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imd pathway is involved in the interaction of drosophila melanogaster with the entomopathogenic bacteria, xenorhabdus nematophila and photorhabdus luminescens.xenorhabdus nematophila/steinernema carpocapsae and photorhabdus luminescens/heterorhabditis bacteriophora are nemato-bacterial complexes highly pathogenic for insects. using a syringe as artificial vector, we have analyzed the effects of the two bacteria, x. nematophila and p. luminescens on the genetic tool insect, drosophila melanogaster. both bacteria were found to kill adult flies in a dose dependent manner with x. nematophila being the fastest. on the other hand, when an injection of non-p ...201020627393
opportunistic nature of the mammalian microsporidia: experimental transmission of trachipleistophora extenrec (fungi: microsporidia) between mammalian and insect hosts.spores of trachipleistophora extenrec, originally isolated from the muscles of the madagascan insectivore hemicentetes semispinosus and maintained by serial passage in severe combined immunodeficiency (scid) mice, were fed to larvae of the egyptian cotton leafworm spodoptera littoralis. extensive infection of larval tissues ensued and caused larval and pupal mortality. the development of t. extenrec in the insect host, studied both by light and electron microscopy, followed generally the same li ...201021188601
identification and expression profile of halloween genes involved in ecdysteroid biosynthesis in spodoptera littoralis.20-hydroxyecdyone (20e), an active form of ecdysteroid, is the key hormone in insect growth and development. the biosynthesis of ecdysteroid is triggered and under the control of the neuropeptide, prothoracicotropic hormone (ptth). to date, five cytochrome p450 enzymes, namely spook (spo), phantom (phm), disembodied (dib), shadow (sad) and shade (shd) related to ecdysteroid biosynthesis, are identified and the character of last four enzymes is well studied in drosophila melanogaster, bombyx mori ...201019682519
transcriptional analysis of a photorhabdus sp. variant reveals transcriptional control of phenotypic variation and multifactorial pathogenicity in insects.photorhabdus luminescens lives in a mutualistic association with entomopathogenic nematodes and is pathogenic for insects. variants of photorhabdus frequently arise irreversibly and are studied because they have altered phenotypic traits that are potentially important for the host interaction. var* is a colonial and phenotypic variant displaying delayed pathogenicity when directly injected into the insect, spodoptera littoralis. in this study, we evaluated the role of transcriptomic modulation i ...201021131515
susceptibility of north-american and european crickets to acheta domesticus densovirus (addnv) and associated epizootics.the european house cricket, acheta domesticus l., is highly susceptible to a. domesticus densovirus (addnv). commercial rearings of crickets in europe are frequently decimated by this pathogen. mortality was predominant in the last larval stage and young adults. infected a. domesticus were smaller, less active, did not jump as high, and the adult females seldom lived more than 10-14 days. the most obvious pathological change was the completely empty digestive caecae. infected tissues included ad ...201021167171
flufenerim, a novel insecticide acting on diverse insect pests: biological mode of action and biochemical aspects.a new chemical compound was tested for its insecticidal activity against several major insect pests. the compound, called "flufenerim", has a core pyrimidine structure and an unknown mode of action and showed potent activity against the sweet potato whitefly bemisia tabaci (gennadius), the green peach aphid myzus persicae (sulzer), and the african cotton leafworm spodoptera littoralis (boisduval); however, it did not show any activity against two thrips species: western flower thrips frankliniel ...201020958045
study of the bacillus thuringiensis vip3aa16 histopathological effects and determination of its putative binding proteins in the midgut of spodoptera littoralis.the bacterium bacillus thuringiensis produces, at the vegetative stage of its growth, vip3a proteins with activity against a broad spectrum of lepidopteran insects. the egyptian cotton leaf worm (spodoptera littoralis) is an important agricultural pest that is susceptible to the vip3aa16 protein of bacillus thuringiensis kurstaki strain bupm95. the midgut histopathology of vip3aa fed larvae showed vacuolization of the cytoplasm, brush border membrane destruction, vesicle formation in the apical ...201020965198
insect eggs suppress plant defence against chewing herbivores.plants activate direct and indirect defences in response to insect egg deposition. however, whether eggs can manipulate plant defence is unknown. in arabidopsis thaliana, oviposition by the butterfly pieris brassicae triggers cellular and molecular changes that are similar to the changes caused by biotrophic pathogens. in the present study, we found that the plant defence signal salicylic acid (sa) accumulates at the site of oviposition. this is unexpected, as the sa pathway controls defence aga ...201020230509
expression of pheromone biosynthesis activating neuropeptide and its receptor (pbanr) mrna in adult female spodoptera exigua (lepidoptera: noctuidae).the full-length cdna of pheromone biosynthesis activating neuropeptide receptor (pbanr) was cloned from the beet armyworm, spodoptera exigua (hübner) (lepidoptera: noctuidae); it included an open reading frame of 1,053 bp encoding 350 amino acids. the pbanr of s. exigua (sepbanr) was structurally characteristic of g protein-coupled receptor and its amino acid sequence shared 98% identity with the pbanr of spodoptera littoralis. both pheromone biosynthesis activating neuropeptide (pban) and pbanr ...201020665850
identification, phylogenetic analysis and expression profile of an anionic insect defensin gene, with antibacterial activity, from bacterial-challenged cotton leafworm, spodoptera littoralis.defensins are a well known family of cationic antibacterial peptides (amps) isolated from fungi, plants, insects, mussels, birds, and various mammals. they are predominantly active against gram (+) bacteria, and a few of them are also active against gram (-) bacteria and fungi. all insect defensins belonging to the invertebrate class have a consensus motif, c-x₅₋₁₆-c-x₃-c-x₉₋₁₀-c-x₄₋₇-cx₁-c. only seven amps have already been found in different lepidopteran species. no report was published on the ...201122067477
phaseoloidin, a homogentisic acid glucoside from nicotiana attenuata trichomes, contributes to the plant's resistance against lepidopteran herbivores.plant trichomes are known for their capability to produce and store secondary metabolites that protect plants from biotic and abiotic stresses. (1)h nmr studies on intact individual trichomes located on the leaf surface of nicotiana attenuata revealed the presence of two major secondary metabolites: nicotine, the signature metabolite of the genus, and phaseoloidin, a homogentisic acid glucoside. this glucoside was reported originally from the seeds of entada phaseoloides, and this is the first r ...201121904938
interactions of spodoptera littoralis haemocytes following injection with the entomopathogenic fungi: beauveria bassiana and nomuraea rileyi.this study compared the cellular interactions of spodopteralittoralis haemocytes with two virulence-different entomopathogenic fungi: beauveriabassiana and nomuraearileyi. using light and transmission microscopy, five types of haemocytes namely, prohaemocytes (prs), plasmatocytes (pls), granulocytes (grs), spherule cells (sps) and oenocytoids (oes) were identified in the 6th instar larvae. prs and pls were found in the haemopoietic tissue. intra-haemocoelic injection of blastospores induced ultr ...201122435162
