the deduced amino acid sequences of cytochrome p450 in t ...201323096085
cloning, characterization, and expression of a new cry1ab gene from dor bt-1, an indigenous isolate of bacillus thuringiensis.a new cry1ab gene was cloned from the promising local isolate, dor bt-1, a bacillus thuringiensis strain isolated from castor semilooper (achaea janata l.) cadavers from castor bean (ricinus communis l.) field. the nucleotide sequence of the cloned cry1ab gene indicated that the open reading frame consisted of 3,465 bases encoding a protein of 1,155 amino acid residues with an estimated molecular weight of 130 kda. homology comparisons revealed that the deduced amino acid sequence of cry1ab had ...201323224937
changes in the activity and the expression of detoxification enzymes in silkworms (bombyx mori) after phoxim feeding.silkworm (bombyx mori) is an economically important insect. however, non-cocoon caused by chemical insecticide poisoning has largely hindered the development of sericulture. to explore the roles of detoxification enzymes in b. mori after insecticide poisoning, we monitored the activity changes of cytochrome p450 monooxygenase, glutathione-s-transferase, and carboxylesterase in b. mori midgut and fatbody after phoxim feeding. at the same time, the expression levels of detoxification enzyme-relate ...201324238284
comparisons of contact chemoreception and food acceptance by larvae of polyphagous helicoverpa armigera and oligophagous bombyx mori.we compared food choice and the initial response to deterrent treated diet between fifth instars of helicoverpa armigera, a polyphagous generalist pest, and bombyx mori, an oligophagous specialist beneficial. bombyx mori was more behaviorally sensitive to salicin than to caffeine. the relative sensitivities were reversed for h. armigera, which was tolerant to the highest levels of salicin found in natural sources but sensitive to caffeine. a single gustatory receptor neuron (grn) in the medial s ...201323779267
fish identification of helicoverpa armigera and mamestra brassicae chromosomes by bac and fosmid probes.since the bombyx mori genome sequence was published, conserved synteny between b. mori and some other lepidopteran species has been revealed by either fish (fluorescence in situ hybridization) with bac (bacterial artificial chromosome) probes or linkage analysis. however, no species belonging to the noctuidae, the largest lepidopteran family which includes serious polyphagous pests, has been analyzed so far with respect to genome-wide conserved synteny and gene order. for that purpose, we select ...201323628856
evolutionary history of x-tox genes in three lepidopteran species: origin, evolution of primary and secondary structure and alternative splicing, generating a repertoire of immune-related proteins.the proteins of the x-tox family have imperfectly conserved tandem repeats of several defensin-like motifs known as cysteine-stabilized αβ (cs-αβ) motifs. these immune-related proteins are inducible and expressed principally in hemocytes, but they have lost the antimicrobial properties of the ancestral defensins from which they evolved. we compared x-tox gene structure and expression in three lepidopteran species (spodoptera frugiperda, helicoverpa armigera and bombyx mori). synteny and phylogen ...201323142192
interaction of glucosinolate content of arabidopsis thaliana mutant lines and feeding and oviposition by generalist and specialist lepidopterans.the diamondback moth, plutella xylostella l. (lepidoptera: plutellidae), is an insect specialized on glucosinolate-containing brassicaceae that uses glucosinolates in host-plant recognition. we used wild-type and mutants of arabidopsis thaliana (l.) heynh. (brassicaceae) to investigate the interaction between plant glucosinolate and myrosinase content and herbivory by larvae of the generalist helicoverpa armigera hübner (lepidoptera: noctuidae) and the specialist p. xylostella. we also measured ...201323218016
comparative studies on the effects of bt-transgenic and nontransgenic cotton on arthropod diversity, seedcotton yield and bollworms control.the effectiveness of commercial bt-cotton in pest management, influence on arthropod diversity, natural enemies, and toxin flow in the insect fauna under field conditions were studied keeping in view the need to assess bioefficacy and biosafety of bt-transgenic cotton. there were no significant differences in oviposition by helicoverpa armigera on bt-transgenic and non-transgenic cottons (9.2 versus 9.6 eggs plants(-100)), while the numbers of h. armigera larvae were significantly more on non-tr ...201324006809
chemically mediated prey-approaching behaviour of the reduviid predator rhynocoris fuscipes (fabricius) (insecta: heteroptera: reduviidae) by y-arm olfactometer.the reduviid predator, rhynocoris fuscipes (fabricius) (heteroptera: reduviidae) is a potential predator inhibiting diverse agroecosystems and preying upon about 50 minor as well as major insect pests. the prey approaching behaviour of r. fuscipes (fabricius) to the hexane extracts of insect pests viz., helicoverpa armigera hubner, spodoptera litura (fabricius), achaea janata linnaeus, dysdercus cingulatus fabricius and mylabris indica thunberg was assessed in y-shaped olfactometer in terms of e ...201324511748
extracellular novel metalloprotease from xenorhabdus indica and its potential as an insecticidal agent.proteases produced by xenorhabdus are known to play a significant role in virulence leading to insect mortality. the present study was undertaken to purify and characterize protease from xenorhabdus indica, an endosymbiont of nematode steinernema thermophilum, and to decipher its role in insect mortality and its efficacy to control helicoverpa armigera. a set of 10 strains of xenorhabdus isolated from different regions of india were screened for protease activity on the basis of zone of clearing ...201323928843
expression of cry1ac in transgenic bt soybean lines and their efficiency in controlling lepidopteran pests.two transgenic lines of the soybean glycine max, mon87701 expressing the cry1ac protein and mon87701rr2y expressing cry1ac +  epsps proteins, were evaluated for their resistance to four lepidopteran pests in the laboratory using detached-leaf bioassays throughout the soybean growth seasons (before anthesis, during anthesis and after anthesis) in china. enzyme-linked immunosorbent assays (elisas) were used to monitor the cry1ac expression in soybean leaves.201323564718
molecular characterization of nucleopolyhedrovirus of three lepidopteran pests using late expression factor-8 gene.a pcr based method for detection of viral dna in nucleopolyhedrovirus of three lepidopterans, spodoptera litura, amsacta albistriga and helicoverpa armigera, was developed by employing the late expression factor-8 (lef-8) gene of three npv using specific primers. the amplicons of 689, 699 and 665 bp were amplified, respectively, and the nucleotide sequences were submitted to genbank and the accession numbers were obtained. the sequences of lef-8 gene of s. litura npv and h. armigera npv matched ...201324426259
