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isolation of an orally active insecticidal toxin from the venom of an australian tarantula.many insect pests have developed resistance to existing chemical insecticides and consequently there is much interest in the development of new insecticidal compounds with novel modes of action. although spiders have deployed insecticidal toxins in their venoms for over 250 million years, there is no evolutionary selection pressure on these toxins to possess oral activity since they are injected into prey and predators via a hypodermic needle-like fang. thus, it has been assumed that spider-veno ...201324039872
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
antifeedant, larvicidal and growth inhibitory bioactivities of novel polyketide metabolite isolated from streptomyces sp. ap-123 against helicoverpa armigera and spodoptera litura.considerable attention has been paid to actinomycetes, especially the secondary metabolites obtained from streptomyces species, as the best alternatives to chemicals as biological control agents for polyphagous pests such as helicoverpa armigera and spodoptera litura. on the basis of their novel biocontrol attributes, novel polyketide metabolite isolated from marine streptomyces sp. ap-123 exhibited significant antifeedant, larvicidal and growth inhibitory activities against polyphagous pests.201323668716
next-generation sequencing-based transcriptome analysis of helicoverpa armigera larvae immune-primed with photorhabdus luminescens tt01.although invertebrates are incapable of adaptive immunity, immunal reactions which are functionally similar to the adaptive immunity of vertebrates have been described in many studies of invertebrates including insects. the phenomenon was termed immune priming. in order to understand the molecular mechanism of immune priming, we employed illumina/solexa platform to investigate the transcriptional changes of the hemocytes and fat body of helicoverpa armigera larvae immune-primed with the pathogen ...201324302999
cantharidin impedes activity of glutathione s-transferase in the midgut of helicoverpa armigera hübner.previous investigations have implicated glutathione s-transferases (gsts) as one of the major reasons for insecticide resistance. therefore, effectiveness of new candidate compounds depends on their ability to inhibit gsts to prevent metabolic detoxification by insects. cantharidin, a terpenoid compound of insect origin, has been developed as a bio-pesticide in china, and proves highly toxic to a wide range of insects, especially lepidopteran. in the present study, we test cantharidin as a model ...201323528854
proteomic and metabolomic profiles of larval hemolymph associated with diapause in the cotton bollworm, helicoverpa armigera.diapause is programmed developmental arrest coupled with the depression of metabolic activity and the enhancement of stress resistance. pupal diapause is induced by environmental signals and is prepared during the prediapause phase. in the cotton bollworm, helicoverpa armigera, the prediapause phase, which contains two sub-phases, diapause induction and preparation, occurs in the larval stage. here, we performed parallel proteomic and metabolomic analyses on h. armigera larval hemolymph during t ...201324180224
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
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
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
identification and characterization of two peptidoglycan recognition proteins with zinc-dependent antibacterial activity from the cotton bollworm, helicoverpa armigera.peptidoglycan recognition proteins (pgrps) specifically bind to peptidoglycan and play an important role in the innate immune responses as pattern recognition receptors (prrs). here we identified and characterized two pgrps (hapgrp-b and hapgrp-c) from the cotton bollworm, helicoverpa armigera. the comparative analysis indicated that five amino acids which are required for t7 lysozyme zn(2+) binding and amidase activity are conserved in hapgrp-b and hapgrp-c, suggesting that the two pgrps are me ...201323295246
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
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
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
effects of a new microbial α-amylase inhibitor protein on helicoverpa armigera larvae.a new microbial α-amylase inhibitor gene was cloned and characterized. the encoded, recombinant, α-amylase inhibitor protein was induced and expressed by isopropyl β-d-1-thiogalactopyranoside (iptg) in escherichia coli m15 cells. the effects of the α-amylase inhibitor protein on helicoverpa armigera larvae were studied. compared to the control, the weight of h. armigera larvae fed the diet with recombinant α-amylase inhibitor protein added at a concentration of 20 μg/g was reduced by 49.8%. the ...201323432599
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 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
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
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
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
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
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
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
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
the remarkable efficiency of a pin-ii proteinase inhibitor sans two conserved disulfide bonds is due to enhanced flexibility and hydrogen bond density in the reactive site loop.capsicum annuum (l.) expresses diverse potato type ii family proteinase inhibitors comprising of inhibitory repeat domain (ird) as basic functional unit. most irds contain eight conserved cysteines forming four disulfide bonds, which are indispensible for their stability and activity. we investigated the functional significance of evolutionary variations in irds and their role in mediating interaction between the inhibitor and cognate proteinase. among the 18 irds encoded by c. annuum, ird-7, -9 ...201423256852
