A >8-year two-generation study on the long-term effects of genetically modified maize (Zea mays) containing cry1Ab/cry2Aj and EPSPS genes on cardiac function and arrhythmia risk of cynomolgus macaques.

Transgenic crops containing Bacillus thuringiensis (Bt) proteins are crucial for managing major agricultural pests such as the corn earworm, Helicoverpa zea (Boddie). The fitness of Bt resistant insects on refuge crops plays an important role in determining the rate of resistance development. Previous research has investigated the fitness costs of Cry1 and Cry2 resistance in H. zea, but limited information is available about the fitness costs associated with Vip3Aa resistance in this pest. Here, we evaluated fitness costs of Vip3Aa-resistant H. zea on three non-Bt hosts: meridic diet, corn ears, and cotton leaves. On meridic diet, we detected recessive fitness costs resulting in lower survival and fecundity, and dominant fitness costs resulting in longer developmental time and reduced egg hatching rates. On corn ears, we observed recessive fitness costs resulting in lower pupal mass, and dominant fitness costs resulting in lower survival and fecundity, longer developmental time, and reduced egg hatching rates. On cotton leaves, we found recessive fitness costs resulting in lower female pupal mass, and dominant fitness costs resulting in lower adult survival and fecundity, and longer developmental time. Significant differences in survivorship, developmental time, pupal mass, and reproduction among the Vip3A-resistant (RR), -susceptible (SS) and -heterozygous (R♂S♀ and R♀S♂) H. zea strains on the three hosts, revealed clear evidence of fitness costs associated with Vip3Aa resistance. These findings support the value of abundant non-Bt refuges in limiting the evolution of H. zea resistance to Vip3Aa in the field. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Transgenic crops producing insecticidal Bacillus thuringiensis (Bt) proteins have revolutionized the control of some pests. However, the evolution of resistance by pests has reduced the efficacy of Bt crops. Pest resistance to Bt crystalline (Cry) proteins has spurred a shift to crops that produce the Bt vegetative insecticidal protein Vip3Aa together with Cry proteins. With widespread field-evolved practical resistance of the major pest Helicoverpa zea (corn earworm or bollworm) to Cry proteins in the United States, Vip3Aa is the only Bt protein in transgenic corn and cotton that is highly effective against many populations. We generated five strains of H. zea with > 100-fold resistance to Vip3Aa in a susceptible genetic background using F2 screens of field populations from Louisiana, Mississippi, and Texas followed by crosses to a susceptible strain and additional laboratory selection with Vip3Aa. The results from diet bioassays show that in these Vip3Aa-resistant strains, cross-resistance to Cry1Ab, Cry1Ac, Cry1A.105, Cry1Fa, and Cry2Ab was not consistent and ranged 1100-fold: from 16-fold negative cross-resistance to 65-fold positive cross-resistance. By crossing a Vip3Aa-resistant strain with a Cry-resistant strain followed by selection with both types of Bt protein, we generated a strain highly resistant to Cry1Ac, Cry2Ab, and Vip3Aa. Cry1Ac and Cry2Ab interacted synergistically with Vip3Aa against this triple-resistant strain, such that combinations of the Cry proteins and Vip3Aa caused higher mortality than expected from their individual toxicity. The observed synergy may increase the durability of Bt crops producing combinations of these proteins against H. zea.

Comprehensive safety assessment of Bt toxins Cry1Ac or Cry2Ae on the non-target insect Hermetia illucens, a natural waste recycler.

Engineering Bacillus thuringiensis Cyt1Aa to function as a surrogate receptor of Cry1A lepidopteran insecticidal proteins.

