RESUMEN

Riptortus pedestris (Hemiptera: Alydidae) is a notable soybean pest, with diapause and non-diapause individuals showing different sensitivities to aggregation pheromones. This study aimed to investigate how R. pedestris detects aggregation pheromones through electroantennogram (EAG) and behavioral experiments, transcriptome sequencing and qRT-PCR, as well as competitive fluorescence-binding assay. Results indicated that diapausing females and males of R. pedestris exhibited a heightened EAG response and were more attracted to the aggregation pheromone components compared to their non-diapause counterparts. Transcriptome sequencing and qRT-PCR analyses revealed significantly higher expression of RpedOBP1 in the antennae of diapause females and males compared to non-diapausing R. pedestris. The competitive fluorescence-binding assay demonstrated that RpedOBP1 displayed the strongest binding affinity to E2HE2H, suggesting its crucial role in recognizing the aggregation pheromone. These findings have the potential to inform the development of integrated pest management strategies utilizing behavioral approaches for bean bug control.

Asunto(s)

Proteínas de Insectos , Feromonas , Animales , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Femenino , Masculino , Feromonas/metabolismo , Hemípteros/fisiología , Hemípteros/genética , Hemípteros/metabolismo , Antenas de Artrópodos/metabolismo , Receptores Odorantes/metabolismo , Receptores Odorantes/genética

RESUMEN

Riptortus pedestris (Hemiptera: Alydidae), a common agricultural pest, is the major causative agent of "soybean staygreen." However, the interactions between chemosensory proteins (CSPs) in R. pedestris and host plant volatiles have yet to be comprehensively studied. In this study, we performed real-time fluorescence quantitative polymerase chain reaction (PCR) to analyze the antennal expression of RpedCSP22 and subsequently analyzed the interactions between 21 soybean volatiles, five aggregation pheromones, and RpedCSP22 protein in vitro using a protein expression system, molecular docking, site-directed mutagenesis, and fluorescence competitive binding experiments. The RpedCSP22 protein showed binding affinity to three soybean volatiles (benzaldehyde, 4-ethylbenzaldehyde, and 1-octene-3-ol), with optimal binding observed under neutral pH conditions, and lost binding ability after site-directed mutagenesis. In subsequent RNA interference (RNAi) studies, gene silencing was more than 90 %, and in silenced insects, electroantennographic responses were reduced by more than 75 % compared to non-silenced insects. Moreover, Y-tube olfactory behavioral assessments revealed that the attraction of R. pedestris to the three soybean volatiles was significantly attenuated. These findings suggest that RpedCSP22 plays an important role in the recognition of host plant volatiles by R. pedestris andprovides a theoretical basis for the development of novel inhibitors targeting pest behavior.

Asunto(s)

Glycine max , Proteínas de Insectos , Compuestos Orgánicos Volátiles , Animales , Glycine max/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/química , Compuestos Orgánicos Volátiles/metabolismo , Mutagénesis Sitio-Dirigida , Simulación del Acoplamiento Molecular , Hemípteros/metabolismo , Hemípteros/genética , Antenas de Artrópodos/metabolismo , Feromonas/metabolismo , Heterópteros/metabolismo , Heterópteros/genética

RESUMEN

Nitenpyram, taking the place of imidacloprid, is a widely used neonicotinoid insecticide to control Nilaparvata lugens in Asia. Two P450s, CYP4CE1 and CYP6ER1, are key factors in the metabolic resistance against nitenpyram and imidacloprid. In this study, we found that CYP4CE1 expression was strongly associated with nitenpyram resistance in 8 field-collected populations, whereas CYP6ER1 expression correlated with imidacloprid resistance. Hence, we focused on nitenpyram metabolism by CYP4CE1, due to that imidacloprid metabolism by CYP6ER1 has intensively investigated. Mass spectrometry analysis revealed that recombinant CYP4CE1 metabolized nitenpyram into three products, N-desmethyl nitenpyram, hydroxy-nitenpyram, and N-desmethyl hydroxy-nitenpyram, with a preference for hydroxylation. In contrast, CYP6ER1 metabolized nitenpyram into a single product, N-desmethyl nitenpyram. These results provide new insights into the specific catalytic mechanisms of P450 enzymes in neonicotinoid metabolism and underscore the importance of different catalytic reactions in neonicotinoid insecticide resistance.