bio-potency of a 21 kda kunitz-type trypsin inhibitor from tamarindus indica seeds on the developmental physiology of h. armigera.a trypsin inhibitor purified from the seeds of tamarindus indica by sephadex g-75, deae-sepharose and trypsin-sepharose cl-4b columns was studied for its antifeedant, larvicidal, pupicidal and growth inhibitory activities against helicoverpa armigera larvae. tamarindus trypsin inhibitor (tti) exhibited inhibitory activity towards total gut proteolytic enzymes of h. armigera (~87%) and bovine trypsin (~84%). lethal doses which caused mortality and weight reduction by 50% were 1% w/w and 0.50% w/w ...201425454525
a nonhost peptidase inhibitor of ~14 kda from butea monosperma (lam.) taub. seeds affects negatively the growth and developmental physiology of helicoverpa armigera.helicoverpa armigera is one of the major devastating pests of crop plants. in this context a serine peptidase inhibitor purified from the seeds of butea monosperma was evaluated for its effect on developmental physiology of h. armigera larvae. b. monosperma peptidase inhibitor on 12% denaturing polyacrylamide gel electrophoresis exhibited a single protein band of ~14 kda with or without reduction. in vitro studies towards total gut proteolytic enzymes of h. armigera and bovine trypsin indicated ...201424860667
aldehyde reductase activity in the antennae of helicoverpa armigera.in the present study, we identified two aldehyde reductase activities in the antennae of helicoverpa species, nadh and nadph-dependent activity. we expressed one of these proteins of h. armigera, aldo-keto reductase (akr), which bears 56% identity to bovine aldose reductase, displays a nadph-dependent activity and is mainly expressed in the antennae of adults. whole-mount immunostaining showed that the enzyme is concentrated in the cells at the base of chemosensilla and in the nerves. the enzyme ...201424580848
nitrate reductase and nitrite as additional components of defense system in pigeonpea (cajanus cajan l.) against helicoverpa armigera herbivory.amylase inhibitors serve as attractive candidates of defense mechanisms against insect attack. therefore, the impediment of helicoverpa armigera digestion can be the effective way of controlling this pest population. nitrite was found to be a potent mixed non-competitive competitive inhibitor of partially purified α-amylase of h. armigera gut. this observation impelled us to determine the response of nitrite and nitrate reductase (nr) towards h. armigera infestation in nine pigeonpea genotypes ( ...201425307464
pigeonpea genotypes influence parasitization preference and survival and development of the helicoverpa armigera larval parasitoid, campoletis chlorideae.studies were undertaken to identify pigeonpea, cajanus cajan (l.) millspaugh and the wild relative of pigeonpea, cajanus scarabaeoides (l.) (accession icpw 125,) genotypes that are hospitable to the pod borer, helicoverpa armigera (hübner) (lepidoptera: noctuidae) larval parasitoid, campoletis chlorideae uchida (hymenoptera: ichneumonidae) for the management of this pest in pigeonpea based cropping systems. percentage parasitization of the h. armigera larvae by the c. chlorideae females was grea ...201425110629
identification and characterization of a sex peptide receptor-like transcript from the western tarnished plant bug lygus hesperus.lygus hesperus females exhibit a post-mating behavioural switch that triggers increased egg laying and decreased sexual interest. in drosophila melanogaster, these changes are controlled by sex peptide (sp) and the sex peptide receptor (dmspr). in helicoverpa armigera, spr (haspr) also regulates some post-mating behaviour; however, myoinhibiting peptides (mips) have been identified as the spr ancestral ligand, indicating that spr is a pleiotropic receptor. in the present study, we identified a t ...201424467643
identification and expression profiling of helicoverpa armigera micrornas and their possible role in the regulation of digestive protease genes.the present investigation is an effort to determine the possible roles of micrornas (mirnas) in the regulation of protease gene expression in helicoverpa armigera upon exposure to plant protease inhibitors (pis). using illumina platform, deep sequencing of 12 small rna libraries was performed from h. armigera larvae fed on artificial diet (ad) or recombinant capsicum annuum pi-7 (rcanpi-7) incorporated diet, at various time intervals (0.5, 2, 6, 12, 24, and 48 h). sequencing data were analyzed w ...201425263090
differential antibiosis against helicoverpa armigera exerted by distinct inhibitory repeat domains of capsicum annuum proteinase inhibitors.plant defensive serine proteinase inhibitors (pis) are known to have negative impact on digestive physiology of herbivore insects and thus have a crucial role in plant protection. here, we have assessed the efficacy and specificity of three previously characterized inhibitory repeat domain (ird) variants from capsicum annuum pis viz., ird-7, -9 and -12 against gut proteinases from helicoverpa armigera. comparative study of in silico binding energy revealed that ird-9 possesses higher affinity to ...201424559910
do pollinator distributions underlie the evolution of pollination ecotypes in the cape shrub erica plukenetii?according to the grant-stebbins model of pollinator-driven divergence, plants that disperse beyond the range of their specialized pollinator may adapt to a new pollination system. although this model provides a compelling explanation for pollination ecotype formation, few studies have directly tested its validity in nature. here we investigate the distribution and pollination biology of several subspecies of the shrub erica plukenetii from the cape floristic region in south africa. we analyse th ...201424071499
conserved rna cis-elements regulate alternative splicing of lepidopteran doublesex.doublesex (dsx) is a downstream key regulator in insect sex determination pathway. in drosophila, alternative splicing of dm-dsx gene is sex-specifically regulated by transformer (tra), in which the functional tra promotes female-specific dm-dsx. however, the sex determination pathway in lepidoptera is not well understood; here we focused on alternative splicing of doublesex (dsx) in two agricultural pests, asian corn borer (ostrinia furnacalis) and cotton bollworm (helicoverpa armigera), as wel ...201424239545
