Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| functional analysis of the abcs of eye color in helicoverpa armigera with crispr/cas9-induced mutations. | many insect pigments are localized in subcellular pigment granules, and transport of pigment precursors from the cytoplasm is accomplished by abc proteins. drosophila melanogaster has three half-transporter genes (white, scarlet, and brown, all affecting eye pigments) and bombyx mori has a fourth (ok). the white, brown, scarlet and ok proteins each have one transmembrane and one cytoplasmic domain and they heterodimerize to form functional transporters with different substrate specificities. we ... | 2017 | 28053351 |
| transgenic pigeonpea events expressing cry1ac and cry2aa exhibit resistance to helicoverpa armigera. | independent transgenic pigeonpea events were developed using two cry genes. transgenic cry2aa-pigeonpea was established for the first time. selected transgenic events demonstrated 100% mortality of helicoverpa armigera in successive generations. lepidopteran insect helicoverpa armigera is the major yield constraint of food legume pigeonpea. the present study was aimed to develop h. armigera-resistant transgenic pigeonpea, selected on the basis of transgene expression and phenotyping. agrobacteri ... | 2017 | 28352969 |
| insecticidal specificity of cry1ah to helicoverpa armigera is determined by binding of apn1 via domain ii loops 2 and 3. | bacillus thuringiensis cry1ah protein is highly toxic against helicoverpa armigera but shows no toxicity against bombyx mori larvae. in contrast, the closely related cry1ai toxin showed the opposite phenotype: high activity against b. mori but no toxicity against h. armigera. analysis of binding of cry1ah to brush border membrane vesicle (bbmv) proteins from h. armigera and b. mori by surface plasmon resonance revealed association of toxin binding with insect specificity. pulldown experiments id ... | 2017 | 27940541 |
| baseline susceptibility of field populations of helicoverpa armigera to bacillus thuringiensis vip3aa toxin and lack of cross-resistance between vip3aa and cry toxins. | the cotton bollworm helicoverpa armigera (hübner) is one of the most damaging cotton pests worldwide. in china, control of this pest has been dependent on transgenic cotton producing a single bacillus thuringiensis (bt) protein cry1ac since 1997. a small, but significant, increase in h. armigera resistance to cry1ac was detected in field populations from northern china. since vip3aa has a different structure and mode of action than cry proteins, bt cotton pyramids containing vip3aa are considere ... | 2017 | 28379206 |
| effects of site-mutations within the 22 kda no-core fragment of the vip3aa11 insecticidal toxin of bacillus thuringiensis. | bacillus thuringiensis vegetative insecticidal proteins (vips) are not homologous to other known cry proteins, and they act against lepidopteran larvae via a unique process. all reported studies on the mode of action of vip3 proteins have been performed on the vip3a family, mostly on the vip3aa subfamily. vip3aa proteins are activated by midgut proteases, and they cross the peritrophic membrane and bind specific proteins in apical membrane epithelial midgut cells, which results in pore formation ... | 2017 | 28321527 |
| next-generation transgenic cotton: pyramiding rnai and bt counters insect resistance. | transgenic crops producing insecticidal proteins from the bacterium bacillus thuringiensis (bt) are extensively cultivated worldwide. to counter rapidly increasing pest resistance to crops that produce single bt toxins, transgenic plant 'pyramids' producing two or more bt toxins that kill the same pest have been widely adopted. however, cross-resistance and antagonism between bt toxins limit the sustainability of this approach. here we describe development and testing of the first pyramids of co ... | 2017 | 28199783 |
| resistance to bacillus thuringiensis toxin cry2ab and survival on single-toxin and pyramided cotton in cotton bollworm from china. | evolution of helicoverpa armigera resistance to bacillus thuringiensis (bt) cotton producing cry1ac is progressing in northern china, and replacement of cry1ac cotton by pyramided bt cotton has been considered to counter such resistance. here, we investigated four of the eight conditions underlying success of the refuge strategy for delaying resistance to cry1ac+cry2ab cotton, a pyramid that has been used extensively against h. armigera outside china. laboratory bioassays of a cry2ab-selected st ... | 2017 | 28127393 |
| effects of soil salinity on the expression of bt toxin (cry1ac) and the control efficiency of helicoverpa armigera in field-grown transgenic bt cotton. | an increasing area of transgenic bacillus thuringiensis (bt) cotton is being planted in saline-alkaline soil in china. the bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. however, how soil salinity affects the expression of bt protein, thus influencing the control efficiency of bt cotton against the cotton bollworm (cbw) helicoverpa armigera (hübner) in the field, is poorly ... | 2017 | 28099508 |
| a single point mutation resulting in cadherin mislocalization underpins resistance against bacillus thuringiensis toxin in cotton bollworm. | transgenic plants that produce bacillus thuringiensis (bt) crystalline (cry) toxins are cultivated worldwide to control insect pests. resistance to b. thuringiensis toxins threatens this technology, and although different resistance mechanisms have been identified, some have not been completely elucidated. to gain new insights into these mechanisms, we performed multiple back-crossing from a 3000-fold cry1ac-resistant btr strain from cotton bollworm (helicoverpa armigera), isolating a 516-fold c ... | 2017 | 28082675 |
| spatio-temporal variation in landscape composition may speed resistance evolution of pests to bt crops. | transgenic crops that express insecticide genes from bacillus thuringiensis (bt) are used worldwide against moth and beetle pests. because these engineered plants can kill over 95% of susceptible larvae, they can rapidly select for resistance. here, we use a model for a pyramid two-toxin bt crop to explore the consequences of spatio-temporal variation in the area of bt crop and non-bt refuge habitat. we show that variability over time in the proportion of suitable non-bt breeding habitat, q, or ... | 2017 | 28046073 |
| activity of selected formulated biorational and synthetic insecticides against larvae of helicoverpa armigera (lepidoptera: noctuidae). | this work studied 17 insecticides belonging to nucleopolyhedrovirus (npv), bacillus thuringiensis (bt kurstaki and bt aizawai), benzoylureas (insect growth regulators [igrs]), carbamates, organophosphates, spinosyns, and diamides against larvae of helicoverpa armigera (hübner), invasive species in the south american continent. larvae of different instars were fed for 7 d with untreated or insecticide-treated diets. mortality was recorded daily for 7 d, and surviving larvae were individually weig ... | 2017 | 28011685 |
