Search Results (1,590)

Genetically modified (GM) plants have been commercially grown for 30 years, and their acceptance depends on a thorough risk assessment. Environmental Risk Assessment (ERA) evaluates potential impacts of releasing GM plants into the environment, whether through cultivation or import for food, feed, and processing. A key component is assessing potential gene flow to crop wild relatives or non-GM crops. For gene flow to significantly affect the environment, transferred genes must provide a selective advantage. Since most GM plants are engineered for herbicide tolerance, insect resistance, or stacked traits, evaluating such advantages is relatively straightforward. New genomic techniques (NGTs) can generate plants with a wider range of traits, including tolerance to biotic and abiotic stress. Although still considered GM in the EU, their genomic changes can complicate detection, identification, and ERA, especially when such traits may offer advantages under stress conditions. This scoping review focuses on gene flow in two crops: oilseed rape (canola) (Brassica napus L.) and potato (Solanum tuberosum L.). In canola, transgene movement can increase weediness, fitness, herbicide resistance, or genetic diversity in feral or related populations. Gene flow in potato is less studied, with concerns centered on contamination risks in the Andean diversity center. Limited data exist for NGT plants, though many are expected to resemble conventionally bred varieties, suggesting comparable environmental impacts. Full article

Eucalyptus spp. are the most important timber and pulpwood species in southern China. This tree species is frequently and severely damaged by the leaf-eating pest Buzura suppressaria, which significantly impairs photosynthesis and hinders the healthy and sustainable development of the Eucalyptus industry. To investigate the defensive responses of Eucalyptus urophylla × Eucalyptus grandis to pest (B. suppressaria)-feeding and leaf-clipping stress, this study measured the temporal changes in defense enzyme activities and defense compounds in Eucalyptus under conditions of pest-feeding and leaf-clipping stresses, aiming to provide a theoretical basis for resistance breeding in Eucalyptus. The results show that pest-feeding and leaf-clipping stress groups significantly affected the peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities in Eucalyptus leaves. Within a short period after stress (3 h), POD activity was significantly reached 444.83 U by leaf-clipping stress, whereas it was significantly inhibited (34.83 U) by pest-feeding stress. PPO activity was significantly enhanced to 95.25 U under pest-feeding stress within 3 h, while leaf clipping induced a lower level of PPO activity (58.75 U). PAL activity was significantly induced to 474.38 U by leaf-clipping stress at 3 h, whereas pest-feeding stress resulted in a moderate increase to 238.00 U. Both pest-feeding and leaf-clipping stresses had significant effects on the contents of defense compounds in Eucalyptus leaves. Within a short period (3 h), both leaf-clipping and pest-feeding stresses significantly induced the accumulation of salicylic acid (0.226 μg/g and 0.326 μg/g, respectively), jasmonic acid (0.239 μg/g and 0.278 μg/g, respectively), and tannin (0.581 μg/g and 0.657 μg/g, respectively). The POD activity and salicylic acid content were identified as the primary factors in Eucalyptus responses to pest-feeding and leaf-clipping stresses. In conclusion, biotic (pest-feeding) and abiotic (leaf-clipping) stresses can induce higher activities of related defense enzymes while also promoting the synthesis of greater quantities of defensive chemical compounds, thereby enhancing the resilience to biotic and abiotic stresses in Eucalyptus. This study provides important practical guidance for insect-resistant Eucalyptus breeding and implementing integrated pest management strategies. Full article

Insect cuticles exhibit remarkable resistance to environmental stresses, largely attributed to cuticular proteins (CPs), which are crucial for insect development and adaptation. CPs also contribute to insecticide resistance, making them a key focus in molecular entomology. Apolygus lucorum, a globally distributed omnivorous pest within the Miridae family (Hemiptera: Heteroptera), inflicts significant economic losses by damaging a wide range of crops. However, information on CPs in the Miridae family remains scarce, limiting our understanding of their molecular mechanisms of adaptation and resistance. Here, we performed a genome-wide identification of CPs in A. lucorum and reanalyzed transcriptomic data under insecticide exposure to identify resistance-related candidates. A total of 211 CPs were identified and classified into 10 subfamilies. Notably, the RR-2, Tweedle, and CPF families showed significant expansions compared to other hemipterans, likely driven by tandem duplication events, which may contribute to A. lucorum’s broad environmental adaptability and host range. Expression profiling revealed two major patterns: one with peak expression during the nymphal stage and another maintained throughout the entire life cycle. Crucially, 75 CPs were upregulated following insecticide treatment, underscoring their potential role in resistance and their value as targets for pest control. Our findings provide a comprehensive foundation for future studies on the molecular functions of CPs in A. lucorum and their involvement in insecticide resistance, paving the way for novel management strategies. Full article