a novel insecticidal groel protein from xenorhabdus nematophila confers insect resistance in tobacco.xenorhabdus nematophila is an entomopathogenic bacteria. it secretes a groel homolog, xngroel protein, toxic to its larval prey. groel belongs to the family of molecular chaperones and is required for proper folding of cellular proteins. oral ingestion of insecticidal xngroel protein is toxic to helicoverpa armigera, leading to cessation of growth and development of the larvae. in the present study, the insecticidal efficacy of xngroel against h. armigera has been evaluated in transgenic tobacco ...201423888329
field evaluation of a botanical formulation from the milky mangrove excoecaria agallocha l. against helicoverpa armigera hübner. in abelmoschus esculentus (lady's finger) and cajanus cajan (pigeon pea).to evaluate a formulation from the milky mangrove tree excoecaria agallocha l. (e. agallocha) against helicoverpa armigera hubner (h. armigera).201425312115
life table and consumption capacity of corn earworm, helicoverpa armigera, fed asparagus, asparagus officinalis.the life table and consumption rate of helicoverpa armigera (hübner) (lepidoptera: noctuidae) reared on asparagus, asparagus officinalis l. (asparagales: asparagaceae) were studied under laboratory conditions to assess their interaction. development, survival, fecundity, and consumption data were analyzed by the age-stage, twosex life table. this study indicated that asparagus is a natural host of h. armigera. however, the poor nutritional content in asparagus foliage and the poor fitness of h. ...201425373181
improved insecticidal toxicity by fusing cry1ac of bacillus thuringiensis with av3 of anemonia viridis.av3, a neurotoxin of anemonia viridis, is toxic to crustaceans and cockroaches but inactive in mammals. in the present study, av3 was expressed in escherichia coli origami b (de3) and purified by reversed-phase liquid chromatography. the purified av3 was injected into the hemocoel of helicoverpa armigera, rendering the worm paralyzed. then, av3 was expressed alone or fusion expressed with the cry1ac in acrystalliferous strain cry(-)b of bacillus thuringiensis. the shape of cry1ac was changed by ...201424375189
srp gene is required for helicoverpa armigera prophenoloxidase activation and nodulation response.srp gene was first identified from the fall webworm, hyphantria cunea as one of genes up-regulated after bacteria injection. a rent study in spodoptera litura showed that stress-induced elevation of srp expression highly correlates with reduced feeding activities and growth retardation of larvae. in this study, we identified a srp gene from the cotton bollworm, helicoverpa armigera, namely ha-srp, and studied its precise roles in insect immunity. expressions of ha-srp were upregulated in h. armi ...201424333441
biocontrol potential of steinernema thermophilum and its symbiont xenorhabdus indica against lepidopteran pests: virulence to egg and larval stages.under laboratory conditions, the biocontrol potential of steinernema thermophilum was tested against eggs and larval stages of two important lepidopteran insect pests, helicoverpa armigera and spodoptera litura (polyphagous pests), as well as galleria mellonella (used as a model host). in terms of host susceptibility of lepidopteran larvae to s. thermophilum, based on the lc50 36 hr after treatment, g. mellonella (lc50 = 16.28 ij/larva) was found to be more susceptible than s. litura (lc50 = 85 ...201424643472
up-regulated death-associated lim-only protein contributes to fitness costs of bacillus thuringiensis cry1ac resistance in helicoverpa armigera.the evolution of bacillus thuringiensis (bt) resistance provides a useful pathway for the study of fitness trade-offs associated with stress adaptation. in a previous study, we used cdna-amplification fragment length polymorphism (cdna-alfp) analysis to identify differentially expressed genes (degs) in cry1ac-susceptible (96s) and -resistant (bt-r) helicoverpa armigera larvae. among these degs, a death-associated lim-only protein (hadalp) was identified. in the current study, the full-length cdn ...201424326206
revisiting rubisco as a protein substrate for insect midgut proteases.gene fragments encoding the large subunit (ls) of rubisco (rbcl) were cloned from various species of host plants of phytophagous lepidoptera and expressed as recombinant proteins in escherichia coli. recombinant rbcls were compared among each other along with casein and native rubisco as proteinaceous substrates for measuring total midgut protease activities of fourth instar larvae of helicoverpa armigera feeding on casein, pieris brassicae feeding on cauliflower, and antheraea assamensis feedin ...201424338735
characterization of nadph-cytochrome p450 reductase gene from the cotton bollworm, helicoverpa armigera.a complete cdna encoding the nadph-cytochrome p450 reductase (hacpr) and its genomic sequence from the cotton bollworm helicoverpa armigera were cloned and sequenced. the open reading frame of hacpr codes for a protein of 687 amino acid residues with a calculated molecular mass of 77.4kda. the hacpr gene spans over 11 kb and its coding region is interrupted by 11 introns. hacpr is ubiquitously expressed in various tissues and at various stages of development. escherichia coli produced hacpr enzy ...201424768738
identification and functional characterization of a peptidoglycan recognition protein from the cotton bollworm, helicoverpa armigera.peptidoglycan recognition proteins (pgrps) specifically bind to peptidoglycans, and play crucial roles as pattern recognition receptors (prrs) in mediating innate immune responses. in this study, we identified and characterized a pgrp (hapgrp-d) from the cotton bollworm, helicoverpa armigera. sequence analysis indicated that hapgrp-d is an amidase-type pgrp. expression of hapgrp-d was upregulated in the hemocytes of h. armigera larvae after injecting gram-negative escherichia coli, gram-positive ...201425044262