Asunto(s)

Proteínas de Insectos , Insecticidas , Neonicotinoides , Oxidación-Reducción , Neonicotinoides/metabolismo , Neonicotinoides/química , Insecticidas/metabolismo , Insecticidas/química , Hidroxilación , Animales , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/química , Desmetilación , Hemípteros/metabolismo , Hemípteros/genética , Hemípteros/enzimología , Nitrocompuestos/metabolismo , Nitrocompuestos/química , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Resistencia a los Insecticidas/genética

RESUMEN

Bemisia tabaci (Gennadius) whitefly (BtWf) is an invasive pest that has already spread worldwide and caused major crop losses. Numerous strategies have been implemented to control their infestation, including the use of insecticides. However, prolonged insecticide exposures have evolved BtWf to resist these chemicals. Such resistance mechanism is known to be regulated at the molecular level and systems biology omics approaches could shed some light on understanding this regulation wholistically. In this review, we discuss the use of various omics techniques (genomics, transcriptomics, proteomics, and metabolomics) to unravel the mechanism of insecticide resistance in BtWf. We summarize key genes, enzymes, and metabolic regulation that are associated with the resistance mechanism and review their impact on BtWf resistance. Evidently, key enzymes involved in the detoxification system such as cytochrome P450 (CYP), glutathione S-transferases (GST), carboxylesterases (COE), UDP-glucuronosyltransferases (UGT), and ATP binding cassette transporters (ABC) family played key roles in the resistance. These genes/proteins can then serve as the foundation for other targeted techniques, such as gene silencing techniques using RNA interference and CRISPR. In the future, such techniques will be useful to knock down detoxifying genes and crucial neutralizing enzymes involved in the resistance mechanism, which could lead to solutions for coping against BtWf infestation.

Asunto(s)

Hemípteros , Resistencia a los Insecticidas , Insecticidas , Hemípteros/genética , Hemípteros/efectos de los fármacos , Hemípteros/metabolismo , Animales , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Genómica , Metabolómica , Proteómica/métodos

RESUMEN

Rice stripe virus (RSV) establishes infection in the ovaries of its vector insect, Laodelphax striatellus. We demonstrate that RSV infection delays ovarian maturation by inhibiting membrane localization of the vitellogenin receptor (VgR), thereby reducing the vitellogenin (Vg) accumulation essential for egg development. We identify the host protein L. striatellus Rab1 protein (LsRab1), which directly interacts with RSV nucleocapsid protein (NP) within nurse cells. LsRab1 is required for VgR surface localization and ovarian Vg accumulation. RSV inhibits LsRab1 function through two mechanisms: NP binding LsRab1 prevents GTP binding, and NP binding LsRab1-GTP complexes stimulates GTP hydrolysis, forming an inactive LsRab1 form. Through this dual inhibition, RSV infection prevents LsRab1 from facilitating VgR trafficking to the cell membrane, leading to inefficient Vg uptake. The Vg-VgR pathway is present in most oviparous animals, and the mechanisms detailed here provide insights into the vertical transmission of other insect-transmitted viruses of medical and agricultural importance.

Asunto(s)

Receptores de Superficie Celular , Tenuivirus , Proteínas de Unión al GTP rab1 , Animales , Femenino , Proteínas de Unión al GTP rab1/metabolismo , Tenuivirus/fisiología , Tenuivirus/metabolismo , Receptores de Superficie Celular/metabolismo , Proteínas del Huevo/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Vitelogeninas/metabolismo , Proteínas de la Nucleocápside/metabolismo , Hemípteros/virología , Hemípteros/metabolismo , Ovario/virología , Ovario/metabolismo , Unión Proteica , Transporte de Proteínas , Membrana Celular/metabolismo , Membrana Celular/virología , Enfermedades de las Plantas/virología

RESUMEN

Graphosoma rubrolineatum (Hemiptera: Pentatomidae) is an important pest of vegetables and herbs (e.g., Umbelliferae and Cruciferae) in China, Siberia, Korea, and Japan. Insects are highly dependent on their olfactory system to detect odorants. However, no molecular-mediated olfactory genes in G. rubrolineatum have yet been identified. In this study, we first established the antennal transcriptome of G. rubrolineatum and identified 189 candidate olfactory genes, including 31 odorant-binding proteins (OBPs), 15 chemosensory proteins (CSPs), four sensory neuron membrane proteins (SNMPs),94 odorant receptors (ORs), 23 ionotropic receptors (IRs), and 22 gustatory receptors (GRs). Additionally, phylogenetic trees were constructed for olfactory genes between G. rubrolineatum and other hemipteran insects. We also detected the expression profiles of ten OBPs, five CSPs, two SNMPs, five ORs, four IRs, and four GRs by real-time quantitative PCR. The results revealed that most genes (GrubOBP1/11/31, GrubCSP3/8, GrubSNMP1a/1b, GrubOrco/OR9/11/13, GrubGR1/4/22, GrubIR25/75h/76b/GluR1) were highly expressed in the antennae, GrubOBP13/31 and GrubCSP4/11/12 were highly expressed in the legs, while GrubOBP20 and GrubGR19 were highly expressed in the wings. Our results will enrich the gene inventory of G. rubrolineatum and provide further insight into the molecular chemosensory mechanisms of G. rubrolineatum.

