Search Results (345)

Bt Cry toxins remain the cornerstone of transgenic crop protection against Lepidopteran pests, yet field-evolved resistance, particularly in invasive species such as Spodoptera frugiperda and Helicoverpa armigera, can threaten their long-term efficacy. This review presents a comprehensive and unified mechanistic framework that synthesizes current understanding of Bt Cry toxin modes of action and the complex, multilayered regulatory mechanisms of field-evolved resistance. Beyond the classical pore-formation model, emerging evidence highlights signal transduction cascades, immune evasion via suppression of Toll/IMD pathways, and tripartite toxin–host–microbiota interactions that can dynamically modulate protoxin activation and receptor accessibility. Resistance arises from target-site alterations (e.g., ABCC2/ABCC3, Cadherin mutations), altered midgut protease profiles, enhanced immune regeneration, and microbiota-mediated detoxification, orchestrated by transcription factor networks (GATA, FoxA, FTZ-F1), constitutive MAPK hyperactivation (especially MAP4K4-driven cascades), along with preliminary emerging findings on non-coding RNA involvement. Countermeasures now integrate synergistic Cry/Vip pyramiding, CRISPR/Cas9-validated receptor knockouts revealing functional redundancy, Domain III chimerization (e.g., Cry1A.105), phage-assisted continuous evolution (PACE), and the emerging application of AlphaFold3 for structure-guided rational redesign of resistance-breaking variants. Future sustainability hinges on system-level integration of single-cell transcriptomics, midgut-specific CRISPR screens, microbiome engineering, and AI-accelerated protein design to preempt resistance trajectories and secure Bt biotechnology within integrated resistance and pest management frameworks. Full article

The western corn rootworm (WCR) and northern corn rootworm (NCR) are the two major belowground insect pests of corn in the U.S. Corn Belt. These species coexist in the same habitat, where their larvae feed on corn roots, increasing the risk of lodging and yield loss. Understanding larval competition between WCR and NCR is crucial for effective insect resistance management and integrated pest management. To assess interspecific larval competition between WCR and NCR, two independent greenhouse trials were conducted. We infested non-Bt corn plants with varying egg ratios of diapause and non-diapause populations of both species and counted the number of adults of each species recovered from each plant. Results showed that WCR consistently exhibited higher emergence rates than NCR, regardless of the initial egg infestation ratio. The observed ratio of NCR to WCR in both diapause and non-diapause groups was significantly lower than expected, suggesting that WCR is more competitive than NCR. The competitive dominance of WCR, coupled with climate warming, may facilitate its northward expansion across the U.S. This could potentially affect local NCR populations and further spread Bt and rotation resistance. Such changes could exacerbate pest management challenges in corn production systems. Integrating knowledge of corn rootworm competition, biology, resistance development, and climate change will be critical for developing informed management strategies to mitigate corn rootworm damage in agroecosystems effectively. Full article

Soybean, Glycine max (L.) Merrill, is usually grown on a large scale, with pest control based on chemical insecticides. However, the overuse of chemicals has led to several adverse effects requiring more sustainable approaches to pest control. Results from Integrated Pest Management (IPM) employed on Brazilian soybean farms indicate that adopters of the technology have reduced insecticide use by approximately 50% relative to non-adopters, with yields comparable to or slightly higher than those of non-adopters. This reduction can be explained not only by the widespread use of Bt soybean cultivars across the country but also by the adoption of economic thresholds (ETs) in a whole Soybean-IPM package, which has reduced insecticide use. However, low refuge compliance has led to the first cases of pest resistance to Cry1Ac, thereby leading to the return of overreliance on chemical control and posing additional challenges for IPM practitioners. The recent global agenda for decarbonized agriculture might help to support the adoption of IPM since less chemical insecticides sprayed over the crops reduces CO₂-equivalent emissions from its application. In addition, consumers’ demand for less pesticide use in food production has favored the increased use of bio-inputs in agriculture, helping mitigate overdependence of agriculture on chemical inputs to preserve yields. Despite the challenges of adopting IPM discussed in this review, the best way to protect soybean yield and preserve the environment remains as IPM, integrating plant resistance (including Bt cultivars), ETs, scouting procedures, selective insecticides, biological control, and other sustainable tools, which help sustain environmental quality in an ecological and economical manner. Soon, those tools will include RNAi, CRISPR-based control strategies, among other sustainable alternatives intensively researched around the world. Full article

