Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| mating compatibility among helicoverpa armigera (lepidoptera: noctuidae) occurring on selected host plants and bt cotton survivors. | helicoverpa armigera (hiibner) (lepidoptera: noctuidae) is a well-known polyphagous insect pest. mating compatibility among the insects occurring on different host plants is essential for free gene flow among populations. we tested the extent of crossability and fecundity of the insects that survived on bacillus thuringiensis (bt) cotton with those occurring on pigeon pea, cajanus cajun (l.) millsp., non-bt cotton, gossypium hirsutum l.; sunflower, helianthus annuus; sorghum, sorghum bicolor l. ... | 2007 | 17598554 |
| cross-resistance studies of cry1ac-resistant strains of helicoverpa armigera (lepidoptera: noctuidae) to cry2ab. | bioassays and binding tests between cry toxins (crylaa, crylab, crylac, and cry2ab) and brush-border membrane vesicles (bbmvs) from larvae of a bacillus thurningiensis (bt)-susceptible (96s) and two crylac-resistant strains (btr and lfr10) were conducted for investigating cross-resistance of crylac-resistant strains to cry2ab in helicoverpa armigera (hiibner) (lepidoptera: noctuidae). the resistance ratio (rr) values of the btr and lfr10 strains to crylac and cry2ab were 2,971- and 1.1-fold and ... | 2007 | 17598555 |
| acute, sublethal and combination effects of azadirachtin and bacillus thuringiensis toxins on helicoverpa armigera (lepidoptera: noctuidae) larvae. | the efficacy of neem (1500 ppm azadirachtin (ai)), delfin wg, a biological insecticide based on selected strain of bacillus thuringiensis berliner (bt) subspecies kurstaki, and cry1ac protein, either individually or in combination, were examined against first to fourth instar helicoverpa armigera (hübner) larvae. using an oral administration method, various growth inhibitory concentrations (ec) and lethal concentrations (lc) were determined for each bioagent. combinations of sublethal concentrat ... | 2007 | 17645816 |
| larvicidal activities against agricultural pests of transgenic escherichia coli expressing combinations of four genes from bacillus thuringiensis. | the genes cry1ac and cry1ca from bacillus thuringiensis subsps. kurstaki hd-73 and aizawai 4j4, respectively, encoding delta-endotoxins against lepidopteran larvae were isolated, cloned and expressed in escherichia coli, with and without cyt1aa (encoding cytolytic protein) and p20 (accessory protein) from subsp. israelensis. nine combinations of the genes under control of an early t7, p a1 inducible promoter, produced the encoding proteins. toxicities were examined against larvae of three major ... | 2007 | 17665174 |
| efficacy of various pyrethroid structures against a highly metabolically resistant isogenic strain of helicoverpa armigera (lepidoptera: noctuidae) from china. | resistance to pyrethroids and other types of insecticides in helicoverpa armigera (hübner) has been documented in many countries. the isolation of specific resistance mechanisms in isogenic strains is an optimal approach to investigate cross-resistance pattern, and to validate resistance breaking pyrethroids. in this study an isogenic metabolic resistance cmr strain was successfully isolated from a field pyrethroid-resistant population of h. armigera. with this strain, cross-resistance among 19 ... | 2007 | 17685437 |
| [expression and insecticidal activity of a novel gene cry2ab4 from bacillus thuringiensis strain b-pr-88]. | the full length cry2ab gene was cloned by pcr-rflp method from bt strain b-pr-88, which was isolated in china with high toxicity to the lepidopteran insect pests. nucleic acid sequence analysis showed that this gene was 1902 base pairs encoding 633 amino acids. this cry gene was named cry2ab4 as a novel gene by bacillus thuringiensis delta endotoxin nomenclature committee. the full open reading frame sequence of the cry2ab4 gene was amplified with a pair of pcr primers l2ab5/l2ab3 designed accor ... | 2007 | 17822035 |
| mutated cadherin alleles from a field population of helicoverpa armigera confer resistance to bacillus thuringiensis toxin cry1ac. | the cotton bollworm helicoverpa armigera is the major insect pest targeted by cotton genetically engineered to produce the bacillus thuringiensis toxin (transgenic bt cotton) in the old world. the evolution of this pest's resistance to b. thuringiensis toxins is the main threat to the long-term effectiveness of transgenic bt cotton. a deletion mutation allele (r(1)) of a cadherin gene (ha_btr) was previously identified as genetically linked with cry1ac resistance in a laboratory-selected strain ... | 2007 | 17827322 |
| evaluation of fungal culture filtrate containing chitinase as a biocontrol agent against helicoverpa armigera. | to evaluate the biocontrol efficacy of culture filtrate containing chitinase from trichoderma harzianum against heliothis. | 2007 | 17953595 |
| functional analysis of polyphenol oxidases by antisense/sense technology. | polyphenol oxidases (ppos) catalyze the oxidation of phenolics to quinones, the secondary reactions of which lead to oxidative browning and postharvest losses of many fruits and vegetables. ppos are ubiquitous in angiosperms, are inducible by both biotic and abiotic stresses, and have been implicated in several physiological processes including plant defense against pathogens and insects, the mehler reaction, photoreduction of molecular oxygen by psi, regulation of plastidic oxygen levels, auron ... | 2007 | 17960074 |
| baculovirus envelope fusion proteins f and gp64 exploit distinct receptors to gain entry into cultured insect cells. | group ii nucleopolyhedroviruses (npvs), e.g. helicoverpa armigera (hear) npv and spodoptera exigua (se) mnpv (multiple npv), lack a gp64-like protein that is present in group i npvs, e.g. autographa californica (ac)mnpv, but have an unrelated envelope fusion protein named f. three acmnpv viruses were constructed by introducing acmnpv gp64, hearnpv f or semnpv f genes, respectively, into a gp64-negative acmnpv bacmid. sf21 cells were incubated with different amounts of inactivated budded virus to ... | 2007 | 18024899 |
| deletion of a helicoverpa armigera nucleopolyhedrovirus gene encoding a virion structural protein (orf107) increases the budded virion titre and reduces in vivo infectivity. | the open reading frame ha107 of helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (hearnpv) encodes a putative protein of 51 kda with homologues in a few group ii npvs and a granulovirus. ha107 was transcribed as polyadenylated transcripts in infected hzam1 insect cells. the transcripts were initiated at two distinct locations, one upstream of ha106 (superoxide dismutase gene, sod) and the second upstream of ha107. by western blot analysis, two forms of the ha107 protein were detecte ... | 2007 | 18024900 |
| identification of vip3a-type genes from bacillus thuringiensis strains and characterization of a novel vip3a-type gene. | to search for novel vip3a proteins for controlling insect pests. | 2007 | 17868317 |
| diverse forms of pin-ii family proteinase inhibitors from capsicum annuum adversely affect the growth and development of helicoverpa armigera. | novel forms of pin-ii type proteinase inhibitor (pis) cdnas (canpis) having three or four inhibitory repeat domains (ird) were isolated from the developing green fruits of capsicum annuum. deduced amino acid (aa) sequences of the canpis showed up to 15% sequence divergence among each other or reported inhibitors (canpi-1af039398, canpi-2af221097). amino acid sequence analysis of these canpis revealed that three ird pis have trypsin inhibitory sites, while four ird canpis have both trypsin and ch ... | 2007 | 17870253 |
| frequency of alleles conferring resistance to the bt toxins cry1ac and cry2ab in australian populations of helicoverpa armigera (lepidoptera: noctuidae). | helicoverpa armigera (hübner) (lepidoptera: noctuidae) is an important lepidopteran pest of cotton (gossypium spp.) in australia and the old world. from 2002, f2 screens were used to examine the frequency of resistance alleles in australian populations of h. armigera to bacillus thuringiensis (bt) crylac and cry2ab, the two insecticidal proteins present in the transgenic cotton bollgard ii. at that time, ingard (expressing cry1ac) cotton had been grown in australia for seven seasons, and bollgar ... | 2007 | 18232402 |