development of transgenic cryia(c) + gna cotton plants via pollen tube pathway method confers resistance to helicoverpa armigera and aphis gossypii glover.elite cotton cultivar sumian16 was transformed with p7rpsbk-mgna-nptii containing bt (cryia(c)), galanthus nivalis agglutinin (gna) resistance genes and selectable marker nptii gene via the pollen tube pathway method and two fertile transgenic bt + gna plants were obtained in the present study. the integration and expression of the bt and gna genes were confirmed by molecular biology techniques and insect bioassays. insect bioassays showed that the transformed plants were highly toxic to bollwor ...201323143495
design, synthesis, and insecticidal evaluation of new pyrazole derivatives containing imine, oxime ether, oxime ester, and dihydroisoxazoline groups based on the inhibitor binding pocket of respiratory complex i.on the basis of complex i receptor protein binding site and commercial tebufenpyrad and tolfenpyrad, four series of novel pyrazole-5-carboxamides containing imine, oxime ether, oxime ester, and dihydroisoxazoline were designed and synthesized via the key intermediate 4-chloro-3-ethyl-n-(4-formylbenzyl)-1-methyl-1h-pyrazole-5-carboxamide. the structures of target compounds were confirmed by ¹h nmr and high-resolution mass spectrum (hrms). the results of bioassays indicated that the target compoun ...201323972278
molecular cloning and mrna expression of a ryanodine receptor gene in the cotton bollworm, helicoverpa armigera.ryanodine receptors (ryrs) are the targets of novel diamide insecticides. the cotton bollworm, helicoverpa armigera, is one of the most important cotton pests in the world. in this study, we report the full-length ryr cdna sequence (named as haryr) of h. armigera. the 16,083-bp contiguous sequence encoded 5, 142 amino acid residues, which shares 80% and 78% overall identities with its homologues in nilaparvata lugens (nlryr) and drosophila melanogaster (dmryr), respectively. all hallmarks of ryr ...201324267694
plasticity of protease gene expression in helicoverpa armigera upon exposure to multi-domain capsicum annuum protease inhibitor.a multi-domain pin-ii type protease inhibitor from capsicum annuum (canpi-7) is known to be effective against the insect pest, helicoverpa armigera. the present study is an attempt to investigate the optimal dose of recombinant canpi-7 (rcanpi-7) for effective antibiosis to h. armigera and further to characterize the responses of digestive proteases upon rcanpi-7 ingestion.201323528893
how predictable are the behavioral responses of insects to herbivore induced changes in plants? responses of two congeneric thrips to induced cotton plants.changes in plants following insect attack are referred to as induced responses. these responses are widely viewed as a form of defence against further insect attack. in the current study we explore whether it is possible to make generalizations about induced plant responses given the unpredictability and variability observed in insect-plant interactions. experiments were conducted to test for consistency in the responses of two congeneric thrips, frankliniella schultzei trybom and frankliniella ...201323691075
chloroplast-targeted expression of recombinant crystal-protein gene in cotton: an unconventional combat with resistant pests.plants transformed with single bt gene are liable to develop insect resistance and this has already been reported in a number of studies carried out around the world where bt cotton was cultivated on commercial scale. later, it was envisaged to transform plants with more than one bt genes in order to combat with resistant larvae. this approach seems valid as various bt genes possess different binding domains which could delay the likely hazards of insect resistance against a particular bt toxin. ...201323643479
cysteine protease enhances plant-mediated bollworm rna interference.oral ingestion of plant-expressed double stranded rna (dsrna) triggers target gene suppression in insect. an important step of this process is the transmission of dsrna from plant to midgut cells. insect peritrophic matrix (pm) presents a barrier that prevents large molecules from entering midgut cells. here, we show that uptake of plant cysteine proteases, such as ghcp1 from cotton (gossypium hirsutum) and atcp2 from arabidopsis, by cotton bollworm (helicoverpa armigera) larvae resulted in atte ...201323460027
draft genome sequence of the paenibacillus sp. strain icgeb2008 (mtcc 5639) isolated from the gut of helicoverpa armigera.paenibacillus sp. strain icgeb2008 (mtcc 5639) is a gram-positive cellulolytic bacterium, isolated from the gut of helicoverpa armigera. here, we report the draft genome sequence of paenibacillus sp. icgeb2008. the annotation of the ~5.7-mb sequence indicated a cluster of genes related to the glycosyl hydrolase family and the butanediol biosynthesis pathway.201323405362
improving the application of vertebrate trait-based frameworks to the study of ecosystem services.1. examining the consequences of environmental change for the provision of ecosystem services can be facilitated through trait-based frameworks that consider linkages between traits that influence a species' response to change and traits that determine its effect on ecosystem services. 2. developing these frameworks requires a systematic approach to trait selection and addressing the interrelationships among the scale of the environmental change, area of ecosystem service provision and the most ...201222435774
wound and methyl jasmonate induced pigeon pea defensive proteinase inhibitor has potency to inhibit insect digestive proteinases.wounding of plants by chewing insects or other damage induces the synthesis of defensive proteinase inhibitors (pi) in both wounded and distal unwounded leaves. in the present paper we report the characterization of inducible defensive pi from pigeon pea (cajanus cajan) and its in vitro interaction with helicoverpa armigera gut proteinases (hgp). we found that pi activity was induced in local as well as systemic leaves of pigeon pea by the wounding and methyl jasmonate (meja) application. consis ...201222721949
stress inducible proteinase inhibitor diversity in capsicum annuum.wound-inducible pin-ii proteinase inhibitors (pis) are one of the important plant serine pis which have been studied extensively for their structural and functional diversity and relevance in plant defense against insect pests. to explore the functional specialization of an array of capsicum annuum (l.) proteinase inhibitor (canpis) genes, we studied their expression, processing and tissue-specific distribution under steady-state and induced conditions. inductions were performed by subjecting c. ...201223153298