Asunto(s)

Antenas de Artrópodos , Proteínas de Insectos , Filogenia , Receptores Odorantes , Transcriptoma , Animales , Antenas de Artrópodos/metabolismo , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Hemípteros/genética , Hemípteros/metabolismo , Perfilación de la Expresión Génica , Olfato/genética

RESUMEN

Arboviruses can be paternally transmitted by male insects to offspring for long-term persistence, but the mechanism remains largely unknown. Here, we use a model system of a destructive rice reovirus and its leafhopper vector to find that insect ribosome-rescuer Pelo-Hbs1 complex expressed on the sperm surface mediates paternal arbovirus transmission. This occurs through targeting virus-containing tubules constituted by viral nonstructural protein Pns11 to sperm surface via Pns11-Pelo interaction. Tubule assembly is dependent on Hsp70 activity, while Pelo-Hbs1 complex inhibits tubule assembly via suppressing Hsp70 activity. However, virus-activated ubiquitin ligase E3 mediates Pelo ubiquitinated degradation, synergistically causing Hbs1 degradation. Importantly, Pns11 effectively competes with Pelo for binding to E3, thus antagonizing E3-mediated Pelo-Hbs1 degradation. These processes cause a slight reduction of Pelo-Hbs1 complex in infected testes, promoting effective tubule assembly. Our findings provide insight into how insect sperm-specific Pelo-Hbs1 complex is modulated to promote paternal virus transmission without disrupting sperm function.

Asunto(s)

Hemípteros , Proteínas de Insectos , Espermatozoides , Animales , Masculino , Espermatozoides/metabolismo , Espermatozoides/virología , Hemípteros/virología , Hemípteros/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Arbovirus , Proteínas HSP70 de Choque Térmico/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Reoviridae/fisiología , Insectos Vectores/virología , Insectos Vectores/metabolismo , Ribosomas/metabolismo , Infecciones por Arbovirus/transmisión , Infecciones por Arbovirus/metabolismo , Infecciones por Arbovirus/virología

RESUMEN

The cotton whitefly, Bemisia tabaci, is considered as a species complex with 46 cryptic species, with Asia II-1 being predominant in Asia. This study addresses a significant knowledge gap in the characterization of odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) in Asia II-1. We explored the expression patterns of OBPs and CSPs throughout their developmental stages and compared the motif patterns of these proteins. Significant differences in expression patterns were observed for the 14 OBPs and 14 CSPs of B. tabaci Asia II-1, with OBP8 and CSP4 showing higher expression across the developmental stages. Phylogenetic analysis reveals that OBP8 and CSP4 form distinct clades, with OBP8 appearing to be an ancestral gene, giving rise to the evolution of other odorant-binding proteins in B. tabaci. The genomic distribution of OBPs and CSPs highlights gene clustering on the chromosomes, suggesting functional conservation and evolutionary events following the birth-and-death model. Molecular docking studies indicate strong binding affinities of OBP8 and CSP4 with various odour compounds like ß-caryophyllene, α-pinene, ß-pinene and limonene, reinforcing their roles in host recognition and reproductive functions. This study elaborates on our understanding of the putative roles of different OBPs and CSPs in B. tabaci Asia II-1, hitherto unexplored. The dynamics of the expression of OBPs and CSPs and their interactions with odour compounds offer scope for developing innovative methods for controlling this global invasive pest.