| [characterization and cloning of the cry2a gene from indigenous isolates of bacillus thuringiensis]. | discovery of novel cry genes of bacillus thuringiensis (bt) with higher toxicity is important for the development of transgenic bt crops resistant to target pests. two new indigenous isolates of bt were characterized for their colony type, crystal inclusion and toxicity with helicoverpa armigera hubner and spodoptera litura linn. screening of cry2a genes from the two new isolates of bt, t30 and t48, by pcr with cry2a family primers showed the presence of cry2a genes only in the isolate t30. furt ... | 2017 | 26299858 |
| molecular cloning and characterization of α-amylase/subtilisin inhibitor from rhizome of ligusticum chuanxiong. | to clone and characterize a novel bi-functional α-amylase/subtilisin inhibitor (lasi) from the rhizome of ligusticum chuanxiong, a traditional chinese medicine. | 2017 | 27752792 |
| the efficacy of beauveria bassiana, jasmonic acid and chlorantraniliprole on larval populations of helicoverpa armigera in chickpea crop ecosystems. | a robust integrated pest management (ipm) programme is needed to reduce the use of insecticides in controlling helicoverpa armigera. therefore, a 2 year field study was conducted to evaluate the use of alternative control measures (biochemical use) for h. armigera relative to exclusively using chemical insecticides. the entomopathogenic fungus beauveria bassiana, jasmonic acid and the insecticide chlorantraniliprole were each applied twice during the chickpea growing season. | 2017 | 27101405 |
| chemical profile and defensive function of the latex of euphorbia peplus. | plant latex is an endogenous fluid secreted from highly specialized laticifer cells and has been suggested to act as a plant defense system. the chemical profile of the latex of euphorbia peplus was investigated. a total of 13 terpenoids including two previously unknown diterpenoids, (2s*,3s*,4r*,5r*,6r*,8r*,l1r*,13s*,14s*,15r*, 16r*)-5,8,15-triacetoxy-3-benzoyloxy-11,16-dihydroxy-9-oxopepluane and (2r*,3r*, 4s*,5r*,7s*,8s*,9s*,l3s*,14s*,15r*)-2,5,8,9,14-pentaacetoxy-3-benzoyloxy-15-hydroxy-7-is ... | 2017 | 28062071 |
| various bioactivity and relationship of structure-activity of matrine analogues. | for the first time, the botanic source natural product matrine was reported to have more potent inhibitory activity against tobacco mosaic virus (tmv) than the commercial virucide ribavirin. on the basis of the structural diversity modification strategy, a series of matrine derivatives was synthesized and systematically evaluated for their antiviral activity against tmv, fungicidal activity, and insecticidal activity. as a result, compounds 3 (inhibitory rate 67.3%, 69.5%, 63.7%, 63.0% at 500 μg ... | 2017 | 28248103 |
| mass rearing and augmentative biological control evaluation of rhynocoris fuscipes (hemiptera: reduviidae) against multiple pests of cotton. | rhynocoris fuscipes (fab.) (hemiptera: reduviidae) is a generalist predator of cotton pests and is commonly found inhabiting cotton-growing regions in southern india. with the goal of integrating this predator in standard management practices used against cotton pests on a commercial scale, (1) we developed a protocol for adult group rearing of this predator inside micro-environmental cages (mecs), and (2) we evaluated the biocontrol potential of mass-produced predators against cotton pests unde ... | 2017 | 28127861 |
| comparative host selection responses of specialist (helicoverpa assulta) and generalist (helicoverpa armigera) moths in complex plant environments. | we tested the behavioral responses of ovipositing females and natal larvae of two sibling species, a generalist helicoverpa armigera (hübner) and a specialist helicoverpa assulta (guenée), to odor sources emitted from different combinations of six plant species (tobacco, nicotiana tabacum; hot pepper, capsicum annuum; tomato, solanum esculentum; cotton, gossypium hirsutum; peanut, arachis hypogaea; maize, zea mays). under the conditions of plant materials versus corresponding controls, both stag ... | 2017 | 28182679 |
| mitochondrial dna and trade data support multiple origins of helicoverpa armigera (lepidoptera, noctuidae) in brazil. | the old world bollworm helicoverpa armigera is now established in brazil but efforts to identify incursion origin(s) and pathway(s) have met with limited success due to the patchiness of available data. using international agricultural/horticultural commodity trade data and mitochondrial dna (mtdna) cytochrome oxidase i (coi) and cytochrome b (cyt b) gene markers, we inferred the origins and incursion pathways into brazil. we detected 20 mtdna haplotypes from six brazilian states, eight of which ... | 2017 | 28350004 |
| beauveria medogensis sp. nov., a new fungus of the entomopathogenic genus from china. | beauveria is among the most ubiquitous genera of entomopathogenic fungi throughout the world. a previously unknown species of the genus was recently discovered from a soil sample collected from tibetan plateau, china and is here described as new to science, b. medogensis sp. nov. the new species is distinguished from its closest relatives based on both morphological characterization and molecular phylogenetic analyses. beauveria medogensis is characterized by globose to subglobose conidia, morph ... | 2016 | 27449678 |
| bioefficacy and persistence of acephate in mungbean vigna radiata (l.) wilczek. | the bioefficacy, persistence and metabolism of foliar application of acephate 75 sp at the respective recommended and double doses of 1500 and 3000 g a.i. ha(-1) were studied on kharif mungbean crop. acephate gave a very effective control of the pod borer, helicoverpa armigera (hubner) at the tested doses on mungbean crop throughout the cropping season, besides recording lower percent pod damage and higher grain yield. the recommended dose of acephate also recorded higher net returns and thus in ... | 2016 | 27262970 |
| cross-species amplification and polymorphism of microsatellite loci in helicoverpa armigera and helicoverpa zea (lepidoptera: noctuidae) in brazilian cropping systems. | the old world bollworm helicoverpa armigera (hübner) was recently discovered in brazil. this species is closely related to the new world bollworm h. zea (boddie), and mating between these species has already been reported under laboratory conditions. here, we tested the cross-species amplification of 20 microsatellite (ssr) loci in field populations of h. armigera and h. zea collected from brazilian cropping systems. seven ssr loci were successfully amplified and polymorphic in both species exce ... | 2016 | 27173200 |
| insecticidal activity of a novel fatty acid amide derivative from streptomyces species against helicoverpa armigera. | helicoverpa armigera, an important pest causes serious damage to grain legumes. the main objective of this study was to isolate and identify the metabolite against h. armigera from a previously characterised streptomyces sp. cai-155. the culture filtrate of cai-155 was extracted using diaion hp-20 and the active fractions were fractionated on silica and c18 column chromatography. the c18 active fraction was further fractionated on silica gel 60 f254 thin layer chromatography (tlc). the most acti ... | 2016 | 26956775 |