genetic dissection of basal defence responsiveness in accessions of arabidopsis thaliana.basal resistance involves a multitude of pathogen- and herbivore-inducible defence mechanisms, ranging from localized callose deposition to systemic defence gene induction by salicylic acid (sa) and jasmonic acid (ja). in this study, we have explored and dissected genetic variation in the responsiveness of basal defence mechanisms within a selection of arabidopsis accessions. responsiveness of ja-induced pdf1.2 gene expression was associated with enhanced basal resistance against the necrotrophi ...201121414016
investigation of the steps involved in the difference of susceptibility of ephestia kuehniella and spodoptera littoralis to the bacillus thuringiensis vip3aa16 toxin.bupm95 is a bacillusthuringiensis subsp. kurstaki strain producing the vip3aa16 toxin with an interesting insecticidal activity against the lepidopteran larvae ephestia kuehniella. study of different steps in the mode of action of this vegetative insecticidal protein on the mediterranean flour moth (e. kuehniella) was carried out in the aim to investigate the origin of the higher susceptibility of this insect to vip3aa16 toxin compared to that of the egyptian cotton leaf worm spodoptera littoral ...201121600212
an expressed sequence tag collection from the male antennae of the noctuid moth spodoptera littoralis: a resource for olfactory and pheromone detection research.nocturnal insects such as moths are ideal models to study the molecular bases of olfaction that they use, among examples, for the detection of mating partners and host plants. knowing how an odour generates a neuronal signal in insect antennae is crucial for understanding the physiological bases of olfaction, and also could lead to the identification of original targets for the development of olfactory-based control strategies against herbivorous moth pests. here, we describe an expressed sequen ...201121276261
mosquito feeding affects larval behaviour and development in a moth.organisms are attacked by different natural enemies present in their habitat. while enemies such as parasitoids and predators will kill their hosts/preys when they successfully attack them, enemies such as micropredators will not entirely consume their prey. however, they can still have important consequences on the performance and ecology of the prey, such as reduced growth, increased emigration, disease transmission. in this paper, we investigated the impact of a terrestrial micropredator, the ...201121991329
potential use of a serpin from arabidopsis for pest control.although genetically modified (gm) plants expressing toxins from bacillus thuringiensis (bt) protect agricultural crops against lepidopteran and coleopteran pests, field-evolved resistance to bt toxins has been reported for populations of several lepidopteran species. moreover, some important agricultural pests, like phloem-feeding insects, are not susceptible to bt crops. complementary pest control strategies are therefore necessary to assure that the benefits provided by those insect-resistant ...201121655276
increase of the bacillus thuringiensis secreted toxicity against lepidopteron larvae by homologous expression of the vip3lb gene during sporulation stage.the vegetative insecticidal vip3a proteins display a wide range of insecticidal spectrum against several agricultural insect pests. the fact that the expression of vip3 genes occurs only during the vegetative growth phase of bacillus thuringiensis is a limiting factor in term of production level. therefore, extending the synthesis of the vip proteins to the sporulation phase is a good alternative to reach high levels of toxin synthesis. in this study, we have demonstrated that the maximal produc ...201121744287
induction and detoxification of maize 1,4-benzoxazin-3-ones by insect herbivores.in monocotyledonous plants, 1,4-benzoxazin-3-ones, also referred to as benzoxazinoids or hydroxamic acids, are one of the most important chemical barriers against herbivores. yet, knowledge about their behavior after attack, mode of action and potential detoxification by specialized insects has remained rudimentary. we chose an innovative analytical approach to understand the role of maize 1,4-benzoxazin-3-ones in plant insect interactions. by combining unbiased metabolomics screens and simultan ...201121838747
The impact of the Bacillus subtilis SPB1 biosurfactant on the midgut histology of Spodoptera littoralis (Lepidoptera: Noctuidae) and determination of its putative receptor.SPB1 is a Bacillus subtilis strain producing a lipopeptide biosurfactant. The insecticidal activity of this biosurfactant was evaluated against the Egyptian cotton leaf worm (Spodoptera littoralis). It displayed toxicity with an LC(50) of 251ng/cm(2). The histopathological changes occurred in the larval midgut of S. littoralis treated with B. subtilis SPB1 biosurfactant were vesicle formation in the apical region, cellular vacuolization and destruction of epithelial cells and their boundaries. L ...201122079884
functional and biochemical characterization of the baculovirus caspase inhibitor mavip35.many viruses express proteins which prevent the host cell death that their infection would otherwise provoke. some insect viruses suppress host apoptosis through the expression of caspase inhibitors belonging to the p35 superfamily. although a number of p35 relatives have been identified, autographa californica (ac) p35 and spodoptera littoralis (spli) p49 have been the most extensively characterized. acp35 was found to inhibit caspases via a suicide substrate mechanism: the caspase cleaves acp3 ...201122170098
the role of abscisic acid and water stress in root herbivore-induced leaf resistance.• herbivore-induced systemic resistance occurs in many plants and is commonly assumed to be adaptive. the mechanisms triggered by leaf-herbivores that lead to systemic resistance are largely understood, but it remains unknown how and why root herbivory also increases resistance in leaves. • to resolve this, we investigated the mechanism by which the root herbivore diabrotica virgifera induces resistance against lepidopteran herbivores in the leaves of zea mays. • diabrotica virgifera infested pl ...201120840610
candidate chemosensory ionotropic receptors in a lepidoptera.a new family of candidate chemosensory ionotropic receptors (irs) related to ionotropic glutamate receptors (iglurs) was recently discovered in drosophila melanogaster. through blast analyses of an expressed sequenced tag library prepared from male antennae of the noctuid moth spodoptera littoralis, we identified 12 unigenes encoding proteins related to d. melanogaster and bombyx mori irs. their full length sequences were obtained and the analyses of their expression patterns suggest that they w ...201121091811
less is more: treatment with bth and laminarin reduces herbivore-induced volatile emissions in maize but increases parasitoid attraction.chemical plant strengtheners find increasing use in agriculture to enhance resistance against pathogens. in an earlier study, it was found that treatment with one such resistance elicitor, bth (benzo-(1, 2, 3)-thiadiazole-7-carbothioic acid s-methyl ester), increases the attractiveness of maize plants to a parasitic wasp. this surprising additional benefit of treating plants with bth prompted us to conduct a series of olfactometer tests to find out if bth and another commercially available plant ...201222456950