functional impact of silencing the helicoverpa armigera sex-peptide receptor on female reproductive behaviour.female helicoverpa armigera sex pheromone production is under the control of pheromone biosynthesis-activating neuropeptide (pban). after mating, females undergo suppression of sex pheromone production and enhanced oviposition as a result of the transfer of male-derived seminal peptides. in a previous study we identified a putative h. armigera sex-peptide receptor (heasp-r) and demonstrated a significant up-regulation in gene expression levels of this receptor in brains and pheromone glands of m ...201222171674
design, synthesis, and insecticidal activity of novel pyrazole derivatives containing α-hydroxymethyl-n-benzyl carboxamide, α-chloromethyl-n-benzyl carboxamide, and 4,5-dihydrooxazole moieties.on the basis of commercial insecticides tebufenpyrad and tolfenpyrad, two series of novel pyrazole-5-carboxamides containing α-hydroxymethyl-n-benzyl or α-chloromethyl-n-benzyl and pyrazoles containing 4,5-dihydrooxazole moieties were designed and synthesized via the key intermediate 2-amino-1-(4-substituted) phenyl ethanol. the structures of target compounds were confirmed by (1)h nmr and elemental analysis or high-resolution mass spectrum (hrms), and their activities against cotton bollworm (h ...201222304385
overexpression of poplar wounding-inducible genes in arabidopsis caused improved resistance against helicoverpa armigera (hübner) larvae.four highly inducible genes of poplar trees, ptdkti5, ptdwin4, ptdpop3 from hybrid poplar (populus trichocarpa × p. deltoides) and ptkti2 from trembling aspen (populus tremuloides michx.) have been individually transformed into arabidopsis thaliana for overexpression. high transcriptional level of each transgene in transgenic arabidopsis lines was confirmed by rt-pcr analysis. the development, body weight and survivorship of cotton bollworm (helicoverpa armigera) fed on four types of transgenic ...201223226090
[expression and synergistic function of enhancin-like gene of agrotis segetum granulovirus].enhancin is an enhancing protein chiefly found in insect baculoviruses. one enhancin homologue was identified, by blast method, in agrotis segetum granulovirus (agsegv) genome, named enhancin-like. sequence analysis indicated that this gene includes the conserved domains, conserved in other enhancin, and it has no signal peptide or a-transmembrane helix. a proline-rich domain, which is similar to those of mammals, is present at its c-terminal. to analyze the synergistic function of agsegv enhanc ...201222764529
metabolism of glucosinolate-derived isothiocyanates to glutathione conjugates in generalist lepidopteran herbivores.the defensive properties of the glucosinolate-myrosinase system in plants of the order brassicales have been attributed to the formation of toxic isothiocyanates generated upon tissue damage. lepidopteran herbivores specialised on brassicaceous plants have been shown to possess biochemical mechanisms preventing the formation of isothiocyanates. yet, no such mechanisms are known for generalist lepidopterans which also occasionally but successfully feed on plants of the brassicales. after feeding ...201222193392
improvement of pest resistance in transgenic tobacco plants expressing dsrna of an insect-associated gene ecr.the adoption of pest-resistant transgenic plants to reduce yield loss and pesticide utilization has been successful in the past three decades. recently, transgenic plant expressing double-stranded rna (dsrna) targeting pest genes emerges as a promising strategy for improving pest resistance in crops. the steroid hormone, 20-hydroxyecdysone (20e), predominately controls insect molting via its nuclear receptor complex, ecr-usp. here we report that pest resistance is improved in transgenic tobacco ...201222685585
in vitro antiviral activity of an alkaline trypsin from the digestive juice of bombyx mori larvae against nucleopolyhedrovirus.alkaline trypsin protein of molecular mass 25,436 da purified from the digestive juice of bombyx mori larvae indicated strong antiviral activity against bombyx mori nucleopolyhedrovirus (bmnpv) under in vitro conditions. partial n-terminal amino acid sequence of the protein was determined and the cdna was cloned based on the amino acid sequence. a homology search of the deduced amino acid sequence of the cdna showed 55% identity with helicoverpa armigera trypsin and the active site of this prote ...201222898997
cis-acting motifs in artificially synthesized expression cassette leads to enhanced transgene expression in tomato (solanum lycopersicum l.).efficacy of artificial synthetic expression modules was compared with native camv35s and decamv35s promoter in transgenic tomato developed by agrobacterium-mediated transformation. the promoters under trial were camv35s-mec (pcami), camv35s (pcamii), decamv35s (pcamiii), synthetic minimal expression cassette (pmec), complete expression cassette (pcec), double enhancer expression cassette (pdec) and triple enhancer expression cassette (ptec) for driving the uida gene for β-glucuronidase (gus) act ...201223137727
the halo effect: suppression of pink bollworm on non-bt cotton by bt cotton in china.in some previously reported cases, transgenic crops producing insecticidal proteins from bacillus thuringiensis (bt) have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce bt toxins. here we used 16 years of field data to determine if bt cotton caused this "halo effect" against pink bollworm (pectinophora gossypiella) in six provinces of the yangtze river valley of china. in this region, the percentage of cotton hectares pl ...201222848685
diverse genetic basis of field-evolved resistance to bt cotton in cotton bollworm from china.evolution of pest resistance reduces the efficacy of insecticidal proteins from bacillus thuringiensis (bt) used in sprays or in transgenic crops. although several pests have evolved resistance to bt crops in the field, information about the genetic basis of field-evolved resistance to bt crops has been limited. in particular, laboratory-selected resistance to bt toxin cry1ac based on recessive mutations in a gene encoding a toxin-binding cadherin protein has been identified in three major cotto ...201222689968
early detection of field-evolved resistance to bt cotton in china: cotton bollworm and pink bollworm.transgenic crops producing bacillus thuringiensis (bt) toxins kill some major insect pests, but pests can evolve resistance and thereby reduce the effectiveness of such bt crops. the main approach for slowing pest adaptation to bt crops uses non-bt host plants as "refuges" to increase survival of susceptible pests. to delay evolution of pest resistance to cotton producing bt toxin cry1ac, several countries have required refuges of non-bt cotton, while farmers in china have relied on "natural" re ...201222537835
specific binding of radiolabeled cry1fa insecticidal protein from bacillus thuringiensis to midgut sites in lepidopteran species.cry1fa insecticidal protein was successfully radiolabeled with (125)i-na. specific binding to brush border membrane vesicles was shown for the lepidopteran species ostrinia nubilalis, spodoptera frugiperda, spodoptera exigua, helicoverpa armigera, heliothis virescens, and plutella xylostella. homologous competition assays were performed to obtain equilibrium binding parameters (k(d) [dissociation constant] and r(t) [concentration of binding sites]) for these six insect species.201222447600