| effects of bacillus thuringiensis cry toxins on developmental and reproductive characteristics of the predator orius albidipennis (hemiptera: anthocoridae) under laboratory conditions. | the effects of cry toxins from bacillus thuringiensis (berliner) (bt) on the anthocorid orius albidipennis reuter were studied under laboratory conditions. tritrophic experiments were performed, in which orius nymphs were fed helicoverpa armigera (hübner) larvae reared on a diet with cry1ac, cry1ab, or cry2ab toxins at different concentrations (0, 1, and 10 microg/ml), when supplemented with ephestia kuehniella zeller eggs. in complementary experiments, the bt cry1ac toxin was directly fed to or ... | 2007 | 18284750 |
| kinetics of plasmid transfer among bacillus cereus group strains within lepidopteran larvae. | the cry toxin encoding plasmid pht73 was transferred from bacillus thuringiensis subspecies kurstaki kt0 to six b. cereus group strains in three lepidopteran (spodoptera exigua, plutella xyllostella and helicoverpa armigera) larvae by conjugation. the conjugation kinetics of the plasmid was precisely studied during the larval infection using a new protocol. the infections were performed with both vegetative and sporulated strains. however, larval death only occurred when infections were made wit ... | 2007 | 17216168 |
| larval feeding induced defensive responses in tobacco: comparison of two sibling species of helicoverpa with different diet breadths. | plants respond differently to damage by different herbivorous insects. we speculated that sibling herbivorous species with different host ranges might also influence plant responses differently. such differences may be associated with the diet breadth (specialization) of herbivores within a feeding guild, and the specialist may cause less intensive plant responses than the generalist. the tobacco nicotinana tabacum l. is the common host plant of a generalist helicoverpa armigera (hübner) and a s ... | 2007 | 17216231 |
| helicoverpa armigera nucleopolyhedrovirus orf80 encodes a late, nonstructural protein. | the helicoverpa armigera nucleopolyhedrovirus (hearnpv) orf80 (ha80) has 765 bp encoding a protein with approximately 254 amino acids and a predicted molecular weight of 30.8 kda. homologues of ha80 are found in most baculovirus sequences, including those from lepidopteran npvs, lepidopteran granuloviruses (gvs), hymenopteran baculoviruses, and one dipteran baculovirus, yet their functions remain unclear. in this study we characterized ha80, and showed that it was transcribed late in infected ho ... | 2007 | 17244484 |
| absence of n-linked glycans from the f2 subunit of the major baculovirus envelope fusion protein f enhances fusogenicity. | the f protein is the major glycoprotein present in the envelopes of budded virus (bv) of members of the family baculoviridae. the f protein mediates low-ph-activated fusion with insect cell membranes. baculovirus f proteins are synthesized as a precursor (f(0)) and cleaved post-translationally into two disulfide-bonded subunits, f(1) (c-terminal, large subunit) and f(2) (n-terminal, small subunit). recently, n-linked glycosylation of the f(1) and f(2) subunits of helicoverpa armigera nucleopolyh ... | 2007 | 17251561 |
| evaluation of the role of cyp6b cytochrome p450s in pyrethroid resistant australian helicoverpa armigera. | the an02 strain of helicoverpa armigera from eastern australia exhibits 50-fold, pbo-suppressible resistance to the pyrethroid insecticide fenvalerate. the semidominant resistance gene rfen1 was previously mapped to aflp linkage group 13. in evaluating the cytochrome p450 genes cyp6b7, cyp6b6, and cyp6b2 as candidates for rfen1, we found that they occur in a tandem array in the genome, next to the gene encoding the para-type sodium channel; the target of pyrethroid insecticides. we mapped these ... | 2007 | 17257205 |
| purification and characterization of recombinant ligand-binding domains from the ecdysone receptors of four pest insects. | cloned ecr and usp cdnas encoding the ecdysone receptors of four insect pests (lucilia cuprina, myzus persicae, bemisia tabaci, helicoverpa armigera) were manipulated to allow the co-expression of their ligand binding domains (lbds) in insect cells using a baculovirus vector. recombinant de/f segment pairs (and additionally, for h. armigera, an e/f segment pair) from the ecr and usp proteins associated spontaneously with high affinity to form heterodimers that avidly bound an ecdysteroid ligand. ... | 2007 | 17275327 |
| host filamentous actin is associated with heliothis armigera single nucleopolyhedrosis virus (hasnpv) nucleocapsid transport to the host nucleus. | vp39 is the major capsid protein of heliothis armigera nucleopolyhedrovirus (hasnpv), and it might have induced the aggregation of host cellular actin in vitro in our previous study. we demonstrated here that vp39 could interact with host actin in vivo in helicoverpazea (hz-am1 cells) through coimmunoprecipitation assay. with confocal immunofluorescence microscopy, it was confirmed further that the released hasnpv nucleocapsids/vp39s in the host cytoplasm (0.5 hours after infection) colocalized ... | 2007 | 17294324 |
| feeding and foraging behaviour of a generalist caterpillar: are third instars just bigger versions of firsts? | similarities and differences in foraging behaviour between first and third instar helicoverpa armigera (hübner) (lepidoptera: noctuidae) on vigna radiata (l.) r. wilczek (fabaceae) (mung bean) were determined by frequent, repeated observation of insects on whole plants. the time apportioned to feeding, resting and searching by these two larval instars differed. third instars were often found feeding on exposed areas of the plant and, if in the terminal parts, would leave these areas more frequen ... | 2007 | 17298685 |
| genetic transformation of chickpea (cicer arietinum l.) with insecticidal crystal protein gene using particle gun bombardment. | here, we report the establishment of an efficient particle gun bombardment mediated genetic transformation in chickpea (cicer arietinum l.) using cryiac gene of bacillus thuringiensis. explants were bombarded with recombinant plasmids engineered for the expression of cryiac transgene in plants and stable transformants regenerated in presence of benzyladenine, kinetin and kanamycin. transformation frequency showed dependence on explant type, cultivars, plasmids, helium pressure and microcarrier t ... | 2007 | 17205334 |
| knockdown of aminopeptidase-n from helicoverpa armigera larvae and in transfected sf21 cells by rna interference reveals its functional interaction with bacillus thuringiensis insecticidal protein cry1ac. | aminopeptidase-n (apn) and cadherin proteins located at the midgut epithelium of helicoverpa armigera have been implicated as receptors for the cry1a subfamily of insecticidal proteins of bacillus thuringiensis. ligand blot analysis with heterologously expressed and purified h. armigera bt receptor with three closely related cry1a proteins tentatively identified haapn1 as an interacting ligand. however, to date there is no direct evidence of apn being a functional receptor to cry1ac in h. armige ... | 2007 | 17213205 |
| variation in susceptibility of helicoverpa armigera (hübner) and helicoverpa punctigera (wallengren) (lepidoptera: noctuidae) in australia to two bacillus thuringiensis toxins. | intra-specific variation in susceptibility of helicoverpa armigera (hübner) and helicoverpa punctigera (wallengren) in australia to the cry1ac and cry2ab delta-endotoxins from bacillus thuringiensis (berliner) (bt) was determined to establish a baseline for monitoring changes that might occur with the use of bt cotton. strains of h. armigera and h. punctigera were established from populations collected primarily from commercial farms throughout the australian cotton belts. strains were evaluated ... | 2007 | 17049552 |