herbivore-induced plant volatiles mediate host selection by a root herbivore.in response to herbivore attack, plants mobilize chemical defenses and release distinct bouquets of volatiles. aboveground herbivores are known to use changes in leaf volatile patterns to make foraging decisions, but it remains unclear whether belowground herbivores also use volatiles to select suitable host plants. we therefore investigated how above- and belowground infestation affects the performance of the root feeder diabrotica virgifera virgifera, and whether the larvae of this specialized ...201222486361
galnac/gal-binding rhizoctonia solani agglutinin has antiproliferative activity in drosophila melanogaster s2 cells via mapk and jak/stat signaling.rhizoctonia solani agglutinin, further referred to as rsa, is a lectin isolated from the plant pathogenic fungus rhizoctonia solani. previously, we reported a high entomotoxic activity of rsa towards the cotton leafworm spodoptera littoralis. to better understand the mechanism of action of rsa, drosophila melanogaster schneider s2 cells were treated with different concentrations of the lectin and fitc-labeled rsa binding was examined using confocal fluorescence microscopy. rsa has antiproliferat ...201222529896
a specialist root herbivore exploits defensive metabolites to locate nutritious tissues.the most valuable organs of plants are often particularly rich in essential elements, but also very well defended. this creates a dilemma for herbivores that need to maximise energy intake while minimising intoxication. we investigated how the specialist root herbivore diabrotica virgifera solves this conundrum when feeding on wild and cultivated maize plants. we found that crown roots of maize seedlings were vital for plant development and, in accordance, were rich in nutritious primary metabol ...201222070646
peripheral regulation by ecdysteroids of olfactory responsiveness in male egyptian cotton leaf worms, spodoptera littoralis.physiological and behavioral plasticity allows animals to adapt to changes in external (environmental) and internal (physiological) factors. in insects, the physiological state modulates adult behavior in response to different odorant stimuli. hormones have the potential to play a major role in the plasticity of the olfactory responses. to explore if peripheral olfactory processing could be regulated by steroid hormones, we characterized the molecular, electrophysiological, and behavioral respon ...201222044719
modulation of the temporal pattern of calling behavior of female spodoptera littoralis by exposure to sex pheromone.we have examined the timing of calling behavior in the female egyptian cotton leafworm, spodoptera littoralis and its modification by exposure to sex pheromone. the calling rhythm of the female moth was found to be circadian, persistent for at least 4 days once it has been entrained, and could be phase shifted by altering the light:dark regime. we also found that female exposure to pheromone affected the rate and duration of calling. a brief exposure to pheromone gland extract increased the prop ...201222001286
ginkgo biloba responds to herbivory by activating early signaling and direct defenses.ginkgo biloba (ginkgoaceae) is one of the most ancient living seed plants and is regarded as a living fossil. g. biloba has a broad spectrum of resistance or tolerance to many pathogens and herbivores because of the presence of toxic leaf compounds. little is known about early and late events occurring in g. biloba upon herbivory. the aim of this study was to assess whether herbivory by the generalist spodoptera littoralis was able to induce early signaling and direct defense in g. biloba by eva ...201222448229
antifeedant activity of fatty acid esters and phytosterols from echium wildpretii.crude extracts and fractions from echium wildpretii h. pearson ex hook. f. subsp. wildpretii (boraginaceae) have been tested against insect species spodoptera littoralis, leptinotarsa decemlineata, and the aphids myzus persicae, diuraphis noxia, metopolophium dirhodum, rhopalosiphum maidis, and rhopalosiphum padi. the etoh extract and the lipid and steroidal fractions of e. wildpretii exhibited significant antifeedant activities against the aphids and l. decemlineata. two bioactive mixtures comp ...201222422524
floral to green: mating switches moth olfactory coding and preference.mating induces profound physiological changes in a wide range of insects, leading to behavioural adjustments to match the internal state of the animal. here, we show for the first time, to our knowledge, that a noctuid moth switches its olfactory response from food to egg-laying cues following mating. unmated females of the cotton leafworm (spodoptera littoralis) are strongly attracted to lilac flowers (syringa vulgaris). after mating, attraction to floral odour is abolished and the females fly ...201222319127
adipokinetic hormone-induced antioxidant response in spodoptera littoralis.the antioxidative potential of the manduca sexta adipokinetic hormone (manse-akh) in the last instar larvae of spodoptera littoralis (noctuidae, lepidoptera) was demonstrated after exposure to oxidative stress (os) elicited by feeding on artificial diet containing tannic acid (ta). determination of protein carbonyls (pcs) and reduced glutathione (gsh) levels, monitoring of activity of antioxidant enzymes catalase (cat), superoxide dismutase (sod) and glutathione-s-transferases (gsts), as well as ...201222085825
multiple calmodulin-like proteins in arabidopsis are induced by insect-derived (spodoptera littoralis) oral secretion.in plant cells, diverse environmental changes often induce transient elevation in the intracellular calcium concentrations, which are involved in signaling pathways leading to the respective cellular reactions. therefore, these calcium elevations need to be deciphered into specific downstream responses. calmodulin-like-proteins (cmls) are calcium-sensing proteins present only in higher plants. they are involved in signaling processes induced by both abiotic as well as biotic stress factors. howe ...201222902684
dynamics of membrane potential variation and gene expression induced by spodoptera littoralis, myzus persicae, and pseudomonas syringae in arabidopsis.biotic stress induced by various herbivores and pathogens invokes plant responses involving different defense mechanisms. however, we do not know whether different biotic stresses share a common response or which signaling pathways are involved in responses to different biotic stresses. we investigated the common and specific responses of arabidopsis thaliana to three biotic stress agents: spodoptera littoralis, myzus persicae, and the pathogen pseudomonas syringae.201223118859
molecular cloning and characterization of ecdysone oxidase and 3-dehydroecdysone-3α-reductase involved in the ecdysone inactivation pathway of silkworm, bombyx mori.molting hormone (ecdysteroid) is one of the most important hormones in insects. the synthesis and inactivation of the ecdysteroid regulate the developmental process of insects. a major pathway of ecdysone inactivation is that ecdysone is converted to 3-dehydroecdysone, and then further to 3-epiecdysone in insects. two enzymes (ecdysone oxidase: eo and 3de-3α-reductase) participate in this pathway. in this study, based on the previously characterized cdnas in spodoptera littoralis, we cloned and ...201222215981
candidate chemosensory genes in female antennae of the noctuid moth spodoptera littoralis.chemical senses are crucial for all organisms to detect various environmental information. different protein families, expressed in chemosensory organs, are involved in the detection of this information, such as odorant-binding proteins, olfactory and gustatory receptors, and ionotropic receptors. we recently reported an expressed sequence tag (est) approach on male antennae of the noctuid moth, spodoptera littoralis, with which we could identify a large array of chemosensory genes in a species ...201222904672
