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Toxins Aug 2022The locusts (Bey-Bienko) and (Zubovski) (Orthoptera Acrididae) and the leaf beetle (Joannis) (Coleoptera, Chrysomelidae) are economically devastating insect species...
The locusts (Bey-Bienko) and (Zubovski) (Orthoptera Acrididae) and the leaf beetle (Joannis) (Coleoptera, Chrysomelidae) are economically devastating insect species in the desert steppes of Northern China. Control is mainly and frequently dependent on highly toxic chemicals. To date, there have been no complete and comprehensive reports of insecticide applications to these key pests. In this study, laboratory bioassays were carried out to determine and compare the toxicity of twelve insecticides to three outbreaking insects, , , and from three typical desert steppe regions, SZWQ, XHQ and WLTQQ, respectively. The responses of the two locust species and the leaf beetle were evaluated by topical application and leaf dip bioassay techniques across a range of concentrations to develop dosage-mortality regressions. The insecticides tested included six chemical insecticides (β-cypermethrin, imidacloprid, phoxim, λ-cyhalothrin, methomyl, chlorantraniliprole) and six biogenic insecticides (spinosad, avermectin, rotenone, matrine, azadiracthin, and methoxyfenozide). The results showed that phoxim, λ-cyhalothrin, β-cypermethrin and spinosad showed highly toxic activity to , , and , while methonyl, chlorantraniliprole, and rotenone were moderately toxic to both locust species and the leaf beetle. The LC values of matrine, azadiractin, and avermectin were more than 1 μg a.i./adult for and , the LC values of which were higher 2 g/L for . Our findings complement information from previous similar studies and will inform future studies relating to the control of outbreaking insects, such as , , and in desert steppes of northern China. This study is also expected to provide basic data on the use of chemical and biogenic insecticides for application in desert steppes.
Topics: Animals; China; Coleoptera; Insecta; Insecticides; Rotenone
PubMed: 36006208
DOI: 10.3390/toxins14080546 -
Chemosphere Oct 2018Silk gland is a major organ of Bombyx mori for the synthesis and secretion of silk protein. Phoxim exposure can be toxic to B. mori and causes a decrease of fibroin...
Silk gland is a major organ of Bombyx mori for the synthesis and secretion of silk protein. Phoxim exposure can be toxic to B. mori and causes a decrease of fibroin synthesis, finally affecting the silk production in industry. To study the mechanism of metabolism and detoxification of silk gland under phoxim exposure, we measured the residual quantity of phoxim in silk gland and hemolymph after phoxim exposure, and the detoxifying enzymes-related genes and enzyme activity were also investigated. Results indicated that the residual amount of phoxim existed up to 24 h in silk gland compared with that in hemolymph, suggesting that phoxim can accumulate in the silk glands within a certain time course. The transcriptional levels of PI3K/Akt genes, including Akt, Tor1, p70s6k and 4e-bp, were up-regulated by 6.919, 1.358, 10.766 and 7.708-fold, respectively. The expression of two downstream genes (CncC and Keap1) was up-regulated by 1.939 and 3.373-fold, respectively. In addition, the transcriptional levels of detoxification-related genes including CYP6AB, CYP306A, CarE2, GST1 and GSTd1 were up-regulated by 1.731, 1.221, 1.366, 1.376 and 6.591-fold, respectively. The enzymatic activity of CYP450, CarE and GST were increased over time. These results provided possible insights into the injury of silk gland and the transcriptional response to detoxifying enzymes-related genes in silkworm after phoxim exposure.
Topics: Animals; Bombyx; Insect Proteins; Organothiophosphorus Compounds; Signal Transduction
PubMed: 30114747
DOI: 10.1016/j.chemosphere.2018.06.167 -
Frontiers in Physiology 2021(Diptera: Sciaridae) is the most serious root maggot pest which causes substantial damage to the Chinese chive. Organophosphate (OP) and neonicotinoid insecticides are...