| novel hydrazone derivatives containing pyridine amide moiety: design, synthesis, and insecticidal activity. | a series of novel hydrazone derivatives containing pyridine amide moiety were designed, synthesized, and evaluated for their insecticidal activity. bioassays indicated that some of the target compounds exhibited good insecticidal activities against nilaparvata lugens (n. lugens), plutella xylostella (p. xylostella), mythimna separata (m. separata), helicoverpa armigera (h. armigera), pyrausta nubilalis (p. nubilalis), and culex pipiens pallens (c. pipiens pallens). in particular, compound 5j rev ... | 2016 | 26832221 |
| synthesis and antiviral, insecticidal, and fungicidal activities of gossypol derivatives containing alkylimine, oxime or hydrazine moiety. | gossypol is a part of the cotton plant's defense system against pathogens and herbivorous insects. to discover gossypol analogs with broad spectrum and high activity, a series of gossypol alkylamine schiff base, oxime and hydrazone derivatives were synthesised and bioassayed. the biological results indicated that most of these derivatives exhibited higher anti-tmv activity than gossypol. interestingly, the activities of compounds 10, 15, 18, 20, 23 and 26 were much higher than that of ribavirin. ... | 2016 | 26337022 |
| adaptation of habrobracon hebetor (hymenoptera: braconidae) to rearing on ephestia kuehniella (lepidoptera: pyralidae) and helicoverpa armigera (lepidoptera: noctuidae). | food characteristics strongly regulate digestive enzymatic activity of insects through direct influences on their midgut mechanisms. insect performance is better on diets that contain nutrients in proportions that fit its digestive enzymes. little is known about the influences of rearing history on parasitism success of habrobracon hebetor say. this research focused on the effect of nutrient regulation on survival, development, and parasitism of h. hebetor. life history and digestive enzyme acti ... | 2016 | 26839317 |
| genome-wide transcriptomic and proteomic analyses of bollworm-infested developing cotton bolls revealed the genes and pathways involved in the insect pest defence mechanism. | cotton bollworm, helicoverpa armigera, is a major insect pest that feeds on cotton bolls causing extensive damage leading to crop and productivity loss. in spite of such a major impact, cotton plant response to bollworm infection is yet to be witnessed. in this context, we have studied the genome-wide response of cotton bolls infested with bollworm using transcriptomic and proteomic approaches. further, we have validated this data using semi-quantitative real-time pcr. comparative analyses have ... | 2016 | 26799171 |
| effect of the postfeeding interval on olfactory responses of thrips to herbivore-induced cotton plants. | we investigated the responses of 3 thrips species, frankliniella schultzei trybom, f. occidentalis pergrande, and thrips tabaci lindeman (thysanoptera: thripidae) to herbivore-damaged and undamaged cotton seedlings (gossypium hirsutum l. [malvales: malvaceae]) at a range of time intervals following damage by adult tetranychus urticae (koch), adult t. ludeni (zacher) (acari: tetranychidae) or helicoverpa armigera (hübner) (lepidoptera: noctuidae) larvae in olfactometer assays. the intensity/frequ ... | 2016 | 26172119 |
| whole genome re-sequencing reveals genome-wide variations among parental lines of 16 mapping populations in chickpea (cicer arietinum l.). | chickpea (cicer arietinum l.) is the second most important grain legume cultivated by resource poor farmers in south asia and sub-saharan africa. in order to harness the untapped genetic potential available for chickpea improvement, we re-sequenced 35 chickpea genotypes representing parental lines of 16 mapping populations segregating for abiotic (drought, heat, salinity), biotic stresses (fusarium wilt, ascochyta blight, botrytis grey mould, helicoverpa armigera) and nutritionally important (pr ... | 2016 | 26822060 |
| characterization of the viral fibroblast growth factor homolog of helicoverpa armigera single nucleopolyhedrovirus. | fibroblast growth factor (fgf) is found throughout multicellular organisms; however, fgf homologs (vfgf) have only been identified among viruses in lepidopteran baculoviruses. the function of vfgfs from group i alphabaculoviruses, including autographa californica multiple nucleopolyhedrovirus (acmnpv) and bombyx mori nucleopolyhedrovirus (bmnpv), involves accelerated killing of infected larvae by both viruses. the vfgf of group ii alphabaculovirus is structurally different from that of group i a ... | 2016 | 27142667 |
| relative fitness of helicoverpa armigera (lepidoptera: noctuidae) on seven host plants: a perspective for ipm in brazil. | the cotton bollworm helicoverpa armigera (hübner) (lepidoptera: noctuidae) is a widespread pest of many cultivated and wild plants in europe, africa, asia, and australia. in 2013, this species was reported in brazil, attacking various host crops in the midwestern and northeastern regions of the country and is now found countrywide. aiming to understand the effects of different host plants on the life cycle of h. armigera, we selected seven species of host plants that mature in different seasons ... | 2016 | 26798139 |
| bt cry1ie toxin does not impact the survival and pollen consumption of chinese honey bees, apis cerana cerana (hymenoptera, apidae). | the cry1ie gene may be a good candidate for the development of bt maize because over-expression of cry1ie is highly toxic to lepidopteran pests such as heliothis armigera hübner and ostrinia furnacalis guenée. the bt cry1ie gene also has no cross resistance with other insecticidal proteins such as cry1ab, cry1ac, cry1ah, or cry1f. chinese honey bees (apis cerana cerana) are potentially exposed to insect-resistant genetically modified (irgm) crops expressing cry1ie toxin via the collection of irg ... | 2016 | 27670271 |
| pheromone lure and trap color affects bycatch in agricultural landscapes of utah. | aerial traps, using combinations of color and attractive lures, are a critical tool for detecting and managing insect pest populations. yet, despite improvements in trap efficacy, collection of nontarget species ("bycatch") plagues many insect pest surveys. bycatch can influence survey effectiveness by reducing the available space for target species and increasing trap screening time, especially in areas where thousands of insects are captured as bycatch in a given season. additionally, bycatch ... | 2016 | 27412193 |