| cloning and characterization of two campoletis chlorideae ichnovirus vankyrin genes expressed in parasitized host helicoverpa armigera. | polydnaviruses, symbionts of parasitic ichneumonid (ichnoviruses, ivs) and braconid (bracoviruses, bvs), are injected into hosts along with wasp eggs. within the host, pdv genes are expressed and their products function to alter lepidopteran host physiology and enable endoparasitoid development. in the present study, we describe two campoletis chlorideae ichnovirus (cciv) viral ankyrin (vankyrin) genes and their transcription. the cciv vankyrin genes possess ankyrin repeat domains that resemble ... | 2007 | 17512002 |
| female sex pheromone suppression and the fate of sex-peptide-like peptides in mated moths of helicoverpa armigera. | insect males produce accessory gland (mag) factors that are transferred in the seminal fluid to females during copulation, and elicit changes in the mated female's behavior and physiology. our previous studies showed that the injection of synthetic drosophila melanogaster sex-peptide (drmsp) into virgin females of the moth helicoverpa armigera causes a significant inhibition of pheromone production. in this and other moth species, pheromone production, correlated with female receptivity, is unde ... | 2007 | 17294422 |
| cloning and characterization of the pheromone biosynthesis activating neuropeptide receptor gene in spodoptera littoralis larvae. | in noctuid moths cuticular pigmentation is regulated by the pyrokinin/pheromone biosynthesis activating neuropeptide (pk/pban) family, which also mediates a variety of other functions in moths and other insects. numerous studies have shown that these neuropeptides exert their functions through activation of the pban receptor (pban-r), with subsequent ca(2+) influx, followed by either activation of camp or direct activation of downstream kinases. recently, several pban-rs have been identified, al ... | 2007 | 17379458 |
| molecular characterization and developmental expression of the gene encoding the prothoracicotropic hormone in the beet armyworm, spodoptera exigua. | prothoracicotropic hormone (ptth), a neuropeptide hormone stimulating the prothoracic glands to synthesize ecdysone, plays an important role in regulating postembryonic development in insects. the cdna encoding ptth was isolated and sequenced from the beet armyworm, spodoptera exigua (spe). the deduced amino acid sequence is composed of a signal peptide, a peptide (65 amino acids) of unknown function, and a mature ptth molecule (111 amino acids). the spe-ptth shows similarities (45.5%-70.3%) to ... | 2007 | 17653666 |
| cloning and expression of the gene encoding the diapause hormone and pheromone biosynthesis activating neuropeptide of the beet armyworm, spodoptera exigua. | diapause hormone (dh) and pheromone biosynthesis activating neuropeptide (pban), two important insect neuropeptides, regulate insect development and sex pheromone biosynthesis, respectively. dh-like immunoreactivity has been detected in the suboesophageal ganglion (sg) of pharate adult of spodoptera exigua (spe) by using an antiserum against helicoverpa armigera dh. a full-length of spe-dh-pban cdna was obtained based on reverse transcription-pcr and rapid amplification of cdna ends strategies. ... | 2007 | 17364826 |
| temporal synergism by microencapsulation of piperonyl butoxide and alpha-cypermethrin overcomes insecticide resistance in crop pests. | a microencapsulated formulation that gives a burst release of piperonyl butoxide (pbo) several hours before a burst release of a conventional pyrethroid can effectively overcome metabolic resistance in bemisia tabaci gennadius, helicoverpa armigera (hübner), aphis gossypii glover and myzus persicae sulzer. this increase in efficacy against resistant pests was reflected in a field trial against b. tabaci on cotton, eliminating the need for two treatments. the ratio between the active insecticide ... | 2007 | 17304634 |
| molecular characterization of diapause hormone and pheromone biosynthesis activating neuropeptide from the black-back prominent moth, clostera anastomosis (l.) (lepidoptera, notodontidae). | using a strategy of rapid amplification of cdna ends, the cdna of diapause hormone (dh) and pheromone biosynthesis activating neuropeptide (pban) was cloned from the head of clostera anastomosis (l.). the cloan-dh-pban cdna contains an open reading frame encoding a 196-amino acid preprohormone, from which five putative fxprl peptides, dh, pban, alpha-sgnp(sgnp, suboesophageal ganglion neuropeptide), beta-sgnp and gamma-sgnp, are released. comparing the deduced amino acid sequences from cdnas of ... | 2007 | 17967345 |
| identification of a kunitz inhibitor from albizzia kalkora and its inhibitory effect against pest midgut proteases. | a purification protocol, involving water extraction, ammonium sulfate precipitation, sepharose 4b-trypsin affinity and fplc superdex g-75 chromatography, was employed to isolate a trypsin inhibitor from albizzia kalkora seeds. the inhibitor, which had a molecular mass of 19,768.23 da, consisted of two disulfide-linked polypeptide chains with approximate molecular mass of 15.5 and 4.5 kda, respectively. it was stable from ph 2-12 for 24 h, whereas it was unstable either above 80 degrees c for 10 ... | 2008 | 18368297 |
| screening for antifeedant and larvicidal activity of plant extracts against helicoverpa armigera (hübner), sylepta derogata (f.) and anopheles stephensi (liston). | plant extracts, especially botanical insecticides, are currently studied more and more because of the possibility of their use in plant protection. biological activity of five solvent plant extracts were studied using fourth instar larvae of gram pod borer helicoverpa armigera (lepidoptera: noctuidae), cotton leaf roller sylepta derogata (lepidoptera: pyralidae) and malaria vector anopheles stephensi (diptera: culicidae). antifeedant and larvicidal activity of acetone, chloroform, ethyl acetate, ... | 2008 | 18679716 |
| nonuniform distribution of glucosinolates in arabidopsis thaliana leaves has important consequences for plant defense. | the spatial distribution of plant defenses within a leaf may be critical in explaining patterns of herbivory. the generalist lepidopteran larvae, helicoverpa armigera (the cotton bollworm), avoided the midvein and periphery of arabidopsis thaliana rosette leaves and fed almost exclusively on the inner lamina. this feeding pattern was attributed to glucosinolates because it was not evident in a myrosinase mutant that lacks the ability to activate glucosinolate defenses by hydrolysis. to measure t ... | 2008 | 18408160 |
| molecular cloning and expression profiles of the acyl-coa-binding protein gene from the cotton bollworm helicoverpa armigera. | acyl-coa-binding protein (acbp), also known as the diazepam-binding inhibitor (dbi), has been identified in diverse species and is evolutionarily conserved in plants and animals. in a recent study, an acbp cdna (haacbp) encoding 85 amino acids was isolated from the cotton bollworm helicoverpa armigera. the isolated protein is highly homologous to the acbp present in the bombyx mori midgut, where it is highly expressed. northern and western blot analyses revealed that haacbp is expressed predomin ... | 2008 | 18481302 |
| baited traps may be an alternative to conventional pesticides in integrated crop management of chicory (compositae) in south africa. | chicory, chicorium intybus l. (compositae), is a major field crop in the eastern cape province of south africa. several pests feed on the leaves of the plant, resulting in reduced yield. the most important of these are the noctuid moths helicoverpa armigera (hübner), chrysodeixis acuta (walker), and trichoplusia orichalcea (f.). the use of attract-and-kill traps offers an alternative to broad-based insecticides in the control of these species. three fields were treated with normal insecticides a ... | 2008 | 18330122 |
