| changes in cry1ac bt transgenic cotton in response to two environmental factors: temperature and insect damage. | the efficacy of cry1ac bacillus thuringiensis (bt) cotton plants against field populations of helicoverpa armigera (hübner) has been inconsistent over the growing season. any reduction in efficacy (where efficacy is the capacity of the plant to affect the survival of the insect) increases the opportunities for h. armigera to evolve resistance to bt toxin. changes in efficacy could be due to changes at the level of gene expression and/or in the physiological makeup of the plant and may be induced ... | 2005 | 16156594 |
| structural organization and expression analysis of the cdna encoding allatotropin in the cotton bollworm, helicoverpa armigera. | the cdna encoding allatotropin (at), which stimulates juvenile hormone (jh) biosynthesis by the adult corpora allata (ca) of lepidoptera, was cloned from helicoverpa armigera (har). har-at cdna encodes a 135-amino acid polypeptide precursor containing a 13-amino acid at sequence identical to manduca sexta at (mas-at). three other h. armigera at cdnas encoding 172, 213, and 246 amino acids were also cloned. the four isoforms were produced by alternative splicing and termed har-at1, -at2, -at3, an ... | 2005 | 16175534 |
| assessing moth migration and population structuring in helicoverpa armigera (lepidoptera: noctuidae) at the regional scale: example from the darling downs, australia. | analysis of gene flow and migration of helicoverpa armigera (hübner) in a major cropping region of australia identified substantial genetic structuring, migration events, and significant population genotype changes over the 38-mo sample period from november 1999 to january 2003. five highly variable microsatellite markers were used to analyze 916 individuals from 77 collections across 10 localities in the darling downs. the molecular data indicate that in some years (e.g., april 2002-march 2003) ... | 2005 | 16539153 |
| population dynamics and gene flow of helicoverpa armigera (lepidoptera: noctuidae) on cotton and grain crops in the murrumbidgee valley, australia. | the population dynamics of helicoverpa armigera (hübner) (lepidoptera: noctuidae) in the murrumbidgee valley, australia, has been characterized using five highly variable microsatellite loci. in the 2001-2002 growing season, there were very high levels of migration into the murrumbidgee valley with no detectable genetic structuring, consistent with previous analyses on a national scale. by contrast, there was significant genetic structuring over the 2002-2003 growing season, with three distinct ... | 2006 | 16573336 |
| cloning, characterization, and expression of a new cry2ab gene from bacillus thuringiensis strain 14-1. | bacillus thuringiensis is the major source for transfer of genes to impart insect resistance in transgenic plants. cry2a proteins of b. thuringiensis are promising candidates for management of resistance development in insects owing to their difference from the currently used cry1a proteins, in structure and insecticidal mechanism. the cry2ab gene was found to lack a functional promoter and, hence, is cryptic in nature. the cry2ab7 gene was cloned from a new indigenous b. thuringiensis strain, 1 ... | 2006 | 16632879 |
| toxicity of several delta-endotoxins of bacillus thuringiensis against helicoverpa armigera (lepidoptera: noctuidae) from spain. | toxicity and larval growth inhibition of 11 insecticidal proteins of bacillus thuringiensis were evaluated against neonate larvae of helicoverpa armigera, a major pest of important crops in spain and other countries, by a whole-diet contamination method. the most active toxins were cry1ac4 and cry2aa1, with lc50 values of 3.5 and 6.3 microg/ml, respectively. at the concentrations tested, cry1ac4, cry2aa1, cry9ca, cry1fa1, cry1ab3, cry2ab2, cry1da, and cry1ja1, produced a significant growth inhib ... | 2005 | 15913643 |
| comparative biological activities of a plaque-purified variant and a turkish native isolate of splinpv-b against spodoptera littoralis (lepidoptera: noctuidae). | the noctuid moth spodoptera littoralis (boisduval) is an important pest of many cultivated plants worldwide and five different geographical nucleopolyhedrovirus (npv) strains of this pest have been isolated to date. two of these, a plaque-purified variant of the s. littoralis npv from morocco (splinpv-m2) and a splinpv isolated from field-infected s. littoralis larvae found in turkey (splinpv-tr1), were compared biologically in terms of infectiveness (median lethal dose, ld50) for third instars ... | 2006 | 16235266 |
