Archives of Insect Biochemistry and Physiology最新文献

This study investigated the effects of Cryptomeria japonica leaf essential oil (CjLEO) on honey bee health, focusing on both toxicity and gene expression modulation. Initial toxicity assessments revealed that high concentrations of CjLEO (75 and 100 ppm) were lethal to honey bees, resulting in complete mortality within a short period. Conversely, a lower concentration of 10 ppm exhibited no significant toxic effects, prompting further investigation into its sublethal impacts. Transcriptome analysis via next-generation sequencing demonstrated that CjLEO at 10 ppm induced significant changes in honey bee gene expression compared to the control group. Principal component analysis (PCA) and differential gene expression (DEG) analysis identified more than 9,000 genes, with notable upregulation of immune-related genes, including hymenoptaecin, abaecin, and apidaecin1. Gene ontology (GO) enrichment analysis indicated that these differentially expressed genes were primarily associated with immune responses, such as defense and innate immune pathways. The chemical composition of CjLEO, characterized by GC–MS, identified 16 compounds, with major components including α-pinene, elemol, α-eudesmol, and kaur-16-ene. These compounds are known for their antimicrobial properties, which likely contribute to the observed immunomodulatory effects. CjLEO at a concentration of 10 ppm enhances honey bee immunity without exhibiting significant toxicity, positioning it a promising candidate for improving honey bee resilience against pathogens. Future research should investigate the mechanisms of immune activation and optimize application methods for practical beekeeping, aiming to improve colony health while reducing dependence on synthetic chemicals.

In animals, social experience plays an important role in the adaptive modification of behavior. Previous social experience changes locomotor activity in Drosophila melanogaster. In females, suppression of locomotion is observed only when flies are in aggregations, but males retain a reduced level of locomotor activity up to 5 days after being isolated from the group. The mechanisms underlying such behavioral plasticity still largely are unknown. In this study, we aimed to identify new candidate genes involved in the social experience-dependent modification of locomotor activity. We tested the effect of social experience on spontaneous locomotor activity in various mutant males, including those with impaired learning and memory, circadian rhythms, some biochemical pathways, and sensory systems. The results of the present study indicate that the biogenic amines and olfactory perception appear to play key roles in social experience-induced changes in locomotor activity. Also, we performed a screen of the collection of mutants carrying random autosomal insertions of PdL transposon. We isolated five candidate genes, of which two genes, Dek and Hel89B, encode proteins related to the formation of the epigenetic code, implying that epigenetic factors regulating gene expression may be involved in social experience-dependent modification of locomotor behavior.

Remote sensing is being increasingly used in agricultural stress management, offering real-time analysis of crop stress beyond what can be observed visually alone. Hopper burn, induced by brown planthopper (BPH, Nilaparvata lugens) is a significant challenge to rice production in India. This study aims to characterize the spectral reflectance of rice plants with different infestation levels of 2^nd instar BPH nymphs across three varieties namely Pusa Basamti-1509, Pusa Basmati-1121, and TN-1 (susceptible variety to BPH). The differential infestation included 0, 5, 10, 20, 40, 80, 100, 200 number of nymphs. The spectral signatures of the crop were collected at 20 and 40 days after infestation (DAI). The results indicated a distinct change in reflectance pattern between healthy and infested rice plants across all three varieties in green (490–559 nm), yellow (560–584 nm), orange (585–639 nm), and red (640–699 nm) region of visible portion as affected by chlorophyll pigments and in NIR region (700–1800 nm) as affected by cell structure and in water absorption (1915 nm) region of SWIR portion. The specific wavelength band (470, 660,750, 1800, 1915 nm) showing a correlation above 0.8 with pest severity level, was identified as sensitive for assessing BPH damage. Analysis of reflectance changes across wavelengths highlighted that the first derivative has a strong correlation between BPH severity and reflectance in the green region (500–540 nm) and red edge position (680–760 nm). The amplitude of the red edge value decreased with an increase in the severity level of insects. This study identifies the sensitivity of visible and near-infrared regions in detecting and assessing BPH infestation severity.

