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Natural enemies such as parasitoids and parasites depend on sensitive olfactory to search for their specific hosts. Herbivore-induced plant volatiles (HIPVs) are vital components in providing host information for many natural enemies of herbivores. However, the olfactory-related proteins involved in the recognition of HIPVs are rarely reported. In this study, we established an exhaustive tissue and developmental expression profile of odorant-binding proteins (OBPs) from Dastarcus helophoroides, an essential natural enemy in the forestry ecosystem. Twenty DhelOBPs displayed various expression patterns in different organs and adult physiological states, suggesting a potential involvement in olfactory perception. In silico AlphaFold2-based modeling and molecular docking showed similar binding energies between six DhelOBPs (DhelOBP4, 5, 6, 14, 18, and 20) and HIPVs from Pinus massoniana. While in vitro fluorescence competitive binding assays showed only recombinant DhelOBP4, the most highly expressed in the antennae of emerging adults could bind to HIPVs with high binding affinities. RNAi-mediated behavioral assays indicated that DhelOBP4 was an essential functional protein for D. helophoroides adults recognizing two behaviorally attractive substances: p-cymene and γ-terpinene. Further binding conformation analyses revealed that Phe 54, Val 56, and Phe 71 might be the key binding sites for DhelOBP4 interacting with HIPVs. In conclusion, our results provide an essential molecular basis for the olfactory perception of D. helophoroides and reliable evidence for recognizing the HIPVs of natural enemies from insect OBPs' perspective. [ABSTRACT FROM AUTHOR]

Sex pheromone-binding proteins (PBPs) play an important role in sex pheromone recognition in Lepidoptera. However, the mechanisms of chemical communication mediating the response to sex pheromones remain unclear in the diurnal moths of the superfamily Zygaenoidea. In this study, Phauda flammans (Walker) (Lepidoptera: Zygaenoidea: Phaudidae) was used as a model insect to explore the molecular mechanism of sex pheromone perception in the superfamily Zygaenoidea. Two novel pheromone-binding proteins (PflaPBP1 and PflaPBP2) from P. flammans were identified. The two pheromone-binding proteins were predominantly expressed in the antennae of P. flammans male and female moths, in which PflaPBP1 had stronger binding affinity to the female sex pheromones Z-9-hexadecenal and (Z, Z, Z)-9, 12, 15-octadecatrienal, PflaPBP2 had stronger binding affinity only for (Z, Z, Z)-9, 12, 15-octadecatrienal, and no apparent binding affinity to Z-9-hexadecenal. The molecular docking results indicated that Ile 170 and Leu 169 are predicted to be important in the binding of the sex pheromone to PflaPBP1 and PflaPBP2. We concluded that PflaPBP1 and PflaPBP2 may be responsible for the recognition of two sex pheromone components and may function differently in female and male P. flammans. These results provide a foundation for the development of pest control by exploring sex pheromone blocking agents and the application of sex pheromones and their analogs for insect pests in the superfamily Zygaenoidea. [ABSTRACT FROM AUTHOR]

Eichhornia crassipes were evaluated in order to investigate the insecticidal activity towards Aphis craccivora adults. The LC50 values were promising and reflected the bio-efficacy of the tested extracts (39 and 42 mg/L), respectively, and reduced the fecundity markedly. Using GC/MS analysis, the major components were n-hexadecanoic, linolenic, hexadecenoic, myristic, stearic acids, linolelaidic acid, methyl ester and some terpenoids, alkaloids, and hydrocarbons. A safety assessment of non-target organisms is essential for the development of new pesticides. In order to guide the rational use of the most potential insecticidal extracts AcF and EtF, the effect of these extracts on body weight, hematological indices, biochemical indicators, and histopathology of some relevant organs of albino rats (as a model for mammals) was investigated. The research outcomes revealed that the LC50 of AcF and EtF extracts had gradually raised body weight for 14 days (p > 0.05). Similarly, there were no remarkable alternations in the complete blood count (CBC); only a slight decrease in the monocytes count (612 ± 159.80 × 103 µL) in the EtF-treated group. There was a notable increase in alanine transferase (ALT) activity (36.73 ± 1.44 IU/L) in the AcF-treated group. No destructive changes were noted with the remaining biochemical parameters. Cholesterol and triglycerides non-significantly increased in the EtF group, whereas, cholesterol levels decreased significantly in the AcF group. In addition, histopathological examination reflected minor changes in AcF and EtF groups in the form of mild inflammation in the lungs and mild vacuolar degeneration in the kidneys, while no lesions were detected in the heart and liver in the same groups. Thus, the present research suggested that AcF and EtF extracts of E. crassipes are safe green insecticides for insect control strategies. [ABSTRACT FROM AUTHOR]