| differential transcript accumulation in cicer arietinum l. in response to a chewing insect helicoverpa armigera and defence regulators correlate with reduced insect performance. | monitoring transcriptional reorganization triggered in response to a particular stress is an essential first step for the functional analysis of genes involved in the process. to characterize cicer arietinum l. defence responses against helicoverpa armigera feeding, transcript patterns elicited by both herbivore and mechanical wounding were profiled and compared, and the application of defence regulators was assessed. a combination of approaches was employed to develop transcript profiles, inclu ... | 2008 | 18544610 |
| responses of helicoverpa armigera to tomato plants previously infected by tomv or damaged by h. armigera. | we report the comparative inducing effects of a phytopathogen and a herbivorous arthropod on the performance of an herbivore. tomato, lycopersicon esculentum mill., was used as the test plant, and tomato mosaic virus (tomv) and corn earworm, helicoverpa armigera hübner, were used as the phytopathogen and herbivore, respectively. there were decreases in the efficiency of conversion of ingested food and efficiency of conversion of digested food when h. armigera was reared on tomato plants that had ... | 2008 | 18286340 |
| mapping the larval midgut lumen proteome of helicoverpa armigera, a generalist herbivorous insect. | the gut lumen is the primary site of digestion and detoxification and thus presents conditions hostile to most proteins. we used 2d-gel electrophoresis and ms/ms de novo peptide sequencing to identify the major proteins stable enough to persist in the midgut lumen of caterpillars of the cotton bollworm helicoverpa armigera, a generalist herbivorous insect and a major crop pest worldwide. as expected, we found several enzymes responsible for digestion of carbohydrates, proteins, and lipids. in ad ... | 2008 | 18314941 |
| oviposition deterrents from eggs of the cotton bollworm, helicoverpa armigera (lepidoptera: noctuidae): chemical identification and analysis by electroantennogram. | our previous results showed that an extract of the abdomens of mated females of the cotton bollworm, helicoverpa armigera, deterred oviposition of conspecifics. in this paper, we found that the extract, in addition to reducing conspecifics' oviposition, could elicit strong electroantennogram responses from mated females. the eag elicitors mainly came from mature chorionated eggs in the ovarioles. laid eggs or their surface extract evoked similar eag responses. the main chemical components of the ... | 2008 | 18316092 |
| the complete nucleotide sequence of the type 5 helicoverpa armigera cytoplasmic polyhedrosis virus genome. | the s1-6, s8, and s9 segments of the type 5 helicoverpa armigera cytoplasmic polyhedrosis virus (hacpv-5, chinese strain) were cloned and sequenced, completing the hacpv-5 genome. we found that each hacpv-5 segment exhibits the conserved terminal sequences aguu and uugc located at the 5' and 3' ends, respectively. we also analyzed the translation initiation codon of the hacpv-5 genome and compared it with the available cypovirus sequences in genbank. we postulated that the conserved purine at th ... | 2008 | 18368473 |
| transcriptional analysis and functional characterization of a gene pair encoding iron-regulated xenocin and immunity proteins of xenorhabdus nematophila. | we describe a two-gene cluster encoding a bacteriocin, xenocin, and the cognate immunity protein in the insect-pathogenic bacterium xenorhabdus nematophila, which infects and kills larval stages of the common crop pest helicoverpa armigera. the two genes, xcina and ximb, are present in the genome as a single transcriptional unit, which is regulated under sos conditions. the stress-inducible promoter was activated by mitomycin c, glucose, and fe(3+) depletion and at an elevated temperature when i ... | 2008 | 18375563 |
| assessment of the suitability of tinopal as an enhancing adjuvant in formulations of the insect pathogenic fungus beauveria bassiana (bals.) vuillemin. | biopesticides based on beauveria bassiana (bals.) vuillemin hold great promise for the management of a wide range of insect pests. the conidia in the biopesticide formulation require an adjuvant to protect them from photoinactivation by sunlight. the suitability of tinopal, an optical brightener used as sunscreen for baculovirus formulations, for use with b. bassiana was assessed. the aim was to study the effect of tinopal on the growth and photoprotection of b. bassiana, and its effect on the s ... | 2008 | 18383501 |
| new cell lines derived from the black cutworm, agrotis ipsilon, that support replication of the a. ipsilon multiple nucleopolyhedrovirus and several group i nucleopolyhedroviruses. | new cell lines were recently developed from the embryos of the black cutworm, agrotis ipsilon (lepidoptera: noctuidae). a primary culture was initiated from 4-day-old a. ipsilon eggs in excell420 medium supplemented with 5% fetal bovine serum. this initial culture produced sufficient cell growth to allow subcultivation and eventually led to the establishment of eight distinct strains. two of these strains (aie1611t and aied6t) were selected for further characterization. extracts of these strains ... | 2008 | 18395741 |
| genetic basis of sex pheromone blend difference between helicoverpa armigera (hübner) and helicoverpa assulta (guenée) (lepidoptera: noctuidae). | the two closely related moth species, helicoverpa armigera and h. assulta, are sympatric in china. both species use a mixture of (z)-11-hexadecenal (z11-16:ald) and (z)-9-hexadecenal (z9-16:ald) as their sex pheromones but in widely different ratios. hybridization and backcrossing experiments between h. armigera and h. assulta were conducted and sex pheromone compositions of the parent species, their f(1) hybrids and backcrosses were compared to study the genetic basis of the production of their ... | 2008 | 18405915 |
| identification of a hydrophobic domain of ha2 essential to morphogenesis of helicoverpa armigera nucleopolyhedrovirus. | the ha2 protein of the helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus (hearnpv) is a wasp homology protein capable of nucleating branched actin filaments in the presence of the arp2/3 complex in vitro. to determine the role of ha2 in the hearnpv life cycle, ha2 knockout and ha2 repair bacmids were constructed. transfection and infection analysis demonstrated that the ha2 null bacmid was unable to produce infectious budded virus (bv), while the repair bacmid rescued the defect. in ... | 2008 | 18234795 |
| cloning and characterization of a novel cry1a toxin from bacillus thuringiensis with high toxicity to the asian corn borer and other lepidopteran insects. | a novel cry1a was cloned from bacillus thuringiensis strain bt8 and expressed in the b. thuringiensis acrystalliferous mutant hd73(-). the gene, designated cry1ah1, encoded a protein with a molecular weight of 134 kda. reverse transcriptase-pcr and western blotting showed that cry1ah was expressed in the host strain bt8. the toxin expressed in hd73(-) exhibited high toxicity against lepidopteran larvae of ostrinia furnacalis, helicoverpa armigera, chilo suppressalis, and plutella xylostella. the ... | 2008 | 18248430 |
| improving the insecticidal activity by expression of a recombinant cry1ac gene with chitinase-encoding gene in acrystalliferous bacillus thuringiensis. | in order to improve the insecticidal activity, the chitinase gene from tobacco (nicotiana tabacum) endochitinase and the cry1ac gene from bacillus thuringiensis were cloned into the vector pht315 and designated as phuaccb5 plasmid. the constructed transcriptional fusion was attempted under the control of the native cry1ac promoter. plasmid phuaccb5 was introduced into b. thuringiensis acrystalliferous by electroporation. analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and w ... | 2008 | 18259812 |