in-vitro antimicrobial, antibiofilm, cytotoxic, antifeedant and larvicidal properties of novel quinone isolated from aegle marmelos (linn.) correa.plant metabolites have wide applications and have the potential to cure different diseases caused by microorganisms. the aim of the study was to evaluate the antimicrobial, antibiofilm, cytotoxic, antifeedant and larvicidal properties of novel quinine isolated from aegle marmelos (linn.) correa.201425359605
complete genome sequence of agrotis segetum granulovirus shanghai strain.the complete nucleotide sequence of agrotis segetum granulovirus shanghai strain (agsegv-l1) was determined and compared with that of agsegv xinjiang strain (agsegv-xj). the circular genome of agsegv-l1 is 131,442 bp and has a g+c content of 37.27 %. it includes 149 orfs, 24 of which are unique to agsegv (agsegv-l1 and agsegv-xj [genbank accession no. nc_005839]). the average level of amino acid sequence identity between agsegv-l1 and other granulovirus (gv) homologues (except agsegv-xj) ranged ...201424519461
20-hydroxyecdysone transcriptionally regulates humoral immunity in the fat body of helicoverpa armigera.20-hydroxyecdysone (20e) increases its titre level during the wandering stage and influences innate immunity in many holometabolous insects. however, the function of 20e as an immune-activator or -suppressor needs to be determined. here, the transcriptome of the peptidoglycan-challenged fat body of the cotton bollworm, helicoverpa armigera, was analysed using illumina sequencing technology. overall, 32 073 unigenes were assembled with a mean length of 643 nucleotides. gene expression dynamics in ...201425224836
combination of endophytic bacillus and beauveria for the management of fusarium wilt and fruit borer in tomato.most of the approaches for biocontrol of pests and diseases have used a single biocontrol agent as antagonist to a single pest or pathogen. this accounts for the inconsistency in the performance of biocontrol agents. the development of a bioformulation possessing a mixture of bioagents could be a viable option for the management of major pests and diseases in crop plants.201424376014
toxicity and cross-resistance of insecticides to cry2ab-resistant and cry2ab-susceptible helicoverpa armigera and helicoverpa punctigera (lepidoptera: noctuidae).since 2004-2005 cotton expressing cry1ac and cry2ab insecticidal proteins from the bacterium bacillus thuringiensis has been commercially available in australia to manage the target pests helicoverpa armigera (hübner) and helicoverpa punctigera (wallengren). in both target species, the frequency of alleles conferring resistance to cry2ab is unexpectedly high in field populations. a significant challenge for managing these pests would occur if resistance to cry2ab toxins inadvertently selected fo ...201426309283
acute, sublethal, and combination effects of azadirachtin and bacillus thuringiensis on the cotton bollworm, helicoverpa armigera.the cotton bollworm, helicoverpa armigera hübner (lepidoptera: noctuidae) is a polyphagous and cosmopolitan insect pest that causes damage to various plants. in this study, the lethal and sublethal effects of azadirachtin and bacillus thuringiensis berliner sub sp . kurstaki (bacillales: bacillaceae) were evaluated on third instar h. armigera under laboratory conditions. the lc50 values of azadirachtin and bt were 12.95 and 96.8 µg a.i./ml, respectively. a total mortality of 56.7% was caused on ...201425373177
development of pod borer-resistant transgenic chickpea using a pod-specific and a constitutive promoter-driven fused cry1ab/ac gene.we studied pod-specific msg promoter from soybean and developed different transgenic lines of chickpea expressing fused cry1ab/ac constitutively and pod specifically for resistance against the destructive pest helicoverpa armigera. crystal (cry) proteins derived from the soil bacterium bacillus thuringiensis (bt) play an important role in controlling infestation of helicoverpa armigera, which has been considered a serious problem in chickpea productivity. this study was undertaken to overcome th ...201425252910
characterization of protein phosphatase 5 from three lepidopteran insects: helicoverpa armigera, mythimna separata and plutella xylostella.protein phosphatase 5 (pp5), a unique member of serine/threonine phosphatases, regulates a variety of biological processes. we obtained full-length pp5 cdnas from three lepidopteran insects, helicoverpa armigera, mythimna separata and plutella xylostella, encoding predicted proteins of 490 (55.98 kda), 490 (55.82 kda) and 491 (56.07 kda) amino acids, respectively. these sequences shared a high identity with other insect pp5s and contained the tpr (tetratricopeptide repeat) domains at n-terminal ...201424823652
coexpression of the silent cry2ab27 together with cry1 genes in bacillus thuringiensis subsp. aizawai sp41 leads to formation of amorphous crystal toxin and enhanced toxicity against helicoverpa armigera.the unexpressed cry2ab27 gene of bacillus thuringiensis subsp. aizawai sp41 (sp41) consists of a single open reading frame (orf) of 1902bp encoding for 634 amino acid residues. the cry2ab27 gene appears to be silent due to the lack of promoter and terminator sequences. in this study we fused the cry2ab27 orf with the cry1ab promoter (500bp) and the terminator (300bp) in vector pht304-18z in order to drive the expression of cry2ab27 in both sp41 and an acrystaliferous, b. thuringiensis subsp. thu ...201424412546
cis-mediated down-regulation of a trypsin gene associated with bt resistance in cotton bollworm.transgenic plants producing insecticidal proteins from the bacterium bacillus thuringiensis (bt) are useful for pest control, but their efficacy is reduced when pests evolve resistance. here we examined the mechanism of resistance to bt toxin cry1ac in the laboratory-selected lf5 strain of the cotton bollworm, helicoverpa armigera. this strain had 110-fold resistance to cry1ac protoxin and 39-fold resistance to cry1ac activated toxin. evaluation of five trypsin genes revealed 99% reduced transcr ...201425427690