Plant nutrient content is spatially and temporally dynamic, exposing insect herbivores to substantial nutritional variability. Such variability can constrain insects to feeding on sub-optimal diets, but it can also allow them to regulate their intake towards an optimal nutrient balance. Nutrient regulation is important in pest management, as the nutritional state of insects may alter their susceptibility to insecticides. Diet macronutrient balance has been shown to significantly affect the susceptibility of Helicoverpa zea larvae to endotoxins produced by transgenic crops containing Bacillus thurigiensis (Bt) genes. However, this was demonstrated using a highly inbred laboratory strain, limiting extrapolation to field populations. Here, we test the impact of field-relevant macronutrient variability on the efficacy of two Bt toxins across three field populations to increase the relevance to resistance monitoring and management. While differences in susceptibility were limited across populations, dietary effects were highly population specific. The Bt toxin that was most affected by diet and the diet that supported optimal survival and performance varied across populations. These findings indicate that nutrition can strongly influence Bt susceptibility, but these effects are influenced by population-level differences. To accurately assess Bt susceptibility in the field, bioassay diets should be tailored to the nutritional ecology of local populations. Full article

The widespread cultivation of transgenic Bt cotton has elevated Apolygus lucorum (Meyer-Dür) to a major pest in cotton agroecosystems. Its rapidly developing resistance to insecticides poses a serious challenge to sustainable agriculture. In this study, we assessed the susceptibility of a field-collected population from Anyang, Henan Province, in relation to a laboratory-susceptible strain, to elucidate the present status and molecular basis of resistance to beta-cypermethrin. First, the toxicity of beta-cypermethrin to A. lucorum was assessed through a diet-incorporation method. Subsequently, the enzymatic activities of carboxylesterase (CarE) and glutathione S-transferase (GST) were measured, and the expression levels of CarE1 and GST1 were quantified by quantitative real-time PCR (qRT-PCR). Finally, the function of candidate genes was confirmed using RNA interference (RNAi) technology. The bioassays results indicated that the median lethal concentration (LC₅₀) for the laboratory and Anyang field strain were 343.34 mg/L and 700.45 mg/L, respectively. Following 48 h of exposure to the LC₃₀ of the susceptible strain, the mortality rate of the field population (20.00%) was significantly lower than that of the laboratory population (33.33%), suggesting an increase in resistance. The field population of A. lucorum exhibited significantly higher activities of CarE (1.61-fold) and GST (1.71-fold) compared to the laboratory strain, accompanied by 3.63- and 4.23-fold overexpression of the corresponding genes CarE1 and GST1. Spatiotemporal expression profiling revealed that CarE1 expression was highest in 4th–5th instar nymphs and adults, with predominant localization in the midgut, while GST1 expression peaked in 4th–5th instar nymphs and was abundant in the midgut and fat body. RNAi-mediated knockdown of CarE1 and GST1 significantly enhanced susceptibility to beta-cypermethrin in field populations, resulting in elevated mortality 48 h post-treatment compared to controls. In conclusion, the field population of A. lucorum has developed considerable resistance to beta-cypermethrin, strongly correlated with overexpression of CarE1 and GST1. These results deepen our understanding of metabolic resistance mechanisms and offer valuable insights for developing targeted pest control strategies. Full article

The global population growth has driven the widespread adoption of genetically modified crops, with Bt maize, due to its insect resistance, becoming the second most widely planted GM crop. However, studies on the effects of continuous Bt maize cultivation on soil ecosystems are limited, and there is an urgent need to assess its ecological safety at the regional scale. To evaluate the potential effects of continuous cultivation of transgenic Bt maize on the soil ecosystem, a five-season continuous planting experiment was conducted using two Bt maize varieties (5422Bt1 and 5422CBCL) and their near-isogenic conventional maize (5422). After five consecutive planting seasons, bulk soil and rhizosphere soil were collected. The main nutrient contents of the bulk soil were measured, and high-throughput sequencing was employed to analyze microbial diversity and community composition in both soil types. The results showed that, compared with the near-isogenic conventional maize 5422, continuous planting of Bt maize varieties 5422Bt1 and 5422CBCL did not affect the contents of organic matter, total nitrogen, total phosphorus, total potassium, alkaline hydrolyzable nitrogen, available phosphorus, or available potassium in bulk soil. Regarding the microbial communities in bulk soil, there were no significant differences in the α-diversity indices of bacteria and fungi after five consecutive seasons of Bt maize cultivation, compared with soils planted with the near-isogenic conventional maize 5422. Proteobacteria and Ascomycota were the dominant phyla of bacteria and fungi, respectively. Principal coordinate analysis (PCoA) and redundancy analysis (RDA) revealed that the structure of microbial communities in bulk soil was primarily influenced by factors such as OM, TP, TN and AN, whereas the Bt maize varieties had no significant effect on the overall community structure. Regarding the rhizosphere soil microbial communities, compared with the near-isogenic conventional maize 5422, the evenness of the bacterial community in the rhizosphere soil of Bt maize decreased, leading to a reduction in overall diversity, whereas species richness showed no significant change. This change in diversity patterns further contributed to the restructuring of the rhizosphere soil microbial community. In contrast, the fungal community showed no significant differences among treatments, and its community structure remained relatively stable. Proteobacteria and Ascomycota were the dominant phyla of bacteria and fungi, respectively. Principal coordinate analysis (PCoA) indicated that continuous cultivation of Bt maize for five seasons had no significant effect on the structure of either bacterial or fungal communities in the rhizosphere soil. In summary, continuous cultivation of Bt maize did not lead to significant changes in soil nutrient contents or microbial community structures, providing a data foundation and theoretical basis for the scientific evaluation of the environmental safety of transgenic maize in agricultural ecosystems. Full article