| effects of single and dual species herbivory on the behavioural responses of three thrips species to cotton seedlings. | this study investigated the olfactory responses of three thrips species [frankliniella schultzei trybom, f. occidentalis pergrande and thrips tabaci lindeman (thysanoptera: thripidae)] to cotton seedlings [gossypium hirsutum l. (malvales: malvaceae)] simultaneously damaged by different combinations of herbivores. cotton seedlings were damaged by foliar feeding tetranychus urticae koch (trombidiforms: tetranychidae), helicoverpa armigera hübner (lepidoptera: noctuidae), aphis gossypii glover (hem ... | 2016 | 27029603 |
| cell culture for production of insecticidal viruses. | while large-scale culture of insect cells will need to be conducted using bioreactors up to 10,000 l scale, many of the main challenges for cell culture-based production of insecticidal viruses can be studied using small-scale (20-500 ml) shaker/spinner flasks, either in free suspension or using microcarrier-based systems. these challenges still relate to the development of appropriate cell lines, stability of virus strains in culture, enhancing virus yields per cell, and the development of seru ... | 2016 | 27565495 |
| differential induction of flavonoids in groundnut in response to helicoverpa armigera and aphis craccivora infestation. | flavonoids are important plant secondary metabolites, which protect plants from various stresses, including herbivory. plants differentially respond to insects with different modes of action. high performance liquid chromatography (hplc) fingerprinting of phenols of groundnut (arachis hypogaea) plants with differential levels of resistance was carried out in response to helicoverpa armigera (chewing insect) and aphis craccivora (sucking pest) infestation. the genotypes used were icgv 86699, icgv ... | 2016 | 27398031 |
| additive effects on the improvement of insecticidal activity: design, synthesis, and insecticidal activity of novel pymetrozine derivatives. | a series of new pymetrozine analogues containing both methyl on the imine carbon and phenoxy group at the pyridine ring were designed and synthesized. their insecticidal activities against bean aphid (aphis craccivora), mosquito larvae (culex pipiens pallens), cotton bollworm (helicoverpa armigera), corn borer (ostrinia nubilalis) and oriental armyworm (mythimna separata) were evaluated. the results of bioassays indicated that most of the target compounds showed good insecticidal activity agains ... | 2016 | 26342545 |
| functional validation of the carbon dioxide receptor in labial palps of helicoverpa armigera moths. | adult moths possess an organ in their labial palps, the labial-palp pit organ, which is specialized for sensing carbon dioxide (co2). they use co2 as a cue to detect healthy plants and find food or lay eggs on them. the molecular bases of the co2 receptor in drosophila melanogaster and aedes aegypti have been reported, but the molecular mechanisms of the co2 receptor in lepidoptera remains elusive. in this study, we first re-examined three putative helicoverpa armigera co2 gustatory receptor gen ... | 2016 | 27060445 |
| transgenic plants expressing the aait/gna fusion protein show increased resistance and toxicity to both chewing and sucking pests. | the adoption of pest-resistant transgenic plants to reduce yield losses and decrease pesticide use has been successful. to achieve the goal of controlling both chewing and sucking pests in a given transgenic plant, we generated transgenic tobacco, arabidopsis, and rice plants expressing the fusion protein, aait/gna, in which an insecticidal scorpion venom neurotoxin (androctonus australis toxin, aait) is fused to snowdrop lectin (galanthus nivalis agglutinin, gna). compared with transgenic tobac ... | 2016 | 25641865 |
| molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the african spider augacephalus ezendami. | the inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. in the present study, we isolated an insecticidal peptide (ae1a) from venom of the african spider augacephalus ezendami (family theraphosidae). injection of ae1a into sheep blowflies (lucil ... | 2016 | 27383378 |
| construction of silkworm midgut cdna library for screen and sequence analysis of peritrophic membrane protein genes. | silkworm is an important economic insect and the model species for lepidoptera. the midgut of silkworm is an important physiological barrier, as its peritrophic membrane (pm) can resist pathogen invasion. in this study, a silkworm midgut cdna library was constructed in order to identify silkworm pm genes. the capacity of the initial library was 6.92 × 10(6) pfu/ml, along with a recombination rate of 92.14% and a postamplification titer of 4.10 × 10(9) pfu/ml. three silkworm pm protein genes were ... | 2016 | 26472595 |
| expression and purification of virus like particles (vlps) of foot-and-mouth disease virus in eri silkworm (samia cynthia ricini) larvae. | foot-and-mouth disease (fmd) is a highly contagious viral disease, which causes severe economic loss to livestock. virus like particles (vlps) produced by recombinant dna technology are gaining importance because of their immunogenic properties and safety in developing a new vaccine for fmd. in the present study, a practical and economically feasible approach of expression, purification and characterization of vlps of fmdv in eri silkworm (samia cynthia ricini) larvae was described. although thr ... | 2016 | 26925448 |
| binding and entry of a non-enveloped t=4 insect rna virus is triggered by alkaline ph. | tetraviruses are small, non-enveloped, rna viruses that exclusively infect lepidopteran insects. their particles comprise 240 copies of a single capsid protein precursor (cp), which undergoes autoproteolytic cleavage during maturation. the molecular mechanisms of capsid assembly and maturation are well understood, but little is known about the viral infectious lifecycle due to a lack of tissue culture cell lines that are susceptible to tetravirus infection. we show here that binding and entry of ... | 2016 | 27614703 |
| yeast one-hybrid screening the potential regulator of cyp6b6 overexpression of helicoverpa armigera under 2-tridecanone stress. | in insect, the cytochrome p450 plays a pivotal role in detoxification to toxic allelochemicals. helicoverpa armigera can tolerate and survive in 2-tridecanone treatment owing to the cyp6b6 responsive expression, which is controlled by some regulatory dna sequences and transcription regulators. therefore, the 2-tridecanone responsive region and transcription regulators of the cyp6b6 are responsible for detoxification of cotton bollworm. in this study, we used yeast one-hybrid to screen two potent ... | 2016 | 26696496 |
| fitness costs to helicoverpa armigera after exposure to sub-lethal concentrations of metarhizium anisopliae sensu lato: study on f1 generation. | the entomopathogenic fungus, metarhizium anisopliae (metsch.) sorokin is a valuable biocontrol agent attacking larval stages of many lepidopteran pests including helicoverpa armigera (hübner). sub-lethal effects of m. anisopliae sensu lato (s.l.) (isolate m14) were investigated on life table parameters of offspring from treated larvae of h. armigera. duration of different life stages was significantly affected by fungal treatments. fecundity was decreased in females derived from h. armigera larv ... | 2016 | 27247225 |