Biological treatment by black soldier fly larvae (BSFL) has proven to be an effective method for the resource utilization of cyanobacteria, but the effects of microcystin-LR (MC-LR) in cyanobacteria on BSFL growth have not been adequately explored. To evaluate the inhibitory effect and toxic mechanism of MC-LR on BSFL, the growth performance and intestinal microbiota were examined after exposure to 0, 10, 100, and 1000 μg/kg of MC-LR. The larval weight and survival rate were each significantly inhibited by 21.53% and 21.49% compared with the control group, respectively, after exposure at a concentration of 1000 μg/kg MC-LR for 16 days. Lipid accumulation, intestinal inflammation, and oxidative stress were observed in three treatment groups, with dose-dependent inflammation ocurring in the intestine. Compared with the control group, superoxide dismutase and catalase activity levels were significantly increased by 74.91% and 49.58%, respectively, which confirmed the occurrence of oxidative stress induced by MC-LR. Furthermore, MC-LR altered the diversity of intestinal microbiota and increased the relative abundance of pathogenic bacteria (e.g., Paenibacillus, Clostridium_sensu_stricto_1, and Lachnoclostridium), which increased the risk of disease in BSFL and contributed to observed metabolic disorders. On the other hand, qRT-PCR analysis further confirmed the occurrence of oxidative stress and the activation of the peroxisome proliferator-activated receptor signaling pathway, resulting in the upregulation of fatty acid synthesis-related genes, ultimately leading to lipid accumulation and apoptosis. These findings provide valuable insights into the ecological risks associated with MC-LR during the process of cyanobacterial resource utilization.

The aim of this study was to investigate how leaf volatiles from Salix alba affect the orientation of Nematus hequensis Xiao adults towards host plants and contribute to the development of plant-based attractants for N. hequensis. Solid-phase microextraction (SPME) coupled with gas chromatograph-mass spectrometry (GC-MS) was used to extract, identify, and screen leaf volatiles from S. alba aged 10–15 years during the peak eclosion of N. hequensis. Electroantennogram (EAG) and Y-shaped olfactometry assays were utilized to identify volatiles with relative content > 1% and determine the optimal concentration for attracting, 1-day-old unmated males and females. The results showed that among the 15 volatiles with a relative content of more than 1%, (E)-2-hexenal, benzaldehyde, and 2-hydroxybenzaldehyde elicited the strongest EAG response in adult males and females at a concentration of 100 μg·μL^-1, with (E)-2-hexenal exhibiting a greater effect than 2-hydroxybenzaldehyde, which in turn was more effective than benzaldehyde. At this concentration, the attractive effects of (E)-2-Hexenal, and benzaldehyde on adult males and females were significant. These findings provide an important basis for developing attractants and repellents used in control of this insect pest.

Heat shock protein 60 (Hsp60), abundantly presents in mitochondria, is a highly conserved chaperone that maintains the stability and functionality of mitochondrial proteins, while also participating in the regulation of various cellular processes. As a member of the heat shock family, Hsp60 significantly influences viral proliferation. However, limited research is available on its role in the proliferation of entomopathogenic baculoviruses, particularly Bombyx mori nucleopolyhedrovirus (BmNPV). Our previous proteomics results showed a significant decrease of Hsp60 acetylation levels after BmNPV infection. To investigate the impact of Hsp60 deacetylation on viral proliferation, site-direct mutagenesis was performed to generate a deacetylated (K/R) mimic of Hsp60. We found that the acetylation level of lysine 362 (K362) decreased after BmNPV challenge. Furthermore, overexpression of deacetylation-mimicking Hsp60 reduced the chaperone activity of Hsp60, leading to impaired mitochondrial function, including increased reactive oxygen species (ROS) levels, decreased mitochondrial membrane potential, and reduced substrate protein Manganese-containing superoxide dismutase (Mn-SOD) activities, ultimately leading to inhibition of viral proliferation. This study establishes lysine 362 acetylation of Hsp60 as a model for Posttranslational modifications induced by host-virus interactions, providing new insights into potential antiviral strategies.