Background: Periprosthetic joint infections (PJIs) of the hip and knee are one of the most severe complications in arthroplasty, often requiring prolonged antibiotic therapy and multiple revision surgeries. The increasing prevalence of multidrug-resistant organisms and biofilm-associated PJIs has renewed interest in bacteriophage therapy as a targeted, adjunctive treatment option in refractory cases. This investigation systematically reviews and discusses the current evidence regarding the application, outcomes, and safety profile of bacteriophage therapy in the management of PJIs. Methods: This systematic review was conducted in accordance with the 2020 PRISMA statement. PubMed, Google Scholar, EMBASE, and Web of Science were accessed in August 2025. No time constraints were used for the search. All clinical studies investigating bacteriophage therapy for bacterial PJIs were considered for eligibility. Results: A total of 18 clinical studies, comprising 53 patients treated with bacteriophage therapy for PJI, were included. The mean follow-up was approximately 13.6 months. Staphylococcus aureus was the most frequent pathogen (18 cases); phage cocktails were used in 33 patients and monophage preparations in 9, all combined with suppressive antibiotic therapy. Persistent or resistant joint pain was reported in only two patients (3.8%), while signs of ongoing infection despite phage therapy were observed in four patients (7.5%). Adverse events following BT were inconsistently reported. Conclusions: Bacteriophage therapy shows promise as an adjunctive treatment for hip and knee PJIs, especially in refractory or multidrug-resistant cases. Current evidence is limited and methodologically weak, underscoring the need for well-designed clinical trials to clarify efficacy, safety, and optimal integration into existing orthopaedic infection protocols. Full article

This study systematically evaluated insect resistance in transgenic poplar lines carrying three distinct Bacillus thuringiensis (Bt) gene vector architectures: a single-gene pb vector (Cry1Ac), a reverse-oriented double-gene n19 vector (Cry1Ac-Cry3A), and a forward-oriented double-gene n5 vector (Cry3A-Cry1Ac). The transgenic lines were accordingly designated as pb8/pb9, n19a/n19b, and DB7/DB16, respectively. Molecular analyses confirmed stable Bt gene integration, with the expression of Cry3A being consistently higher than that of Cry1Ac expression. Bioassays showed that dual-gene lines conferred broader insect resistance to pests than that of single-gene lines against both lepidopteran (Hyphantria cunea) and coleopteran (Plagiodera versicolora, Anoplophora glabripennis) pests. In contrast, the single-gene line pb9 exhibited specialized, high efficacy against H. cunea, achieving 100% mortality. Transcriptomic analysis of P. versicolora larvae fed the double-gene high-resistance n19a line and low-resistance DB16 line revealed multi-level molecular responses to Bt stress, including up-regulation of toxin-activating proteases, altered receptor expression, and suppression of growth-related genes. These changes were associated with significant developmental delay (8.33–20.83% reduction in the molting index). Our findings characterize the insect resistance and molecular profiles of the six transgenic poplar lines, as follows: multi-gene lines (n19a/n19b and DB7/DB16) confer broad-spectrum pest resistance, whereas single-gene lines (pb8/pb9) exhibit targeted efficacy. These results support the utility of these lines for pest-specific poplar breeding programs. Full article