| gene cloning and expression of cadherin in midgut of helicoverpa armigera and its cry1a binding region. | cadherins belong to one of the families of animal glycoproteins responsible for calcium-dependent cell-cell adhesion. recent literatures showed that the cadherin-like in midgut of several insects served as the receptor of bt toxin cry1a and the variation of cadherin-like is related to insect's resistance to cry1a. the full-length cdna encoding cadherin-like of helicoverpa armigera is cloned by degenerate pcr and race techniques and the gene was designated as btr-harm, which is 5581 bp in full-le ... | 2005 | 16248428 |
| characterization of orf2 and its encoded protein of the helicoverpa armigera nucleopolyhedrovirus. | the open reading frame 2 (ha2) of the helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (hasnpv), a conserved gene in most baculoviruses from lepidopteran insects such as p78/83 of the autographa californica mnpv, was characterized. it is 1,242 bp long and potentially encodes a 45.9 kda. ha2 is conserved among baculoviruses from lepidopteran insects. ha2 transcripts were detected from 16 to 96 h post infection (hpi) of hzam1 cells. rabbit polyclonal antiserum against a gst-ha2 fusion ... | 2006 | 16249044 |
| purification and characterization of cry1ac toxin binding proteins from the brush border membrane of helicoverpa armigera midgut. | several cry1ac binding proteins from midgut of helicoverpa armigera were purified using toxin-affinity chromatography. enzyme assays showed that the purified proteins had strong aminopeptidase activity. the n-terminal sequences confidently identified a 124-kda binding protein as an aminopeptidase n (apn), and some similarity suggests that a 162-kda binding protein may also be an apn. two minor binding proteins were not characterized. | 2005 | 16252132 |
| higher accumulation of proteinase inhibitors in flowers than leaves and fruits as a possible basis for differential feeding preference of helicoverpa armigera on tomato (lycopersicon esculentum mill, cv. dhanashree). | tomato (lycopersicon esculentum, mill; cultivar- dhanashree) proteinase inhibitors (pis) were tested for their trypsin inhibitory (ti) and helicoverpa armigera gut proteinases inhibitory (hgpi) activity in different organs of the tomato plants. analysis of ti and hgpi distribution in various parts of the plant showed that flowers accumulated about 300 and 1000 times higher levels of ti while 700 and 400 times higher levels of hgpi as compared to those in leaves and fruits, respectively. field ob ... | 2005 | 16256155 |
| 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 |
| resistance monitoring of helicoverpa armigera (lepidoptera: noctuidae) to bt insecticidal protein during 2001-2004 in china. | susceptibility of helicoverpa armigera (hübner) (lepidoptera: noctuidae) field populations to the crylac toxin of bacillus thuringiensis berliner (bt) were monitored from 1997 to 2004 in china. during 2001-2004, 53 strains from the bt cotton planting region were sampled. the range of concentration producing 50% inhibition of larval development to third instar (ic50) values among different populations in 2001, 2002, 2003, and 2004 was 0.014-0.046, 0.010-0.062, 0.005-0.062, and 0.005-0.035 microg/ ... | 2006 | 16813327 |
| differential adsorption of occluded and nonoccluded insect-pathogenic viruses to soil-forming minerals. | soil represents the principal environmental reservoir of many insect-pathogenic viruses. we compared the adsorption and infectivity of one occluded and two nonoccluded viruses, helicoverpa armigera single nucleopolyhedrovirus (hasnpv) (baculoviridae), cricket paralysis virus (crpv) (dicistroviridae), and invertebrate iridescent virus 6 (iiv-6) (iridoviridae), respectively, in mixtures with a selection of soil-forming minerals. the relative infective titers of hasnpv and crpv were unchanged or sl ... | 2006 | 16820456 |
| restraining erwinia virulence by expression of n-acyl homoserine lactonase gene pro3a-aiia in bacillus thuringiensis subsp leesis. | to widen the biological control function of a genetically modified bacillus thuringiensis subsp leesis strain bmb-005, an acyl homoserine lactonase (ahl lactonase) gene aiia transcribed by the promoter of insecticidal crystal protein coding gene cry3a, was transformed into strain bmb-005. the amount of ahl lactonase protein produced by transformant bmb821a was 2.4-fold more than that produced by bmb-005. ahl-degradation assay showed that transformant bmb821a could degrade more ahls molecules tha ... | 2006 | 16838380 |