| identification of a toxic serralysin family protease with unique thermostable property from s. marcescens fs14. | a serralysin family protease (serralysin-like protease b, spb) with unique v-shaped thermostable property was isolated and identified from the serratia marcescens fs14 by biochemical and molecular biological methods. it is the first time to report the isolation of a native serralysin family protease directly from serratia species except the well-studied serralysin. spb has an optimum ph at 8.0 and an optimum temperature at 37°c. it shows high proteolytic activities after pretreated at 4-50°c for ... | 2016 | 27543346 |
| artificial mirna-mediated silencing of ecdysone receptor (ecr) affects larval development and oogenesis in helicoverpa armigera. | the insect pests are real threat to farmers as they affect the crop yield to a great extent. the use of chemical pesticides for insect pest control has always been a matter of concern as they pollute the environment and are also harmful for human health. bt (bacillus thuringensis) technology helped the farmers to get rid of the insect pests, but experienced a major drawback due to the evolution of insects gaining resistance towards these toxins. hence, alternative strategies are high on demand t ... | 2016 | 27476930 |
| bacterial expression and kinetic analysis of carboxylesterase 001d from helicoverpa armigera. | carboxylesterasesare an important class of detoxification enzymes involved in insecticide resistance in insects. a subgroup of helicoverpa armigera esterases, known as clade 001, was implicated in organophosphate and pyrethroid insecticide resistance due to their overabundance in resistant strains. in this work, a novel carboxylesterasegene 001d of h. armigera from china was cloned, which has an open reading frame of 1665 nucleotides encoding 554 amino acid residues. we used a series of fusion p ... | 2016 | 27049381 |
| insecticidal efficacy and persistence of a co-occluded binary mixture of helicoverpa armigera nucleopolyhedrovirus (hearnpv) variants in protected and field-grown tomato crops on the iberian peninsula. | a binary co-occluded mixture (hearsp1b:lb6) of helicoverpa armigera single nucleopolyhedrovirus (hearnpv) variants was previously found to be highly pathogenic under laboratory conditions. the insecticidal efficacy and persistence of this mixture were determined in greenhouse and field-grown tomato crops in spain and portugal. | 2016 | 25960129 |
| a glycoprotein α-amylase inhibitor from withania somnifera differentially inhibits various α-amylases and affects the growth and development of tribolium castaneum. | identification and characterisation of plant defensive molecules enrich our resources to design crop protection strategies. in particular, plant-derived proteinaceous inhibitor(s) of insect digestive enzymes appear to be a safe, sustainable and attractive option. | 2016 | 27770482 |
| reproductive cost associated with juvenile hormone in bt-resistant strains of helicoverpa armigera (lepidoptera: noctuidae). | transgenic bacillus thuringiensis (bt) crops are increasingly significant in pest control, but resistance development of target pests is a major issue in the sustainable deployment of bt crops. the fitness cost of resistance in target pests is regarded as one of the main factors delaying resistance when adopting the refuge strategy. in this study, we compared the life-history traits of three independent sets of helicoverpa armigera (hübner, 1809) adults, of each there were a susceptible populati ... | 2016 | 27986942 |
| expression of recombinant and mosaic cry1ac receptors from helicoverpa armigera and their influences on the cytotoxicity of activated cry1ac to spodoptera litura sl-hp cells. | bacillus thuringiensis (bt) toxin receptors play important roles in the killing of pests, and investigation on characterization of the receptors is essential for utilization of bt and management of insect resistance. here, recombinant and mosaic receptors of bt cry1ac toxin from helicoverpa armigera were expressed in spodoptera litura sl-hp cells and their influences on cytotoxicity of activated cry1ac toxin were investigated. when h. armigera aminopeptidase n1 (apn1), alkaline phosphatase 2 (al ... | 2016 | 25412589 |
| enhancement of bacillus thuringiensis insecticidal activity by combining cry1ac and bi-functional toxin hwtx-xi from spider. | in order to assess the potency of bi-functional hwtx-xi toxin from spider ornithoctonus huwena in improving the insecticidal activity of bacillus thuringiensis, a fusion gene of cry1ac and hwtx-xi was constructed and expressed in an acrystalliferous b. thuringiensis strain cry(-)b. western blot analysis and microscopic observation revealed that the recombinant strain could express 140-kda cry1ac-hwtx-xi fusion protein and produce parasporal inclusions during sporulation. bioassay using the larva ... | 2016 | 25721170 |
| prevalence of cry2-type genes in bacillus thuringiensis isolates recovered from diverse habitats in india and isolation of a novel cry2af2 gene toxic to helicoverpa armigera (cotton boll worm). | insecticidal cry and vip genes from bacillus thuringiensis (bt) have been used for control of lepidopteran insects in transgenic crops. however, novel genes are required for gene pyramiding to delay evolution of resistance to the currently deployed genes. two pcr-based techniques were employed for screening of cry2-type genes in 129 bt isolates from diverse habitats in india and 27 known bt strains. cry2ab-type genes were more prevalent than cry2aa- and cry2ac-type genes. correlation between sou ... | 2016 | 27805417 |
| insecticidal activity and histopathological effects of vip3aa protein from bacillus thuringiensis on spodoptera litura. | vegetative insecticidal proteins (vips) are insecticidal proteins synthesized by bacillus thuringiensis during the vegetative stage of growth. in this study, vip3aa protein, obtained by in vitro expression of the vip3aa gene from b. thuringiensis wb5, displayed high insecticidal activity against spodoptera litura aside from spodoptera exigua and helicoverpa armigera. bioassay results showed that the toxicity of vip3aa protein against s. litura larvae statistically decreased along with the increa ... | 2016 | 27435544 |
| isolation and characterization of gut bacterial proteases involved in inducing pathogenicity of bacillus thuringiensis toxin in cotton bollworm, helicoverpa armigera. | bacillus thuringiensis toxin proteins are deployed in transgenic plants for pest management. the present studies were aimed at characterization of gut bacterial proteases involved in activation of inactive cry1ac protoxin (pro-cry1ac) to active toxin in helicoverpa armigera. bacterial strains were isolated from h. armigera midgut and screened for their proteolytic activation toward pro-cry1ac. among 12 gut bacterial isolates seven isolates showed proteolytic activity, and proteases from three is ... | 2016 | 27766093 |