characterization of multisugar-binding c-type lectin (splilec) from a bacterial-challenged cotton leafworm, spodoptera littoralis.various proteins that display carbohydrate-binding activity in a ca(2+)-dependent manner are classified into the c-type lectin family. they have one or two c-type carbohydrate-recognition domains (crds) composed of 110-130 amino acid residues in common. c-type lectins mediate cell adhesion, non-self recognition, and immuno-protection processes in immune responses and thus play significant roles in clearance of invaders, either as cell surface receptors for microbial carbohydrates or as soluble p ...201222916161
cml42-mediated calcium signaling coordinates responses to spodoptera herbivory and abiotic stresses in arabidopsis.in the interaction between arabidopsis (arabidopsis thaliana) and the generalist herbivorous insect spodoptera littoralis, little is known about early events in defense signaling and their link to downstream phytohormone pathways. s. littoralis oral secretions induced both ca²⁺ and phytohormone elevation in arabidopsis. plant gene expression induced by oral secretions revealed up-regulation of a gene encoding a calmodulin-like protein, cml42. functional analysis of cml42 plants revealed more res ...201222570470
laboratory evaluation of isaria fumosorosea against spodoptera littoralis.isaria fumosorosea (syn. paecilomyces fumosoroseus) is potentially useful for the biological control of economically important agricultural and forest insect pests. we evaluated efficacy of two strains of this entomopathogenic fungus against last instar larvae and pupae of egyptian cotton leafworm, spodoptera littoralis. the first strain was apopka 97 which is an active ingredient of commercial biopesticide preferal wg (biobest, belgium). the second strain was isolated from cameraria ohridella a ...201223885438
direct proof of ingested food regurgitation by spodoptera littoralis caterpillars during feeding on arabidopsis.oral secretions of herbivorous lepidopteran larvae contain a mixture of saliva and regurgitant from the insect gut. different compounds from the oral secretions can be recognized by the host plants and, thus, represent elicitors that induce plant defenses against feeding herbivores. exogenously applied oral secretions can initiate the biosynthesis of jasmonates, phytohormones involved in the regulation of plant defense. however, it is not known (a) whether or not non-manipulated insects indeed r ...201222653569
toxicity of allyl esters in insect cell lines and in spodoptera littoralis larvae.we investigated the effects of five allyl esters, two aromatic (allyl cinnamate and allyl 2-furoate) and three aliphatic (allyl hexanoate, allyl heptanoate, and allyl octanoate) in established insect cell lines derived from different species and tissues. we studied embryonic cells of the fruit fly drosophila melanogaster (s2) (diptera) and the beet armyworm spodoptera exigua (se4) (lepidoptera), fat body cells of the colorado potato beetle leptinotarsa decemlineata (cpb) (coleoptera), ovarian ce ...201223589218
metabolism of glucosinolate-derived isothiocyanates to glutathione conjugates in generalist lepidopteran herbivores.the defensive properties of the glucosinolate-myrosinase system in plants of the order brassicales have been attributed to the formation of toxic isothiocyanates generated upon tissue damage. lepidopteran herbivores specialised on brassicaceous plants have been shown to possess biochemical mechanisms preventing the formation of isothiocyanates. yet, no such mechanisms are known for generalist lepidopterans which also occasionally but successfully feed on plants of the brassicales. after feeding ...201222193392
insect oral secretions suppress wound-induced responses in arabidopsis.the induction of plant defences and their subsequent suppression by insects is thought to be an important factor in the evolutionary arms race between plants and herbivores. although insect oral secretions (os) contain elicitors that trigger plant immunity, little is known about the suppressors of plant defences. the arabidopsis thaliana transcriptome was analysed in response to wounding and os treatment. the expression of several wound-inducible genes was suppressed after the application of os ...201221994175
varied response of spodoptera littoralis against arabidopsis thaliana with metabolically engineered glucosinolate profiles.upon herbivory glucosinolates are known to be degraded into a cascade of secondary products that can be detrimental for certain herbivores. we performed herbivory bioassays using first and second instar generalist lepidoptera larvae spodoptera littoralis on arabidopsis thaliana engineered to overexpress novel glucosinolates. a differential response in larval feeding patterns was observed on the plants engineered with novel glucosinolates. larvae fed on plants overexpressing 4-hydroxybenzyl gluco ...201221835629
transcriptome analysis of intraspecific competition in arabidopsis thaliana reveals organ-specific signatures related to nutrient acquisition and general stress response pathways.plants are sessile and therefore have to perceive and adjust to changes in their environment. the presence of neighbours leads to a competitive situation where resources and space will be limited. complex adaptive responses to such situation are poorly understood at the molecular level.201223194435
four 13-lipoxygenases contribute to rapid jasmonate synthesis in wounded arabidopsis thaliana leaves: a role for lipoxygenase 6 in responses to long-distance wound signals.damage-inducible defenses in plants are controlled in part by jasmonates, fatty acid-derived regulators that start to accumulate within 30 s of wounding a leaf. using liquid chromatography-tandem mass spectrometry, we sought to identify the 13-lipoxygenases (13-loxs) that initiate wound-induced jasmonate synthesis within a 190-s timeframe in arabidopsis thaliana in 19 single, double, triple and quadruple mutant combinations derived from the four 13-lox genes in this plant. all four 13-loxs were ...201323171345
separation of early and late responses to herbivory in arabidopsis by changing plasmodesmal function.herbivory results in an array of physiological changes in the host that are separable from the associated physical damage. we have made the surprising observation that an arabidopsis line (pdko3) mutated in genes encoding plasmodesmal proteins is defective in some, but not all, of the typical plant responses to herbivory. we tested the responses of plasma transmembrane potential (vm) depolarization, voltage gated k(+) channel activity, cytosolic calcium [ca2+]cyt and reactive oxygen species (ros ...201322775399
a porin-like protein from oral secretions of spodoptera littoralis larvae induces defense-related early events in plant leaves.insect herbivory on plants is a complex incident consisting of at least two different aspects, namely mechanical damage and chemical challenge, as feeding insects introduce oral secretions (os) into the wounded tissue of the attacked plant. mechanical wounding alone is sufficient to induce a set of defense-related reactions in host plants, but some early events such as membrane potential (vm) changes and cytosolic ca²⁺-elevations can be triggered only by herbivores suggesting that os-derived mol ...201323845235
oral insecticidal activity of plant-associated pseudomonads.biocontrol pseudomonads are most known to protect plants from fungal diseases and to increase plant yield, while intriguing aspects on insecticidal activity have been discovered only recently. here, we demonstrate that fit toxin producing pseudomonads, in contrast to a naturally fit-deficient strain, exhibit potent oral activity against larvae of spodoptera littoralis, heliothis virescens and plutella xylostella, all major insect pests of agricultural crops. spraying plant leaves with suspension ...201323033861