(Diptera: Sciaridae) is the most serious root maggot pest which causes substantial damage to the Chinese chive. Organophosphate (OP) and neonicotinoid insecticides are widely used chemical pesticides and play important roles in controlling . However, a strong selection pressure following repeated pesticide applications has led to the development of resistant populations of this insect. To understand the insecticide resistance mechanism in , gene expression analysis might be required. Appropriate reference gene selection is a critical prerequisite for gene expression studies, as the expression stability of reference genes can be affected by experimental conditions, resulting in biased or erroneous results. The present study shows the expression profile of nine commonly used reference genes [, , , , , , , , and )] was systematically analyzed under insecticide stress. Moreover, we also evaluated their expression stability in other experimental conditions, including developmental stages, sexes, and tissues. Five programs (NormFinder, geNorm, BestKeeper, RefFinder, and Δ) were used to validate the suitability of candidate reference genes. The results revealed that the most appropriate sets of reference genes were and across phoxim; and across chlorpyrifos and chlorfluazuron; α and across imidacloprid; α and α across developmental stages; and across larvae; α and across tissues, and and across sex. These results will facilitate the standardization of RT-qPCR and contribute to further research on gene function under insecticides stress.
PubMed: 35087425
DOI: 10.3389/fphys.2021.818210 -
Biomedical Chromatography : BMC Jul 2019A simple pretreatment method with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated to simultaneously determine dichlorvos and phoxim...
A simple pretreatment method with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated to simultaneously determine dichlorvos and phoxim in tobacco and soil matrices. Satisfactory linearity (R ≥ 0.9991) of the method was obtained for both analytes. The limits of detection and limits of quantification for dichlorvos and phoxim in three matrices were 0.0015-0.006 and 0.005-0.02 mg/kg, respectively. Average recoveries were 78.24-92.21% for dichlorvos and 76.62-100.51% for phoxim in soil, green tobacco leaves and cured tobacco leaves. The intra- and inter-day relative standard deviations were <6%. The established method was successfully applied for the residual analysis of dichlorvos and phoxim in real soil and tobacco samples. The results indicated that the established method could be used to detect trace amounts of dichlorvos and phoxim in tobacco. The data could also help the Chinese government establish maximum residue limits of dichlorvos and phoxim on tobacco and establish proper and safe use of dichlorvos and phoxim on tobacco plants in China.
Topics: Chromatography, Liquid; Dichlorvos; Limit of Detection; Linear Models; Organothiophosphorus Compounds; Pesticide Residues; Plant Leaves; Reproducibility of Results; Tandem Mass Spectrometry; Nicotiana
PubMed: 30897223
DOI: 10.1002/bmc.4537 -
Photochemical & Photobiological... Jan 2023The control of the camel tick, Hyalomma dromedarii is very crucial. This study evaluated the novel toxicity of photosensitizers and Phoxim insecticide against H....
The control of the camel tick, Hyalomma dromedarii is very crucial. This study evaluated the novel toxicity of photosensitizers and Phoxim insecticide against H. dromedarii males using the adult immersion tests. Ticks were subjected to sunlight for 10 min post-treatment (PT). The optical characters of the applied materials were determined by UV-Vis spectroscopy (250-900 nm wavelengths). The intensity of spectra decreased as dye concentration decreased. The optical bandgap energies of the dyes at different concentrations were not changed as the concentration changed and decreased as the absorption peak of individual dyes red-shifted. The mortalities 72 h PT reached 42.2%, 44.4%, 51.1%, 71.1%, 46.7%, 48.9%, 44.4%, and 55.6% for chlorophyllin, echinochrome, field stain, methylene blue, phthalocyanine, rhodamine 6G, riboflavin, and safranin, respectively. Methylene blue recorded the highest median lethal concentration (LC = 127 ppm) followed by safranin, field stain, rhodamine 6G, phthalocyanine, echinochrome riboflavin, and chlorophyllin (LC = 209, 251, 271, 303, 324, 332, and 362 ppm, respectively, 72 h PT). Their median lethal time, LT, values PT with 240 ppm were 45, 87, 96, 72, 129, 115, 131, and 137 h, respectively. The relative toxicities of the LC values 72 h PT showed that chlorophyllin, echinochrome, field stain, methylene blue, phthalocyanine, rhodamine 6G, riboflavin, and safranin were 3.2, 3.6, 4.6, 9.1, 3.8, 4.3, 3.5, and 5.6 times, respectively, more effective than Phoxim. Methylene blue, safranin, and field stain showed a broad absorbance area indicating a large photoactivity and better phototoxicity and could be used as alternative agents to synthetic acaricides.
Topics: Animals; Male; Ticks; Acaricides; Camelus; Methylene Blue; Ixodidae; Riboflavin
PubMed: 36127561
DOI: 10.1007/s43630-022-00301-4 -
Comparative Biochemistry and... Sep 2019Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) is a preponderant endoparasitoid wasp, attacking the larvae of many lepidopteran pests. We present the first...