| distribution and metabolism of bt-cry1ac toxin in tissues and organs of the cotton bollworm, helicoverpa armigera. | crystal (cry) proteins derived from bacillus thuringiensis (bt) have been widely used in transgenic crops due to their toxicity against insect pests. however, the distribution and metabolism of these toxins in insect tissues and organs have remained obscure because the target insects do not ingest much toxin. in this study, several cry1ac-resistant strains of helicoverpa armigera, fed artificial diets containing high doses of cry1ac toxin, were used to investigate the distribution and metabolism ... | 2016 | 27399776 |
| high expression of cry1ac protein in cotton (gossypium hirsutum) by combining independent transgenic events that target the protein to cytoplasm and plastids. | transgenic cotton was developed using two constructs containing a truncated and codon-modified cry1ac gene (1,848 bp), which was originally characterized from bacillus thuringiensis subspecies kurstaki strain hd73 that encodes a toxin highly effective against many lepidopteran pests. in construct i, the cry1ac gene was cloned under fmvde, a strong constitutively expressing promoter, to express the encoded protein in the cytoplasm. in construct ii, the encoded protein was directed to the plastids ... | 2016 | 27391960 |
| cyclic di-gmp contributes to adaption and virulence of bacillus thuringiensis through a riboswitch-regulated collagen adhesion protein. | cyclic di-gmp is a ubiquitous second messenger that regulates diverse cellular processes in bacteria by binding to various protein or riboswitch effectors. in bacillus thuringiensis bmb171, a c-di-gmp riboswitch termed bc2 rna resides in the 5'-untranslated region (5'-utr) of an mrna that encodes a collagen adhesion protein (cap). the expression of cap was strongly repressed in parent strain bmb171 because of the presence of bc2 rna but was significantly promoted in the bc2 rna markerless deleti ... | 2016 | 27381437 |
| functional validation of cadherin as a receptor of bt toxin cry1ac in helicoverpa armigera utilizing the crispr/cas9 system. | cadherins have been identified as receptors of bacillus thuringiensis (bt) cry1a toxins in several lepidopteran insects including the cotton bollworm, helicoverpa armigera. disruption of the cadherin gene hacad has been genetically linked to resistance to bt toxin cry1ac in h. armigera. by using the crispr/cas9 genome editing system (clustered regularly interspaced short palindromic repeats/crispr-associated protein 9), hacad from the cry1ac-susceptible scd strain of h. armigera was successfully ... | 2016 | 27343383 |
| assessment of bt trait purity in different generations of transgenic cottons. | adequate expression of bt (bacillus thuringiensis) toxins and purity of seeds of bt-transgenic cottons are important for controlling bollworms, and thereby increasing the cotton productivity. therefore, we examined the variability in expression of bt toxin proteins in the seeds and in leaves of different cotton (gossypium hirsutum (l.) hybrids (jkch 226, jkch 1947, jkch durga, jkch ishwar, jkch varun kdchh 441 and kdchh 621) expressing bt toxins in f₁ and f₂ generations, using bioassays against ... | 2016 | 27295920 |
| activation of bt protoxin cry1ac in resistant and susceptible cotton bollworm. | crystalline (cry) proteins from bacillus thuringiensis (bt) are used extensively for insect control in sprays and transgenic plants, but their efficacy is reduced by evolution of resistance in pests. here we evaluated reduced activation of cry1ac protoxin as a potential mechanism of resistance in the invasive pest helicoverpa armigera. based on the concentration killing 50% of larvae (lc50) for a laboratory-selected resistant strain (lf120) divided by the lc50 for its susceptible parent strain ( ... | 2016 | 27257885 |
| molecular cloning, expression, and identification of bre genes involved in glycosphingolipids synthesis in helicoverpa armigera (lepidoptera: noctuidae). | glycosphingolipids (gsls) play important roles in the cellular biology of vertebrate and invertebrate organisms, such as cell differentiation, tumor metastasis, and cell coordination. gsls also serve as receptors for different bacterial toxins. for example, in the nematode caenorhabditis elegans, gsls function as receptors of the insecticidal cry toxins produced by bacillus thuringiensis (bt), and mutations in bre genes involved in gsls synthesis resulted in resistance to cry5 toxin in this orga ... | 2016 | 27190043 |
| characterization of the resistance to vip3aa in helicoverpa armigera from australia and the role of midgut processing and receptor binding. | crops expressing genes from bacillus thuringiensis (bt crops) are among the most successful technologies developed for the control of pests but the evolution of resistance to them remains a challenge. insect resistant cotton and maize expressing the bt vip3aa protein were recently commercialized, though not yet in australia. we found that, although relatively high, the frequency of alleles for resistance to vip3aa in field populations of h. armigera in australia did not increase over the past fo ... | 2016 | 27095284 |
| cloning, characterization and expression of a novel haplotype cry2a-type gene from bacillus thuringiensis strain swk1, native to himalayan valley kashmir. | bacillus thuringiensis (bt) is a gram positive bacterium which is effectively being used in pest management strategies as an eco-friendly bioinsecticide. in the present study a new cry2a gene was cloned from a promising indigenous b. thuringiensis swk1 strain previously characterized for its toxicity against spodoptera litura and helicoverpa armigera larvae. the nucleotide sequence of the cloned cry2a gene pointed out that the open reading frame has 1902 bases encoding a polypeptide of 634 amino ... | 2016 | 26906447 |
| resistance to bacillus thuringiensis mediated by an abc transporter mutation increases susceptibility to toxins from other bacteria in an invasive insect. | evolution of pest resistance reduces the efficacy of insecticidal proteins from the gram-positive bacterium bacillus thuringiensis (bt) used widely in sprays and transgenic crops. recent efforts to delay pest adaptation to bt crops focus primarily on combinations of two or more bt toxins that kill the same pest, but this approach is often compromised because resistance to one bt toxin causes cross-resistance to others. thus, integration of bt toxins with alternative controls that do not exhibit ... | 2016 | 26872031 |
| molecular and insecticidal characterization of vip3a protein producing bacillus thuringiensis strains toxic against helicoverpa armigera (lepidoptera: noctuidae). | vegetative insecticidal proteins (vip) represent the second generation of insecticidal proteins produced by bacillus thuringiensis (bt) during the vegetative growth stage of growth. bt-based biopesticides are recognized as viable alternatives to chemical insecticides; the latter cause environmental pollution and lead to the emergence of pest resistance. to perform a systematic study of vip genes encoding toxic proteins, a total of 30 soil samples were collected from diverse locations of kashmir ... | 2016 | 26751639 |