Triple Negative Breast Cancers (TNBCs) are heterogeneous and aggressive tumors with a median overall survival of less than two years. Despite the availability of new drugs, the prognosis remains poor, implicating a more aggressive clinical course in the metastatic setting. This study investigated the effects of metronomic treatment (mCHT) with 5-fluorouracil (5-FU) plus vinorelbine (VNR) on spheroids derived from two different TNBC cell lines (BT-549 and MDA-MB-231) and a patient-derived primary cell line (MS-186). mCHT significantly reduced spheroid growth and altered spheroid architecture, with a pronounced effect in second-generation spheroids, enriched in self-renewing cancer stem cells (CSCs). Expression of CSC-related markers (CD44, CD133, NOTCH-1, and MYC) was more significantly altered—both at the mRNA and protein levels—by mCHT than by standard treatment (STD). In MS-186-derived spheroids, mCHT downregulated EZH2 and STAT3, key regulators of CSC maintenance, and reduced H3K27ac, suggesting a global epigenetic reprogramming. Unlike STD, which partially and transiently reduced stemness markers, mCHT achieved sustained suppression, indicating preferential targeting of therapy-resistant CSCs. These results indicate mCHT as a promising strategy for specifically aiming at the CSC-like compartment in TNBC, underscoring a therapeutic approach that reprograms key epigenetic networks and overcomes resistance to treatment. Full article

Objective: Identifying biomarkers that predict metastatic potential or guide treatment selection is critical for improving breast cancer (BC) management. Previously, we established the Mitotic Network Activity Index (MNAI) as a prognostic marker in BC. Here, we bioinformatically and experimentally evaluated MNAI as a biomarker for metastasis risk and therapeutic response. Methods: We used Kaplan–Meier and Cox proportional hazard regression analyses to assess the association between MNAI and distant metastasis-free survival (DMFS) across 14 published BC datasets. A total of 16 publicly available clinical trial datasets, including the I-SPY trials, were used to evaluate the predictive value of MNAI for treatment response. Additionally, wound-healing and transmembrane assays were conducted to determine the effects of PLK1, CHEK1, and BUB1 inhibition on BC cell migration and invasion. Results: High MNAI levels were strongly associated with shorter DMFS. Multivariate analysis further confirmed MNAI as an independent risk factor for DMFS, beyond estrogen receptor status and PAM50-based molecular subtypes. Functionally, pharmacologic disruption of the mitotic network using PLK1, CHEK1, or BUB1 inhibitors significantly reduced cell migration and invasion in MDA-MB-231 and BT-549 BC cell lines. Moreover, BC cells with high MNAI increased sensitivity to microtubule-targeting agents such as docetaxel, paclitaxel, and ixabepilone but increased resistance to tamoxifen, AKT1/2 inhibitors, and mTOR inhibitors. Consistent with these findings, analysis of 16 clinical trial cohorts revealed that patients with high MNAI achieved higher pathological complete response rates to taxane-containing and ixabepilone-based therapies. Conclusions: Our findings demonstrate the MNAI as a clinically actionable biomarker that can refine risk stratification and guide the selection of targeted or chemotherapy regimens, advancing precision medicine in BC management. Full article

Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by a lack of targetable receptors, leading to limited treatment options and a critical need for novel therapeutic strategies. This study aimed to evaluate the potential of azelastine, a clinically approved H1-antihistamine, for drug repositioning against TNBC and to elucidate its underlying HRH1-independent mechanism of action. Cell viability assays (CCK-8) were performed on TNBC cell lines (MDA-MB-231 and BT-549) following treatment with azelastine and its major metabolite, desmethyl azelastine. After observing ambiguous clinical associations between HRH1 expression and patient prognosis, HRH1 dependency was assessed through histamine stimulation and HRH1 knockdown (siRNA). Subsequently, the role of ADP-ribosylation factor 1 (ARF1), found to be overexpressed in TNBC and linked to poor prognosis, was investigated using ARF1 knockdown (siRNA), co-treatment with the Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1 (GBF1) inhibitor golgicide A (GCA), and co-treatment with the Drp1 inhibitor M-divi 1. Azelastine and desmethyl azelastine potently reduced MDA-MB-231 cell viability in a dose- and time-dependent manner, achieving cell survivals of 61.3 ± 6.1% (30 µM) and 34.9 ± 3.7% (50 µM) for azelastine, and 52.4 ± 12.5% (30 µM) for desmethyl azelastine, respectively, after 72 h, with an IC₅₀ of 35.93 µM determined for azelastine in MDA-MB-231 cells. Additionally, azelastine significantly reduced the viability of BT-549 cells. Bioinformatic analysis of clinical datasets revealed HRH1 downregulation in tumors and, functionally, neither histamine stimulation nor HRH1 knockdown mediated azelastine cytotoxicity in cell culture. Importantly, ARF1 expression was significantly upregulated in TNBC and associated with poor prognosis. Co-treatment with GCA, preventing ARF1 activation, restored viability to near-control levels, supporting dependence on the GBF1–ARF1 activation axis of azelastine, whereas the Dynamic-related protein 1 (Drp1) inhibitor M-divi 1 not only partially rescued CCK-8-based cell viability but also normalized azelastine-induced loss of MitoTracker™ Red CMXRos signal and partially preserved (4′,6-diamidino-2-phenylindole) DAPI-based cell density, indicating Drp1-dependent mitochondrial dysfunction. Furthermore, azelastine selectively reduced p-ERK phosphorylation in the cell signaling pathway. Azelastine exerts potent anticancer effects in TNBC cells via an HRH1-independent, ARF1-dependent mechanism that attenuates the Extracellular signal-regulated kinase (ERK)–Drp1 axis, and induces Drp1-dependent mitochondrial dysfunction, independent of its canonical HRH1 receptor function. This ARF1-dependent mechanism provides strong scientific rationale for the drug repositioning of azelastine as an effective therapeutic agent for ARF1-driven TNBC. Full article

