Genome-wide identification, characterization, and expression profiling of ATP-binding cassette (ABC) transporter genes potentially associated with abamectin detoxification in Cydia pomonella

Sublethal and transgenerational effects of lambda-cyhalothrin and abamectin on the development and reproduction of <i>Cydia pomonella</i>

AbstractThe codling moth Cydia pomonella (Lepidoptera: Tortricidae) is a major invasive pest of pome fruits and walnuts worldwide. Lambda-cyhalothrin (LCT) and abamectin (AM) have been frequently used in C. pomonella control, but control of this pest is very difficult because shortly after hatching, larvae of this insect bore tunnels and hide inside host plant fruit. In this study, a simulated field spray bioassay method was developed against neonate larvae of C. pomonella and concentration-response bioassays were conducted to evaluate the susceptibility of the neonate larvae to LCT and AM. Exposure of neonate larvae to sublethal concentrations (LC30) of LCT or AM significantly reduced the survival rate of larvae (4th and 5th instars), lowered the mean weight of larvae and pupae, and decreased the daily maximal number of eggs laid and the total number of eggs laid (fecundity) per female. The sublethal effects, including reduced body mass, mean fecundity and net reproductive rate, extended mean generation time, and shortened oviposition period, were also found in transgenerational offspring. Furthermore, the transgenerational maternal effects were more obvious for AM than LCT, in comparison to the control. Additionally, the estimated population size was decreased by exposure to LC30 of LCT and AM, and the observed reduction of fecundity and population size within and across generations was likely the result of the downregulation of the reproduction-related vitellogenin gene (CpVg) after exposure to LC30 of LCT and AM. These results provide a better understanding of the overall effects of LCT and AM on C. pomonella and the transgenerational effects which should be taken into consideration when using insecticides in order to control C. pomonella.

Metabolic functional redundancy of the CYP9A subfamily members leads to P450-mediated <i>lambda</i>-cyhalothrin resistance in <i>Cydia pomonella</i>

ABSTRACTBACKGROUNDThe evolution of insect resistance to pesticides poses a continuing threat to sustainable pest management. While much is known about the molecular mechanisms that confer resistance in model insects and few agricultural pests, far less is known about fruit pests.RESULTSHere we found that functional redundancy and preference of metabolism by cytochrome P450 monooxygenases (P450s) genes in the CYP9A subfamily confer resistance to lambda-cyhalothrin in Cydia pomonella, a major invasive pest of pome fruit. A total of four CYP9A genes, including CYP9A61, CYP9A120, CYP9A121, and CYP9A122, were identified from C. pomonella. Among these, CYP9A120, CYP9A121, and CYP9A122 were predominantly expressed in the midgut of larvae. The expression levels of these P450 genes were significantly induced by LD10 of lambda-cyhalothrin and were overexpressed in a field-evolved lambda-cyhalothrin resistant population. Knockdown of CYP9A120 and CYP9A121 by RNA-mediated interference (RNAi) increased the susceptibility of larvae to lambda-cyhalothrin. In vitro assays demonstrated that recombinant P450s expressed in Sf9 cells can metabolize lambda-cyhalothrin, but with functional redundancy and divergence through regioselectivity of metabolism. CYP9A121 preferred to convert lambda-cyhalothrin to 2′-hydroxy-lambda-cyhalothrin, whereas CYP9A122 only generated 4′-hydroxy metabolite of lambda-cyhalothrin. Although possesses a relatively low metabolic capability, CYP9A120 balanced catalytic competence to generate both 2′- and 4′-metabolites.CONCLUSIONCollectively, these results reveal that metabolic functional redundancy of three members of the CYP9A subfamily leads to P450-mediated lambda-cyhalothrin resistance in C. pomonella, thus representing a potential adaptive evolutionary strategy during its worldwide expansion.