| insect odour perception: recognition of odour components by flower foraging moths. | odours emitted by flowers are complex blends of volatile compounds. these odours are learnt by flower-visiting insect species, improving their recognition of rewarding flowers and thus foraging efficiency. we investigated the flexibility of floral odour learning by testing whether adult moths recognize single compounds common to flowers on which they forage. dual choice preference tests on helicoverpa armigera moths allowed free flying moths to forage on one of three flower species; argyranthemu ... | 2006 | 16846910 |
| effectiveness of two insect growth regulators against bemisia tabaci (gennadius) (homoptera: aleyrodidae) and helicoverpa armigera (hübner) (lepidoptera: noctuidae) and their impact on population densities of arthropod predators in cotton in pakistan. | field efficacies of two insect growth regulators (igrs) at two recommended application rates, buprofezin at 370 and 555 g ai ha(-1) and lufenuron at 37 and 49 g ai ha(-1), were determined against the sweet potato whitefly, bemisia tabaci (gennadius), and the cotton bollworm, helicoverpa armigera (hübner), in experimental plots of cotton at the directorate of cotton research, faisalabad, pakistan. adverse effects of the igrs on populations of associated arthropod predators, namely geocorids, chry ... | 2006 | 16862616 |
| open reading frame 132 of helicoverpa armigera nucleopolyhedrovirus encodes a functional per os infectivity factor (pif-2). | open reading frame 132 (ha132) of helicoverpa armigera nucleopolyhedrovirus (hearnpv) is a homologue of per os infectivity factor 2 (pif-2) of spodoptera exigua multiple nucleopolyhedrovirus. sequence analysis indicated that ha132 encoded a protein of 383 aa with a predicted molecular mass of 44.5 kda. alignment of ha132 and its baculovirus homologues revealed that ha132 was highly conserved among baculoviruses, with 14 absolutely conserved cysteine residues. rt-pcr indicated that ha132 was firs ... | 2006 | 16894194 |
| identification and molecular detection of a deletion mutation responsible for a truncated cadherin of helicoverpa armigera. | cadherins are a class of receptor proteins for bacillus thuringiensis cry1a toxins. disruption of a cadherin gene (ha_btr) is associated with cry1ac resistance in the cotton bollworm helicoverpa armigera [xu, x., yu, l., wu, y., 2005. disruption of a cadherin gene associated with resistance to cry1ac delta-endotoxin of b. thuringiensis in h. armigera. appl. environ. microbiol. 71, 948-954]. determination of the genomic dna sequences of ha_btr gene showed that the wild type ha_btr coding sequence ... | 2006 | 16935222 |
| the cytotoxic fimbrial structural subunit of xenorhabdus nematophila is a pore-forming toxin. | we have purified a fimbrial shaft protein (mrxa) of xenorhabdus nematophila. the soluble monomeric protein lysed larval hemocytes of helicoverpa armigera. osmotic protection of the cells with polyethylene glycol suggested that the 17-kda mrxa subunit makes pores in the target cell membrane. the internal diameter of the pores was estimated to be >2.9 nm. electron microscopy confirmed the formation of pores by the fimbrial subunit. mrxa protein oligomerized in the presence of liposomes. electrophy ... | 2006 | 16950919 |
| absolute configuration of volicitin from the regurgitant of lepidopteran caterpillars and biological activity of volicitin-related compounds. | volicitin [n-(17-hydroxylinolenoyl)-l-glutamine] and n-linolenoyl-l-glutamine are known as insect-produced plant volatile elicitors. the absolute configuration of the hydroxylinolenoyl moiety of volicitin from three noctuid species, helicoverpa armigera, mythimna separata and spodoptera litura, was determined to be all 17s in high enantiomeric excess. when treated with 30 pmol of (17s)- and (17r)-volicitin, corn seedlings were induced to release volatiles, there being no significant difference i ... | 2006 | 16960380 |
| a true summer diapause induced by high temperatures in the cotton bollworm, helicoverpa armigera (lepidoptera: noctuidae). | summer diapause in the cotton bollworm, helicoverpa armigera (hübner), which prolongs the pupal stage, particularly in males, is induced by high temperatures. in the laboratory, summer-diapausing pupae of h. armigera were induced at high temperatures (33-39 degrees c) with a photoperiod of ld8:16; winter-diapausing and non-diapausing pupae, cultured at 20 degrees c with a photoperiod of ld8:16 and at 27 degrees c, ld16:8, respectively, acted as a control. retention time of eye spots, weight, and ... | 2006 | 16979652 |
| monitoring and management strategy for helicoverpa armigera resistance to bt cotton in china. | the cotton bollworm, helicoverpa armigera, is one of the most important insect pests in cotton growing regions of china. transgenic cotton that expresses a gene derived from the bacterium bacillus thuringiensis (bt) has been deployed for combating cotton bollworm since 1997. natural refugees derived from the mixed planting system consisting of cotton, corn, soybean, vegetables, peanut and others on single-family farms of a small scale were used for delaying the evolution of resistance to bt cott ... | 2007 | 17467730 |