| in-plant protection against helicoverpa armigera by production of long hprna in chloroplasts. | expressing double-stranded rna (dsrna) in transgenic plants to silence essential genes within herbivorous pests is referred to as trans-kingdom rna interference (tk-rnai) and has emerged as a promising strategy for crop protection. however, the dicing of dsrna into sirnas by the plant's intrinsic rnai machinery may reduce this pesticidal activity. therefore, genetic constructs, encoding ∼200 nt duplex-stemmed-hairpin (hp) rnas, targeting the acetylcholinesterase gene of the cotton bollworm, heli ... | 2016 | 27746796 |
| expansion of a bitter taste receptor family in a polyphagous insect herbivore. | the insect taste system plays a central role in feeding behaviours and co-evolution of insect-host interactions. gustatory receptors form the interface between the insect taste system and the environment. from genome and transcriptome sequencing we identified 197 novel gustatory receptor (gr) genes from the polyphagous pest helicoverpa armigera. these grs include a significantly expanded bitter receptor family (180 grs) that could be further divided into three categories based on polypeptide len ... | 2016 | 27032373 |
| identification of abcc2 as a binding protein of cry1ac on brush border membrane vesicles from helicoverpa armigera by an improved pull-down assay. | cry1ac toxin-binding proteins from helicoverpa armigera brush border membrane vesicles were identified by an improved pull-down method that involves coupling cry1ac to cnbr agarose combined with liquid chromatography-tandem mass spectrometry (lc-ms/ms). according to the lc-ms/ms results, cry1ac toxin could bind to six classes of aminopeptidase-n, alkaline phosphatase, cadherin-like protein, atp-binding cassette transporter subfamily c protein (abcc2), actin, atpase, polycalin, and some other pro ... | 2016 | 27037552 |
| proteomic analysis of mamestra brassicae nucleopolyhedrovirus progeny virions from two different hosts. | mamestra brassicae nucleopolyhedrovirus (mabrnpv) has a wide host range replication in more than one insect species. in this study, a sequenced mabrnpv strain, mabrnpv-cta, was used to perform proteomic analysis of both bvs and odvs derived from two infected hosts: helicoverpa armigera and spodoptera exigua. a total of 82 and 39 viral proteins were identified in odvs and bvs, respectively. and totally, 23 and 76 host proteins were identified as virion-associated with odvs and bvs, respectively. ... | 2016 | 27058368 |
| conserved chemosensory proteins in the proboscis and eyes of lepidoptera. | odorant-binding proteins (obps) and chemosensory proteins (csps) are endowed with several different functions besides being carriers for pheromones and odorants. based on a previous report of a csp acting as surfactant in the proboscis of the moth helicoverpa armigera, we revealed the presence of orthologue proteins in two other moths plutella xylostella and chilo suppressalis, as well as two butterflies papilio machaon and pieris rapae, using immunodetection and proteomic analysis. the unusual ... | 2016 | 27877091 |
| development of a novel-type transgenic cotton plant for control of cotton bollworm. | the transgenic bt cotton plant has been widely planted throughout the world for the control of cotton budworm helicoverpa armigera (hubner). however, a shift towards insect tolerance of bt cotton is now apparent. in this study, the gene encoding neuropeptide f (npf) was cloned from cotton budworm h. armigera, an important agricultural pest. the npf gene produces two splicing mrna variants-npf1 and npf2 (with a 120-bp segment inserted into the npf1 sequence). these are predicted to form the matur ... | 2016 | 26841044 |
| molecular characterization and function analysis of the vitellogenin receptor from the cotton bollworm, helicoverpa armigera (hübner) (lepidoptera, noctuidae). | developing oocytes accumulate plentiful yolk protein during oogenesis through receptor-mediated endocytosis. the vitellogenin receptor (vgr), belonging to the low-density lipoprotein receptor (ldlr) family, regulates the absorption of yolk protein. in this work, the full-length vitellogenin receptor (havgr) in the cotton bollworm helicoverpa armigera was identified, encoding a 1817 residue protein. sequence alignment revealed that the sequence of havgr contained all of the conservative structura ... | 2016 | 27192057 |
| transcriptome comparison of the sex pheromone glands from two sibling helicoverpa species with opposite sex pheromone components. | differences in sex pheromone component can lead to reproductive isolation. the sibling noctuid species, helicoverpa armigera and helicoverpa assulta, share the same two sex pheromone components, z9-16:ald and z11-16:ald, but in opposite ratios, providing an typical example of such reproductive isolation. to investigate how the ratios of the pheromone components are differently regulated in the two species, we sequenced cdna libraries from the pheromone glands of h. armigera and h. assulta. after ... | 2015 | 25792497 |
| the steroid hormone 20-hydroxyecdysone via nongenomic pathway activates ca2+/calmodulin-dependent protein kinase ii to regulate gene expression. | the steroid hormone 20-hydroxyecdysone (20e) triggers calcium signaling pathway to regulate 20e response gene expression, but the mechanism underlying this process remains unclear. we propose that the 20e-induced phosphorylation of ca(2+)/calmodulin-dependent protein kinase ii (camkii) serves an important function in 20e response gene transcription in the lepidopteran insect helicoverpa armigera. camkii showed increased expression and phosphorylation during metamorphosis. 20e elevated camkii pho ... | 2015 | 25670853 |
| 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 ... | 2015 | 26583651 |
| 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 ... | 2015 | 26174024 |
| 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 ... | 2015 | 25885820 |
| 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 ... | 2015 | 26437857 |
| 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 ... | 2015 | 26001831 |
| 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 ... | 2015 | 26502992 |
| 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 ... | 2015 | 26655641 |
| cross-resistance and interactions between bt toxins cry1ac and cry2ab against the cotton bollworm. | to delay evolution of pest resistance to transgenic crops producing insecticidal proteins from bacillus thuringiensis (bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. we conducted laboratory diet experiments with the cotton bollworm, helicoverpa armigera, to evaluate cross-resistance and interactions between two toxins in pyramided bt cotton (cry1ac and cry2ab). selection with cry1ac for 125 generations produced 1000-fold resistance to cry1ac and ... | 2015 | 25586723 |