Asunto(s)

Hemípteros , Proteínas de Insectos , Filogenia , Receptores Odorantes , Animales , Hemípteros/metabolismo , Hemípteros/genética , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Receptores Odorantes/química , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/química , Regulación del Desarrollo de la Expresión Génica , Simulación del Acoplamiento Molecular , Sesquiterpenos Policíclicos/metabolismo , Limoneno/metabolismo , Sesquiterpenos/metabolismo

RESUMEN

Trade-offs between evolutionary gain and loss are prevalent in nature, yet their genetic basis is not well resolved. The evolution of insect resistance to insecticide is often associated with strong fitness costs; however, how the fitness trade-offs operates remains poorly understood. Here, we show that the mitogen-activated protein kinase (MAPK) pathway and its upstream and downstream actors underlie the fitness trade-offs associated with insecticide resistance in the whitefly Bemisia tabaci. Specifically, we find a key cytochrome P450 gene CYP6CM1, that confers neonicotinoids resistance to in B. tabaci, is regulated by the MAPKs p38 and ERK through their activation of the transcription factor cAMP-response element binding protein. However, phosphorylation of p38 and ERK also leads to the activation of the transcription repressor Cap "n" collar isoform C (CncC) that negatively regulates exuperantia (Ex), vasa (Va), and benign gonial cell neoplasm (Bg), key genes involved in oogenesis, leading to abnormal ovary growth and a reduction in female fecundity. We further demonstrate that the transmembrane G protein-coupled receptor (GPCR) neuropeptide FF receptor 2 (NPFF2) triggers the p38 and ERK pathways via phosphorylation. Additionally, a positive feedback loop between p38 and NPFF2 leads to the continuous activation of the MAPK pathways, thereby constitutively promoting neonicotinoids resistance but with a significant reproductive cost. Collectively, these findings provide fundamental insights into the role of cis-trans regulatory networks incurred by GPCR-MAPK signaling pathways in evolutionary trade-offs and applied knowledge that can inform the development of strategies for the sustainable pest control.

Asunto(s)

Hemípteros , Proteínas de Insectos , Resistencia a los Insecticidas , Sistema de Señalización de MAP Quinasas , Receptores Acoplados a Proteínas G , Animales , Hemípteros/genética , Hemípteros/metabolismo , Resistencia a los Insecticidas/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Femenino , Insecticidas/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética

RESUMEN

Multiple species within the order Hemiptera cause severe agricultural losses on a global scale. Aphids and whiteflies are of particular importance due to their role as vectors for hundreds of plant viruses, many of which enter the insect via the gut. To facilitate the identification of novel targets for disruption of plant virus transmission, we compared the relative abundance and composition of the gut plasma membrane proteomes of adult Bemisia tabaci (Hemiptera: Aleyrodidae) and Myzus persicae (Hemiptera: Aphididae), representing the first study comparing the gut plasma membrane proteomes of two different insect species. Brush border membrane vesicles were prepared from dissected guts, and proteins extracted, identified and quantified from triplicate samples via timsTOF mass spectrometry. A total of 1699 B. tabaci and 1175 M. persicae proteins were identified. Following bioinformatics analysis and manual curation, 151 B. tabaci and 115 M. persicae proteins were predicted to localize to the plasma membrane of the gut microvilli. These proteins were further categorized based on molecular function and biological process according to Gene Ontology terms. The most abundant gut plasma membrane proteins were identified. The ten plasma membrane proteins that differed in abundance between the two insect species were associated with the terms "protein binding" and "viral processes." In addition to providing insight into the gut physiology of hemipteran insects, these gut plasma membrane proteomes provide context for appropriate identification of plant virus receptors based on a combination of bioinformatic prediction and protein localization on the surface of the insect gut.

Asunto(s)

Áfidos , Tracto Gastrointestinal , Proteínas de Insectos , Insectos Vectores , Virus de Plantas , Animales , Proteínas de Insectos/metabolismo , Insectos Vectores/virología , Insectos Vectores/metabolismo , Áfidos/virología , Áfidos/metabolismo , Tracto Gastrointestinal/virología , Tracto Gastrointestinal/metabolismo , Proteínas de la Membrana/metabolismo , Hemípteros/virología , Hemípteros/metabolismo , Proteoma , Membrana Celular/metabolismo