| 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 |
| functional role of the cytoplasmic tail domain of the major envelope fusion protein of group ii baculoviruses. | f proteins from baculovirus nucleopolyhedrovirus (npv) group ii members are the major budded virus (bv) viral envelope fusion proteins. they undergo furin-like proteolysis processing in order to be functional. f proteins from different baculovirus species have a long cytoplasmic tail domain (ctd), ranging from 48 (spodoptera litura multicapsid npv [mnpv]) to 78 (adoxophyes honmai npv) amino acid (aa) residues, with a nonassigned function. this ctd is much longer than the ctd of gp64-like envelop ... | 2006 | 17071930 |
| cross-species investigation of helicoverpa armigera microsatellites as potential markers for other related species in the helicoverpa--heliothis complex. | primers previously designed to amplify microsatellite dna markers in the old world bollworm, helicoverpa armigera, larvae were tested in three closely related species: the corn earworm, helicoverpa zea, tobacco budworm, heliothis virescens, and heliothis subflexa. of the fourteen loci surveyed, only four loci (hab60, hac14, hac87, harssr1) consistently demonstrated scorable single-copy microsatellite bands. of these four, length polymorphism was identified only in the hab60 marker (160 bp, 140 b ... | 2005 | 17119629 |
| group i but not group ii npv induces antiviral effects in mammalian cells. | nucleopolyhedrovirus (npv) is divided into group i and group ii based on the phylogenetic analysis. it has been reported that group i npvs such as autographa californica multiple npv (acmnpv) can transduce mammalian cells, while group ii npvs such as helicoverpa armigera single npv (hasnpv) cannot. here we report that acmnpv was capable of stimulating antiviral activity in human hepatoma cells (smmc-7721) manifested by inhibition of vesicular stomatitis virus (vsv) replication. in contrast, the ... | 2006 | 17172054 |
| importance of virus-medium interactions on the biological activity of wild-type heliothine nucleopolyhedroviruses propagated via suspension insect cell cultures. | in vitro serial passaging of nucleopolyhedroviruses often results in virus instability, leading to reduction of both yield and biological activity of polyhedra (virus occlusion bodies). in this study, uncloned helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus (hasnpv) and cloned helicoverpa zea single-nucleocapsid nucleopolyhedrovirus (hzsnpv) were each serially passaged five times in both low cost (vpm) and commercial (excell 401) media using h. zea cell cultures. when the experimen ... | 2006 | 16716412 |
| 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 |
| effects of cry1ac toxin of bacillus thuringiensis and nuclear polyhedrosis virus of helicoverpa armigera (hübner) (lepidoptera: noctuidae) on larval mortality and pupation. | in the laboratory, the percentage mortality and pupation of helicoverpa armigera (hübner) were investigated when larvae were exposed to cry1ac of bacillus thuringiensis berliner, nuclear polyhedrosis virus of h. armigera (hanpv) or cry1ac and hanpv together. the results revealed that interactions between cry1ac and hanpv varied with bioassay method and concentration of the suspension. when larvae were infected using a suspension containing both hanpv and cry1ac, most combinations of cry1ac (62.5 ... | 2006 | 16770833 |
| common genomic structure for the lepidoptera cadherin-like genes. | a cadherin-like protein present in the midgut epithelial cells of lepidoptera is associated with insect resistance to bacillus thuringiensis cry toxins. we describe for the first time the genes that encode the cadherin-like proteins in ostrinia nubilalis, helicoverpa armigera, and bombyx mori, and analyze their organization. these genes encompass 19.6 kb, 20.0 kb, and 41.8 kb of genomic dna, respectively, and despite the size heterogeneity, they are all composed of 35 exons that are linked by 34 ... | 2006 | 16905280 |
| vip3a is responsible for the potency of bacillus thuringiensis 9816c culture supernatant against helicoverpa armigera and spodoptera exigua. | culture supernatant of bacillus thuringiensis 9816c had high toxicity against helicoverpa armigera and spodoptera exigua. however, it lost insecticidal activities after being bathed in boiling water for 5 min. acrystalliferous mutants of bt9816c (bt9816c-np1 and bt9816c-np2) cured of its endogenous plasmids no longer possessed vip3a gene and toxicity. the 89 kd protein which existed in bt9816c supernatant disappeared in the two mutants' supernatant; nevertheless, the two mutants still exhibited ... | 2006 | 16778351 |