assessing the role of non-cotton refuges in delaying helicoverpa armigera resistance to bt cotton in west africa.non-cotton host plants without bacillus thuringiensis (bt) toxins can provide refuges that delay resistance to bt cotton in polyphagous insect pests. it has proven difficult, however, to determine the effective contribution of such refuges and their role in delaying resistance evolution. here, we used biogeochemical markers to quantify movement of helicoverpa armigera moths from non-cotton hosts to cotton fields in three agricultural landscapes of the west african cotton belt (cameroon) where bt ...201225568029
pre-feeding of a glycolipid binding protein lec-8 from caenorhabditis elegans revealed enhanced tolerance to cry1ac toxin in helicoverpa armigera.crystal toxins from bacillus thuringiensis bind to glycolipids and glycoproteins using two different lectin domains in the toxin protein. our previous observations suggested that the sequestration of crystal toxin depends on the functional interaction of a toxin lectin with glycolipids. given the finding that competition of a galectin lec-8 with cry5b for binding to glycolipids resulting in reduced bt toxicity in nematode, it is interesting to explore the role of lec-8 in insects. here, we repor ...201224371572
characterization of three pheromone-binding proteins (pbps) of helicoverpa armigera (hübner) and their binding properties.three pheromone-binding proteins of helicoverpa armigera were cloned and expressed in escherichia coli. in order to characterize their physiological properties, ligand-binding experiments were performed using five biologically relevant substances including sex pheromones and interspecific signals. the results showed that one of the pheromone-binding proteins, harmpbp1, binds strongly to each of the two principal pheromone components of h. armigera, (z)-11-tetradecenal and (z)-9-hexadecenal, but ...201222549127
expression profiles of six novel c-type lectins in response to bacterial and 20e injection in the cotton bollworm (helicoverpa armigera).c-type lectins can act as pattern recognition receptors (prrs) and play an important role in innate immunity. two c-type lectins (hactl1 and hactl2) have been previously identified in the cotton bollworm (helicoverpa armigera). here we isolate six c-type lectins from h. armigera (hactl3, 4, 5, 6, 7 and 8). all six new hactls encode a signal peptide (or partial signal peptide) and complete tandem carbohydrate-recognition domains (crds). hactl4, 5, 6, 7 and 8 mrna increased in the fat body after i ...201222516747
membrane targeting of an alpha-like tetravirus replicase is directed by a region within the rna-dependent rna polymerase domain.the members of the family tetraviridae are small positive-sense insect rna viruses that exhibit stringent host specificity and a high degree of tissue tropism, suggesting that complex virus-host interactions are likely to occur during infection and viral replication. the alpha-like replicase of helicoverpa armigera stunt virus (hasv) (genus omegatetravirus) has been proposed to associate with membranes of the endocytic pathway, which is similar to semliki forest virus, sindbis virus and rubella ...201222535773
phylogenetic position and replication kinetics of heliothis virescens ascovirus 3h (hvav-3h) isolated from spodoptera exigua.insect-specific ascoviruses with a circular genome are distributed in the usa, france, australia and indonesia. here, we report the first ascovirus isolation from spodoptera exigua in hunan, china. dna-dna hybridization to published ascoviruses demonstrated that the new china ascovirus isolate is a variant of heliothis virescens ascovirus 3a (hvav-3a), thus named hvav-3h. we investigated the phylogenetic position, cell infection, vesicle production and viral dna replication kinetics of hvav-3h, ...201222792245
expression of chitinase genes of metarhizium anisopliae isolates in lepidopteran pests and on synthetic media.pathogenecity of the well characterized entomopathogenic fungus metarhizium anisopliae used for biocontrol of a wide range of insect pests secretes hydrolytic enzymes that degrade the host cuticle. the chitinolytic activity of high and low virulent isolates of m. anisopliae was assayed on minimal medium (mm) + colloidal chitin and mm supplemented with insect cuticles. ex- pression pattern of four chitinase genes (chitinase (chi), chi 1, chi 2, chi 3) was profiled during pathogenic stages of the ...201222581664
semi-selective fatty acyl reductases from four heliothine moths influence the specific pheromone composition.sex pheromones are essential in moth mate communication. information on pheromone biosynthetic genes and enzymes is needed to comprehend the mechanisms that contribute to specificity of pheromone signals. most heliothine moths use sex pheromones with (z)-11-hexadecenal as the major component in combination with minor fatty aldehydes and alcohols. in this study we focus on four closely related species, heliothis virescens, heliothis subflexa, helicoverpa armigera and helicoverpa assulta, which us ...201222615947
orf85 of hearnpv encodes the per os infectivity factor 4 (pif4) and is essential for the formation of the pif complex.orf85 of helicoverpa armigera nucleopolyhedrovirus (hearnpv) encodes a homologue of the per os infectivity factor 4 (pif-4) of autographa californica multiple nucleocapsid nucleopolyhedrovirus (acmnpv). in this paper, the functions of ha85, particularly in relation to oral infection and interactions with other pifs were investigated. an ha85-disrupted recombinant hearnpv was generated and resulted in a complete loss of oral infectivity. western blotting and co-immunoprecipitation (co-ip) analyse ...201222386821
improving the robustness of a low-cost insect cell medium for baculovirus biopesticides production, via hydrolysate streamlining using a tube bioreactor-based statistical optimization routine.a critical component of an in vitro production process for baculovirus biopesticides is a growth medium that is efficacious, robust, and inexpensive. an in-house low-cost serum-free medium, vpm3, has been shown to be very promising in supporting helicoverpa armigera nucleopolyhedrovirus (hasnpv) production in h. zea insect cell suspension cultures, for use as a biopesticide against the heliothine pest complex. however, vpm3 is composed of a significant number of undefined components, including f ...201222323401