Rhynchophorus ferrugineus (Olivier, 1790) (Coleoptera: Dryophthoridae), commonly known as the red palm weevil (RPW), is a globally significant pest that threatens economically important palm trees. Its cryptic infestation behavior leads to irreversible damage and eventual host plant death. Current control methods using broad-spectrum insecticides are largely ineffective due to resistance development and their adverse effects on nontarget organisms, necessitating novel strategies. This study integrates proteomics and transcriptomics data to explore the molecular landscape of RPW and identify pathways for targeted pest management. A total of 16,954 transcripts and 983 proteins were identified across three developmental stages (larvae, male adults, and female adults), with a notable decline in protein numbers from larvae to adult. Differential expression analysis revealed 7540 proteins varying significantly between developmental stages. Through subtractive analysis, 218 proteins meeting stringent inclusion and exclusion criteria were identified. These proteins underwent pathway enrichment analysis, mapping to 39 enriched pathways (p-value and an FDR of < 0.01). Among these, two pathways involving three key enzymes were highlighted as high-potential targets for developing insect-specific insecticides and diet-specific control strategies. This is the first comprehensive proteomics study analyzing the whole body of RPW across its developmental stages. The findings emphasize critical pathways, their enzyme components, and the regulation of these enzymes, offering novel insights for sustainable and targeted pest management solutions.

Japanese pine sawyer beetle (JPSB), Monochamus alternatus is a forest insect pest with damaging to pine trees through vectoring plant-parasitic nematodes. In our previous work, the entomopathogenic Metarhizium anisopliae JEF-197 was effective in controlling JPSB adults. However some of JPSB adults survived well even against the fungal treatment. Now here in this work, we analyzed the transcriptome of JEF-197 from the fungus-treated JPSB adults which still survived in 8 days after the treatment. The day was determined based on the lethal time 50 (LT₅₀) in our previous study. As a control, JEF-197 was cultured on 1/4SDA for 8 days. The plate-cultured JEF-197 transcripts were used for building-up an index in the abundance analysis using kallisto to investigate the gene regulation. Additionally, transcripts from the JEF-197-treated PSB were analyzed to find possible fungal transcripts to enlarge the index of abundance analysis. In the following differentially expressed gene (DEG) analysis, most JEF-197 transcripts showed significant down-regulations in JPSB adults 8 days after treatment, which were presented as clustering heatmap, PCA, MA and Volcano plots. The GO enrichment analysis showed similar results, in which most of pathways were significantly suppressed. Metabolic and biosynthesis metabolisms were most dominantly downregulated pathways. Particularly, many genes of glucose metabolisms were significantly suppressed, including genes for glycolysis, TCA, ATP & nucleotide synthesis, and glycogen & chitin production. This work suggests that JEF-197 lost its own glucose metabolism in the survived JPSB adults, and the survival could be involved in the active and continuous host defense mechanisms. It gives us questions what factors would be involved in the different response of individual to the fungal treatment and what happens if live and dead hosts were pooled in RNA-sequencing.

The primary vector of the West Nile virus, Culex pipiens, undergoes reproductive dormancy during the adverse winter season. While our current understanding has mainly focused on cellular signals and phenotypic shifts occurring at a global scale during diapause, information on tissue-specific transcriptomic changes remains limited. This knowledge gap is a major challenge in interpreting the regulatory mechanisms at the tissue level. To address this, the present work utilized RNA-seq technology to investigate the transcriptional changes in the head that house the brain and crucial endocrinal organs such as corpora allata. We obtained RNA samples from the heads of diapausing and nondiapausing female mosquitoes at two specific time intervals, ZT0 and ZT16, and then subjected them to sequencing. Our results revealed differences in differentially expressed genes between diapause and non-diapause at ZT0 and ZT16, highlighting the phenotypic and diel variations in gene expression. We also selected twelve genes associated with the diapause phenotype and examined the transcript abundance at six different time points over 24 h. qRT-PCR analysis showed similar up- and downregulation of transcripts between the diapause and nondiapause phenotypes thus validating the results of RNA-seq. In summary, our study identified new genes with phenotypic and diel differentiation in their expression, potentially linking photoperiod to seasonal reproductive dormancy in insects. The newly presented information will significantly advance our understanding of head-specific genes crucial for insect diapause.