| spider venom toxin protects plants from insect attack. | many of the toxin proteins, that have been heterogeneously expressed in agricultural crops to provide resistance to insect pests, are too specific or are only mildly effective against the major insect pests. spider venoms are a complex cocktail of toxins that have evolved specifically to kill insects. here we show that the omega-actx-hv1a toxin (hvt), a component of the venom of the australian funnel web spider (hadronyche versuta) that is a calcium channel antagonist, retains its biological act ... | 2006 | 16779650 |
| microbial communities in the larval midgut of laboratory and field populations of cotton bollworm (helicoverpa armigera). | we compared the bacterial communities in the larval midgut of field and laboratory populations of a polyphagous pest, the cotton bollworm (helicoverpa armigera), using denaturing gradient gel electrophoresis (dgge) of amplified 16s rdna sequences and 16s library sequence analysis. dgge profiles and 16s rdna library sequence analysis indicated similar patterns of midgut microbial community structure and diversity: specific bacterial types existed in both populations, and a more diverse microbial ... | 2006 | 17215900 |
| 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 |
| 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 |
| [domain swapping of cry1aa and cry1ca from bacillus thuringiensis influence crystal formation and toxicity]. | bacillus thuringiensis has been successfully used for agricultural pest and medical insect control with its significant benefits based on environmental and safety considerations. however, the deficiency of this pesticide, such as limited spectrum of insecticidal activity, low toxicity to the targets and the inducement of insect resistance, results in the urgent need to exploit new resources of b. thuringiensis or to modify known strains by genetic engineering. in this study, six recombinant baci ... | 2006 | 17302152 |
| 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 |
| a new cell line from larval fat bodies of the bollworm, helicoverpa armigera (lepidoptera: noctuidae). | a new cell line, designated iozcas-ha-i, was initiated from the fat body of larvae of helicoverpa armigera (lepidoptera: noctuidae) in tnm-fh medium containing 10% fetal bovine serum. spherical cells were predominant among the various cell types. the cell line showed a typical lepidopteran chromosome pattern ranging from 58 to 239 chromosomes in the majority of the cells. it was confirmed to have originated from the h. armigera by the dna amplification- fingerprinting polymerase chain reaction ( ... | 2006 | 17316061 |
| 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 |
| phylogenetic analysis of heliothis armigera cytoplasmic polyhedrosis virus type 14 and a series of dwarf segments found in the genome. | full-length nucleotide sequences for the genome segments (s1-s6) of heliothis armigera cytoplasmic polyhedrosis virus type 14 (hacpv-14) have been characterized. each segment consists of a single open reading frame with conserved motifs agaa and agcu at the 5' and 3' ends, respectively. comparison of the proteins of hacpv-14 with those of other members of the family reoviridae suggests that s1 encodes an rna-dependent rna polymerase (rdrp), whilst s2 encodes a major capsid protein of the virus. ... | 2007 | 17325373 |
| characterization of the rna-binding regions in protein p36 of heliothis armigera cypovirus 14. | some proteins of cypovirus (cpv) bind to rna, probably contributing to the replication of viral genome. however, little is known about whether any protein from heliothis armigera cypovirus (hacpv) could bind to rna. in this study, we cloned the orf of segment 9 (s9) of hacpv, serotype 14, into pmal-c2x for the generation and purification of maltose binding protein (mbp) fused protein p36 (mbp-p36). the analysis of the rna-binding properties of mbp-p36 revealed that p36, but not mbp alone, bound ... | 2007 | 17350708 |
| induction of apoptosis in saccharomyces cerevisiae results in the spontaneous maturation of tetravirus procapsids in vivo. | the tetraviridae are a family of small, non-enveloped, insect rna viruses consisting of one or two single-stranded, positive-sense genomic rnas encapsidated in an icosahedral capsid with t=4 symmetry. tetravirus procapsids undergo maturation when exposed to a low ph environment in vitro. while the structural biology of the conformational changes that mediate acid-dependent maturation is well understood, little is known about the significance of acid-dependent maturation in vivo. to address this ... | 2007 | 17412989 |