Insect pest control in crop production incurs substantial economic costs annually on a global scale. Although broad-spectrum chemical pesticides were once considered the most effective solution, their overreliance has led to adverse effects on beneficial insects, human health, and the environment, as well as the development of pesticide-resistant insect populations. Consequently, there is an urgent need for alternative pest management strategies that minimize pesticide use and reduce unintended impacts on natural enemies, thereby maintaining ecological balance. Host plant resistance plays a pivotal role in integrated pest management (IPM). However, developing pest-resistant varieties through conventional breeding methods can be time-consuming and challenging due to the involvement of multiple quantitative traits controlled by various genetic loci. One promising biotechnological approach is the development of fusion proteins, engineered molecules that combine the functional properties of two or more distinct proteins. These fusion proteins effectively target specific insect pests while minimizing environmental impact. Importantly, they overcome key limitations of single-gene constructs, including narrow target range and rapid resistance development. Numerous fusion proteins have been successfully developed and deployed in various crop plants, demonstrating their versatility and broad-spectrum activity against major insect pests. This review discusses fusion protein technologies and their application in developing transgenic crops with enhanced resistance to insect pests.

Insecticidal toxins from Bacillus thuringiensis (Bt) have been extensively and successfully used in genetically engineered crops for decades but continue to face challenges from the adaptive resistance in the insect population. The Bt binary toxin Vip1Ad1(Vip1) and Vip2Ag1(Vip2), a promising next-generation candidate gene combination for transgenic crops, have demonstrated high efficacy against the destructive coleopteran pest white grubs, however, their mode of action remains largely elusive. In this study, we report cryo-EM structures of the heptameric Vip1-pore and Vip2-bound Vip1-pore complex, capturing a series of putative assembly-related intermediates that suggest a binary toxin assembly and translocation pathway. Together with structure-guided mutagenesis, these data provide insights into a sequential assembly of binary complex and a sequence-independent translocation mechanism. Proof-of-principle experiments showed successful delivery of a desired protein cargo into host cells based on the mini-Vip2-Vip1 pore system, paving the way for developing much needed extracellular pesticidal protein delivery platforms. These findings not only clarify the assembly and translocation mechanism of the binary insecticidal toxin pair but also offer an excellent alternative model to investigate human-pathogenic pore-forming toxins because of its similarity and biosafety.

Bacillus thuringiensis (Bt) protein released from transgenic crops and their subsequent complexation with heavy metals pose potential ecological risks that remain inadequately assessed. Understanding the interfacial behavior of these complexes is essential for predicting their mobility and bioavailability in soils. Thus, this study investigated the co-adsorption of Bt protein (Cry1Ac) with Zn2+ and Cd2+ onto soil minerals (SiO2 and Al2O3) using dissipative quartz crystal microbalance (QCM-D). Results showed that the adsorption capacity reached a maximum at pH 6. The increased ionic strength suppressed adsorption on the negatively charged SiO2 surface, but enhanced adsorption on the positively charged Al₂O₃ surface. Furthermore, the maximum equilibrium sorption capacity, determined from isotherm analysis, was significantly higher for the Cry1Ac-Zn2⁺ (2.957 × 10-3mg·cm⁻2) than for the Cry1Ac-Cd2⁺ complex (7.250 × 10-4mg·cm⁻2) the Al₂O₃ surface. However, the opposite trend was observed on the SiO2 surface. The analysis of the adsorption mechanism revealed that the primary driving force was electrostatic interaction between mineral surfaces and Cry1Ac-Cd2⁺/Zn2⁺. Furthermore, the formation of complexes between the metal ions and the protein, potentially leading to metal ion bridging and subsequent bilayer adsorption, constituted a significant secondary mechanism contributing to the overall adsorption capacity and layer structure. These findings highlight the critical role of mineral surfaces in modulating the transport and potential bioavailability of heavy metals in the presence of Bt proteins. The study provides key parameters for improving risk assessment of heavy metal mobility in areas cultivated with transgenic Bt crops, supporting more accurate evaluation and mitigation of associated ecological impacts.