interaction of the koinobiont parasitoid microplitis rufiventris of the cotton leafworm, spodoptera littoralis, with two entomopathogenic rhabditids, heterorhabditis bacteriophora and steinernema carpocapsae.entomopathogenic nematodes are generally considered beneficial organisms. however, they can affect beneficial insects such as parasitoids. the interaction between the entomopathogenic nematodes heterorhabditis bacteriophora poinar (rhabditida: heterorhabditidae) and steinernema carpocapsae weiser, and the parasitoid microplitis rufiventris kokujev (hymenoptera: braconidae) was investigated in the laboratory. in non-parasitized hosts, spodoptera littoralis boisduval (lepidoptera: noctuidae) larva ...201324219656
ml3: a novel regulator of herbivory-induced responses in arabidopsis thaliana.ml (md2-related lipid recognition) proteins are known to enhance innate immune responses in mammals. this study reports the analysis of the putative ml gene family in arabidopsis thaliana and suggests a role for the ml3 gene in herbivory-associated responses in plants. feeding by larvae of the lepidopteran generalist herbivore spodoptera littoralis and larvae of the specialist herbivore plutella xylostella activated ml3 transcription in leaf tissues. ml3 loss-of-function arabidopsis plants were ...201323314818
non-photochemical quenching capacity in arabidopsis thaliana affects herbivore behaviour.under natural conditions, plants have to cope with numerous stresses, including light-stress and herbivory. this raises intriguing questions regarding possible trade-offs between stress defences and growth. as part of a program designed to address these questions we have compared herbivory defences and damage in wild type arabidopsis thaliana and two "photoprotection genotypes", npq4 and oepsbs, which respectively lack and overexpress psbs (a protein that plays a key role in qe-type non-photoche ...201323301046
screening and identification of a bacillus thuringiensis strain s1/4 with large and efficient insecticidal activities.the bacterium bacillus thuringiensis was recognized for its entomopathogenic activities related to cry and cyt proteins forming the δ-endotoxins and some extracellular activities like the vegetative insecticidal proteins (vip) and cry1i. these activities may act specifically against diverse organisms and some of them typically characterize each strain. here, we screened a set of 212 b. thuringiensis strains to search the higher insecticidal activities. these strains had bipyramidal and cubic cry ...201322915162
microbial control of the cotton leafworm spodoptera littoralis (boisd.) by egyptian bacillus thuringiensis isolates.four local bacillus thuringiensis (bt) isolates that had been serologically identified as bt var. kurstaki (btk2, btk3, and btk66) and bt var. mexicanensis (btm27), in addition to two reference strains (4d20 and 4ac1), were laboratory assayed as microbial control agents against the egyptian cotton leafworm spodoptera littoralis (boisd.). polymerase chain reaction (pcr) amplification analysis revealed that each of the six experimental strains carries, at least, a cry1 type gene which expresses a ...201322983675
high entomotoxicity and mechanism of the fungal galnac/gal-specific rhizoctonia solani lectin in pest insects.whole insect assays where rhizoctonia solani agglutinin (rsa) was fed to larval stages of the cotton leaf-worm spodoptera littoralis and the pea aphid acyrthosiphon pisum demonstrated a high concentration-dependent entomotoxicity, suggesting that this galnac/gal-specific fungal lectin might be a good control agent for different pest insects. rsa at 10 mg/g in the solid diet of 2nd-instar caterpillars caused 84% weight reduction after 8 days with none of the caterpillars reaching the 4th-instar s ...201323291362
arabidopsis basic helix-loop-helix transcription factors myc2, myc3, and myc4 regulate glucosinolate biosynthesis, insect performance, and feeding behavior.arabidopsis thaliana plants fend off insect attack by constitutive and inducible production of toxic metabolites, such as glucosinolates (gss). a triple mutant lacking myc2, myc3, and myc4, three basic helix-loop-helix transcription factors that are known to additively control jasmonate-related defense responses, was shown to have a highly reduced expression of gs biosynthesis genes. the myc2 myc3 myc4 (myc234) triple mutant was almost completely devoid of gs and was extremely susceptible to the ...201323943862
histopathological effects and determination of the putative receptor of bacillus thuringiensis cry1da toxin in spodoptera littoralis midgut.bacillus thuringiensis subsp. aizawai strain hd133, known by its effectiveness against spodoptera species, produces many insecticidal proteins including cry1ab, cry1ca and cry1da. in the present study, the insecticidal activity of cry1da against spodoptera littoralis was investigated. it showed toxicity with an lc(50) of 224.4 ng/cm(2) with 95% confidence limits of (178.61-270.19) and an lc(90) of 467.77 ng/cm(2) with 95% confidence limits of (392.89-542.65). the midgut histopathology of cry1da ...201323220238
occurrence of bacillus thuringiensis and their phages in yemen soil.bacillus thuringiensis (bt) isolates were found in all samples of soil in nine governorates of yemen. from 384 isolates of bacillus recovered from these soil samples after acetate selection, 104 isolates (27.1 %) were bt. five isolates of bt were selected and insecticidal activity was tested against culex pipiens, callosobruchus maculatus and spodoptera littoralis. the bt isolate yh18 gave toxicity to all tested insects larvae. this study extended to isolate phages active against the selected bt ...201324426317
protease inhibitor from insect silk-activities of derivatives expressed in vitro and in transgenic potato.several recombinant derivatives of serine protease inhibitor called silk protease inhibitor 2 (spi2), which is a silk component in galleria mellonella (lepidoptera, insecta), were prepared in the expression vector pichia pastoris. both the native and the recombinant protease inhibitors were highly active against subtilisin and proteinase k. the synthetic spi2 gene with ala codon in the p1 position was fused with mgfp-5 to facilitate detection of the transgene and its protein product. a construct ...201323824530
a comparison of the olfactory gene repertoires of adults and larvae in the noctuid moth spodoptera littoralis.to better understand the olfactory mechanisms in a lepidopteran pest model species, the cotton leafworm spodoptera littoralis, we have recently established a partial transcriptome from adult antennae. here, we completed this transcriptome using next generation sequencing technologies, namely 454 and illumina, on both adult antennae and larval tissues, including caterpillar antennae and maxillary palps. all sequences were assembled in 77,643 contigs. their analysis greatly enriched the repertoire ...201323565215
nicotiana attenuata mpk4 suppresses a novel jasmonic acid (ja) signaling-independent defense pathway against the specialist insect manduca sexta, but is not required for the resistance to the generalist spodoptera littoralis.how plants tailor their defense responses to attack from different insects remains largely unknown. here, we studied the role of a mitogen-activated protein kinase (mapk), mpk4, in the resistance of a wild tobacco nicotiana attenuata to two herbivores, the specialist manduca sexta and the generalist spodoptera littoralis. stably transformed n. attenuata plants silenced in mpk4 (irmpk4) were generated and characterized for traits important for defense against herbivores. only the oral secretions ...201323672856