Odorant-binding proteins (OBPs) typically act as transporters of odor molecules and play an important role in insect host location. Here, we identified an OBP in brown planthopper (BPH) Nilaparvata lugens salivary glands via transcriptome sequencing. Real-time quantitative PCR and Western blotting analysis results showed that NlugOBP11 was highly expressed in salivary glands and secreted into rice plant during feeding, suggesting that it assists in BPH feeding on rice. Functional analysis in N. lugens saliva revealed that silencing this gene by RNA interference decreased the BPH stylet performance in the phloem of rice plants, reduced sap sucking, and ultimately led to insect death. Moreover, overexpression of NlugOBP11 in rice protoplasts or Nicotiana benthamiana leaves inhibited the production of defense-related signaling molecule salicylic acid in rice plant. The results demonstrate that NlugOBP11 is not only essential for BPH feeding, but also acts as an effector that inhibits plant defense. [ABSTRACT FROM AUTHOR]

Environmental problems have always received immense attention from scientists. Toxicants pollution is a critical environmental concern that has posed serious threats to human health and agricultural production. Heavy metals and pesticides are top of the list of environmental toxicants endangering nature. This review focuses on the toxic effect of heavy metals (cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn)) and pesticides (insecticides, herbicides, and fungicides) adversely influencing the agricultural ecosystem (plant and soil) and human health. Furthermore, heavy metals accumulation and pesticide residues in soils and plants have been discussed in detail. In addition, the characteristics of contaminated soil and plant physiological parameters have been reviewed. Moreover, human diseases caused by exposure to heavy metals and pesticides were also reported. The bioaccumulation, mechanism of action, and transmission pathways of both heavy metals and pesticides are emphasized. In addition, the bioavailability in soil and plant uptake of these contaminants has also been considered. Meanwhile, the synergistic and antagonistic interactions between heavy metals and pesticides and their combined toxic effects have been discussed. Previous relevant studies are included to cover all aspects of this review. The information in this review provides deep insights into the understanding of environmental toxicants and their hazardous effects. [ABSTRACT FROM AUTHOR]

Odorant binding proteins play a key role in the olfactory system and are involved in the odor perception and discrimination of insects. To investigate the potential physiological functions of SaveOBP9 in Sitobion avenae, fluorescence ligand binding experiments, molecular docking, RNA interference, and behavioral tests were performed. Fluorescence binding assay results showed that SaveOBP9 had broad and high (Ki < 10 μM) binding abilities with most of the wheat volatiles, but was more obvious at pH 7.4 than pH 5.0. The binding sites of SaveOBP9 to the volatiles were predicted well by three-dimensional docking structure modeling and molecular docking. Moreover, S. avenae showed a strong behavioral response with the four compounds of wheat. The reduction in mRNA transcript levels after the RNA interference significantly reduced the expression level of SaveOBP9 and induced the non-significant response of S. avenae to the tetradecane, octanal, decanal, and hexadecane. This study provides evidence that SaveOBP9 might be involved in the chemoreception of wheat volatile organic compounds and can successfully contribute in the integrated management programs of S. avenae. [ABSTRACT FROM AUTHOR]

Sex pheromone-binding proteins (PBPs) play an important role in sex pheromone recognition in Lepidoptera. However, the mechanisms of chemical communication mediating the response to sex pheromones remain unclear in the diurnal moths of the superfamily Zygaenoidea. In this study, Phauda flammans (Walker) (Lepidoptera: Zygaenoidea: Phaudidae) was used as a model insect to explore the molecular mechanism of sex pheromone perception in the superfamily Zygaenoidea. Two novel pheromone-binding proteins ( PflaPBP1 and PflaPBP2 ) from P. flammans were identified. The two pheromone-binding proteins were predominantly expressed in the antennae of P. flammans male and female moths, in which PflaPBP1 had stronger binding affinity to the female sex pheromones Z -9-hexadecenal and ( Z , Z , Z )-9, 12, 15-octadecatrienal, PflaPBP2 had stronger binding affinity only for ( Z , Z , Z )-9, 12, 15-octadecatrienal, and no apparent binding affinity to Z -9-hexadecenal. The molecular docking results indicated that Ile 170 and Leu 169 are predicted to be important in the binding of the sex pheromone to PflaPBP1 and PflaPBP2. We concluded that PflaPBP1 and PflaPBP2 may be responsible for the recognition of two sex pheromone components and may function differently in female and male P. flammans . These results provide a foundation for the development of pest control by exploring sex pheromone blocking agents and the application of sex pheromones and their analogs for insect pests in the superfamily Zygaenoidea.