RESUMEN

Molting is a key solution to growth restriction in insects. The periodic synthesis and degradation of chitin, one of the major components of the insect epidermis, is necessary for insect growth. MicroRNA (miRNA) have been implicated in molting regulation, yet their involvement in the interplay interaction between the chitin synthesis pathway and 20-hydroxyecdysone signaling remains poorly understood. In this study, soluble trehalase (Tre1) and phosphoacetylglucosamine mutase (PAGM) were identified as targets of conserved miR-8-3p and miR-2a-3, respectively. The expression profiles of miR-8-3p-SfTre1 and miR-2a-3-SfPAGM exhibited an opposite pattern during the different developmental stages, indicating a negative regulatory relationship between them. This relationship was confirmed by an in vitro dual-luciferase reporter system. Overexpression of miR-8-3p and miR-2a-3 by injection of mimics inhibited the expression of their respective target genes and increased mortality, leading to death in the pre-molting, and molting death phenomena. They also caused a decrease in chitin content and expression levels of key genes in the chitin synthesis pathway (SfTre1, SfTre2, SfHK, SfG6PI, SfGFAT, SfGNA, SfPAGM, SfUAP, SfCHS1, SfCHS1a, and SfCHS1b). Conversely, the injection of miRNA inhibitors resulted in the upregulation of the expression levels of these genes. Following 20E treatment, the expression levels of miR-8-3p and miR-2a-3 decreased significantly, while their corresponding target genes increased significantly. These results indicate that miR-8-3p and miR-2a-3 play a regulatory role in the molting of Sogatella furcifera by targeting SfTre1 and SfPAGM, respectively. These findings provide new potential targets for the development of subsequent new control strategies.

Asunto(s)

Quitina , MicroARNs , Muda , Animales , MicroARNs/genética , MicroARNs/metabolismo , Muda/genética , Hemípteros/genética , Hemípteros/crecimiento & desarrollo , Hemípteros/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Ninfa/crecimiento & desarrollo , Ninfa/genética , Ninfa/metabolismo

RESUMEN

Selecting appropriate reference genes is crucial for ensuring the accuracy and reliability of gene expression study using reverse transcription-quantitative PCR (RT-qPCR). To screen the optimal reference genes for analyzing gene expression in different tissues of the vector leafhopper Psammotettix striatus which causes extensive damage to a wide range of crops by vectoring multiple plant pathogenic microorganisms, the transcriptome data from Malpighian tubules (MTs) of P. striatus were mined. Twenty alternative candidate reference genes were initially selected for screening, among which seven genes with diverse Gene Ontology (GO) annotations were choosed as candidate reference genes, i.e., ribosomal protein L7A (RPL7A), ribosomal protein S28 (RPS28), ribosomal protein L22 (RPL22), ribosomal protein LP2 (RPLP2), H3 histone family 3A (H3F3A), elongation factor 1γ (EF-1γ), and elongation factor 1α (EF-1α). Gene expression levels in different tissues of P. striatus adults were examined using RT-qPCR, and their expression stability was analyzed using multiple reference gene screening software. This study revealed EF-1α as the most abundantly expressed gene, while RPL22 exhibited the lowest expression levels. EF-1α showed the most stable expression, whereas RPS28 showed the least stability. Various software tools confirmed EF-1α as the most stable single reference gene, and EF-1α and RPLP2 an optimal combination. This study provides a foundation for future investigation of the transmission of pathogenic microorganisms mediated by the vector leafhoppers, the function of the MTs, the biosynthesis of brochosomes, the coevolutionary processes and nutritional interactions of symbionts and host insects, and the gene expression study of other sap-sucking insects.

Asunto(s)

Perfilación de la Expresión Génica , Hemípteros , Transcriptoma , Animales , Hemípteros/genética , Hemípteros/metabolismo , Perfilación de la Expresión Génica/métodos , Estándares de Referencia , Insectos Vectores/genética , Genes de Insecto , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo

RESUMEN

Aspongopus chinensis Dallas, 1851 (Hemiptera: Dinidoridae), an edible and medicinal insect, usually found in China and Southeast Asia, offers substantial potential for various applications. The reproductive cycle of this particular insect occurs annually because of reproductive diapause, leading to inadequate utilization of available natural resources. Despite its considerable ecological importance, the precise mechanisms underlying diapause in A. chinensis are not yet well understood. In this study, we conducted an analysis of comparing the microRNA (miRNA) regulation in the diapause and non-diapause gonads of A. chinensis and identified 303 differentially expressed miRNAs, among which, compared with the diapause group, 76 miRNAs were upregulated and 227 miRNAs downregulated. The results, regarding the Enrichment analysis of miRNA-targeted genes, showed their involvement in several essential biological processes, such as lipid anabolism, energy metabolism, and gonadal growth. Interestingly, we observed that the ATP-binding cassette pathway is the only enriched pathway, demonstrating the capability of these targeted miRNAs to regulate the reproductive diapause of A. chinensis through the above essential pathway. The current study provided the role of gonadal miRNA expression in the control of reproductive diapause in A. chinensis, the specific regulatory mechanism behind this event remained unknown and needed more investigation.