The tensile strength of stabilized clayey soil is a key indicator of its resistance to cracking and directly governs its performance when used as subgrade fill. In this study, ordinary Portland cement and polyacrylate-based super-absorbent polymers (SAP) were combined to stabilize four typical high-water content clayey soils sourced from Northern Bavaria. The optimal SAP content was determined based on absorption capacity by the tea-bag method. Subsequently, the effects of cement content and curing period on the Brazilian tensile strength (BTS) of clayey soils were investigated, and the correlation between Brazilian tensile strength and unconfined compressive strength (UCS) was discussed. The results indicated the following: the optimal SAP content was 0.3%; the BTS increased significantly with higher cement content and a longer curing period; the failure modes of BTS specimens were revealed, including multiple non-through fracture, non-central fracture, and central fracture; a strong linear correlation was established between BTS and UCS, with the proportional coefficient ranging from 0.129 to 0.233. The findings of this study can provide a valuable reference for the design and application of cement-SAP stabilized soils in practical engineering. Full article

The attachment–invasion locus protein Ail of pathogenic Yersinia strains is an important virulence factor, both for invasion of eucaryotic cells and for serum resistance. In other Yersinia strains, e.g., those belonging to biotype (BT) 1A of Yersinia enterocolitica, ail has only occasionally been described. Sequence analysis of 370 BT 1A isolates in our laboratory revealed 41 (11.1%) which were ail-positive. Most of these isolates were recovered from minced meat and tonsils of wild boars, and belonged to 17 MLST allele profiles. A closer look at DNA sequences surrounding ail disclosed that the gene in most isolates is embedded in DNA regions encoding phage proteins. The genomes of four prophages belonging to four different phylogenetic clusters were determined and analyzed by in silico studies. These have sizes of 34.9 and 50.7 kb, and are closely related to each other but not to known phages. Unlike other regions of the prophages, the integrases and attachment sites of some of them diverge, leading to different integration sites in the isolates. In a fifth cluster, ail is relocated at a position on the Y. enterocolitica chromosome that is several hundred kilobases apart from those of the other clusters, but surrounded by prophage-related sequences. In addition, highly pathogenic 1B/O:8 strains contain a DNA segment which includes ail and is 65 to 94% identical to the prophage sequences determined in this study. Full article

Establishing refuges is a primary strategy for managing resistance in target pests against Bt maize. The larval feeding and dispersal, and adult oviposition behaviors of Spodoptera exigua (Hübner) on Bt and non-Bt maize plants are critical factors in determining optimal refuge configurations. This study employed laboratory and field experiments to evaluate the larval feeding and dispersal behaviors, as well as the oviposition preferences of S. exigua moths, on Bt (Cry1Ab + Vip3Aa19) and non-Bt maize plants. Results showed that as time of the choice test increased, the larval selection rate on Bt maize leaves declined progressively, with all instars (1st–5th) preferring to feed on non-Bt maize. After 48 h, the selection rates of larvae for non-Bt and Bt maize were 40.63–66.25% and 9.38–33.75%, respectively. Female moths exhibited no significant oviposition preference between Bt and non-Bt plants under undamaged conditions; however, when non-Bt maize was infested by the larvae, females preferentially oviposited on Bt maize plants (73.55%). Under the seed-mixture refuge pattern in field conditions, increasing the proportion of non-Bt maize significantly enhanced larval dispersal distances and facilitated larval transit damage between Bt and non-Bt plants. Our research clarifies the behavioral patterns of S. exigua on Bt and non-Bt maize, provides a scientific basis for optimizing refuge strategy to delay the development of resistance. Full article