differential contribution of transcription factors to arabidopsis thaliana defense against spodoptera littoralis.in response to insect herbivory, arabidopsis plants activate the synthesis of the phytohormone jasmonate-isoleucine, which binds to a complex consisting of the receptor coi1 and jaz repressors. upon proteasome-mediated jaz degradation, basic helix-loop-helix transcription factors (tfs) myc2, myc3, and myc4 become activated and this results in the expression of defense genes. although the jasmonate (ja) pathway is known to be essential for the massive transcriptional reprogramming that follows he ...201323382734
volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions.volatile organic compounds (vocs) released by soil microorganisms influence plant growth and pathogen resistance. yet, very little is known about their influence on herbivores and higher trophic levels. we studied the origin and role of a major bacterial voc, 2,3-butanediol (2,3-bd), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. one of the major contributors to 2,3-bd in the headspace of soil-grown maize seedlings was identified as enterobact ...201324127750
distribution of neuropeptides in the antennal lobes of male spodoptera littoralis.olfaction is an important sensory modality that regulates a plethora of behavioural expressions in insects. processing of olfactory information takes place in the primary olfactory centres of the brain, namely the antennal lobes (als). neuropeptides have been shown to be present in the olfactory system of various insect species. in the present study, we analyse the distribution of tachykinin, fmrfamide-related peptides, allatotropin, allatostatin, myoinhibitory peptides and sifamide in the al of ...201323955643
specific response to herbivore-induced de novo synthesized plant volatiles provides reliable information for host plant selection in a moth.animals depend on reliable sensory information for accurate behavioural decisions. for herbivorous insects it is crucial to find host plants for feeding and reproduction, and these insects must be able to differentiate suitable from unsuitable plants. volatiles are important cues for insect herbivores to assess host plant quality. it has previously been shown that female moths of the egyptian cotton leafworm, spodoptera littoralis (lepidoptera: noctuidae), avoid oviposition on damaged cotton gos ...201323737555
determination and analysis of the genome sequence of spodoptera littoralis multiple nucleopolyhedrovirus.the spodoptera littoralis multiple nucleopolyhedrovirus (splimnpv), a pathogen of the egyptian cotton leaf worm s. littoralis, was subjected to sequencing of its entire dna genome and bioassay analysis comparing its virulence to that of other baculoviruses. the annotated splimnpv genome of 137,998 bp was found to harbor 132 open reading frames and 15 homologous repeat regions. four unique genes not present in spltmnpv were identified, as were 14 genes that were absent or translocated by comparis ...201323219924
modulation of reproductive behaviors by non-host volatiles in the polyphagous egyptian cotton leafworm, spodoptera littoralis.in order to locate mates, food, and oviposition sites, insects mainly rely on volatile cues released by their sexual partners, food sources, and host and non-host plants. calling, mating, and oviposition behaviors, as well as fecundity and longevity, of newly emerged spodoptera littoralis (bois.) moths were recorded in the presence of volatiles from leaves of a host plant, gossypium hirsutum (cotton) and two non-host plants, adhatoda vasica (av) or picea abies (spruce), either alone or in host/n ...201324105603
quantitative and ultrastructural changes in the haemocytes of spodoptera littoralis (boisd.) treated individually or in combination with spodoptera littoralis multicapsid nucleopolyhedrovirus (splimnpv) and azadirachtin.the total haemocyte count (thc) and the possible ultrastructural alterations induced in the haemocytes of the fourth larval instars of the egyptian cotton leafworm, spodoptera littoralis (boisd.) (lepidoptera: noctuidae), 96 h post-feeding on a semi-synthetic diet, treated with the lc50 of spodoptera littoralis multicapsid nucleopolyhedrovirus (splimnpv) and the lc50 of azadirachtin alone, and the lc25 of splimnpv combined with the lc25 of azadirachtin were studied and compared to the control. s ...201425041832
herbivory and floral signaling: phenotypic plasticity and tradeoffs between reproduction and indirect defense.plant defense against herbivores may compromise attraction of mutualists, yet information remains limited about the mechanisms underlying such signaling tradeoffs. here, we investigated the effects of foliar herbivory by two herbivore species on defense compounds, floral signaling, pollinator and parasitoid attraction, and seed production. herbivory generally reduced the quantity of many floral volatile organic compounds vocs) in brassica rapa. by contrast, floral color, flower diameter, and pla ...201424684288
molecular evolution of the odorant and gustatory receptor genes in lepidopteran insects: implications for their adaptation and speciation.lepidoptera (comprised of butterflies and moths) is one of the largest groups of insects, including more than 160,000 described species. chemoreception plays important roles in the adaptation of these species to a wide range of niches, e.g., plant hosts, egg-laying sites, and mates. this study investigated the molecular evolution of the lepidopteran odorant (or) and gustatory receptor (gr) genes using recently identified genes from bombyx mori, danaus plexippus, heliconius melpomene, plutella xy ...201425038840
combinatorial effect of bacillus thuringiensis kurstaki and photorhabdus luminescens against spodoptera littoralis (lepidoptera: noctuidae).spodoptera littoralis, one of the major pests of many important crop plants, is more susceptible to bacillus thuringiensis aizawai delta-endotoxins than to those of bacillus thuringiensis kurstaki. within the framework of the development of efficient bioinsecticides and the prevention against insect resistance, we tested the effect of mixing b. thuringiensis kurstaki delta-endotoxins and photorhabdus luminescens cells on s. littoralis growth. the obtained results showed that the growth inhibitio ...201423908000
a novel recombinant baculovirus overexpressing a bacillus thuringiensis cry1ab toxin enhances insecticidal activity.baculoviruses have been genetically modified to express foreign genes under powerful promoters in order to accelerate their speed of killing. in this study a truncated form of cry1ab gene derived from bacillus thuringinsis (bt) subsp. aegypti isolate bt7 was engineered into the genome of the baculovirus autographa californica multiple nuclearpolyhedrosis wild type virus, in place of the polyhedrin gene by using homologous recombination in spodoptera frugiperda (sf) cells between a transfer vecto ...201424735532
new bacillus thuringiensis toxin combinations for biological control of lepidopteran larvae.cyt1aa from bacillus thuringiensis israelensis is known by its synergistical activity with b. thuringiensis and bacillus sphaericus toxins. it is able to improve dipteran specific toxins activity and can prevent or overcome larval resistance to those proteins. the objective of the current study was to investigate the possible improvement of larvicidal activity of b. thuringiensis kurstaki expressing heterogeneous proteins cyt1a and p20. cyt1a98 and p20 genes encoding the cytolytic protein (cyt1a ...201424444881
selection and characterisation of an hd1-like bacillus thuringiensis isolate with a high insecticidal activity against spodoptera littoralis (lepidoptera: noctuidae).spodoptera littoralis (boisduval) larvae are known by their susceptibility to bacillus thuringiensis subsp. aizawai strains. in order to prevent the appearance of b. thuringiensis (bt) resistance and to develop economical bt-based biopesticides, the selection and the characterisation of a b. thuringiensis isolate toxic against s. littoralis larvae and overproducing δ-endotoxins were investigated.201424124020