The management of Culex pipiens (Diptera: Culicidae), key vectors of arboviruses like West Nile virus, necessitates sustainable alternatives to chemical insecticides. This study screened indigenous entomopathogenic fungi (EPF) from forest soils in Achaia, Greece, for their larvicidal efficacy against Cx. pipiens biotype molestus. Fifteen fungal isolates were obtained via insect baiting and identified as Beauveria and Metarhizium species. A comprehensive bioassay at 1 × 10⁸ conidia mL⁻¹ revealed significant variation in pathogenicity after 72 h. Two isolates, Beauveria bassiana (BB) (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae (K3(1)) (Hypocreales: Clavicipitaceae), exhibited the highest virulence among the tested isolates, each causing 60% mortality with a rapid median lethal time (LT₅₀) of ~18.5 h. Survival analysis, Cox modeling, and non-linear kinetic modeling (Gompertz/Richards) classified three distinct virulence clusters: high/rapid, moderate/consistent, and low/delayed. A pathogenicity network analysis and a composite virulence index further validated BB and K3(1) as the most effective candidates. These results demonstrate the high isolate specificity of fungal efficacy and underscore the importance of screening local fungal diversity. The identified high-virulence isolates represent promising, environmentally sound candidates for the development of targeted biopesticides. Future research should focus on formulation for aquatic environments and integration into resistance-resilient integrated vector management programs. Full article

The diamondback moth (Plutella xylostella) severely threatens global oilseed rape (Brassica napus L.) production. This study demonstrates that CRISPR/Cas9-mediated knockout of two homologous BnaFAH, involved in tyrosine degradation, confers enhanced Brassica napus resistance to Plutella xylostella under a 2-day short-day (SD2) photoperiod. Multi-omics analyses revealed that this resistance is associated with a coordinated response: BnaFAH deficiency triggers reactive oxygen species (ROS) accumulation, which is closely associated with activating the jasmonic acid (JA) biosynthetic and signaling pathways. This led to significant upregulation of key JA biosynthetic genes and accumulation of JA, its precursors (OPDA, OPC-4, and OPC-6), and bioactive conjugates (JA-Ile and JA-Phe). Pharmacological analyses support the central role of JA, as exogenous application of methyl jasmonate (MeJA) enhanced insect resistance, whereas the JA biosynthesis inhibitor DIECA suppressed resistance. Scavenging ROS with sodium selenite prevented both JA pathway upregulation and insect resistance, suggesting that ROS may act upstream to activate the JA biosynthetic and signaling pathways. These findings support a previously unrecognized “photoperiod-dependent ROS-JA” defense module, revealing how metabolic perturbation under specific environmental cues can be co-opted to enhance plant immunity, offering new targets for breeding resistant rapeseed varieties. Full article

Cyantraniliprole, a second-generation diamide insecticide, exhibits broad-spectrum efficacy against numerous insect pests due to its selective activation of insect ryanodine receptors (RyRs). This activation triggers uncontrolled calcium release from the sarcoplasmic reticulum, resulting in sustained muscle contraction, paralysis, and ultimately death. Its unique mode of action, which is different from that of organophosphates, carbamates, pyrethroids, and neonicotinoids, helps minimize cross-resistance, making it a valuable component of integrated pest management (IPM). However, continuous field use has led to the development of resistance, primarily mediated by target-site mutations within the RyR transmembrane domain (e.g., G4946E, I4743M, and I4790K) and by enhanced metabolic detoxification via cytochrome P450 monooxygenases, carboxylesterases, and glutathione S-transferases. These mechanisms often confer cross-resistance to other diamide insecticides, thereby complicating resistance management. Moreover, sublethal exposures can disrupt insect growth, development, and reproduction, potentially accelerating resistance evolution. In addition, cyantraniliprole poses ecological risks due to its toxicity to non-target organisms such as aquatic species, including zebrafish and water fleas, pollinators such as honeybees, and soil fauna, as well as the environmental persistence of its major metabolite, J9Z38. This review comprehensively integrated current knowledge on the molecular mechanisms of action, genetic and metabolic bases of resistance, sublethal effects, and ecotoxicological impacts of cyantraniliprole, along with its environmental fate, plant uptake and translocation, and residue dynamics in agricultural systems. Finally, we discuss potential risk-mitigation strategies, including formulation optimization, application-method improvements, and resistance monitoring. Overall, this review aims to provide a comprehensive scientific foundation for the sustainable use, resistance management, and regulatory assessment of this widely used insecticide. Full article