Identification of glutathione-S-transferase genes by transcriptome analysis in Meteorus pulchricornis (Hymenoptera: Braconidae) and their expression patterns under stress of phoxim and cypermethrin.
Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) is a preponderant endoparasitoid wasp, attacking the larvae of many lepidopteran pests. We present the first body transcriptome dataset for M. pulchricornis. In total, 50,781,796 clean reads were obtained and 33,144 unigenes were assembled; 15,458 unigenes showed a significant similarity (E value < 10) to known proteins in the NCBI non-redundant protein database. Gene ontology and cluster of orthologous group analyses were performed to classify the functions of genes. To better understand the role of glutathione-S-transferases (GSTs) in detoxification mechanism in M. pulchricornis, we identified seventeen GST genes (MpulGSTs) from the body transcriptome. Among these, fifteen MpulGSTs belonged to cytosolic GSTs and the other two belonged to microsomal classes. The cytosolic GSTs were classified into four different clades: four in delta, three in omega, seven in sigma, and one in zeta. The expression levels of these MpulGSTs after exposure to sub-lethal concentrations of phoxim and cypermethrin were determined using real-time quantitative polymerase chain reaction: seven MpulGSTs (MpulGSTD3, MpulGSTS1, MpulGSTS2, MpulGSTS4, MpulGSTS6 MpulGSTO3, and MpulGSTmic1) and 11 MpulGSTs (MpulGSTD1, MpulGSTD2, MpulGSTD3, MpulGSTO2, MpulGSTS1, MpulGSTS2, MpulGSTS3, MpulGSTS4, MpulGSTS5, MpulGSTS7, and MpulGSTmic1) were highly expressed, respectively. These results suggested that GST genes may play a pivotal role in detoxification process in M. pulchricornis. Our findings would provide a theoretical base for elucidating insecticide susceptibility and should promote functional research on specific GST genes in parasitoid wasps.
Topics: Animals; Gene Expression Profiling; Gene Expression Regulation; Glutathione Transferase; Hymenoptera; Insecticides; Organothiophosphorus Compounds; Pyrethrins
PubMed: 31319266
DOI: 10.1016/j.cbd.2019.100607 -
Journal of Agricultural and Food... May 2022The diamondback moth, (L.), has evolved with varying degrees of resistance to almost all major classes of insecticides and has become the most resistant pest worldwide....
The diamondback moth, (L.), has evolved with varying degrees of resistance to almost all major classes of insecticides and has become the most resistant pest worldwide. The multiresistance to different types of insecticides has been frequently reported in , but little is known about the mechanism. In this study, a carboxylesterase (CarE) gene, , was found significantly overexpressed in a field-evolved multiresistant population and can be dramatically induced by eight of nine tested insecticides. Results of the real-time quantitative polymerase chain reaction (RT-qPCR) showed that was predominantly expressed in the midgut and malpighian tubule of larvae. Knockdown of dramatically increased the susceptibility of the larvae to β-cypermethrin, bifenthrin, chlorpyrifos, fenvalerate, malathion, and phoxim, while overexpression of in increased the tolerance of the fruit flies to these insecticides obviously. More importantly, gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay showed that the recombinant PxαE14 expressed in exhibited metabolic activity against the six insecticides. The homology modeling, molecular docking, and molecular dynamics simulation analyses showed that these six insecticides could stably bind to PxαE14. Taken together, these results demonstrate that constitutive and inductive overexpression of contributes to detoxification of multiple insecticides involved in multiresistance in . Our findings provide evidence for understanding the molecular mechanisms underlying the multiresistance in insect pests.
Topics: Animals; Chromatography, Liquid; Drosophila melanogaster; Insecticide Resistance; Insecticides; Larva; Molecular Docking Simulation; Moths; Tandem Mass Spectrometry
PubMed: 35510781
DOI: 10.1021/acs.jafc.2c01867 -
Journal of Hazardous Materials Jun 2024Trichoderma can enhance the metabolism of organophosphate pesticides in plants, but the mechanism is unclear. Here, we performed high-throughput transcriptome sequencing...