a screening of five bacillus thuringiensis vip3a proteins for their activity against lepidopteran pests.five bacillus thuringiensis vip3a proteins (vip3aa, vip3ab, vip3ad, vip3ae and vip3af) and their corresponding trypsin-activated toxins were tested for their toxicity against eight lepidopteran pests: agrotis ipsilon, helicoverpa armigera, mamestra brassicae, spodoptera exigua, spodoptera frugiperda, spodoptera littoralis, ostrinia nubilalis and lobesia botrana. toxicity was first tested at a high dose at 7 and 10 days. no major differences were found when comparing protoxins vs. trypsin-activat ...201424508583
neomycin inhibition of (+)-7-iso-jasmonoyl-l-isoleucine accumulation and signaling.the majority of plant defenses against insect herbivores are coordinated by jasmonate (jasmonic acid, ja; (+)-7-iso-jasmonoyl-l-isoleucine, ja-ile)-dependent signaling cascades. insect feeding and mimicking herbivory by application of oral secretions (os) from the insect induced both cytosolic ca(2+) and jasmonate-phytohormone elevation in plants. here it is shown that in arabidopsis thaliana upon treatment with os from lepidopteran spodoptera littoralis larvae, the antibiotic neomycin selective ...201424859518
quantitative analysis of herbivore-induced cytosolic calcium by using a cameleon (yc 3.6) calcium sensor in arabidopsis thaliana.ca(2+) is a key player in plant cell responses to biotic and abiotic stress. owing to the central role of cytosolic ca(2+) ([ca(2+)]cyt) during early signaling and the need for precise determination of [ca(2+)]cyt variations, we used a cameleon yc 3.6 reporter protein expressed in arabidopsis thaliana to quantify [ca(2+)]cyt variations upon leaf mechanical damage (md), herbivory by 3rd and 5th instar larvae of spodoptera littoralis and s. littoralis oral secretions (os) applied to md. yc 3.6 all ...201424331428
inoculation of transgenic resistant potato by phytophthora infestans affects host plant choice of a generalist moth.pathogen attack and the plant's response to this attack affect herbivore oviposition preference and larval performance. introduction of major resistance genes against phytophthora infestans (rpi-genes), the cause of the devastating late blight disease, from wild solanum species into potato changes the plant-pathogen interaction dynamics completely, but little is known about the effects on non-target organisms. thus, we examined the effect of p. infestans itself and introduction of an rpi-gene in ...201526053171
insect herbivory-elicited gaba accumulation in plants is a wound-induced, direct, systemic, and jasmonate-independent defense response.the non-proteinogenic amino acid γ-aminobutyric acid (gaba) is present in all organisms analyzed so far. in invertebrates gaba acts as a neurotransmitter; in plants different functions are under discussion. among others, its involvement in abiotic stress reactions and as a defensive compound against feeding insects is suggested. gaba is synthesized from glutamate by glutamate decarboxylases and degraded by gaba-transaminases. here, in arabidopsis thaliana, gad1/2 double mutants showing reduced g ...201526734035
systemic cytosolic ca(2+) elevation is activated upon wounding and herbivory in arabidopsis.calcium ion (ca(2+) ) signalling triggered by insect herbivory is an intricate network with multiple components, involving positive and negative regulators. real-time, noninvasive imaging of entire arabidopsis thaliana rosettes was employed to monitor cytosolic free calcium ([ca(2+) ]cyt ) elevations in local and systemic leaves in response to wounding and spodoptera littoralis feeding. luminescence emitted by the cytosol-localized ca(2+) reporter aequorin was imaged using a high-resolution phot ...201525996806
trade-off between constitutive and inducible resistance against herbivores is only partially explained by gene expression and glucosinolate production.the hypothesis that constitutive and inducible plant resistance against herbivores should trade-off because they use the same resources and impose costs to plant fitness has been postulated for a long time. negative correlations between modes of deployment of resistance and defences have been observed across and within species in common garden experiments. it was therefore tested whether that pattern of resistance across genotypes follows a similar variation in patterns of gene expression and ch ...201525716695
xenorhabdus bovienii cs03, the bacterial symbiont of the entomopathogenic nematode steinernema weiseri, is a non-virulent strain against lepidopteran insects.xenorhabdus bacteria (γ-proteobacteria: enterobacteriaceae) have dual lifestyles. they have a mutualistic relationship with steinernema nematodes (nematoda: steinernematidae) and are pathogenic to a wide range of insects. each steinernema nematode associates with a specific xenorhabdus species. however, a xenorhabdus species can have multiple nematode hosts. for example, xenorhabdus bovienii (xb) colonizes at least nine steinernema species from two different phylogenetic clades. the steinernema- ...201525315609
a deletion mutant ndv200 of the bacillus thuringiensis vip3br insecticidal toxin gene is a prospective candidate for the next generation of genetically modified crop plants resistant to lepidopteran insect damage.ectopic expression of a deletion mutant ( ndv200 ) of bacillus thuringiensis vip3br gene in tobacco plant provided almost complete protection against major crop pests cotton boll worm ( helicoverpa armigera ), black cut worm ( agrotis ipsilon ) and cotton leaf worm ( spodoptera littoralis ). whereas vip3br transgenic tobacco plant failed to protect themselves from these insects and showed resistance towards cotton leaf worm only. an analogous form of the bacillus thuringiensis vip3aa insecticida ...201525912191
effects of tannin-rich host plants on the infection and establishment of the entomopathogenic nematode heterorhabditis bacteriophora.parasitized animals can self-medicate. as ingested plant phenolics, mainly tannins, reduce strongyle nematode infections in mammalian herbivores. we investigated the effect of plant extracts known to be anthelmintic in vertebrate herbivores on the recovery of the parasitic entomopathogenic nematode heterorhabditis bacteriophora infecting african cotton leafworm (spodoptera littoralis). nematode infective juveniles (ijs) were exposed to 0, 300, 900, 1200, 2400 ppm of pistacia lentiscus l. (lentis ...201525935140
highly toxic and broad-spectrum insecticidal local bacillus strains engineered using protoplast fusion.protoplast fusion was performed between a local bacillus thuringiensis uv-resistant mutant 66/1a (bt) and bacillus sphaericus ghai (bs) to produce new bacillus strains with a wider spectrum of action against different insects. bt is characterized as sensitive to polymyxin and streptomycin and resistant to rifampicin and has shown 87% mortality against spodoptera littoralis larvae at concentration of 1.5 × 10(7) cells/ml after 7 days of feeding; bs is characterized as resistant to polymyxin and s ...201525485592
histopathological and combinatorial effects of the metalloprotease inha1 and cry proteins of bacillus thuringiensis against spodoptera littoralis.the zinc metalloprotease (inha) of bacillus thuringiensis specifically hydrolyzes cecropins and attacins, two antibacterial peptides in the immune hemolymph of insects, leading to a high resistance of the bacteria to the humoral defense system of its host. in the present study, the inha gene of b. thuringiensis strain bupm28 was cloned and the nucleotide sequence analysis revealed that it was identical to that of b. thuringiensis 8010. the expressed inha1 protein in escherichia coli showed toxic ...201526358555