| expression of mel gene improves the uv resistance of bacillus thuringiensis. | to improve ultraviolet (uv) resistance of bacillus thuringiensis for increasing the duration of the bt product applied in the field, a genetically engineered strain bt td841 that produced both melanin and cry1a protein was constructed, and its uv resistance was evaluated in the laboratory. | 2008 | 18266703 |
| the f protein of helicoverpa armigera single nucleopolyhedrovirus can be substituted functionally with its homologue from spodoptera exigua multiple nucleopolyhedrovirus. | f proteins of group ii nucleopolyhedroviruses (npvs) are envelope fusion proteins essential for virus entry and egress. an f-null helicoverpa armigera single nucleocapsid npv (hearnpv) bacmid, habacdeltaf, was constructed. this bacmid could not produce infectious budded virus (bv) when transfected into hzam1 cells, showing that f protein is essential for cell-to-cell transmission of bvs. when habacdeltaf was pseudotyped with the homologous f protein (habacdeltaf-haf, positive control) or with th ... | 2008 | 18272771 |
| type 1 fimbriae of insecticidal bacterium xenorhabdus nematophila is necessary for growth and colonization of its symbiotic host nematode steinernema carpocapsiae. | xenorhabdus nematophila produces type 1 fimbriae on the surface of phase i cells. fimbriae mediate recognition and adhesion of the bacteria to its target cell. to investigate the role of fimbriae in the biology of x. nematophila, we have produced a fimbrial mutant strain by insertional inactivation of the mrxa gene, encoding the structural subunit of type 1 fimbriae. phenotypic characterization of the mutant revealed loss of fimbriae on the cell surface. cell surface characteristics like dye abs ... | 2008 | 18279345 |
| transgenic cotton expressing synthesized scorpion insect toxin aahit gene confers enhanced resistance to cotton bollworm (heliothis armigera) larvae. | a synthetic scorpion hector insect toxin (aahit) gene, under the control of a camv35s promoter, was cloned into cotton via agrobacterium tumefaciens-mediated transformation. southern blot analyses indicated that integration of the transgene varied from one to more than three estimated copies per genome; seven homozygous transgenic lines with one copy of the t-dna insert were then selected by pcr and southern blot analysis. aahit expression was from 0.02 to 0.43% of total soluble protein determin ... | 2008 | 17939056 |
| changes of inheritance mode and fitness in helicoverpa armigera (hübner) (lepidoptera: noctuidae) along with its resistance evolution to cry1ac toxin. | the changes of inheritance mode and fitness of resistance in helicoverpa armigera (hübner) along with its resistance evolution to cry1ac toxin were evaluated in the laboratory. the resistance levels reached 170.0-, 209.6- and 2893.3-fold, on selection of the field population in the 16th (btr-f(16)), 34th (btr-f(34)) and 87th (btr-f(87)) generation with artificial diet containing cry1ac toxin, respectively. as the resistance levels increased, more larvae feeding on the bt cotton expressing cry1ac ... | 2008 | 17950749 |
| an insecticidal groel protein with chitin binding activity from xenorhabdus nematophila. | xenorhabdus nematophila secretes insecticidal proteins to kill its larval prey. we have isolated an approximately 58-kda groel homolog, secreted in the culture medium through outer membrane vesicles. the protein was orally insecticidal to the major crop pest helicoverpa armigera with an lc50 of approximately 3.6 microg/g diet. for optimal insecticidal activity all three domains of the protein, apical, intermediate, and equatorial, were necessary. the apical domain alone was able to bind to the l ... | 2008 | 18667427 |
| expression of v-cath gene from hearnpv in tobacco confers an antifeedant effect against helicoverpa armigera. | biotechnology solutions for insect control on crops largely depend on the expression of bacillus thuringiensis insecticidal proteins to kill pests. v-cath, a cathepsin l-like cysteine protease from baculoviruses, has been shown to play an essential role in host insect liquefaction. in this study, the v-cath gene from helicoverpa armigera single nucleopolyhedrovirus (hearnpv) was cloned into the pbi121 binary vector under the control of camv35s promoter, and was expressed in tobacco via agrobacte ... | 2008 | 18722486 |
| functional studies of per os infectivity factors of helicoverpa armigera single nucleocapsid nucleopolyhedrovirus. | a combined functional investigation on the four per os infectivity factors (pifs) of helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (hearnpv) was conducted in this study. hearnpv bacmids with deletions of p74 (ha20), pif1 (ha111), pif2 (ha132) and pif3 (ha98) were constructed individually by homologous recombination in escherichia coli cells. repaired bacmids with respective pifs were also constructed. western blot analyses revealed that all four pifs were structural components of ... | 2008 | 18753243 |
| proteomic analysis of the peritrophic matrix from the gut of the caterpillar, helicoverpa armigera. | the peritrophic matrix from the midgut of the caterpillar, helicovera armigera, was solubilized by treatment with anhydrous trifluoromethanesulfonic acid, apparently by depolymerisation of its chitin component. this allowed the efficient extraction of proteins in a technique that may be broadly applicable to the analysis of other structures containing chitin. gel electrophoresis and mass spectrometry of tryptic peptides were used to identify the extracted proteins with gut-expressed cdna sequenc ... | 2008 | 18760362 |
| diet factors responsible for the change of the glucose oxidase activity in labial salivary glands of helicoverpa armigera. | we investigated the change of the glucose oxidase (gox) activity in labial salivary glands of helicoverpa armigera larvae fed with the artificial diet or host plant tobacco and the major factors responsible for such a change. throughout larval development, the labial salivary gox activities in caterpillars reared on the artificial diet were remarkably higher than those fed with the plant. after fifth-instar plant-fed caterpillars were transferred to the artificial diet, their labial salivary gox ... | 2008 | 18481298 |
| effectiveness of bacillus thuringiensis-transgenic chickpeas and the entomopathogenic fungus metarhizium anisopliae in controlling helicoverpa armigera (lepidoptera: noctuidae). | the use of genetically modified (bt) crops expressing lepidopteran-specific cry proteins derived from the soil bacterium bacillus thuringiensis is an effective method to control the polyphagous pest helicoverpa armigera. as h. armigera potentially develops resistance to cry proteins, bt crops should be regarded as one tool in integrated pest management. therefore, they should be compatible with biological control. bioassays were conducted to understand the interactions between a cry2aa-expressin ... | 2008 | 18487396 |
| diversity of aminopeptidases, derived from four lepidopteran gene duplications, and polycalins expressed in the midgut of helicoverpa armigera: identification of proteins binding the delta-endotoxin, cry1ac of bacillus thuringiensis. | helicoverpa armigera midgut proteins that bind the bacillus thuringiensis (bt) delta-endotoxin cry1ac were purified by affinity chromatography. sds-page showed that several proteins were eluted with n-acetylgalactosamine and no further proteins were detected after elution with urea. tandem mass spectral data for tryptic peptides initially indicated that the proteins resembled aminopeptidases (apns) from other lepidopterans and cdna sequences for seven apns were isolated from h. armigera through ... | 2008 | 18549954 |
| unusually high frequency of genes encoding vegetative insecticidal proteins in an australian bacillus thuringiensis collection. | of 188 australian bacillus thuringiensis strains screened for genes encoding soluble insecticidal proteins by polymerase chain reaction/restriction-length fragment polymorphism (rflp) analysis, 87% showed the presence of such genes. although 135 isolates (72%) produced an rflp pattern identical to that expected for vip3a genes, 29 isolates possessed a novel vip-like gene. the novel vip-like gene was cloned from b. thuringiensis isolate c81, and sequence analysis demonstrated that it was 94% iden ... | 2008 | 18592309 |