Trichoderma can enhance the metabolism of organophosphate pesticides in plants, but the mechanism is unclear. Here, we performed high-throughput transcriptome sequencing of roots upon Trichoderma asperellum (TM) inoculation and phoxim (P) application in tomato (Solanum lycopersicum L.). A total of 4059 differentially expressed genes (DEGs) were obtained, including 2110 up-regulated and 1949 down-regulated DEGs in P vs TM+P. COG and KOG analysis indicated that DEGs were mainly enriched in signal transduction mechanisms. We then focused on the pesticide detoxification pathway and screened out cytochrome P450 CYP736A12 as a putative gene for functional analysis. We suppressed the expression of CYP736A12 in tomato plants by virus-induced gene silencing and analyzed tissue-specific phoxim residues, oxidative stress markers, glutathione pool, GST activity and related gene expression. Silencing CYP736A12 significantly increased phoxim residue and induced oxidative stress in tomato plants, by attenuating the TM-induced increased activity of antioxidant and detoxification enzymes, redox homeostasis and transcripts of detoxification genes including CYP724B2, GSH1, GSH2, GR, GPX, GST1, GST2, GST3, and ABC. The study revealed a critical mechanism by which TM promotes the metabolism of phoxim in tomato roots, which can be useful for further understanding the Trichoderma-induced xenobiotic detoxification and improving food safety.
Topics: Solanum lycopersicum; Cytochrome P-450 Enzyme System; Plant Roots; Organothiophosphorus Compounds; Pesticide Residues; Oxidative Stress; Hypocreales
PubMed: 38631252
DOI: 10.1016/j.jhazmat.2024.134299 -
Insects Oct 2021The 70 kDa heat shock proteins play important roles in protecting organisms against environmental stresses, which are divided into stress-inducible forms (HSP70s) and...
The 70 kDa heat shock proteins play important roles in protecting organisms against environmental stresses, which are divided into stress-inducible forms (HSP70s) and heat shock cognates (HSC70s). In this study, heat shock protein 70 family was identified in the whole genome of the silkworm. Based on the known nomenclature and phylogenetic analysis, four HSP70s and five HSC70s were classified. Relatively, heat shock cognates were more conservative and were constitutively expressed in various tissues of the silkworm larvae. Under thermal (37 °C and 42 °C) and cold (2 °C) stresses, the expressions of , , and were up-regulated, and the highest induction reached 4147.3, 607.1, and 1987.3 times, respectively. Interestingly, , , and also showed slight induced expressions in the fat body and/or midgut under thermal stresses. In addition, the expression of was induced by dichlorvos and phoxim insecticides, while most HSC70 genes were inhibited. The results suggested that stress-inducible forms play more important roles in adaptation to various stresses than HSC70s.
PubMed: 34680697
DOI: 10.3390/insects12100928 -
Journal of Hazardous Materials Oct 2020Athetis lepigone is one of the most severe polyphagous pests, and it has developed resistance to different chemical insecticides. Insects primarily rely on the olfactory...
Athetis lepigone is one of the most severe polyphagous pests, and it has developed resistance to different chemical insecticides. Insects primarily rely on the olfactory system to recognize various environmental chemicals, including xenobiotics such as insecticides. Here, we expressed two A. lepigone pheromone-binding proteins (AlepPBP2 and AlepPBP3), and observed they had higher binding affinities to phoxim than other insecticides, with Ki was 3.30 ± 0.38 μM and 3.27 ± 0.10 μM, respectively. Molecular dynamics simulation, binding mode analysis, and computational alanine scanning showed that six residues (Phe15, Phe39, Ile55, Leu65, Ile97, and Phe122) of AlepPBP2 and three residues (Phe12, Ile52, and Ile134) of AlepPBP3 maybe as potential residues that can change protein ability to bind an organophosphorus insecticide phoxim. Then, we used site-directed mutagenesis assay to mutate these residues into alanine, respectively. Subsequently, the binding assays displayed that Phe15, Phe39, and Ile97 of AlepPBP2, Phe12 and Ile134 of AlepPBP3 caused a significant decrease of AlepPBPs binding ability to phoxim, suggesting they should play crucial roles in the AlepPBPs/phoxim interactions. Our findings could further advance in using PBPs as unique targets to design and develop precise and environmentally-friendly pest control agents with high insecticidal potential using a computer-aided drug design (CADD) approach.
Topics: Animals; Carrier Proteins; Insect Proteins; Insecticides; Olfaction Disorders; Pheromones
PubMed: 32388456
DOI: 10.1016/j.jhazmat.2020.122777