Dillapiol is a naturally occurring methylenedioxyphenyl compound with insecticide-synergizing activity comparable to piperonyl butoxide (PBO). This study identified structurally related molecules with practical potential for managing insecticide-resistant insects. Six new dillapiol analogs, containing ester- or ether-linked side chains, were synthesized and evaluated as pyrethrum synergists against the Colorado potato beetle (CPB) Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). Their activity was assessed through bioassays and by quantifying inhibition of Phase I and II detoxification enzymes in vitro and in vivo. All six compounds displayed higher synergistic activity by ingestion than by topical exposure, and each structural class included at least one compound with a synergism ratio greater than 20. In the resistant CPB strain (RS-CPB), two ester compounds inhibited P450 monooxygenase activity in vitro as effectively as PBO, while dillapiol and one ether analog reduced P450 activity in vivo. Notably, all six analogs reduced glutathione S-transferase (GST) activity; the most active was an ether analog with an in vitro IC₅₀ of 0.23 (±0.04) mM. Dillapiol also significantly reduced GST activity in vivo. These analogs demonstrated PBO-equivalent P450 inhibition combined with unique GST inhibition and show promise as alternative synergists for managing insecticide-resistant insects. Full article

The artificially modified Bacillus thuringiensis (Bt) protein can target lepidopteran pests, and planting genetically modified crops with insect-resistant traits is environmentally friendly. However, it is still uncertain whether the exogenous insect-resistant proteins in genetically modified crops will affect the soil rhizosphere microorganisms. This study utilized 16S rDNA sequencing technology to analyze the rhizosphere soil of insect-resistant genetically modified corn LD05 and its control variety Zheng58 at five developmental stages: before sowing, seedling stage, jointing stage, silk emergence stage, and maturity stage. Each sample was taken with six biological replicates, resulting in a total of 60 sequencing samples, with an average of 4368 OTUs obtained per sample. Both alpha and beta analyses showed that LD05 and Zheng58 did not have a significant impact on the soil rhizosphere microbial community. The developmental stage rather than the variety was the main factor causing differences in the bacterial community. Overall, there was no significant difference in the bacterial diversity between the insect-resistant genetically modified corn LD05 and its control variety Zheng58. The results provide useful information for understanding the impact of genetically modified crops on soil microbial communities and also provide a theoretical basis for the safety evaluation of LD05. Full article

Sesame is an oilseed crop threatened by a phyllody disease associated with the presence of phytoplasmas, which can reduce yields by up to 80%. The molecular identification of these bacteria in crops located in Western Iran was achieved from samples showing symptoms of diverse intensity and types. For biological characterization, the pathogen was also dodder-transmitted to periwinkle plants. After nucleic acid extraction and nested PCR using phytoplasma-specific primer pairs amplifying part of the 16S rRNA gene, it was possible to amplify DNA fragments from both symptomatic sesame samples and dodder-inoculated periwinkle plants. The virtual RFLP pattern from the 16S rRNA gene sequences using iPhyClassifier indicated the presence of phytoplasma strains in 16SrII-D and 16SrIX-C subgroups. The identity percentage values of the obtained amplified sequences corroborated by the phylogenetic analysis identified them as ‘Candidatus Phytoplasma australasiaticum’ and ‘Ca. P. phoenicium’, respectively. The two phytoplasma strains were detected in different sesame samples collected in the same field. The coexistence of two phytoplasmas may influence the observed differences in disease severity and suggests appropriate management strategies, since diverse insect vectors were reported alongside diverse phytoplasmas associated with this disease. Moreover, the widespread disease presence strongly suggests the breeding of resistant varieties. Full article

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), poses a significant threat to global tomato production. However, environmentally sustainable management strategies for this pest, as well as its mechanisms of insecticide resistance, remain insufficiently understood. Broflanilide, a novel meta-diamide compound, can bind specifically to the transmembrane domain of the RDL subunit, causing prolonged opening of the chloride channel, disruption of neurotransmission, and ultimately insect paralysis and death. This study employed the leaf immersion method to conduct bioassays on the second-instar larvae of T. absoluta to evaluate physiological responses to sublethal concentrations of the novel amide insecticide broflanilide. Subsequently, high-throughput transcriptome sequencing was performed to investigate changes in gene expression and metabolic pathways. Bioassay results determined the larval sublethal concentrations of broflanilide to be 0.136 mg/L (LC₁₀) and 0.210 mg/L (LC₃₀). Sublethal exposure significantly prolonged the larval period, reduced pupal weight, and inhibited fecundity of female adults. Transcriptomic and qPCR analyses revealed that, compared with the control (CK), expression of the vitellogenin gene Vg decreased by 15.99% and 30.27% under LC₁₀ and LC₃₀ treatments, respectively, while its receptor gene VgR decreased by 11.56% and 24.49%. Similarly, expression of chitin synthase genes chs1 and chs2 declined by 13.56% and 30.17% (chs1), and 7.85% and 19.45% (chs2), respectively. Gene expression analysis elucidated how sublethal insecticides treatment impact larval development and fecundity. Furthermore, the study revealed upregulation of cytochrome P450-mediated detoxification pathways and Toll/Imd immune signaling pathways under broflanilide stress, indicating activation of a coordinated defense response in T. absoluta. Sublethal broflanilide exposure modulated larval gene expression to balance growth, development, and stress adaptation. Such exposure exerts selective pressure on susceptible populations, potentially driving adaptive shifts in detoxification metabolism and contributing to the development of field resistance. These findings advance our understanding of the sublethal effects of novel insecticides and provide valuable insights for insecticide deployment strategies and resistance management. Full article