| a global approach to resistance monitoring. | transgenic crops producing insecticidal toxins from the bacterium bacillus thuringiensis (bt) have been grown in many parts of the world since 1996. in the united states, the environmental protection agency (epa) has required that industry submit insect resistance management (irm) plans for each bt corn and cotton product commercialized. a coalition of stakeholders including the epa, usda, academic scientists, industry, and grower organizations have cooperated in developing specific irm strategi ... | 2007 | 17467005 |
| ha2 from the helicoverpa armigera nucleopolyhedrovirus: a wasp-related protein that activates arp2/3-induced actin filament formation. | filamentous actin is required for the productive replication of lepidopteran nucleopolyhedroviruses. we have demonstrated that nucleocapsids of the helicoverpa armigera nucleopolyhedrovirus (hearnpv) are capable of nucleating actin polymerization in vitro in a dose-dependent manner. actin polymerization is the main mechanism used in cell locomotion and is also utilized by the listeria bacteria and by vaccinia virus for intracellular and intercellular movements. the wasp family of proteins has be ... | 2007 | 17467839 |
| monitoring and adaptive resistance management in australia for bt-cotton: current status and future challenges. | in the mid-1990 s the australian cotton industry adopted an insect-resistant variety of cotton (ingard) which expresses the bt toxin cry1ac that is specific to a group of insects including the target helicoverpa armigera. a conservative resistance management plan (rmp), that restricted the area planted to ingard, was implemented to preserve the efficacy of cry1ac until two-gene transgenic cotton was available. in 2004/05 bollgard ii replaced ingard as the transgenic cotton available in australia ... | 2007 | 17470372 |
| helicoverpa armigera baseline susceptibility to bacillus thuringiensis cry toxins and resistance management for bt cotton in india. | transgenic cotton that produces insecticidal proteins from bacillus thuringiensis (bt), often referred to as bt cotton, is widely grown in many countries. bt cotton with a single cry1a gene and stacked also with cry2a gene has provided satisfactory protection against the damage by the lepidopteran bollworms, especially the cotton bollworm, helicoverpa armigera (hübner) which is considered as a key pest. the baseline susceptibility of the larvae of h. armigera to cry1ac and other toxins carried o ... | 2007 | 17475275 |
| 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 |
| the heptad repeats region is essential for acmnpv p10 filament formation and not the proline-rich or the c-terminus basic regions. | baculovirus p10 protein is a small conserved protein and is expressed as bundles of filaments in the host cell during the late phase of virus infection. so far the published results on the domain responsible for filament structural formation have been contradictory. electron microscopy revealed that the c-terminus basic region was involved in filament structural formation in the autographa californica multiple nucleocapsid nucleopolyhedrovirus (acmnpv) [van oers, m.m., flipsen, j.t., reusken, c. ... | 2007 | 17481692 |
| the diversity of bt resistance genes in species of lepidoptera. | although the mode of action of cry1a toxins produced by bacillus thuringiensis is fairly well understood, knowledge of the molecular mechanisms by which lepidopteran species have evolved resistance to them is still in its infancy. the most common type of resistance has been called "mode 1" and is characterized by recessive inheritance, >500-fold resistance to and reduced binding by at least one cry1a toxin, and negligible cross-resistance to cry1c. in three lepidopteran species, heliothis viresc ... | 2007 | 17482643 |
| bacterial expression and cellular localization of helicoverpa armigera nucleopolyhedrovirus orf33 in infected host cells. | helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (hearsnpv) is a selective, highly infectious pathogen to h. armigera and has been extensively used for the control of this pest. this study presents the bacterial expression and localization of ha33 in infected host cells. the ha33 protein expressed in escherichia coli had protein size of 17kda. western blot analysis using polyclonal antibody showed that the product of ha33 in infected helicoverpa zea cells (hzam1) was a 31kda protein ... | 2006 | 16579466 |