Glutathione <i>S</i>-Transferase Genes are Involved in <i>Lambda</i>-Cyhalothrin Resistance in <i>Cydia pomonella</i> via Sequestration

Transcriptional identification of differentially expressed genes during the prepupal–pupal transition in the oriental armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae)

AbstractThe oriental armyworm, Mythimna separata (Walker) is a serious pest of agriculture that does particular damage to Gramineae crops in Asia, Europe, and Oceania. Metamorphosis is a key developmental stage in insects, although the genes underlying the metamorphic transition in M. separata remain largely unknown. Here, we sequenced the transcriptomes of five stages; mature larvae (ML), wandering (W), and pupation (1, 5, and 10 days after pupation, designated P1, P5, and P10) to identify transition-associated genes. Four libraries were generated, with 22,884, 23,534, 26,643, and 33,238 differentially expressed genes (DEGs) for the ML-vs-W, W-vs-P1, P1-vs-P5, and P5-vs-P10, respectively. Gene ontology enrichment analysis of DEGs showed that genes regulating the biosynthesis of the membrane and integral components of the membrane, which includes the cuticular protein (CP), 20-hydroxyecdysone (20E), and juvenile hormone (JH) biosynthesis, were enriched. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that DEGs were enriched in the metabolic pathways. Of these DEGs, thirty CP, seventeen 20E, and seven JH genes were differentially expressed across the developmental stages. For transcriptome validation, ten CP, 20E, and JH-related genes were selected and verified by real-time PCR quantitative. Collectively, our results provided a basis for further studies of the molecular mechanism of metamorphosis in M. separata.

Expression profiles of Cry1Ab protein and its insecticidal efficacy against the invasive fall armyworm for Chinese domestic GM maize DBN9936

Influence of seasonal migration on the development of the insecticide resistance of oriental armyworm ( Mythimna separata ) to λ ‐cyhalothrin

The Sensitivity of Field Populations of Metopolophium dirhodum (Walker) (Hemiptera: Aphididae) to Seven Insecticides in Northern China

Insect pests are primarily controlled by insecticides. However, the sensitivity decreases and insecticide resistance is problematic for the effective management of agriculturally important insects, including Metopolophium dirhodum, which is an aphid that commonly feeds on cereals. The insecticide sensitivity status and potential resistance of M. dirhodum field populations remain relatively unknown. In this study, the susceptibility of 19 M. dirhodum populations from seven provinces in Northern China to neonicotinoids, pyrethroids, organophosphates, and a macrolide (abamectin) was determined in 2017–2019. The results indicated that two populations were highly resistant to thiamethoxam, with a relative resistance ratio (RLR) of 134.03 and 103.03, whereas one population was highly resistant to beta-cypermethrin (RLR of 121.42). On the basis of the RLR, the tested M. dirhodum populations ranging from susceptible to showing moderate levels of resistance to imidacloprid (RLR of 1.50 to 57.29), omethoate (RLR of 1.07 to 18.73), and abamectin (RLR of 1.10 to 25.89), but they were ranging from susceptible to showing tolerance or low levels of resistance to bifenthrin (RLR of 1.14 to 6.02) and chlorpyrifos (RLR of 1.11 to 7.59). Furthermore, a pair-wise correlation analysis revealed a significant correlation between the median lethal concentrations (LC50) for beta-cypermethrin and thiamethoxam, reflecting the cross-resistance between these two insecticides. The data obtained in our study provide timely information about aphid insecticide sensitivity, which may be used to delay the evolution of M. dirhodum insecticide resistance in Northern China.