non-recessive bt toxin resistance conferred by an intracellular cadherin mutation in field-selected populations of cotton bollworm.transgenic crops producing bacillus thuringiensis (bt) toxins have been planted widely to control insect pests, yet evolution of resistance by the pests can reduce the benefits of this approach. recessive mutations in the extracellular domain of toxin-binding cadherin proteins that confer resistance to bt toxin cry1ac by disrupting toxin binding have been reported previously in three major lepidopteran pests, including the cotton bollworm, helicoverpa armigera. here we report a novel allele from ...201223285292
molecular characterization of novel serovars of bacillus thuringiensis isolates from india.novel bacillus thuringiensis isolates gs4, gn24 and up1 were isolated and characterized by determination of serotyping, insecticidal protein by sds-page, plasmid composition, cry gene content and insect toxicity. serologically two isolates gs4 and up1 were allocated to the h3abce which is a new serovar while isolate gn24 was of h3ab type. isolate gs4 produced flat crystal inclusions while up1 produced cuboidal crystals. pcr analysis found that both isolates contained cry1 and cry1ac genes. the m ...201223997321
the characterization of sapin2b, a plant trichome-localized proteinase inhibitor from solanum americanum.proteinase inhibitors play an important role in plant resistance of insects and pathogens. in this study, we characterized the serine proteinase inhibitor sapin2b, which is constitutively expressed in solanum americanum trichomes and contains two conserved motifs of the proteinase inhibitor ii (pin2) family. the recombinant sapin2b (rsapin2b), which was expressed in escherichia coli, was demonstrated to be a potent proteinase inhibitor against a panel of serine proteinases, including subtilisin ...201223203117
host plant induced variation in gut bacteria of helicoverpa armigera.helicoverpa are important polyphagous agricultural insect pests and they have a worldwide distribution. in this study, we report the bacterial community structure in the midgut of fifth instar larvae of helicoverpa armigera, a species prevalent in the india, china, south asia, south east asia, southern & eastern africa and australia. using culturable techniques, we isolated and identified members of bacillus firmus, bacillus niabense, paenibacillus jamilae, cellulomonas variformis, acinetobacter ...201222292034
candidate olfaction genes identified within the helicoverpa armigera antennal transcriptome.antennal olfaction is extremely important for insect survival, mediating key behaviors such as host preference, mate choice, and oviposition site selection. multiple antennal proteins are involved in olfactory signal transduction pathways. of these, odorant receptors (ors) and ionotropic receptors (irs) confer specificity on olfactory sensory neuron responses. in this study, we identified the olfactory gene repertoire of the economically important agricultural pest moth, helicoverpa armigera, by ...201223110222
resistance of australian helicoverpa armigera to fenvalerate is due to the chimeric p450 enzyme cyp337b3.worldwide, increasing numbers of insects have evolved resistance to a wide range of pesticides, which hampers their control in the field and, therefore, threatens agriculture. members of the carboxylesterase and cytochrome p450 monooxygenase superfamilies are prominent candidates to confer metabolic resistance to pyrethroid insecticides. both carboxylesterases and p450 enzymes have been shown to be involved in pyrethroid resistance in australian helicoverpa armigera, the noctuid species possessi ...201222949643
a sugar gustatory receptor identified from the foregut of cotton bollworm helicoverpa armigera.helicoverpa armigera (hübner) is one of the most polyphagous and cosmopolitan pest species, the larvae of which feed on numerous important crops. the gustatory system is critical in guiding insect feeding behavior. here, we identified a gustatory receptor from h. armigera, hagr9, which shows high levels of identity to dmgr43a from drosophila melanogaster and bmgr9 from bombyx mori. reverse transcriptase pcr (rt-pcr) revealed hagr9 is highly expressed in larval foregut, with little or no expressi ...201223224441
identification of micrornas in helicoverpa armigera and spodoptera litura based on deep sequencing and homology analysis.the current identification of micrornas (mirnas) in insects is largely dependent on genome sequences. however, the lack of available genome sequences inhibits the identification of mirnas in various insect species. in this study, we used a mirna database of the silkworm bombyx mori as a reference to identify mirnas in helicoverpa armigera and spodoptera litura using deep sequencing and homology analysis. because all three species belong to the lepidoptera, the experiment produced reliable result ...201223289012
characterization of three novel sine families with unusual features in helicoverpa armigera.although more than 120 families of short interspersed nuclear elements (sines) have been isolated from the eukaryotic genomes, little is known about sines in insects. here, we characterize three novel sines from the cotton bollworm, helicoverpa armigera. two of them, hase1 and hase2, share similar 5' -structure including a trna-related region immediately followed by conserved central domain. the 3' -tail of hase1 is significantly similar to that of one line retrotransposon element, harte1.1, in ...201222319625
field evolved resistance in helicoverpa armigera (lepidoptera: noctuidae) to bacillus thuringiensis toxin cry1ac in pakistan.helicoverpa armigera (hübner) is one of the most destructive pests of several field and vegetable crops, with indiscriminate use of insecticides contributing to multiple instances of resistance. in the present study we assessed whether h. armigera had developed resistance to bt cotton and compared the results with several conventional insecticides. furthermore, the genetics of resistance was also investigated to determine the inheritance to cry1ac resistance. to investigate the development of re ...201223077589
modified artificial diet for rearing of tobacco budworm, helicoverpa armigera, using the taguchi method and derringer's desirability function.with the aim to improve the mass rearing feasibility of tobacco budworm, helicoverpa armigera hübner (lepidoptera: noctuidae), design of experimental methodology using taguchi orthogonal array was applied. to do so, the effect of 16 ingredients of an artificial diet including bean, wheat germ powder, nipagin, ascorbic acid, formaldehyde, oil, agar, distilled water, ascorbate, yeast, chloramphenicol, benomyl, penicillin, temperature, humidity, and container size on some biological characteristics ...201223425103
biological activities of solanum pseudocapsicum (solanaceae) against cotton bollworm, helicoverpa armigera hübner and armyworm, spodoptera litura fabricius (lepidotera: noctuidae).to evaluate the antifeedant, insecticidal and growth inhibition activities of solanum pseudocapsicum (s. pseudocapsicum) seed extracts against spodoptera litura (s. litura) and helicoverpa armigera (h. armigera).201223593579