densovirus is a mutualistic symbiont of a global crop pest (helicoverpa armigera) and protects against a baculovirus and bt biopesticide.mutualistic associations between symbiotic bacteria and their hosts are common within insect systems. however, viruses are often considered as pathogens even though some have been reported to be beneficial to their hosts. herein, we report a novel densovirus, helicoverpa armigera densovirus-1 (hadnv-1) that appears to be beneficial to its host. hadnv-1 was found to be widespread in wild populations of h. armigera adults (>67% prevalence between 2008 and 2012). in wild larval populations, there w ...201425357125
dual cry2ab and vip3a resistant strains of helicoverpa armigera and helicoverpa punctigera (lepidoptera: noctuidae); testing linkage between loci and monitoring of allele frequencies.considerable attention has been given to delaying the evolution of insect resistance to toxins produced by transgenic crops. the major pests of cotton in australia are the lepidoptera helicoverpa armigera (hubner, 1805) and helicoverpa punctigera (wallengren), and the toxins deployed in current and imminent transgenic cotton varieties are cry1ac, cry2ab and vip3a from bacillus thuringiensis. in this study, lines that carry alleles conferring resistance to cry2ab and vip3a were isolated using f2 ...201425195454
pirb-cry2aa hybrid protein exhibits enhanced insecticidal activity against spodoptera exigua larvae.previous study revealed that the n-terminal region of pirb toxin from photorhabdus luminescens showed 20.5% identity and 41.5% similarity to the domain i of cry2a toxin of bacillus thuringiensis. the encoding sequence of the domain i of cry2aa protein was replaced by the encoding gene of corresponding domain of pirb protein. expression of pirb-cry2aa chimeric gene in b. thuringiensis acrystalliferous strain cry(-)b leads to the formation of crystals with irregular shape. bioassay showed that pir ...201424879991
molecular and insecticidal characterization of a novel cry-related protein from bacillus thuringiensis toxic against myzus persicae.this study describes the insecticidal activity of a novel bacillus thuringiensis cry-related protein with a deduced 799 amino acid sequence (~89 kda) and ~19% pairwise identity to the 95-kda-aphidicidal protein (sequence number 204) from patent us 8318900 and ~40% pairwise identity to the cancer cell killing cry proteins (parasporins cry41ab1 and cry41aa1), respectively. this novel cry-related protein contained the five conserved amino acid blocks and the three conserved domains commonly found i ...201425384108
draft genome sequence of bacillus thuringiensis serovar tolworthi strain na205-3, an isolate toxic for helicoverpa armigera.we report here the complete annotated 6,510,053-bp draft genome sequence of bacillus thuringiensis serovar tolworthi strain na205-3, which is toxic for helicoverpa armigera. this strain potentially contains nine insecticidal toxin genes homologous to cry1aa12, cry1ab1, cry1ab8, cry1ba1, cry1af1, cry1ia10, vip1bb1, vip2ba2, and vip3aa6.201424625875
mis-splicing of the abcc2 gene linked with bt toxin resistance in helicoverpa armigera.toxins from the bacterium bacillus thuringiensis (bt) are used widely for insect control in sprays and transgenic plants, but their efficacy is reduced when pests evolve resistance. previous work showed that mutations in a gene encoding the transporter protein abcc2 are linked with resistance to bt toxins cry1ab, cry1ac or both in four species of lepidoptera. here we compared the abcc2 gene of helicoverpa armigera (haabcc2) between susceptible strains and a laboratory-selected strain with >1,000 ...201425154974
characterization of parasporin gene harboring indian isolates of bacillus thuringiensis.bacillus thuringiensis (bt) is popularly known as insecticidal bacterium. however, non-insecticidal bt strains are more extensively available in natural environment than the insecticidal ones. parasporin (ps) is a collection of genealogically heterogeneous cry proteins synthesized in non-insecticidal isolates of bt. an important character generally related with ps proteins is their strong cytocidal activity preferentially on human cancer cells of various origins. identification and characterizat ...201428324389
quantitative analysis of fitness costs associated with the development of resistance to the bt toxin cry1ac in helicoverpa armigera.transgenic bacillus thuringiensis (bt) crops play an increasing role in pest control, and resistance management is a major issue in large-scale cultivation of bt crops. the fitness cost of resistance in targeted pests is considered to be one of the main factors delaying resistance when using the refuge strategy. by comparing 10 resistant helicoverpa armigera (hubner) strains, showing various resistance levels to bt toxin (cry1ac), to a susceptible strain, we showed an increasing fitness cost cor ...201425005122
stable bacillus thuringiensis transgene introgression from brassica napus to wild mustard b. juncea.transgenic canola (brassica napus) with a bacillus thuringiensis cry1ac gene and a green fluorescent protein (gfp) marker gene was used in hybridization experiments with wild brassica juncea. hybrid f1 and successive five backcross generations were obtained. the pod-set frequency on backcrossed b. juncea plants was over 66%, which suggested relatively high crossing compatibility between the hybrids and wild species. the seed setting in bc1 was the least of all generations tested, and then increa ...201425219305
evaluation of total phenolic compounds and insecticidal and antioxidant activities of tomato hairy root extract.tomatoes are one of the most consumed crops in the whole world because of their versatile importance in dietary food as well as many industrial applications. they are also a rich source of secondary metabolites, such as phenolics and flavonoids. in the present study, we described a method to produce these compounds from hairy roots of tomato (thrs). agrobacterium rhizogenes strain a4 was used to induce hairy roots in the tomato explants. the ri t-dna was confirmed by polymerase chain reaction am ...201424635720