Bacillus thuringiensis insecticidal proteins have been safely and effectively used for several decades as tools for insect pest control either as active ingredients in biopesticides or via transgenic expression in crop plants (GM crops). While the first generations of GM crops in the 1990s expressed only three-domain Cry proteins, GM corn and cotton varieties expressing vegetative insecticidal proteins from the Vip3 class began to be cultivated in the late 2000s (Vip3A). Here we describe a comprehensive food and feed safety assessment of Vip3Cb1, the first member of the Vip3C class to be expressed in commercial varieties of GM crops. Bioinformatic protein safety screens reiterate the placement of Vip3Cb1 as an insecticidal member of the Vip3 protein class and demonstrate a lack of homology to known allergens or toxins. In vitro characterization of the thermal stability and digestive fate demonstrates that dietary exposure to an intact, functional form of Vip3Cb1 is highly unlikely. Vip3Cb1 also showed no measurable effects in an in vivo acute oral toxicity study in mice. By weight of evidence, the bioinformatics assessments, in vitro and in vivo studies, history of safe use, and the previously reported mechanism of action similar to Vip3A collectively demonstrate no indication of a risk of Vip3Cb1 to the health of humans or animals and reinforces the overall safety of the Vip3 class of insecticidal proteins.

Bacillus thuringiensis insecticidal proteins have been safely and effectively used for several decades as tools for insect pest control either as active ingredients in biopesticides or via transgenic expression in crop plants (GM crops). While the first generations of GM crops in the 1990s expressed only three-domain Cry proteins, GM corn and cotton varieties expressing vegetative insecticidal proteins from the Vip3 class began to be cultivated in the late 2000s (Vip3A). Here we describe a comprehensive food and feed safety assessment of Vip3Cb1, the first member of the Vip3C class to be expressed in commercial varieties of GM crops. Bioinformatic protein safety screens reiterate the placement of Vip3Cb1 as an insecticidal member of the Vip3 protein class and demonstrate a lack of homology to known allergens or toxins. In vitro characterization of the thermal stability and digestive fate demonstrates that dietary exposure to an intact, functional form of Vip3Cb1 is highly unlikely. Vip3Cb1 also showed no measurable effects in an in vivo acute oral toxicity study in mice. By weight of evidence, the bioinformatics assessments, in vitro and in vivo studies, history of safe use, and the previously reported mechanism of action similar to Vip3A collectively demonstrate no indication of a risk of Vip3Cb1 to the health of humans or animals and reinforces the overall safety of the Vip3 class of insecticidal proteins.

Transgenic crops expressing Cry proteins are widely cultivated to reduce crop damage from insect pests. However, Cry proteins can leach from transgenic crop detritus into nearby aquatic ecosystems, potentially affecting nontarget organisms. Here, we assess the impacts of exposure to a commonly used Cry protein, Cry1Ab, on net-spinning caddisflies (Hydropsychidae), a common and ecologically important group of stream insects. We collected and genetically barcoded 1,862 larval caddisflies from 25 streams across the Midwestern United States, comparing populations from Cry1Ab-positive and Cry1Ab-negative streams. We evaluated potential impacts associated with body size, developmental stage, species assemblages, and mitochondrial haplotype diversity. Overall, we observed limited effects of Cry1Ab exposure, including most comparisons showing no difference between Cry1Ab-positive and Cry1Ab-negative streams with the exception of second instar Hydropsyche betteni, which showed significantly reduced body size at Cry1Ab-positive sites. Mean developmental stage within species and species assemblages showed no consistent association with Cry1Ab. In contrast, environmental variables such as water temperature, stream width, and watershed land use were stronger predictors of body size, instar progression, and species assemblages. Haplotype networks revealed strong geographic structure but no genetic patterns related to Cry1Ab exposure. These results indicate that Cry1Ab exposure is not a major driver of morphological, developmental, or genetic variation in Hydropsychid caddisflies under natural field conditions. Environmental gradients remain the dominant structuring force, although further work is needed to assess potential context-dependent or cumulative effects of transgenic crop byproducts in aquatic ecosystems.