| use of a cry1ac-resistant line of helicoverpa armigera (lepidoptera: noctuidae) to detect novel insecticidal toxin genes in bacillus thuringiensis. | this paper describes a screening strategy incorporating resistant insect lines for discovery of new bacillus thuringiensis toxins against a background of known genes that would normally mask the activity of additional genes and the application of that strategy. a line of helicoverpa armigera with resistance to cry1ac (line isoc) was used to screen cry1ac-expressing strains of b. thuringiensis for additional toxins with activity against h. armigera. using this approach, a number of cry1ac-produci ... | 2008 | 18592310 |
| isolations of cry2ab resistance in australian populations of helicoverpa armigera (lepidoptera: noctuidae) are allelic. | alleles conferring resistance to cry2ab toxin occur at a frequency of 0.0033 in australian populations of helicoverpa armigera (hübner) (lepidoptera: noctuidae), and it is evident that detectable levels of resistance predated the introduction of transgenic cotton expressing this toxin. from 2002 until 2006, 10 such resistant alleles were scored. here, we examine colonies established from five of the 10 isolates by using complementation tests to determine their genetic relationships. the results ... | 2008 | 18613594 |
| resistance allele frequency to bt cotton in field populations of helicoverpa armigera (lepidoptera: noctuidae) in china. | resistance evolution in target insects to bacillus thurningiensis (bt) cotton, gossypium hirsutum l., is a main threat to bt cotton technology. an increasing trend of population density of helicoverpa armigera (hübner) (lepidoptera: noctuidae) has been observed since 2001 in qiuxian county (hebei, china), where bt cotton has been planted dominantly since 1998. this region was selected in 2006 and 2007 for estimating frequency of gene alleles conferring resistance to bt cotton by screening the f1 ... | 2008 | 18613597 |
| degradation of the insecticidal toxin produced by bacillus thuringiensis var. kurstaki by extracellular proteases produced by chrysosporium sp. | some cry proteins produced by the soil bacterium bacillus thuringiensis (bt) or by transgenic bt plants persist in agricultural soils for an extended period of time, which may pose a hazard for nontarget soil organisms. the aims of our study were to screen for soil fungi capable of degrading the cry1ac toxin and to identify the mechanisms that lead to the inactivation of this protein. | 2008 | 18028364 |
| effects of helicoverpa armigera (noctuidae, lepidoptera) host stages on some developmental parameters of the uniparental endoparasitoid meteorus pulchricornis (braconidae, hymenoptera). | a single choice test was performed to examine developmental strategies in the uniparental endoparasitoid meteorus pulchricornis and its host, the cotton bollworm helicoverpa armigera. the results support the dome-shaped model in which the fitness functions are 'dome-shaped' relative to size (and age) of host at parasitism. older and, hence, larger host larvae were simply not better hosts for the developing parasitoids. although parasitoid size (measured as cocoon weight and adult hind tibia leng ... | 2008 | 18076779 |
| plant cyclotides disrupt epithelial cells in the midgut of lepidopteran larvae. | several members of the rubiaceae and violaceae plant families produce a series of cyclotides or macrocyclic peptides of 28-37 aa with an embedded cystine knot. the cyclic peptide backbone together with the knotted and strongly braced structure confers exceptional chemical and biological stability that has attracted attention for potential pharmaceutical applications. cyclotides display a diverse range of biological activities, such as uterotonic action, anti-hiv activity, and neurotensin antagon ... | 2008 | 18202177 |
| bacillus thuringiensis cry1ac toxin-binding and pore-forming activity in brush border membrane vesicles prepared from anterior and posterior midgut regions of lepidopteran larvae. | it is generally accepted that bacillus thuringiensis cry toxins insert into the apical membrane of the larval midgut after binding to specific receptors, and there is evidence that the distribution of binding molecules along the midgut is not uniform. by use of the voltage-sensitive dye disc(3)(5) and (125)i-labeled cry1ac, we have measured the effect of cry1ac in terms of permeabilization capacity and of binding parameters on brush border membrane vesicles (bbmv) prepared from the anterior and ... | 2008 | 18223107 |
| molecular characters and expression analysis of the gene encoding eclosion hormone from the asian corn borer, ostrinia furnacalis. | using rapid amplification of cdna ends (race), the cdna encoding eclosion hormone (eh) was cloned from the brain of ostrinia furnacalis. the full osf-eh cdna is 986 bp and contains a 267 bp open reading frame encoding an 88 amino acid preprohormone, which including a hydrophobic 26 amino acid signal peptide and a 62 amino acid mature peptide. the mature osf-eh shows high identity with manduca sexta (95.2%), helicoverpa armigera (91.9%) and bombyx mori (85.5%), but low identify with tribolium cas ... | 2008 | 17852339 |
| disruption of ha_btr alters binding of bacillus thuringiensis delta-endotoxin cry1ac to midgut bbmvs of helicoverpa armigera. | disruption of the ha_btr (a cadherin gene) is genetically linked to resistance to cry1ac delta-endotoxin of bacillus thuringiensis in the gybt strain of helicoverpa armigera. brush border membrane vesicles (bbmvs) prepared from midguts of both the cry1ac-resistant gybt strain (homozygous for a deletion knockout of ha_btr) and the susceptible gy strain (homozygous for the wild type of ha_btr) possessed saturable and specific binding ability to (125)i-cry1ac. the binding constant (k(d)) of the gy ... | 2008 | 17681529 |
| molecular cloning and characterization of hearm caspase-1 from helicoverpa armigera. | members of the caspase family play a central and evolutionary role in programmed cell death (pcd), which removes unwanted, damaged and dangerous cells during development to maintain homeostasis. in this paper, we describe the cloning and characterization of a caspase from the cotton bollworm, helicoverpa armigera, named hearm caspase-1. the 1,350 bp full-length cdna contains an 885 bp open reading frame (orf) that encodes a hearm caspase-1 proenzyme of 294 amino acids. the deduced protein is hig ... | 2008 | 17541728 |
| molecular cloning and characterization of a c-type lectin from the cotton bollworm, helicoverpa armigera. | c-type lectins participate in pathogen recognition and other defense responses in innate immunity as well as in cell-cell interactions. a new cdna encoding a 335-residue polypeptide containing two tandem c-type lectin domains was cloned from the haemocytes of helicoverpa armigera (ha-lectin). northern hybridizations revealed that the mrna of ha-lectin was expressed constitutively in haemocytes, and was up-regulated following injections of bacteria, yeast, or virus. ha-lectin expression was also ... | 2008 | 17568670 |
| characterization of the cry1ac17 gene from an indigenous strain of bacillus thuringiensis subsp. kenyae. | an indigenously isolated strain of bacillus thuringiensis subsp. kenyae exhibited toxicity against lepidopteran as well as dipteran insects. the lepidopteran active cry1ac protoxin gene coding sequence of 3.5 kb from this strain was cloned into vector pet28a(+). however, it could not be expressed in commonly used escherichia coli expression hosts, bl21(de3) and bl21(de3)plyss. this gene is classified as cry1ac17 in the b. thuringiensis toxic nomenclature database. the coding sequence of this gen ... | 2008 | 18795364 |