tradeoff between reproduction and resistance evolution to bt-toxin in helicoverpa armigera: regulated by vitellogenin gene expression.evolution of resistance to insecticides usually has fitness tradeoffs associated with adaptation to the stress. the basic regulation mechanism of tradeoff between reproduction and resistance evolution to bacillus thuringiensis (bt) toxin in the cotton bollworm, helicoverpa armigera (ha), based on the vitellogenin (vg) gene expression was analyzed here. the full-length cdna of the vg gene havg (jx504706) was cloned and identified. havg has 5704 base pairs (bp) with an open reading frame (orf) of ...201424555504
a screening of five bacillus thuringiensis vip3a proteins for their activity against lepidopteran pests.five bacillus thuringiensis vip3a proteins (vip3aa, vip3ab, vip3ad, vip3ae and vip3af) and their corresponding trypsin-activated toxins were tested for their toxicity against eight lepidopteran pests: agrotis ipsilon, helicoverpa armigera, mamestra brassicae, spodoptera exigua, spodoptera frugiperda, spodoptera littoralis, ostrinia nubilalis and lobesia botrana. toxicity was first tested at a high dose at 7 and 10 days. no major differences were found when comparing protoxins vs. trypsin-activat ...201424508583
response of last instar helicoverpa armígera larvae to bt toxin ingestion: changes in the development and in the cyp6ae14, cyp6b2 and cyp9a12 gene expression.bt crops are able to produce cry proteins, which were originally present in bacillus thuringiensis bacteria. although bt maize is very efficient against corn borers, spanish crops are also attacked by the earworm h. armigera, which is less susceptible to bt maize. many mechanisms could be involved in this low susceptibility to the toxin, including the insect's metabolic resistance to toxins due to cytochrome p450 monooxygenases. this paper examines the response of last instar h. armigera larvae ...201424910993
identification and characterization of the sudanese bacillus thuringiensis and related bacterial strains for their efficacy against helicoverpa armigera and tribolium castaneum.forty-four isolates of bacillus thuringiensis like bacteria from various sources in different locations from sudan were tested for their insecticidal activity. the toxicity of these isolates ranged from 6.6 to 70% to the neonates of cotton bollworm, helicoverpa armigera at 10 ppm concentration. the most effective ones are kb-29, st-6 and wh-1 comparable with hd-1. toxicity of isolates to larvae of the red flour beetle, tribolium castaneum ranged from 20 to 100%. isolates st-2 and st-23 gave 100% ...201424956895
synthetic fusion-protein containing domains of bt cry1ac and allium sativum lectin (asal) conferred enhanced insecticidal activity against major lepidopteran pests.different transgenic crop plants, developed with δ-endotoxins of bacillus thuringiensis (bt) and mannose-specific plant lectins, exhibited significant protection against chewing and sucking insects. in the present study, a synthetic gene (cry-asal) encoding the fusion-protein having 488 amino acids, comprising di and dii domains from bt cry1ac and allium sativum agglutinin (asal), was cloned and expressed in escherichia coli. ligand blot analysis disclosed that the fusion-protein could bind to m ...201424355805
cadherin mutation linked to resistance to cry1ac affects male paternity and sperm competition in helicoverpa armigera.several lepidopteran pests of cotton have cadherin-based resistance to the bacillus thuringiensis (bt) toxin cry1ac. cadherins are transmembrane proteins that mediate cell-cell adhesion and tissue morphogenesis, suggesting that fitness costs associated with cadherin mutations may be present in many aspects of life history. to evaluate whether cadherin-based resistance is associated with fitness costs reducing male paternity in helicoverpa armigera, we examined the effects of a major cadherin res ...201425220924
diversity in gut microflora of helicoverpa armigera populations from different regions in relation to biological activity of bacillus thuringiensis δ-endotoxin cry1ac.transgenic crops expressing toxin proteins from bacillus thuringiensis (bt) have been deployed on a large scale for management of helicoverpa armigera. resistance to bt toxins has been documented in several papers, and therefore, we examined the role of midgut microflora of h. armigera in its susceptibility to bt toxins. the susceptibility of h. armigera to bt toxin cry1ac was assessed using log-dose-probit analysis, and the microbial communities were identified by 16s rrna sequencing. the h. ar ...201425195523
evaluation of the synergistic activities of bacillus thuringiensis cry proteins against helicoverpa armigera (lepidoptera: noctuidae).with the aim of identifying cry proteins that would be useful in the management of the economically important lepidopteran pest helicoverpa armigera, the larvicidal activities of binary combinations (1:1 ratios) of six cry proteins (cry1aa, cry1ab, cry1ac, cry1ca, cry2aa and cry9aa) were evaluated against h. armigera neonate larvae using droplet feeding bioassays. determination of the ld50 values of individual cry proteins and mixtures of cry proteins enabled assessment of the nature of the inte ...201424963598
antibiotics influence the toxicity of the delta endotoxins of bacillus thuringiensis towards the cotton bollworm, helicoverpa armigera.the cotton bollworm, helicoverpa armigera is one of the most important crop pests worldwide. it has developed high levels of resistance to synthetic insecticides, and hence, bacillus thuringiensis (bt) formulations are used as a safer pesticide and the bt genes have been deployed in transgenic crops for controlling this pest. there is an apprehension that h. armigera might develop resistance to transgenic crops in future. therefore, we studied the role of gut microbes by eliminating them with an ...201425059716
central projections of gustatory receptor neurons in the medial and the lateral sensilla styloconica of helicoverpa armigera larvae.food selection behavior of lepidopteran larvae is predominantly governed by the activation of taste neurons present in two sensilla styloconica located on the galea of the maxilla. in this study, we present the ultrastructure of the sensilla styloconica and the central projection pattern of their associated receptor neurons in larvae of the heliothine moth, helicoverpa armigera. by means of light microscopy and scanning electron microscopy, the previous findings of two morphologically fairly sim ...201424740428