development of insect resistant maize plants expressing a chitinase gene from the cotton leaf worm, spodoptera littoralis.due to the importance of chitinolytic enzymes for insect, nematode and fungal growth, they are receiving attention concerning their development as biopesticides or chemical defense proteins in transgenic plants and as microbial biocontrol agents. targeting chitin associated with the extracellular matrices or cell wall by insect chitinases may be an effective approach for controlling pest insects and pathogenic fungi. the ability of chitinases to attack and digest chitin in the peritrophic matrix ...201526658494
the arabidopsis pep-pepr system is induced by herbivore feeding and contributes to ja-mediated plant defence against herbivory.a number of plant endogenous elicitors have been identified that induce pattern-triggered immunity upon perception. in arabidopsis thaliana eight small precursor proteins, called propeps, are thought to be cleaved upon danger to release eight peptides known as the plant elicitor peptides peps. as the expression of some propeps is induced upon biotic stress and perception of any of the eight peps triggers a defence response, they are regarded as amplifiers of immunity. besides the induction of de ...201526034129
identification and comparative expression analysis of odorant binding protein genes in the tobacco cutworm spodoptera litura.insect odorant binding proteins (obps) are thought to involve in insects' olfaction perception. in the present study, we identified 38 obp genes from the antennal transcriptomes of spodoptera litura. tissue expression profiles analysis revealed that 17 of the 38 slitobp transcripts were uniquely or primarily expressed in the antennae of both sexes, suggesting their putative role in chemoreception. the rpkm value analysis revealed that seven obps (slitpbp1-3, slitgobp1-2, slitobp3 and slitobp5) a ...201526346731
the green gut: chlorophyll degradation in the gut of spodoptera littoralis.chlorophylls, the most prominent natural pigments, are part of the daily diet of herbivorous insects. the spectrum of ingested and digested chlorophyll metabolites compares well to the pattern of early chlorophyll-degradation products in senescent plants. intact chlorophyll is rapidly degraded by proteins in the front- and midgut. unlike plants, insects convert both chlorophyll a and b into the corresponding catabolites. maldi-tof/ms imaging allowed monitoring the distribution of the chlorophyll ...201526467450
a physiological and behavioral mechanism for leaf herbivore-induced systemic root resistance.indirect plant-mediated interactions between herbivores are important drivers of community composition in terrestrial ecosystems. among the most striking examples are the strong indirect interactions between spatially separated leaf- and root-feeding insects sharing a host plant. although leaf feeders generally reduce the performance of root herbivores, little is known about the underlying systemic changes in root physiology and the associated behavioral responses of the root feeders. we investi ...201526430225
inhibition kinetics of acid and alkaline phosphatases by atrazine and methomyl pesticides.the main objective of this work was to investigate the kinetic characteristics of acid and alkaline phosphatases isolated from different sources and to study the effects of the herbicide atrazine and insecticide methomyl on the activity and kinetic properties of the enzymes. acid phosphatase (acp) was isolated from the tomato plant (solanum lycopersicum l. var. lycopersicum); alkaline phosphatase (alp) was isolated from two sources, including mature earthworms (aporrectodea caliginosa) and larva ...201525996812
identification and characterization of a fatty acyl reductase from a spodoptera littoralis female gland involved in pheromone biosynthesis.fatty acyl-coa reductases (fars), the enzymes that catalyse reduction of a fatty acyl-coa to the corresponding alcohol in insect pheromone biosynthesis, are postulated to play an important role in determining the proportion of each component in the pheromone blend. for the first time, we have isolated and characterized from the egyptian cotton leaf worm spodoptera littoralis (lepidoptera: noctuidae) a far cdna (slit-far1), which appeared to be expressed only in the pheromone gland and was undete ...201525558806
behavioral and metabolic effects of sublethal doses of two insecticides, chlorpyrifos and methomyl, in the egyptian cotton leafworm, spodoptera littoralis (boisduval) (lepidoptera: noctuidae).insecticides have long been used as the main method in limiting agricultural pests, but their widespread use has resulted in environmental pollution, development of resistances, and biodiversity reduction. the effects of insecticides at low residual doses on both the targeted crop pest species and beneficial insects have become a major concern. in particular, these low doses can induce unexpected positive (hormetic) effects on pest insects, such as surges in population growth exceeding what woul ...201626566611
deep-tissue confocal imaging of the central projections of ovipositor sensory afferents in the egyptian cotton leafworm, spodoptera littoralis.the pre-ovipositon behavior of moths is largely dependent upon the cues that a gravid female perceives while assessing potential oviposition sites. assessment of such sites is accomplished, at least in part, by mechanosensory and gustatory sensilla located on the ovipositor whose sensory neurons project into the terminal abdominal ganglion (tag). using anterograde backfill staining, confocal laser scanning microscopy, and three dimensional reconstruction, we traced and analyzed the central proje ...201626774745
effect of exogenous ecdysteroids on growth, development, and fertility of the egyptian cotton leafworm spodoptera littoralis boisd. (lepidoptera: noctuidae). 201617425056
innate and learned prey-searching behavior in a generalist predator.early colonization by zyginidia scutellaris leafhoppers might be a key factor in the attraction and settling of generalist predators, such as orius spp., in maize fields. in this paper, we aimed to determine whether our observations of early season increases in field populations of orius spp. reflect a specific attraction to z. scutellaris-induced maize volatiles, and how the responses of orius predators to herbivore-induced volatiles (hipvs) might be affected by previous experiences on plants i ...201627343054
aboveground insect herbivory increases plant competitive asymmetry, while belowground herbivory mitigates the effect.insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. a possibility is that insects alter the competitive symmetry between plant species. the effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. it is unclear how these biotic and abiotic factors interactively affect competition. in a greenhouse ...201627069805
herbivore-triggered electrophysiological reactions: candidates for systemic signals in higher plants and the challenge of their identification.in stressed plants, electrophysiological reactions (elrs) are presumed to contribute to long-distance intercellular communication between distant plant parts. because of the focus on abiotic stress-induced elrs in recent decades, biotic stress-triggered elrs have been widely ignored. it is likely that the challenge to identify the particular elr types (action potential [ap], variation potential, and system potential [sp]) was responsible for this course of action. thus, this survey focused on in ...201626872949
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