| detection of chromosomally located and plasmid-borne genes on 20 kb dna fragments in parasporal crystals from bacillus thuringiensis. | the association of 20 kb heterologous dna fragments with the parasporal crystals from native and recombinant bacillus thuringiensis strains was analyzed, respectively. the cry2aa10 gene cloned in plasmid phc39 was transformed into b. thuringiensis subsp. kurstaki strains cry b and hd73, producing recombinant strains cry b(phc39) and hd73(phc39). sds-page and scanning electron microscopy analyses demonstrated that the recombinant cry b(phc39) produced cuboidal crystals of cry2aa10 protoxin, while ... | 2007 | 17516045 |
| ligand binding by recombinant domains from insect ecdysone receptors. | the ligand binding domains (lbds) from the ecr and usp proteins of four insect pests (lucilia cuprina, myzus persicae, bemisia tabaci, helicoverpa armigera) were purified as recombinant heterodimers. the k(d) values for [(3)h]-ponasterone a binding by lbd heterodimers that included the hinge regions (i.e., de/f heterodimers) ranged 0.7-2.5 nm, with k(i) values for ecdysteroid and dibenzoylhydrazine ligands ranging from 0.1 nm to >448 microm. the k(d) and k(i) values for a recombinant h. armigera ... | 2007 | 17517338 |
| 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 |
| effects of larval host plants on over-wintering preparedness and survival of the cotton bollworm, helicoverpa armigera (hübner) (lepidoptera: noctuidae). | laboratory colonies of cotton bollworm larvae, helicoverpa armigera, kept at 20 degrees c under a photoperiod of l:d=10:14 were fed on five host plants (cotton, corn, kidney bean, tobacco and tomato) and an artificial diet (control) to determine the effects of larval host quality on survival and pupal over-wintering preparedness. a separate experiment showed that diapausing pupae weighed more and contained greater nutrient stores than did non-diapausing pupae. diapausing pupae reared on differen ... | 2007 | 17597144 |
| resistance to bacillus thuringiensis toxin cry2ab in a strain of helicoverpa armigera (lepidoptera: noctuidae) in australia. | transgenic cotton, gossypium hirsutum l., expressing the crylac and cry2ab genes from bacillus thuringiensis (bt) berliner variety kurstaki in a pyramid (bollgard ii) was widely planted for the first time in australia during the 2004-2005 growing season. before the first commercial bollgard ii crops, limited amounts of cotton expressing only the crylac gene (ingard) was grown for seven seasons. no field failures due to resistance to crylac toxin were observed during that period and a monitoring ... | 2007 | 17598553 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| induction of a nonoccluded baculovirus persistently infecting heliothis zea cells by heliothis armigera and trichoplusia ni nuclear polyhedrosis viruses. | a nonoccluded singly enveloped baculovirus (baculovirus x) persistently infects heliothis zea (imc-hz-1) cells in culture. singly enveloped nuclear polyhedrosis viruses from h. zea and heliothis armigera, and multiply enveloped nuclear polyhedrosis viruses from trichoplusia ni, spodoptera frugiperda, and spodoptera littoralis were all found to induce baculovirus x. experiments are reported which use metabolic inhibitors and inactivated inducing virus to show that it is probable that a structural ... | 1981 | 18635066 |
| 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 |
| 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 |
| olfactory receptor neurons in two heliothine moth species responding selectively to aliphatic green leaf volatiles, aromatic compounds, monoterpenes and sesquiterpenes of plant origin. | moths of the subfamily heliothinae are suitable models for comparative studies of plant odour information encoded by the olfactory system. here we identify and functionally classify types of olfactory receptor neurons by means of electrophysiological recordings from single receptor neurons linked to gas chromatography and to mass spectrometry. the molecular receptive ranges of 14 types in the two polyphagous species heliothis virescens and helicoverpa armigera are presented. the receptor neurons ... | 2005 | 15917371 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| expression and activity of a probable toxin from photorhabdus luminescens. | as an insect pathogen, photorhabdus luminescens possesses an arsenal of toxins. here we cloned and expressed a probable toxin from p. luminescens subsp. akhurstii ynd185, designated as photorhabdus insecticidal toxin (pit). the pit gene shares 94% nucleotide and 98% predicted amino acid sequence identity with plu1537, a predicted orf from p. luminescens subsp. laumondii tt01 and 30% predicted amino acid sequence similarity to a fragment of a 13.6 kda insecticidal crystal protein gene of bacillus ... | 2009 | 18409059 |