Insect resistance is a predominant trait in the globally approved genetically modified (GM) crops. The cry1Ab transgene is featured in over 25% of globally approved insect resistant GM events including both single as well as stacked trait events. GM maize notably contributes for 87% among the approved GM events with cry1Ab gene. GM detection of cry1Ab gene in maize seeds and food products is important for authentication purpose in the countries where GM maize events with cry1Ab gene such as Bt11, Bt176, MON810 are approved, and for surveillance of unauthorized occurrence of such events in the countries where these are not approved. Cost-efficient and rapid GM detection methods are essential for decentralized monitoring for unauthorized GM events across agricultural fields, border inspections, and food supply chains, and for regulatory compliance enabling quick decision-making. A rapid GM detection method employing loop-mediated isothermal amplification (LAMP) was developed for visual analysis of cry1Ab gene in GM maize. The developed assay showed acceptable specificity, which could reliably detect as low as 0.005% of cry1Ab within 60min. Practical applicability of this assay was also verified for GM detection in maize containing products. The developed method offers a convenient, rapid and cost-effective tool for checking the cry1Ab gene either for regulatory purpose in the countries where the GM crops with cry1Ab gene are restricted or for confirmatory purpose for the samples with cry1Ab gene whenever required.

Vip3Aa toxin is a Bacillus thuringiensis (Bt)-derived insecticidal protein widely deployed in transgenic crops, and sensitive residue analysis of Vip3Aa toxin is required for agricultural surveillance. Here, we generated an anti-Vip3Aa toxin monoclonal antibody (mAb, H12-mAb) together with a polyclonal antibody preparation (pAbs, Y26-pAbs) and evaluated their binding affinities (1.34 × 107 and 6.35 × 107 L/mol, respectively). Using this pair of antibodies, we built three complementary assay formats to detect Vip3Aa toxin: a double antibody sandwich ELISA (DAS-ELISA) for routine quantification, an aggregation-induced emission fluorescent microspheres (AIE)-based fluorescent immunoassay (AIE-FLIA) for enhanced sensitivity, and a gold nanoparticle (AuNPs)-based lateral flow immunoassay (AuNPs-LFIA) for rapid screening. The resulting limits of detection (LODs) were 9.68 ng/mL (DAS-ELISA), 1.95 ng/mL (AIE-FLIA), and 31.25 ng/mL (AuNPs-LFIA), which are well below the reported Vip3Aa expression (> μg/g) levels in transgenic tissues. Method performance was verified in representative agricultural matrices, providing intra-assay recoveries of 90.3-99.1% with coefficients of variation (CVs) of 1.4-9.7% and inter-assay recoveries 83.6-99.9% with CVs of 2.9-10.6%. Additionally, the AIE-FLIA and AuNPs-LFIA also exhibited good practicality and applicability on detecting Vip3Aa toxin. Overall, these multi-modal immunoassays enable both laboratory quantification and rapid field-oriented screening of Vip3Aa toxin in agricultural samples.

Exogenous protein degradation dynamics during transgenic maize straw degradation in soil and the mechanisms underlying soil microbial community construction remain unclear. Applying null-model analysis to determine these mechanisms is important for assessing transgenic crop straw return-to-field-related impacts on dynamic soil quality and microbial ecological function changes. A laboratory leaf degradation burial simulation was conducted to establish an exogenous protein Cry1A.401 soil degradation model and clarify its behaviors. Coupled Illumina MiSeq 16S rDNA sequencing–soil physicochemical factor analysis was used to evaluate soil microbial community characteristic and diversity changes during leaf degradation and explore soil microbial community construction mechanisms and driving factors. The results revealed that exogenous protein Cry1A.401 released from transgenic insect-resistant maize leaves exhibited consistent degradation characteristics, decreasing rapidly at the initial stage but slowly at the middle/late stages. The diversity levels within/between soil microbial community groups did not significantly differ. Coexistence was the dominant interaction type among soil microbial communities. Community assembly occurred stochastically and was limited primarily by diffusion. Insights into the putative mechanistic links among Bacillus thuringiensis (Bt) proteins, soil properties, and microorganisms are provided. Our understanding of the ecological impacts of exogenous Bt proteins released into soil via leaves on soil ecosystems was enhanced.