| reproductive biology of two nontarget insect species, aphis gossypii (homoptera: aphididae) and orius sauteri (hemiptera: anthocoridae), on bt and non-bt cotton cultivars. | transgenic bt cotton, engineered to continuously produce activated delta-endotoxins of the soil bacteria bacillus thuringiensis, holds great promise in controlling helicoverpa armigera and other lepidopteran pests. however, it also may impact the invertebrate community, which needs to be clarified. the effects of bt cotton on two nontarget insects, aphis gossypii and orius sauteri, were assessed under semifield and laboratory conditions. mean total duration of nymphal stages of a. gossypii was s ... | 2008 | 18801270 |
| suppression of cotton bollworm in multiple crops in china in areas with bt toxin-containing cotton. | transgenic cotton that has been engineered to produce insecticidal toxins from bacillus thuringiensis (bt) and so to resist the pest cotton bollworm (helicoverpa armigera) has been widely planted in asia. analysis of the population dynamics of h. armigera from 1992 to 2007 in china indicated that a marked decrease in regional outbreaks of this pest in multiple crops was associated with the planting of bt cotton. the study area included six provinces in northern china with an annual total of 3 mi ... | 2008 | 18801998 |
| solubilization, activation, and insecticidal activity of bacillus thuringiensis serovar thompsoni hd542 crystal proteins. | cry15aa protein, produced by bacillus thuringiensis serovar thompsoni hd542 in a crystal together with a 40-kda accompanying protein, is one of a small group of nontypical, less well-studied members of the cry family of insecticidal proteins and may provide an alternative for the more commonly used cry proteins in insect pest management. in this paper, we describe the characterization of the cry15aa and 40-kda protein's biochemical and insecticidal properties and the mode of action. both protein ... | 2008 | 18836017 |
| specific binding of bacillus thuringiensis cry2a insecticidal proteins to a common site in the midgut of helicoverpa species. | for a long time, it has been assumed that the mode of action of cry2a toxins was unique and different from that of other three-domain cry toxins due to their apparent nonspecific and unsaturable binding to an unlimited number of receptors. however, based on the homology of the tertiary structure among three-domain cry toxins, similar modes of action for all of them are expected. to confirm this hypothesis, binding assays were carried out with (125)i-labeled cry2ab. saturation assays showed that ... | 2008 | 18931285 |
| a homolog of the vaccinia virus d13l rifampicin resistance gene is in the entomopoxvirus of the parasitic wasp, diachasmimorpha longicaudata. | the parasitic wasp, diachasmimorpha longicaudata (ashmead) (hymenoptera: braconidae), introduces an entomopoxvirus (dlepv) into its caribbean fruit fly host, anastrepha suspensa. (loew) (diptera: tephritidae), during oviposition. dlepv has a 250-300 kb unipartite dsdna genome, that replicates in the cytoplasm of the host's hemocytes, and inhibits the host's encapsulation response. the putative proteins encoded by several dlepv genes are highly homologous with those of poxviruses, while others ap ... | 2008 | 20345294 |
| introgression of a disrupted cadherin gene enables susceptible helicoverpa armigera to obtain resistance to bacillus thuringiensis toxin cry1ac. | a disrupted allele (r1) of a cadherin gene (ha_btr) is genetically associated with incompletely recessive resistance to bacillus thuringiensis toxin cry1ac in a cry1ac-selected strain (gybt) of helicoverpa armigera. the r1 allele of ha_btr was introgressed into a susceptible scd strain by crossing the gybt strain to the scd strain, followed by repeated backcrossing to the scd strain and molecular marker assisted family selection. the introgressed strain (designated as scd-r1, carrying homozygous ... | 2009 | 18954492 |
| bacillus thuringiensis bel protein enhances the toxicity of cry1ac protein to helicoverpa armigera larvae by degrading insect intestinal mucin. | bacillus thuringiensis has been used as a bioinsecticide to control agricultural insects. bacillus cereus group genomes were found to have a bacillus enhancin-like (bel) gene, encoding a peptide with 20 to 30% identity to viral enhancin protein, which can enhance viral infection by degradation of the peritrophic matrix (pm) of the insect midgut. in this study, the bel gene was found to have an activity similar to that of the viral enhancin gene. a bel knockout mutant was constructed by using a p ... | 2009 | 19542344 |
| trichogramma (hymenoptera: trichogrammatidae) ecology in a tropical bt transgenic cotton cropping system: sampling to improve seasonal pest impact estimates in the ord river irrigation area, australia. | trichogramma westwood (hymenoptera: trichogrammatidae) cause high mortality rates in the potentially resistant pest species, helicoverpa armigera (hübner) (lepidoptera: noctuidae), and are considered integral to the resistance management plan for bacillus thuringiensis transgenic cotton, gossypium hirsutum l., production in the ord river irrigation area (oria), western australia. measured as percentage of parasitism, trichogramma activity seems highly variable over time; yet, it contributes sign ... | 2009 | 19610415 |
| cry2ab tolerance response of helicoverpa armigera (lepidoptera: noctuidae) populations from crylac cotton planting region. | helicoverpa armigera (hübner) (lepidoptera: noctuidae) is an important lepidopteran pest of cotton, gossypium hirsutum l., in asia. transgenic cotton expressing the cry1ac gene from bacillus thuringiensis (bt) has been widely planted for control of this pest. for managing the potential risk from resistance evolution in this pest, a new transgenic bt cotton containing cry1ac and cry2ab genes (gene pyramided strategy) was designed as a successor of cry1ac cotton. this article reports on levels of ... | 2009 | 19610441 |
| assessing the susceptibility of cruciferous lepidoptera to cry1ba2 and cry1ca4 for future transgenic cruciferous vegetables. | advances in transgenic plants expressing bacillus thuringiensis (bt) insecticidal gene(s) offer a promising alternative to traditional insecticides for control of lepidopteran pests on important cruciferous vegetable crops such as cabbage and cauliflower. a public-private partnership, the collaboration on insect management for brassicas in asia and africa (cimbaa), was formed in 2005 with the goal of developing dual-gene bt cauliflower and cabbage, initially for india, to replace the use of broa ... | 2009 | 20069851 |
| susceptibility of helicoverpa armigera (lepidoptera: noctuidae) to cry1ac and cry2ab2 insecticidal proteins in four countries of the west african cotton belt. | transgenic cotton, gossypium hirsutum l., producing cry1ac and cry2ab2 insecticidal proteins from bacillus thuringiensis (bt) was first planted in burkina faso (west africa) in 2008. here, we provide the first baseline data on susceptibility of helicoverpa armigera (hübner) (lepidoptera: noctuidae) populations collected in west africa (benin, cameroon, nigeria, and chad) to cry1ac and cry2ab2 toxins incorporated separately or in combination in a semisynthetic diet. for populations collected in 2 ... | 2009 | 20069861 |
| relationships among activities of extracellular enzyme production and virulence against helicoverpa armigera in beauveria bassiana. | extracellular enzymes produced by beauveria bassiana, are believed to play a key role in cuticle hydrolysis. enzyme production and pathogenicity has been found to be positively correlated. twenty-eight isolates of b. bassiana, collected from different geographical regions and host ranges were characterized by in vitro extracellular enzyme production and sds-page techniques for discerning biochemical basis for virulence among the different isolates. in vitro analysis of extracellular enzymes like ... | 2009 | 19025880 |
| winged bean chymotrypsin inhibitors retard growth of helicoverpa armigera. | two putative kunitz-type chymotrypsin inhibitor genes (wci2 and wci5) were isolated from winged bean (psophocarpus tetragonolobus (l.) dc). while wci2 has previously been characterized, wci5 represents a new member of the wci family. wci5 was exclusively expressed in winged bean seeds. theoretical translation of both the genes resulted into polypeptides of 207 amino acids with 86% sequence similarity. the polypeptide sequences contain four half-cysteine residues and a well-conserved leu(65)-ser( ... | 2009 | 19059315 |