expression in antennae and reproductive organs suggests a dual role of an odorant-binding protein in two sibling helicoverpa species.odorant-binding proteins (obps) mediate both perception and release of semiochemicals in insects. these proteins are the ideal targets for understanding the olfactory code of insects as well as for interfering with their communication system in order to control pest species. the two sibling lepidopteran species helicoverpa armigera and h. assulta are two major agricultural pests. as part of our aim to characterize the obp repertoire of these two species, here we focus our attention on a member o ...201222291900
increased frequency of pink bollworm resistance to bt toxin cry1ac in china.transgenic crops producing insecticidal proteins from bacillus thuringiensis (bt) kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. the main approach for delaying pest adaptation to bt crops uses non-bt host plants as "refuges" to increase survival of susceptible pests. to delay evolution of pest resistance to transgenic cotton producing bt toxin cry1ac, the united states and some other countries have required refuges of non-bt cotton, while farmers in c ...201222238687
co-expression and synergism analysis of vip3aa29 and cyt2aa3 insecticidal proteins from bacillus thuringiensis.vegetative insecticidal protein (vip3) from bacillus thuringiensis shows high activity against lepidopteran insects. cytolytic δ-endotoxin (cyt) also has high toxicity to dipteran larvae and synergism with other crystal proteins (cry), but synergism between cyt and vip3 proteins has not been tested. we analyzed for synergism between cyt2aa3 and vip3aa29. both cyt2aa3 and vip3aa29 genes were co-expressed in escherichia coli strain bl21 carried on vector pcoladuet-1. vip3aa29 showed insecticidal a ...201222218570
toxicity of bacillus thuringiensis cry proteins to helicoverpa armigera (lepidoptera: noctuidae) in south africa.the susceptibility of one of the most important pests in southern africa, helicoverpa armigera (lepidoptera: noctuidae), to bacillus thuringiensis cry proteins was evaluated by bioassay. cry proteins were produced in escherichia coli bl21 cells that were transformed with plasmids containing one of six cry genes. the toxicity of each cry protein to h. armigera larvae was determined by the diet contamination method for second instar larvae and the droplet feeding method for neonate larvae. for eac ...201222019386
genome sequence of acinetobacter sp. strain ha, isolated from the gut of the polyphagous insect pest helicoverpa armigera.in this study, acinetobacter sp. strain ha was isolated from the midgut of a fifth-instar larva of helicoverpa armigera. here, we report the draft genome sequence (3,125,085 bp) of this strain that consists of 102 contigs, 2,911 predicted coding sequences, and a g+c content of 41%.201222933775
rna interference as a cellular defense mechanism against the dna virus baculovirus.in insects, the rna interference (rnai) pathway plays a major role in antiviral responses, as shown against many rna viruses. the response includes the cleavage of double-stranded rna genome or intermediates, produced during replication, into viral short interfering rnas (v-sirnas). using deep sequencing, we found that a large number of small reads of ∼20 nucleotides from helicoverpa armigera larvae infected with helicoverpa armigera single nucleopolyhedrovirus (hasnpv) were mapped to certain op ...201223055564
adenylate kinase 2 (ak2) promotes cell proliferation in insect development.adenylate kinase 2 (ak2) is a phosphotransferase that catalyzes the reversible reaction 2adp(gdp) ↔ atp(gtp) + amp and influences cellular energy homeostasis. however, the role of ak2 in regulating cell proliferation remains unclear because ak2 has been reported to be involved in either cell proliferation or cell apoptosis in different cell types of various organisms.201223020757
isolation and identification of insect intestinal mucin haiim86--the new target for helicoverpa armigera biocontrol.there are many more glycoproteins in helicoverpa armigera peritrophic membrane than midgut separated by sds-page analysis after periodic acid-schiff (pas) and coomassie staining. the peritrophic membrane (pm) of h. armigera larvae contains about forty associated proteins. a cdna library was constructed from h. armigera midgut mrna to study the new target for pest biocontrol. an antiserum against spodoptera exigua integral/total pm proteins cross reacted with several h. armigera pm proteins and w ...201121448339
sialome of a generalist lepidopteran herbivore: identification of transcripts and proteins from helicoverpa armigera labial salivary glands.although the importance of insect saliva in insect-host plant interactions has been acknowledged, there is very limited information on the nature and complexity of the salivary proteome in lepidopteran herbivores. we inspected the labial salivary transcriptome and proteome of helicoverpa armigera, an important polyphagous pest species. to identify the majority of the salivary proteins we have randomly sequenced 19,389 expressed sequence tags (ests) from a normalized cdna library of salivary glan ...201122046331
design, synthesis and insecticidal activities of novel pyrazole amides containing hydrazone substructures.background: pyrazole and hydrazone derivatives possess good insecticidal activities; their substructural units are widely used in pesticide design. in an effort to discover new molecules with good insecticidal activities, a series of pyrazole amide derivatives containing hydrazone substructures were synthesised and bioassayed. results: bioassays demonstrated that some of the title compounds exhibited notable control of plutella xylostella (linnaeus), helicoverpa armigera (hübner), culex pipiens ...201122190278
development of quenching and washing protocols for quantitative intracellular metabolite analysis of uninfected and baculovirus-infected insect cells.metabolomics refer to the global analysis of small molecule metabolites in a biological system, and can be a powerful tool to elucidate and optimize cellular processes, particularly when integrated into a systems biology framework. determining the endometabolome in cultured animal cells is especially challenging, due to the conflicting demands for rapid quenching of metabolism and retention of membrane integrity, while cells are separated from the complex medium. the challenge is magnified in vi ...201122166686
comparative analysis of the udp-glycosyltransferase multigene family in insects.udp-glycosyltransferases (ugt) catalyze the conjugation of a range of diverse small lipophilic compounds with sugars to produce glycosides, playing an important role in the detoxification of xenobiotics and in the regulation of endobiotics in insects. recent progress in genome sequencing has enabled an assessment of the extent of the ugt multigene family in insects. here we report over 310 putative ugt genes identified from genomic databases of eight different insect species together with a tran ...201122155036