Dendroctonus armandi is a major primary pest of Chinese white pine in the Qinling–Bashan forest region. By feeding on the phloem and vectoring symbiotic fungi that cause blue stain in the sapwood, it drives rapid decline and mortality of host trees. As a key wood-boring forest insect, its outbreaks are closely linked to adaptive strategies in energy metabolism. Adipokinetic hormone (AKH) is a highly conserved insect neuropeptide and plays a major role in regulating energy metabolism. This study aimed to determine how the AKH gene regulates energy use in D. armandi under different stress conditions. We cloned the DaAKH gene and its receptor gene, DaAKHR, from D. armandi. DaAKH and DaAKHR showed the highest expression in emerged adults and the lowest levels in pupae. In larvae and in adult males and females, DaAKH transcripts were predominantly expressed in the head, whereas DaAKHR was enriched in the fat body. Under starvation and cold stress, DaAKH and DaAKHR expression were significantly upregulated; under heat stress, expression first increased and then decreased. Across stress treatments, RNAi significantly downregulated DaAKH and DaAKHR expression in D. armandi. Under starvation, RNAi reduced mortality, lowered lipid metabolism, and led to lipid accumulation, thereby mitigating premature energy depletion and starvation-induced death. By contrast, under heat and cold stress, RNAi significantly increased mortality, significantly reduced triglyceride and glycogen consumption, and suppressed metabolism. These results indicate that DaAKH and DaAKHR regulate energy allocation under starvation stress and help maintain adaptive capacity under temperature stress in D. armandi. By tuning energy metabolism, DaAKH and DaAKHR help resist environmental stress and maintain reproduction and population size. This study advances understanding of the physiological responses and molecular mechanisms of D. armandi under stress conditions and provides a new avenue for metabolism-targeted control. Full article

Cuticular proteins (CPs)—key components of the insect exoskeleton—not only regulate development but also serve as structural barriers that enhance resistance against environmental stressors. This study identified CP gene families in Apis mellifera and analyzed their expression patterns during the worker capped brood development stages from mature larva to pre-eclosion. Using a comprehensive genome-wide bioinformatic approach, we identified 85 CP genes in A. mellifera which comprise six families: CPR (n = 43), CPAPs (n = 27), CPF (n = 2), Tweedle (n = 2), CPLCP (n = 8) and Apidermin (n = 3). Analysis of CP gene evolutionary relationship revealed that each CP family forms a distinct, relatively independent clade. Domain and motif analyses confirmed that all CPR members harbor a conserved Chitin_Bind_4 domain, consistent with CPR family structures in other taxa. Additionally, CPAP members possess one or three Chitin-binding Peritrophin-A domain (CBM_14), CPF members possess a conserved Pupal cuticle protein C1 domain (Cuticle_3), and Tweedle members contain a conserved domain of unknown function (DUF243). In addition, the analysis found no conserved domain within the CPLCP and Apidermin families. RNA-seq data revealed dynamic expression patterns of AmCPs during pupal development, with each gene family displaying a relatively characteristic temporal profile. Quantitative PCR validation of eight highly expressed CPR genes at 9 days post-capping confirmed the RNA-seq results. This work provides a comprehensive bioinformatic characterization and transcriptional analysis of CP genes in A. mellifera, offering a foundation for future functional studies on cuticle formation and identifying candidate genes potentially involved in cuticle development in honeybees. This work relies on transcriptomic data and in silico analyses. All proposed biological roles are hypothetical and require experimental validation. Full article