| cloning and tissue-specific expression of a chitin deacetylase gene from helicoverpa armigera (lepidoptera: noctuidae) and its response to bacillus thuringiensis. | chitin deacetylases (cdas) convert chitin into chitosan, the n-deacetylated form of chitin, which influences the mechanical and permeability properties of structures such as the cuticle and peritrophic matrices. in this article, a new cda encoding gene, hacda2, was cloned by reverse transcription-polymerase chain reaction method in helicoverpa armigera (hübner) (lepidoptera: noctuidae), with an open reading frame of 1,611 bp. the deduced protein composed of 536 amino acid residues with a signal ... | 2015 | 26163665 |
| transgenic cotton plants expressing double-stranded rnas target hmg-coa reductase (hmgr) gene inhibits the growth, development and survival of cotton bollworms. | rna interference (rnai) has been developed as a powerful technique in the research of functional genomics as well as plant pest control. in this report, double-stranded rnas (dsrna) targeting 3-hydroxy-3-methylglutaryl coenzyme a reductase (hmgr) gene, which catalyze a rate-limiting enzymatic reaction in the mevalonate pathway of juvenile hormone (jh) synthesis in cotton bollworm, was expressed in cotton plants via agrobacterium tumefaciens-mediated transformation. pcr and sothern analysis revea ... | 2015 | 26435695 |
| comparative performance of modified full-length and truncated bacillus thuringiensis-cry1ac genes in transgenic tomato. | bt-cry1ac gene has been reputedly effective against helicoverpa armigera a notorious lepidopteran pest. reports on the expression of full-length and truncated cry1ac genes in plants for effective resistance against helicoverpa sp. have been documented however, their performance is still ambiguous. moreover, the question remains to be addressed that truncation of 3' end of the native gene was documented and suggested for active insecticidal toxin production while the most successful transgenic ev ... | 2015 | 25977893 |
| in-silico determination of insecticidal potential of vip3aa-cry1ac fusion protein against lepidopteran targets using molecular docking. | study and research of bt (bacillus thuringiensis) transgenic plants have opened new ways to combat insect pests. over the decades, however, insect pests, especially the lepidopteran, have developed tolerance against bt delta-endotoxins. such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. in this computational study, functional domains of bacillus thuringiensis crystal delta-endotoxin (cry1ac) insectici ... | 2015 | 26697037 |
| proteomic analysis of the influence of cu(2+) on the crystal protein production of bacillus thuringiensis x022. | bacillus thuringiensis x022, a novel strain isolated from soil in china, produces diamond-shaped parasporal crystals. specific mineral nutrients, such as mg, cu, and mn, influence insecticidal crystal proteins (icp) expression and the effects of these elements vary significantly. however, the molecular mechanisms of the effects caused by mineral elements have yet to be reported. | 2015 | 26438125 |
| elimination of gut microbes with antibiotics confers resistance to bacillus thuringiensis toxin proteins in helicoverpa armigera (hubner). | helicoverpa armigera is one of the most important pests worldwide. transgenic crops with toxin genes from bacillus thuringiensis (bt) have been deployed on a large scale to control this pest. the insecticidal activity of bt is probably influenced by the insect midgut microbes, which vary across crop hosts and locations. therefore, we examined the role of gut microbes in pathogenicity of bt toxins in the h. armigera. antibiotic cocktail was used for the complete elimination of the h. armigera gut ... | 2015 | 26384494 |
| 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 ... | 2015 | 25678461 |
| endogenous expression of a bt toxin receptor in the cry1ac-susceptible insect cell line and its synergistic effect with cadherin on cytotoxicity of activated cry1ac. | although many insect cell lines derived from various tissues are available, it is unclear whether endogenous receptors of bacillus thuringiensis (bt) crystal toxins are expressed in these cell lines. in the present study, we demonstrated that the ovaries-derived spodoptera litura sl-hp cell line was susceptible to activated cry1ac although larvae of s. litura are not susceptible to the toxin. assays of the transcriptome revealed that thirteen atp-binding cassette transporter genes (abc) were exp ... | 2015 | 25662100 |
| large-scale test of the natural refuge strategy for delaying insect resistance to transgenic bt crops. | the 'natural refuge strategy" for delaying insect resistance to transgenic cotton that produces insecticidal proteins from bacillus thuringiensis (bt) relies on refuges of host plants other than cotton that do not make bt toxins. we tested this widely adopted strategy by comparing predictions from modeling with data from a four-year field study of cotton bollworm (helicoverpa armigera) resistance to transgenic cotton producing bt toxin cry1ac in six provinces of northern china. bioassay data rev ... | 2015 | 25503384 |
| 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 ... | 2015 | 25143318 |
| 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 ... | 2015 | 25111652 |
| 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 ... | 2015 | 25678849 |
| 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 ... | 2015 | 25912191 |
| identification of a thioredoxin peroxidase gene involved in resistance to nucleopolyhedrovirus infection in helicoverpa armigera with rna interference. | thioredoxin peroxidases (tpxs) play a crucial role in protection against oxidative damage in several insect species. however, studies on the characteristics and functions of tpxs in helicoverpa armigera are lacking. in this study, a novel 2-cys tpx gene from h. armigera (hatpx) was identified. sequence analysis revealed that hatpx is highly conserved and shares two catalysis regions (vcp) with other insect species. hatpx mrna was found to be expressed in an age-dependent manner and was ubiquitou ... | 2015 | 26238928 |
| 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 ... | 2015 | 25929852 |
| rab3 is involved in cellular immune responses of the cotton bollworm, helicoverpa armigera. | rab3, a member of the rab gtpase family, has been found to be involved in innate immunity. however, the precise function of this gtpase in innate immunity remains unknown. in this study, we identified a rab3 gene (ha-rab3) from the cotton bollworm, helicoverpa armigera and studied its roles in innate immune responses. expression of ha-rab3 was upregulated in the hemocytes of h. armigera larvae after the injection of escherichia coli or chromatography beads. the dsrna-mediated knockdown of ha-rab ... | 2015 | 25662061 |