phospholipase cγ1 connects the cell membrane pathway to the nuclear receptor pathway in insect steroid hormone signaling.in addition to the classical nuclear receptor pathway, there is a nongenomic pathway in the cell membrane that regulates gene expression in animal steroid hormone signaling; however, this mechanism is unclear. here, we report that the insect steroid hormone 20-hydroxyecdysone (20e) regulates calcium influx via phospholipase cγ1 (plcg1) to modulate the protein kinase c phosphorylation of the transcription factor ultraspiracle (usp1) in the lepidopteran insect helicoverpa armigera. the plcg1 mrna ...201424692553
juvenile hormone prevents 20-hydroxyecdysone-induced metamorphosis by regulating the phosphorylation of a newly identified broad protein.the steroid hormone 20-hydroxyecdysone (20e) initiates insect molting and metamorphosis. by contrast, juvenile hormone (jh) prevents metamorphosis. however, the mechanism by which jh inhibits metamorphosis remains unclear. in this study, we propose that jh induces the phosphorylation of broad isoform z7 (brz7), a newly identified protein, to inhibit 20e-mediated metamorphosis in the lepidopteran insect helicoverpa armigera. the knockdown of brz7 in larvae inhibited metamorphosis by repressing th ...201425096576
a transferrin gene associated with development and 2-tridecanone tolerance in helicoverpa armigera.the full-length cdna (2320 bp) encoding a putative iron-binding transferrin protein from helicoverpa armigera was cloned and named hatrf. the putative hatrf sequence included 670 amino acids with a molecular mass of approximately 76 kda. quantitative pcr results demonstrated that the transcriptional level of hatrf was significantly higher in the sixth instar and pupa stages as compared with other developmental stages. hatrf transcripts were more abundant in fat bodies and in the epidermis than i ...201425430818
insect resistance to bacillus thuringiensis toxin cry2ab is conferred by mutations in an abc transporter subfamily a protein.the use of conventional chemical insecticides and bacterial toxins to control lepidopteran pests of global agriculture has imposed significant selection pressure leading to the rapid evolution of insecticide resistance. transgenic crops (e.g., cotton) expressing the bt cry toxins are now used world wide to control these pests, including the highly polyphagous and invasive cotton bollworm helicoverpa armigera. since 2004, the cry2ab toxin has become widely used for controlling h. armigera, often ...201526583651
a toxin-binding alkaline phosphatase fragment synergizes bt toxin cry1ac against susceptible and resistant helicoverpa armigera.evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (cry) proteins from the bacterium bacillus thuringiensis (bt) in sprays and transgenic plants. in this study, laboratory selection with cry1ac yielded five strains of cotton bollworm, helicoverpa armigera, with resistance ratios at the median lethal concentration (lc50) of activated cry1ac ranging from 22 to 1700. reduced activity and reduced transcription of an alkaline phosphatase prot ...201525885820
high nucleotide diversity and limited linkage disequilibrium in helicoverpa armigera facilitates the detection of a selective sweep.insecticides impose extreme selective pressures on populations of target pests and so insecticide resistance loci of these species may provide the footprints of 'selective sweeps'. to lay the foundation for future genome-wide scans for selective sweeps and inform genome-wide association study designs, we set out to characterize some of the baseline population genomic parameters of one of the most damaging insect pests in agriculture worldwide, helicoverpa armigera. to this end, we surveyed nine ...201526174024
sequence analysis, expression profiles and function of thioredoxin 2 and thioredoxin reductase 1 in resistance to nucleopolyhedrovirus in helicoverpa armigera.the thioredoxin system, including nadph, thioredoxin (trx), and thioredoxin reductase (trxr), plays significant roles in maintaining intracellular redox homeostasis and protecting organisms against oxidative damage. in this study, the characteristics and functions of h. armigera hatrx2 and hatrxr1 were identified. sequence analysis showed that hatrx2 and hatrxr1 were both highly conserved and shared high sequence identity with other insect counterparts. the mrna of hatrx2 was expressed the highe ...201526502992
multicopper oxidase-1 is required for iron homeostasis in malpighian tubules of helicoverpa armigera.multicopper oxidases (mcos) are enzymes that contain 10 conserved histidine residues and 1 cysteine residue. mco1 has been extensively investigated in the midgut because this mco is implicated in ascorbate oxidation, iron homeostasis and immune responses. however, information regarding the action of mco1 in malpighian tubules is limited. in this study, helicoverpa armigera was used as a model to investigate the function of mco1 in malpighian tubules. sequence analysis results revealed that hamco ...201526437857
high throughput profiling of the cotton bollworm helicoverpa armigera immunotranscriptome during the fungal and bacterial infections.innate immunity is essential in defending against invading pathogens in invertebrates. the cotton bollworm, helicoverpa armigera (hübner) is one of the most destructive lepidopteran pests, which causes enormous economic losses in agricultural production worldwide. the components of the immune system are largely unknown in this insect. the application of entomopathogens is considered as an alternative to the chemical insecticides for its control. however, few studies have focused on the molecular ...201526001831
nmr structure and function of helicoverpa armigera sterol carrier protein-2, an important insecticidal target from the cotton bollworm.the cotton bollworm, helicoverpa armigera, has developed strong resistance to many insecticides. sterol carrier protein-2 (scp-2) is an important non-specific lipid transfer protein in insects and appears to be a potential new target. in order to elucidate the structure and function of helicoverpa armigera scp-2 (hascp-2), nmr spectroscopy, docking simulations, mutagenesis and bioassays were performed. hascp-2 composed of five α-helices and four stranded β-sheets. the folds of α-helices and β-sh ...201526655641