Forest pests and diseases are some of the major disturbances affecting the stability of forest ecosystems. Accurate identification of insect-infested trees is therefore crucial for assessing forest health and implementing precision forestry management. This study focuses on stand-level detection of cypress trees (Cupressus funebris Endl.) that were affected by the cypress bark beetle (Phloeosinus aubei Perris), and the framework enables individual tree segmentation, insect-infested tree detection, and stand infestation assessment. Firstly, individual trees were extracted from Light Detection and Ranging (LiDAR) point cloud data using the layer-stacking seed point algorithm. Based on the segmented tree crowns, four vegetation indices (Visible Atmospherically Resistant Index (VARI), Visible-band Difference Vegetation Index (VDVI), Red-Green Index (RGI), and Color Index of Vegetation Extraction (CIVE)) were calculated from Unmanned Aerial Vehicle (UAV) RGB imagery. Insect-infested cypress trees were extracted through threshold segmentation. Through visual interpretation, the optimal vegetation index was determined and the infestation rate at the stand level was calculated. Based on the above framework, a total of 1368 trees were identified in the cypress stand, with a segmentation Precision of 82.51%, a Recall of 80.00%, and an F1-score of 81.24%. RGI achieved the best performance (Precision = 100.00%, Recall = 86.96%, F1-score = 93.02%) and identified 20 infested trees, accounting for 1.46% of the cypress stand. Supplementary experiments further confirm the superiority of the RGI index and the μ ± 2σ thresholding method. These results demonstrate that the proposed method enables rapid detection of the infested cypress trees, effective monitoring of stand health and infestation severity, thereby supporting informed decision-making in pest control and forest management. Full article

The white-backed planthopper, Sogatella furcifera, and the brown planthopper, Nilaparvata lugens, severely impact rice production, necessitating effective selection methods for resistant cultivars. S. furcifera poses a significant threat to rice cultivation, particularly in Asia. Through this study, we aimed to establish an effective approach to identifying resistant rice varieties based on feeding behavior, physiological and chemical responses, and genetic analysis. Three key activities were involved: (1) evaluation of planthopper feeding behavior utilizing the honeydew drop method, the electrical penetration graph technique, and growth rate analysis; (2) investigation into the physiological and chemical traits of rice; and (3) analysis of resistance-related gene expression. The results indicated larger honeydew drop areas, fewer and shorter probing events, and structural defenses such as increased trichome density in resistant rice genotypes, likely hindering insect attachment and feeding. We confirmed the suitability of the growth rate method for resistance screening. Gene expression analysis identified PR10a upregulation in resistant rice, suggesting a molecular basis for resistance. This study enables the selection of rice varieties resistant to planthoppers, supporting sustainable pest management and breeding programs. The findings support sustainable pest management by enabling the targeted selection of resistant varieties, ultimately aiding in the development of rice genotypes with enhanced resistance across growth stages. Full article

Sugarcane (Saccharum spp.) is a globally vital sugar crop, yet its productivity faces severe challenges from infestation by Chilo sacchariphagus. To decipher the plant’s molecular and metabolic defense mechanisms, this study applied an integrated transcriptomic and metabolomic analysis to three field-grown sugarcane cultivars (Zhongtang 4, 5, and 6) under natural borer stress. The transcriptomic analysis identified a total of 34,004 differentially expressed genes (DEGs), of which 18,674 were up-regulated, and 15,330 were down-regulated. The three cultivars exhibited distinct transcriptional regulatory patterns: Z4 and Z5 showed a global suppression-type response and a strong activation-type response, respectively, and Z6 presented a balanced-type response. A functional enrichment analysis revealed that the DEGs were significantly involved in metabolic processes, stress response, plant hormone signal transduction, phenylpropanoid biosynthesis, and plant-pathogen interaction pathways. Metabolomic analysis detected 963 differentially accumulated metabolites (DAMs), primarily including flavonoids, phenolic acids, amino acids and their derivatives, and lipids. These metabolites were significantly enriched in pathways such as amino acid metabolism, biosynthesis of secondary metabolites, and glutathione metabolism. Integrated multi-omics analysis further revealed strong synergistic regulatory relationships between gene expression and metabolite accumulation, particularly in defense-related secondary metabolic pathways, such as phenylpropanoid and flavonoid biosynthesis. Several key regulatory hubs were identified, including novel transcripts and D-xylulose-5-phosphate. Sugarcane employs a genetic background-dependent, multi-layered transcriptional reprogramming and metabolic restructuring to cope with borer stress. Cultivars Z4 and Z6 tend to activate and accumulate defensive compounds, while Z5 exhibits a different pattern of metabolic resource allocation. This research provides a systematic elucidation of the molecular mechanisms underlying insect resistance in sugarcane and offers important candidate genes and metabolites for breeding resistant varieties. Full article