Complete sequence and gene organization of the Nosema heliothidis ribosomal RNA gene region.By sequencing the entire ribosomal RNA (rRNA) gene region of Nosema heliothidis isolated from cotton bollworm (Helicoverpa armigera), we showed that its gene organization is similar to the type species, Nosema bombycis: the 5'-large subunit rRNA (2,490 bp)-internal transcribed spacer (192 bp)-small subunit rRNA (1,232 bp)-intergenic spacer (274 bp)-5S rRNA (115 bp)-3'. We constructed two phylogenetic trees, analyzed phylogenetic relationships, examined rRNA organization of microsporidia, and com ...201121895841
bioinsecticidal activity of murraya koenigii miraculin-like protein against helicoverpa armigera and spodoptera litura.miraculin-like proteins, belonging to the kunitz superfamily, are natural plant defense agents against pests and predators, and therefore are potential biopesticides for incorporation into pest-resistant crops. here, a miraculin-like protein from murraya koenigii was assessed for its in vitro and in vivo effects against two polyphagous lepidopteran insect pests, helicoverpa armigera and spodoptera litura. m. koenigii miraculin-like protein (mkmlp) inhibited the trypsin-like activity and total pr ...201121948662
Putative phosphorylation sites on WCA domain of HA2 is essential for Helicoverpa armigera single nucleopolyhedrovirus replication.Protein phosphorylation is one of the most common post-translational modification processes that play an essential role in regulating protein functionality. The Helicoverpa armigera single nucleopolyhedrovirus (HearNPV) orf2-encoded nucleocapsid protein HA2 participates in orchestration of virus-induced actin polymerization through its WCA domain, in which phosphorylation status are supposed to be critical in respect to actin polymerization. In the present study, two putative phosphorylation sit ...201121847755
Increased plant volatile production affects oviposition, but not larval development, in the moth Helicoverpa armigera.It is well established that herbivorous insects respond to changes in plant odour production, but little attention has been given to whether these responses relate to direct fitness costs of plant volatile production on insect growth and survival. Here, we use transgenic Nicotiana tabacum (tobacco) plants that produce relatively large amounts of the volatile (S)-linalool to study whether the responses of egg-laying herbivorous insects to linalool production relate directly to the growth and surv ...201121993797
Trade-offs of host use between generalist and specialist Helicoverpa sibling species: adult oviposition and larval performance.Much attention has been paid to the question of the relative importance of female behaviour versus larval feeding capacities in determining the host range of herbivorous insects. Host-use trade-offs displayed by generalist and specialist sister species of the genus Helicoverpa were evaluated to examine the relationship between maternal choice and offspring performance. The prediction of optimal oviposition theory, that females will choose to lay eggs on plants on which their offspring perform be ...201121863244
Molecular characterization of Bacillus thuringiensis isolated from diverse habitats of India.Bacillus thuringiensis (Bt) strains were isolated from 94 samples from different geographical regions. Novel types of crystalline inclusion bodies were observed from some of the isolates. Crystalline inclusions of bipyramidal, spherical and cuboidal morphology were found produced by most of the isolates. Isolate GS12 showed crystal on one side of spore while isolate GM108 formed crystals on both termini of spore. Isolate GN31 produced large sized bipyramidal crystals. SDS-PAGE analysis of the sp ...201122144134
Compatibility of garlic (Allium sativum L.) leaf agglutinin and Cry1Ac d-endotoxin for gene pyramiding.d-Endotoxins produced by Bacillus thuringiensis (Bt) have been used as bio-pesticides for the control of lepidopteran insect pests. Garlic (Allium sativum L.) leaf agglutinin (ASAL), being toxic to several sap-sucking pests and some lepidopteran pests, may be a good candidate for pyramiding with d-endotoxins in transgenic plants for enhancing the range of resistance to insect pests. Since ASAL shares the midgut receptors with Cry1Ac in Helicoverpa armigera, there is possibility of antagonism in ...201121870043
Early warning of cotton bollworm resistance associated with intensive planting of Bt cotton in China.Transgenic crops producing Bacillus thuringiensis (Bt) toxins kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to promote survival of susceptible pests. To delay pest resistance to transgenic cotton producing Bt toxin Cry1Ac, farmers in the United States and Australia planted refuges of non-Bt cotton, while farmers in China have relied on "natural" r ...201121857961
bacillus thuringiensis protein cry6b (bgsc id 4d8) is toxic to larvae of hypera postica.insecticidal proteins produced by strains of bacillus thuringenesis are specific toward target pests. one of the bt proteins, cry 1ac has been used successfully for controlling crop predation by polyphagous pests helicoverpa armigera. structurally, bt proteins consist of three domains; domain i and iii are fairly homologous in various bt proteins while domain ii is hypervariable. the hypervariable domain ii is believed to be responsible for specificity toward target pest. successful deployment o ...201120835830
isolation and characterization of baculoviruses from three major lepidopteran pests in the semi-arid tropics of india.baculoviruses were isolated from three major lepidopteran pests, helicoverpa armigera, spodoptera litura and amsacta albistriga in the semi-arid tropics during natural epizootic conditions at icrisat fields, patancheru, andhra pradesh, india. biological, morphological and biochemical analysis identified these isolates as nucleopolyhedroviruses (npvs). scanning electron microscopy of the occlusion bodies (obs) purified from diseased larvae revealed polyhedral particles of size approximately 0.5-2 ...201123637499
study of the pest community of velvetleaf (abutilon theophrasti medic.).velvetleaf (abutilon theophrasti medicus 1787) is one of the most economically threatening weed plant in hungary. researching biological control against it, and identifying a possible and effective biocontrol agent is an important challenge, as chemical control is difficult and expensive, and there is an increasing claim to practice slight plant protection. entomological studies were made in several parts of the world, for evaluating the species, occuring in velvetleaf, but none of these kind of ...201122696962
isolation and characterization of a novel alphanodavirus.nodaviridae is a family of non-enveloped isometric viruses with bipartite positive-sense rna genomes. the nodaviridae family consists of two genera: alpha- and beta-nodavirus. alphanodaviruses usually infect insect cells. some commercially available insect cell lines have been latently infected by alphanodaviruses.201121682922