responses of 9 lepidopteran species to bacillus thuringiensis: how useful is phylogenetic relatedness for selecting surrogate species for nontarget arthropod risk assessment?to evaluate phylogenetic relatedness as a proxy for susceptibility to bacillus thuringiensis (bt) when selecting species to act as surrogates for others in prerelease testing, we examined the responses of 11 laboratory-reared lepidopteran colonies, comprising members of 2 families, 5 genera, and 9 species, to a commercial bt preparation. survival, pupal mass, and timing of pupation and adult emergence of 2 noctuids (spodoptera litura and helicoverpa armigera) and 7 tortricids (cnephasia jactatan ...201525111652
a deletion mutant ndv200 of the bacillus thuringiensis vip3br insecticidal toxin gene is a prospective candidate for the next generation of genetically modified crop plants resistant to lepidopteran insect damage.ectopic expression of a deletion mutant ( ndv200 ) of bacillus thuringiensis vip3br gene in tobacco plant provided almost complete protection against major crop pests cotton boll worm ( helicoverpa armigera ), black cut worm ( agrotis ipsilon ) and cotton leaf worm ( spodoptera littoralis ). whereas vip3br transgenic tobacco plant failed to protect themselves from these insects and showed resistance towards cotton leaf worm only. an analogous form of the bacillus thuringiensis vip3aa insecticida ...201525912191
establishment and characterization of a novel cell line from midgut tissue of helicoverpa armigera (lepidoptera: noctuidae).the midgut of lepidopteran larvae serves as a target for many pathogens such as bacillus thuringiensis (bt). cell lines originating from midgut tissues will be very helpful tools in many research fields. however, to date, no bt-susceptible midgut-derived cell lines are available. here, we reported that a novel cell line, designated as hnu-ha-mg1, was established from midgut tissue of the fourth instar larvae of helicoverpa armigera. this cell line grew well in grace's insect cell culture medium ...201525678461
molecular docking and site-directed mutagenesis of a bacillus thuringiensis chitinase to improve chitinolytic, synergistic lepidopteran-larvicidal and nematicidal activities.bacterial chitinases are useful in the biocontrol of agriculturally important pests and fungal pathogens. however, the utility of naturally occurring bacterial chitinases is often limited by their low enzyme activity. in this study, we constructed mutants of a bacillus thuringiensis chitinase with enhanced activity based on homology modeling, molecular docking, and the site-directed mutagenesis of target residues to modify spatial positions, steric hindrances, or hydrophilicity/hydrophobicity. w ...201525678849
fitness costs of reproductive capacity and ovarian development in a bt-resistant strain of the cotton bollworm helicoverpa armigera (hübner) (lepidoptera: noctuidae).the cotton bollworm helicoverpa armigera has developed resistance to the insecticidal cry1ac toxins produced by bacillus thuringiensis (bt) in china. to gain a better understanding of the fitness cost associated with resistance evolution, reproductive capacities and ovarian development were examined in four strains of h. armigera: a cry1ac-susceptible strain (96s); a cry1ac-resistant strain fed on an artificial diet with cry1ac toxin for 135 generations (btr); two strains derived from btr: a str ...201525186022
baseline sensitivity of maize borers in india to the bacillus thuringiensis insecticidal proteins cry1a.105 and cry2ab2.among the major pests of maize in india are two stem borers, chilo partellus (swinhoe) and sesamia inferens (walker), and an earworm, helicoverpa armigera (hübner). as a pest control strategy, transgenic bacillus thuringiensis (bt) maize hybrids are undergoing regulatory trials in india. we have determined the sensitivity of the target lepidopterans to the insecticidal bt proteins expressed in bt maize, as this determines product efficacy and the resistance management strategy to be adopted. mai ...201525143318
an encapsidated viral protein and its role in rna packaging by a non-enveloped animal rna virus.alphatetraviruses are small (+) ssrna viruses with non-enveloped, icosahedral, t=4 particles that assemble from 240 copies of a single capsid protein precursor. this study is focused on the mechanisms underlying selection and packaging of genomic vrnas by helicoverpa armigera stunt virus. we demonstrate that the viral protein, p17, is packaged at low levels (between 4 and 8 copies per capsid) raising the possibility of icosahedral asymmetry in wild-type particles. p17 promotes packaging of vrna2 ...201525577149
the endoparasitoid campoletis chlorideae induces a hemolytic factor in the herbivorous insect helicoverpa armigera.although lysis of invading organisms is a major innate form of immunity used by invertebrates, it remains unclear whether herbivorous insects have hemolysin or not. to address this general question, we tested the hemolytic (hl) activity of the hemolymph and tissue extracts from various stages of the polyphagous insect helicoverpa armigera (hübner) against the erythrocytes from chicken, duck, and rabbit. an hl activity was identified in the hemolymph of h. armigera larvae. further studies demonst ...201525929852
improvement in the uv resistance of baculoviruses by displaying nano-zinc oxide-binding peptides on the surfaces of their occlusion bodies.the sensitivity of baculoviruses to uv radiation severely limits their large-scale application as biological insecticides. the polyhedron envelope of a baculovirus, which is composed of carbohydrate and polyhedron envelope protein (pep), is a significant structure for the stability and persistence of occlusion bodies (obs) under environmental conditions. the results of this study revealed that the rough pitted surface phenotype of a pep-null autographa californica multiple nucleopolyhedrovirus ( ...201525895092
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