| resistance of helicoverpa armigera to cry1ac toxin from bacillus thuringiensis is due to improper processing of the protoxin. | the bacterium bacillus thuringiensis produces icps (insecticidal crystal proteins) that are deposited in their spore mother cells. when susceptible lepidopteran larvae ingest these spore mother cells, the icps get solubilized in the alkaline gut environment. of approx. 140 insecticidal proteins described thus far, insecticidal protein cry1ac has been applied extensively as the main ingredient of spray formulation as well as the principal icp introduced into crops as transgene for agricultural cr ... | 2009 | 19146482 |
| using an f(2) screen to monitor frequency of resistance alleles to bt cotton in field populations of helicoverpa armigera (hübner) (lepidoptera: noctuidae). | in an effort to control the most devastating cotton pest, helicoverpa armigera (hübner), in qiuxian county (hebei, china), bt cotton has been planted almost exclusively since 1998 in this area. owing to the high insecticidal selection pressures in this region, monitoring of bt resistance in h. armigera is necessary so that proactive actions can be implemented before field control measures fail. from 2003 to 2005, an f(2) screen was conducted in order to monitor bt resistance in h. armigera popul ... | 2009 | 19165746 |
| modified female calling behaviour in cry1ac-resistant helicoverpa armigera (lepidoptera: noctuidae). | the resistance risk in helicoverpa armigera (hübner) to transgenic cotton that expresses cry1ac from bacillus thuringiensis (bt) has raised concerns about the sustainable deployment of bt cotton. mating behaviour between resistant and susceptible individuals is an important factor that affects resistance evolution of the insect. the female calling behaviours of the cry1ac-resistant strain and its susceptible control were compared in the laboratory to understand the difference in mating biology. | 2009 | 19165761 |
| constitutive expression of a trypsin protease inhibitor confers multiple stress tolerance in transgenic tobacco. | protease inhibitors have been reported to confer insect resistance in transgenic plants, except for a rice protease inhibitor that conferred drought tolerance in transgenic rice plants. we have cloned a protease inhibitor of tobacco that is expressed under treatment with aba, hydrogen peroxide, methyl jasmonate and wounding. the cdna codes for a six-domain serine protease inhibitor with a deduced sequence of 396 amino acids. we have generated transgenic tobacco plants expressing the protease inh ... | 2009 | 19179349 |
| characterization of a c-type lectin from the cotton bollworm, helicoverpa armigera. | c-type lectins can specifically recognize sugars on the surface of microorganisms and cause a series of immune responses to effectively resist pathogenic invasions. in previous work in our laboratory, we obtained a c-type lectin from helicoverpa armigera (ha-lectin). it has two different carbohydrate recognition domains (crds) crd1 and crd2 arranged in tandem. in this study, recombinant crd1 and crd2 were expressed separately in escherichia coli and purified. they have the ability to agglutinate ... | 2009 | 19185587 |
| differential elicitation of proteases and protease inhibitors in two different genotypes of chickpea (cicer arietinum) by salicylic acid and spermine. | elicitation of proteases and protease inhibitors (pis) by salicylic acid (sa) and spermine (spm) was investigated in roots and shoots of two different genotypes of chickpea cultivars iccv10 and l550, which were resistant and susceptible to wilt disease, respectively. sa and spm were found to suppress the elicitation of proteases in the resistant cv, whereas they induce it in susceptible cv. elicitation of new trypsin and chymotrypsin inhibitors was observed in the roots and shoots of resistant c ... | 2009 | 19201507 |
| seasonal migration of helicoverpa armigera (lepidoptera: noctuidae) over the bohai sea. | the seasonal migration of the helicoverpa armigera (hübner) (lepidoptera: noctuidae) over the bohai sea was observed with a searchlight trap and an entomological radar located on a small island in the center of the sea, and through a network of light-traps around the bohai region. the h. armigera moths were observed to migrate over the sea at least as early as may and light trapping through a network suggested migration might start as early as april, as soon as the moths had emerged from overwin ... | 2009 | 19253623 |
| effects of bacillus thuringiensis toxin cry1ac and cytoplasmic polyhedrosis virus of helicoverpa armigera (hübner) (hacpv) on cotton bollworm (lepidoptera: noctuidae). | in this study, interactions on the mortality and debilitating effects between cry1ac, a toxic protein produced by bacillus thuringiensis (berliner) and hacpv (chinese strain) on first and third instars larvae of helicoverpa armigera were evaluated in laboratory. when first instar was exposed to combination of bt cotton leaf discs containing hacpv (6 x 10(6), 1 x 10(7), and 3 x 10(7) pib ml(-1)) the effect on mortality was additive, when such instar larvae exposed to combination of cry1ac (0.9, 2 ... | 2009 | 19269293 |
| efficient constitutive expression of chitinase in the mother cell of bacillus thuringiensis and its potential to enhance the toxicity of cry1ac protoxin. | previous studies revealed that chitinase could enhance the insecticidal activity of bacillus thuringiensis and it has been used in combination with b. thuringiensis widely. however, the expression of b. thuringiensis chitinase is rather low and needs induction by chitin, which limits its field application. it would make sense to constitutively express the chitinase at a sufficiently high level to offer advantages in biological control of pests. in this study, a signal peptide-encoding sequence-d ... | 2009 | 19277644 |
| cloning and characterization of two novel crystal protein genes, cry54aa1 and cry30fa1, from bacillus thuringiensis strain btmc28. | bacillus thuringiensis strain btmc28 was isolated from the soil sample in china. two novel crystal protein genes were found by using the pcr-rflp method. moreover, the full-length sequences of two novel genes were obtained by a single oligonucleotide nested (son)-pcr upstream and downstream strategy. sequence analysis revealed that one gene encoded a polypeptide of 673 amino acid residues with a molecular mass of 76.3 kda, 38% identical to cry10aa, and the other encoded a polypeptide of 687 amin ... | 2009 | 19280260 |
| aerosol infectivity of a baculovirus to trichoplusia ni larvae: an alternative larval inoculation strategy for recombinant protein production. | the baculovirus-insect expression system is a popular tool for recombinant protein production. the standard method for infecting insect larvae with recombinant baculovirus for protein production involves either feeding occlusion bodies or injecting budded virus into the cuticle. in this study, we showed that the recombinant autographa californica multiple nucleopolyhedrovirus (acmnpv) at titers >10(8) pfu/ml efficiently infected trichoplusia ni (t. ni) larvae through aerosol inoculation of budde ... | 2009 | 19334290 |
| efficient screening and breeding of bacillus thuringiensis subsp. kurstaki for high toxicity against spodoptera exigua and heliothis armigera. | spodoptera exigua is one of the most renowned agricultural pest insects and relatively insensitive to bacillus thuringiensis subsp. kurstaki strains which are widely used commercial products to control lepidopterans such as heliothis armigera. in the current study, we have developed a new and efficient approach to screen and breed a b. thuringiensis subsp. kurstaki strain exhibiting high toxicity against s. exigua while retaining its high toxicity against h. armigera. uv and diethyl sulfate meth ... | 2009 | 19337765 |