ubiquitins of bombyx mori nucleopolyhedrovirus and helicoverpa armigera nucleopolyhedrovirus show distinct subcellular localization in infected cells.ubiquitin (ub) is a conserved protein that regulates a number of processes in eukaryotic cells. nearly all lepidopteran baculoviruses encode ub homologs showing a partial sequence identity with human ub (hu-ub). in this study, the sequence, predicted 3d-structure and subcellular localization of ub homologs encoded by two different nucleopolyhedroviruses of bombyx mori (bmnpv) and helicoverpa armigera (hanpv) were compared. ubs of bmnpv and hanpv (bm-ub, ha-ub, respectively) shared only 73% of se ...201121692557
in silico designing of insecticidal small interfering rna (sirna) for helicoverpa armigera control.helicoverpa armigera, a polyphagous lepidopteron insect pest causes severe yield loss in cotton, legumes, tomato, okra and other crops. application of chemical pesticides although effective, has human health and environmental safety concerns. moreover, development of resistance against most of the available pesticides is compelling to look for alternative strategies. adoption of bt transgenic crops have resulted in reduction in pesticide consumption and increasing crop productivity. however, sus ...201121702227
a host-plant specialist, helicoverpa assulta, is more tolerant to capsaicin from capsicum annuum than other noctuid species.plant secondary compounds not only play an important role in plant defense, but have been a driving force for host adaptation by herbivores. capsaicin (8-methyl-n-vanillyl-6-nonenamide), an alkaloid found in the fruit of capsicum spp. (solanaceae), is responsible for the pungency of hot pepper fruits and is unique to the genus. the oriental tobacco budworm, helicoverpa assulta (lepidoptera: noctuidae), is a specialist herbivore feeding on solanaceous plants including capsicum annuum, and is one ...201121704632
specific binding of activated vip3aa10 to helicoverpa armigera brush border membrane vesicles results in pore formation.helicoverpa armigera is one of the most harmful pests in china. although it had been successfully controlled by cry1a toxins, some h. armigera populations are building up resistance to cry1a toxins in the laboratory. vip3a, secreted by bacillus thuringiensis, is another potential toxin against h. armigera. previous reports showed that activated vip3a performs its function by inserting into the midgut brush border membrane vesicles (bbmv) of susceptible insects. to further investigate the binding ...201121824478
Rapid detection of vip1-type genes from Bacillus cereus and characterization of a novel vip binary toxin gene.A PCR-restriction fragment length polymorphism (PCR-RFLP) method for identifying vegetative insecticidal protein (vip) 1-type genes from Bacillus cereus was developed by designing specific primers based on the conserved regions of the genes to amplify vip1-type gene fragments. PCR products were digested with endonuclease AciI, and four known vip1-type genes were identified. Vip1Ac and vip1Aa-type genes appeared in 17 of 26 B. cereus strains. A novel vip1-type gene, vip1Ac1, was identified from B ...201122092859
a cry1ac toxin variant generated by directed evolution has enhanced toxicity against lepidopteran insects.cry1ac insecticidal crystal proteins produced by bacillus thuringiensis (bt) have become an important natural biological agent for the control of lepidopteran insects. in this study, a cry1ac toxin gene from bacillus thuringiensis 4.0718 was modified by using error-prone pcr, staggered extension process (step) shuffling combined with red/et homologous recombination to investigate the insecticidal activity of delta-endotoxin cry1ac. a cry1ac toxin variant (designated as t524n) screened by insect ...201120669019
helicoverpa armigera nucleopolyhedrovirus occlusion-derived virus-associated protein, ha100, affects oral infectivity in vivo but not virus replication in vitro.orf100 (ha100) of helicoverpa armigera nucleopolyhedrovirus (hearnpv) has been reported as one of the unique genes of group ii alphabaculoviruses encoding a protein located in the occlusion-derived virus (odv) envelope and nucleocapsid. the protein consists of 510 aa with a predicted mass of 58.1 kda and is a homologue of poly(adp-ribose) glycohydrolase in eukaryotes. western blot analysis detected a 60 kda band in hearnpv-infected hzam1 cells starting at 18 h post-infection. transient expressio ...201121325478
relationships between exogenous-toxin quantity and increased biomass of transgenic bt crops under elevated carbon dioxide.field-otc experiments were conducted with the goals of ascertaining if increased biomass in bt transgenic cotton and rice grown under elevated co(2) results in diminished exogenous-bt toxin, and assessing the effectiveness of bt transgenes against lepidopteran pests. bt cotton responded differently, in terms of bt-toxin quantity, than bt rice, and both indicated differences among developmental stages. dramatic biomass increase significantly diluted bt-toxin content in 45-das ("days after seedlin ...201121349582
spider toxin (hvt) gene cloned under phloem specific rss1 and rolc promoters provides resistance against american bollworm (heliothis armigera).spider venoms are neurotoxin proteins that can kill insects. spider toxin hvt gene was cloned under two phloem specific rss1 and rolc promoters, transformed into tobacco plants through agrobacterium-mediated transformation and tested against heliothis armigera larvae. transgenic plants were confirmed through pcr. first instar larvae of h. armigera were released on detached leaves of transformed and non-transformed plants. insect bioassays showed 93-100% mortality of h. armigera larvae within 72  ...201121369907
a btb domain-containing gene is upregulated by immune challenge.20-hydroxyecdysone (20e) is an important hormone that regulates the development of insects. although previous evidence revealed that 20e promotes innate immunity in insects, the mechanism involved is still unclear. in this study, the habbp gene from helicoverpa armigera is cloned, which contains btb (broad-complex, tramtrack, and bric-a-brac), a back (btb and carboxyl-terminus kelch repeats), and phr (pam, highwire, and rpm) domains. rt-pcr analysis of habbp and western blot analysis of habbp sh ...201121374716
reduced levels of membrane-bound alkaline phosphatase are common to lepidopteran strains resistant to cry toxins from bacillus thuringiensis.development of insect resistance is one of the main concerns with the use of transgenic crops expressing cry toxins from the bacterium bacillus thuringiensis. identification of biomarkers would assist in the development of sensitive dna-based methods to monitor evolution of resistance to bt toxins in natural populations. we report on the proteomic and genomic detection of reduced levels of midgut membrane-bound alkaline phosphatase (malp) as a common feature in strains of cry-resistant heliothis ...201121390253
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