Asunto(s)

Diapausa de Insecto , Hemípteros , MicroARNs , Animales , MicroARNs/metabolismo , MicroARNs/genética , Hemípteros/genética , Hemípteros/metabolismo , Hemípteros/crecimiento & desarrollo , Hemípteros/fisiología , Gónadas/metabolismo , Gónadas/crecimiento & desarrollo , Femenino , Masculino , Reproducción

RESUMEN

Odorant-binding proteins (OBPs) are crucial in insect olfaction. The most abundant expressed OBP of citrus psyllids, DcitOBP9 encodes 148 amino acids. DcitOBP9 lacks a transmembrane structure and possesses a 17-amino acid signal peptide at the N-terminus. Characterized by the six conserved cysteine sites, DcitOBP9 is classified as the Classical-OBP family. RT-qPCR experiments revealed ubiquitous expression of DcitOBP9 across all developmental stages of the citrus psyllid, with predominant expression in adults antennae. Fluorescence competitive binding assays demonstrated DcitOBP9's strong affinity for ocimene, linalool, dodecanoic acid, and citral, and moderate affinity for dimethyl trisulfide. Additionally, it binds to myrcia, (-)-trans-caryophyllene, (±)-Citronellal, nonanal, and (+)-α-pinene. Among them, ocimene, linalool, and dodecanoic acid were dynamically bound to DcitOBP9, while citral was statically bound to DcitOBP9. Molecular docking simulations with the top five ligands indicated that amino acid residues V92, S72, P128, L91, L75, and A76 are pivotal in the interaction between DcitOBP9 and these odorants. These findings suggest DcitOBP9's involvement in the citrus psyllid's host plant recognition and selection behaviors, thereby laying a foundation for elucidating the potential physiological and biological functions of DcitOBP9 and developing attractants.

Asunto(s)

Hemípteros , Proteínas de Insectos , Simulación del Acoplamiento Molecular , Receptores Odorantes , Animales , Hemípteros/genética , Hemípteros/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/química , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Receptores Odorantes/química , Citrus/metabolismo , Citrus/genética , Unión Proteica , Secuencia de Aminoácidos , Filogenia

RESUMEN

In holometabolous insects, such as Drosophila and Bombyx, prothoracicotropic hormone (PTTH) is well established to be critical in controlling developmental transitions and metamorphosis by stimulating the biosynthesis of ecdysone in the prothoracic glands (PGs). However, the physiological role of PTTH and the receptor Torso in hemimetabolous insects remains largely unexplored. In this study, homozygous PTTH- and Torso-null mutants of the brown planthopper (BPH), Nilaparvata lugens, were successfully generated by employing clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR-Cas9). Further characterization showed that both NlPTTH-/- and NlTorso-/- mutants exhibited prolonged nymphal duration and increased final adult size. Enzyme-linked immunosorbent assay (ELISA) revealed that NlPTTH-/- and NlTorso-/- mutants exhibited a significant reduction in 20-hydroxyecdysone (20E) in fifth-instar nymphs at 48 h post-ecdysis compared to Wt controls. Furthermore, our results indicated that both NlPTTH-/- and NlTorso-/- mutants had shortened lifespan, reduced female fecundity, and reduced egg hatching rates in adults. These findings suggest a conserved role for the PTTH-Torso signaling system in the regulation of developmental transitions by stimulating ecdysone biosynthesis in hemimetabolous insects.

Asunto(s)

Ecdisona , Hemípteros , Hormonas de Insectos , Proteínas de Insectos , Transducción de Señal , Animales , Femenino , Masculino , Tamaño Corporal , Ecdisona/metabolismo , Regulación del Desarrollo de la Expresión Génica , Hemípteros/crecimiento & desarrollo , Hemípteros/genética , Hemípteros/metabolismo , Homeostasis , Hormonas de Insectos/metabolismo , Hormonas de Insectos/genética , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Metamorfosis Biológica , Reproducción