Exogenous Strigolactones alleviate KCl stress by regulating photosynthesis, ROS migration and ion transport in Malus hupehensis Rehd

Resveratrol improves the iron deficiency adaptation of Malus baccata seedlings by regulating iron absorption

Abstract Background Resveratrol (Res), a phytoalexin, has been widely reported to participate in plant resistance to fungal infections. However, little information is available on its role in abiotic stress, especially in iron deficiency stress. Malus baccata is widely used as apple rootstock in China, but it is sensitive to iron deficiency. Results In this study, we investigated the role of exogenous Res in M. baccata seedings under iron deficiency stress. Results showed that applying 100 μM exogenous Res could alleviate iron deficiency stress. The seedlings treated with Res had a lower etiolation rate and higher chlorophyll content and photosynthetic rate compared with the apple seedlings without Res treatment. Exogenous Res increased the iron content in the roots and leaves by inducing the expression of MbAHA genes and improving the H+-ATPase activity. As a result, the rhizosphere pH decreased, iron solubility increased, the expression of MbFRO2 and MbIRT1 was induced, and the ferric-chelated reductase activity was enhanced to absorb large amounts of Fe2+ into the root cells under iron deficiency conditions. Moreover, exogenous Res application increased the contents of IAA, ABA, and GA3 and decreased the contents of DHZR and BL for responding to iron deficiency stress indirectly. In addition, Res functioned as an antioxidant that strengthened the activities of antioxidant enzymes and thus eliminated reactive oxygen species production induced by iron deficiency stress. Conclusion Resveratrol improves the iron deficiency adaptation of M. baccata seedlings mainly by regulating iron absorption.

Insecticide resistance in the Cydia pomonella (L): Global status, mechanisms, and research directions

Diet-mediated effects of cadmium on fitness-related traits and detoxification and antioxidative enzymes in the oriental armyworm, Mythimna separata

Overexpression of Glutathione S-Transferase Genes in Field λ-Cyhalothrin-Resistant Population of Cydia pomonella: Reference Gene Selection and Expression Analysis

Review on Structures of Pesticide Targets

Molecular targets play important roles in agrochemical discovery. Numerous pesticides target the key proteins in pathogens, insect, or plants. Investigating ligand-binding pockets and/or active sites in the proteins’ structures is usually the first step in designing new green pesticides. Thus, molecular target structures are extremely important for the discovery and development of such pesticides. In this manuscript, we present a review of the molecular target structures, including those of antiviral, fungicidal, bactericidal, insecticidal, herbicidal, and plant growth-regulator targets, currently used in agrochemical research. The data will be helpful in pesticide design and the discovery of new green pesticides.

Identification and Functional Characterization of a Sigma Glutathione S-Transferase CpGSTs2 Involved in λ-Cyhalothrin Resistance in the Codling Moth Cydia pomonella

CpGSTd3 is a lambda-Cyhalothrin Metabolizing Glutathione S-Transferase from Cydia pomonella (L.)

Cytochrome P450-Mediated λ-Cyhalothrin-Resistance in a Field Strain of Helicoverpa armigera from Northeast China

LC50 of lambda-cyhalothrin stimulates reproduction on the moth Mythimna separata (Walker)

Comparative Transcriptome Analysis Between Resistant and Susceptible Rice Cultivars Responding to Striped Stem Borer (SSB), Chilo suppressalis (Walker) Infestation

Comparative Analysis of Recombinant Cytochrome P450 CYP9A61 from Cydia pomonella Expressed in Escherichia coli and Pichia pastoris

Characterization of Multiple Heat-Shock Protein Transcripts from Cydia pomonella: Their Response to Extreme Temperature and Insecticide Exposure

Gene expression analysis and enzyme assay reveal a potential role of the carboxylesterase gene CpCE-1 from Cydia pomonella in detoxification of insecticides

Toxicity of Six Insecticides on Codling Moth (Lepidoptera: Tortricidae) and Effect on Expression of Detoxification Genes

Characterization of glutathione S-transferases from Sus scrofa, Cydia pomonella and Triticum aestivum: Their responses to cantharidin

Characterization of a lambda-cyhalothrin metabolizing glutathione S-transferase CpGSTd1 from Cydia pomonella (L.)

Effect of temperature and sorbitol in improving the solubility of carboxylesterases protein CpCE-1 from Cydia pomonella and biochemical characterization

Molecular Cloning and Expression of CYP9A61: A Chlorpyrifos-Ethyl and Lambda-Cyhalothrin-Inducible Cytochrome P450 cDNA from Cydia pomonella