RESUMEN

Peroxisomes are ubiquitous cellular organelles participating in a variety of critical metabolic reactions. PEX14 is an essential peroxin responsible for peroxisome biogenesis. In this study, we identified the human PEX14 homolog in the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae). N. lugens PEX14 (NlPEX14) showed significant topological similarity to its human counterpart. It is expressed throughout all developmental stages, with the highest expression observed in adult insects. Down-regulation of NlPEX14 through injection of NlPEX14-specific double-strand RNA impaired nymphal development. Moreover, females subjected to dsNlPEX14 treatment exhibited a significantly reduced lifespan. Additionally, we found abnormal ovarian development and a significant decrease in the number of eggs laid in NlPEX14-downregulated females. Further experiments support that the shortening of lifespan and the decrease in female fecundity can be attributed, at least partially, to the accumulation of fatty acids and reduced expression of vitellogenin. Together, our study reveals an indispensable function of NlPEX14 for insect reproduction and establishes a causal connection between the phenotypes and peroxisome biogenesis, shedding light on the importance of peroxisomes in female fecundity.

Asunto(s)

Fertilidad , Hemípteros , Proteínas de Insectos , Animales , Hemípteros/genética , Hemípteros/metabolismo , Hemípteros/fisiología , Hemípteros/crecimiento & desarrollo , Femenino , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Peroxisomas/metabolismo , Longevidad , Ninfa/crecimiento & desarrollo , Ninfa/metabolismo , Ninfa/genética , Peroxinas/metabolismo , Peroxinas/genética , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Vitelogeninas/metabolismo , Vitelogeninas/genética

RESUMEN

Structure-activity relationships of diazinoyl nicotinic insecticides (diazinoyl isomers and 5- or 6-substituted pyrazin-2-oyl analogues) are considered in terms of affinity to the insect nicotinic acetylcholine receptor (nAChR) and insecticidal activity against the imidacloprid-resistant brown planthopper. Among the test compounds, 3-(6-chloropyridin-3-ylmethyl)-2-(pyrazinoyl)iminothiazoline shows the highest potency in nAChR affinity and insecticidal activity. Aplysia californica acetylcholine binding protein (AChBP) mutants (Y55W + Q57R and Y55W + Q57T) are utilized to compare molecular recognition of nicotinic insecticides with diverse pharmacophores. N-nitro- or N-cyanoimine imidacloprid or acetamiprid, respectively, exhibits a high affinity to these AChBP mutants at a similar potency level. Intriguingly, the pyrazin-2-oyl analogue has a higher affinity to AChBP Y55W + Q57R than that to Y55W + Q57T, thereby indicating that pyrazine nitrogen atoms contact Arg57 guanidinium and Trp55 indole NH. Furthermore, nicotine prefers AChBP Y55W + Q57T over Y55W + Q57R, conceivably suggesting that the protonated nicotine is repulsed by Arg57 guanidinium, consistent with its inferior potency to insect nAChR.

Asunto(s)

Hemípteros , Proteínas de Insectos , Insecticidas , Neonicotinoides , Receptores Nicotínicos , Animales , Insecticidas/química , Insecticidas/farmacología , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/química , Receptores Nicotínicos/genética , Hemípteros/química , Hemípteros/genética , Hemípteros/efectos de los fármacos , Hemípteros/metabolismo , Relación Estructura-Actividad , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/química , Neonicotinoides/química , Neonicotinoides/farmacología , Neonicotinoides/metabolismo , Nitrocompuestos/química , Nitrocompuestos/farmacología , Nitrocompuestos/metabolismo , Aplysia/química , Aplysia/metabolismo , Aplysia/genética , Nicotina/química , Nicotina/metabolismo , Nicotina/análogos & derivados , Nicotina/farmacología

RESUMEN

BACKGROUND: MicroRNAs (miRNAs) are non-coding RNAs that play a pivotal role in antiviral infection. The miR184-3p has been identified to promote rice black streaked dwarf virus (RBSDV) infection in vector Laodelphax striatellus, whether it targets other genes of L. striatellus to modulate RBSDV propagation remains unknown. RESULTS: We first analyzed the expression profiles of miR184-3p and its role in regulating RBSDV infection in L. striatellus. Then the candidate genes expression of miR184-3p were systemically analyzed with gain and loss function of miR184-3p, and the interaction of candidate gene, ecdysone inducible protein 78 (Eip78) with miR184-3p was verified by dual luciferase reporter assay. We found Eip78 is evolutionary conserved among agricultural pests and predominantly expressed in the central nervous system (CNS) of L. striatellus. Knockdown of Eip78 effectively increased RBSDV propagation and transmission. Blockade with Eip78 antibody or injection with Eip78 protein could significantly regulate RBSDV infection. Further analysis revealed that knockdown of Eip78 specifically suppresses RBSDV infection in the head part but not in the body part of L. striatellus. Besides, knockdown of ecdysone receptor (EcR) notably restricted Eip78 expression and increased RBSDV accumulation in L. striatellus. CONCLUSIONS: Taken together, we identified a novel target gene of miR184-3p, Eip78, a member of the ecdysone signaling pathway, and revealed the anti-RBSDV role of Eip78 in the CNS of L. striatellus. These results shed light on the interaction mechanisms of miRNAs, virus and ecdysone signaling pathway in insect vector. © 2024 Society of Chemical Industry.

Asunto(s)

Hemípteros , Proteínas de Insectos , Insectos Vectores , MicroARNs , Animales , MicroARNs/genética , MicroARNs/metabolismo , Hemípteros/virología , Hemípteros/genética , Hemípteros/metabolismo , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Insectos Vectores/virología , Insectos Vectores/genética , Virus de Plantas/fisiología , Virus de Plantas/genética , Enfermedades de las Plantas/virología , Ecdisona/metabolismo

RESUMEN

BACKGROUND: Helopeltis cinchonae (Hemiptera: Miridae) is a major pest of tea plantations in Asia. Conventional control of pests with pesticides is unsustainable. Therefore, safe and eco-friendly alternatives, such as pheromones, are required to manage the pest. RESULTS: In gas chromatography-electroantennographic detection (GC-EAD) analysis of whole-body extracts of virgin female H. cinchonae, two compounds elicited electroantennogram (EAG) responses from male antennae. These were identified as hexyl (R)-3-acetoxybutyrate and (R)-1-acetoxy-5-butyroxyhexane using gas chromatography-mass spectrometry (GC-MS) analysis compared to synthetic compounds. This is the first study to report 1-acetoxy-5-butyroxyhexane as an insect pheromone component. The synthetic compounds elicited dose-dependent EAG responses from the antennae of male H. cinchonae. In two field trapping experiments, the individual compounds were highly attractive to male H. cinchonae when dispensed from polyethylene vials. However, higher catches were obtained with blends of the two compounds in a 1:10 ratio. The blend of racemic compounds was as attractive as the blend of (R)-enantiomers. CONCLUSIONS: We reported that 1-acetoxy-5-butyroxyhexane and hexyl 3-acetoxybutyrate are components of the female-produced sex pheromone of H. cinchonae, but further work is required on the blend and loading of pheromone and on trap design to provide an optimized system for monitoring and control of this pest. The results may also facilitate the identification of the pheromones of other Helopeltis species, which are major pests in many crops. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Asunto(s)

Camellia sinensis , Hormonas Esteroides Gonadales , Hemípteros , Control de Plagas , Hemípteros/química , Hemípteros/metabolismo , Hormonas Esteroides Gonadales/biosíntesis , Hormonas Esteroides Gonadales/química , Femenino , Animales , Tiocarbamatos/química , Tiocarbamatos/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Masculino

RESUMEN

CAPA neuropeptides regulate the diuresis/ antidiuresis process in insects by activating specific cognate receptor, CAPAr. In this study, we characterized the CAPAr gene (BtabCAPAr) in the whitefly, Bemisia tabaci Asia II 1. The two alternatively spliced isoforms of BtabCAPAr gene, BtabCAPAr-1 and BtabCAPAr-2, having six and five exons, respectively, were identified. The BtabCAPAr gene expression was highest in adult whitefly as compared to gene expression in egg, nymphal and pupal stages. Among the three putative CAPA peptides, CAPA-PVK1 and CAPA-PVK2 strongly activated the BtabCAPAr-1 with very low EC50 values of 0.067 nM and 0.053 nM, respectively, in heterologous calcium mobilization assays. None of the peptide activated the alternatively spliced isoform BtabCAPAr-2 that has lost the transmembrane segments 3 and 4. Significant levels of mortality were observed when whiteflies were fed with CAPA-PVK1 at 1.0 µM (50.0%), CAPA-PVK2 at 100.0 nM (43.8%) and CAPA-tryptoPK 1.0 µM (40.0%) at the 96 h after the treatment. This study provides valuable information to design biostable peptides to develop a class of insecticides.

Asunto(s)

Hemípteros , Neuropéptidos , Animales , Péptidos/metabolismo , Neuropéptidos/química , Neuropéptidos/genética , Neuropéptidos/metabolismo , Transducción de Señal , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Hemípteros/genética , Hemípteros/metabolismo