Genetically Modified (GM) is a technology that involves inserting DNA into genome of the organism. Plants can be genetically modified by inserting a particular DNA sequence into their genome to confer new or different traits. The growing demand for genetically modified (GM crops is a result of features like insect and herbicide tolerance. High nutritional content, improved production, and extended shelf life are further advantages of genetically modified crops. Whereas the human health, environmental safety, labelling, consumer choice, and intellectual property rights are frequently the topics of debates and public concern regarding GM foods and crops. A Pew Research Centre study performed between October 2019 and March 2020 found that 48% of respondents believed GM foods to be dangerous, 13% claimed they were safe, and 37% were unable to voice an opinion because they lacked the necessary information. This paper would discuss the controversies and moratoriums associated with GM crops/foods in India. Further this paper also highlights the approach of the higher judiciary towards the biosafety issues posed by the commercialization of Genetically Modified crops/food.

Transgenic crops expressing Bacillus thuringiensis (Bt) toxins effectively control major insect pests; however, the emergence of pest resistance can diminish their long-term effectiveness. The predominant strategy for delaying the progression of pest resistance to Bt crops boosts the survival of susceptible insects through “refuges” of host plants that do not produce cry toxins. Ideally, most of the resistant insects emerging from Bt crops will mate with the more abundant susceptible insects from nearby refuges. As Bt cotton has been widely adopted by Indian farmers since 2002, a proactive strategy was introduced to delay resistance to Bt proteins by planting 20 % of the field area with non-Bt cotton as a structured refuge. But to increase yields, farmers forego refuge planting. This reluctance resulted in short-term gains through increased yields but led the pink bollworm (PBW) to develop resistance to single-stacked gene Bt cotton by 2010 and to BGII by 2015. Thus, an extensive study assessing and comparing different refugia-in-bag (RIB) patterns for the bollworm complex, with special emphasis on PBW was conducted at Agricultural Research Station (ARS), Dharwad. Isogenic lines of Bt cotton hybrid (KCH-14K59 BG II) and its non-Bt were planted, following recommended agronomic practices. The pooled results indicated that the commercial RIB, fixed 5 % RIB, and fixed 10 % RIB treatments were statistically at par in terms of good boll opening (GBO), bad boll opening (BBO), and locule damage across all treatments. However, the highest seed cotton yield was recorded in T1 (13.45 q/ha), followed by T5 (12.37 q/ha) and T4 (11.78 q/ha), while the lowest yield was observed in T2 (6.62 q/ha). There was no infestation of Helicoverpa on Bt plants across the different treatments; however, PBW incidence and damage were predominant in all the blocks of both Bt and non-Bt plants.

Biotic and/or abiotic stressors dampen crop productivity and affect sustainability worldwide. To address these challenges, it is crucial to associate the desired stress-responsive genes with specific stress-inducible promoters for developing plant varieties with broad-spectrum stress tolerance. In this study, the promoter region of the anthocyanidin synthase (ANS) gene from banana was thoroughly analysed, and its tissue-specific expression, in response to various environmental insults was delineated. Comprehensive analyses such as transcript abundance-based expression profiling and evaluation of ProANS-GUS activity in transgenic lines was performed and the expression patterns thus obtained were corroborated with the presence of corresponding cis-elements in the promoter region. Transcription of the ANS gene was strongly altered by the imposition of environmental stresses or signaling molecules. MusaANS transcripts in banana were significantly suppressed by exposure to high salinity, salicylic acid or abscisic acid, while its expression was stimulated by methyl jasmonate as well as drought. In PMusaANS-GUS transformed tobacco lines, PMusaANS activity was mainly observed in the vascular tissue under control conditions. Drought, salinity, MeJA, salicylic acid and ABA strongly activated PMusaANS whereas, ethephon suppressed its activity. Thorough scrutiny of PMusaANS showed the presence of a diverse array of stress and phytochemical response-associated cis-elements, such as ARR1AT (cytokinin), ACGTATERD1 (drought), DPBFCOREDCDC3 (ABA), ABREOSRAB21 (ABA), ASF1MOTIFCAMV (salicylic acid), ERELEE4 (ethylene) and BIHD1OS (pathogen response). Based on the results, PMusaANS is differentially activated under stress and hence is an excellent stress-inducible candidate promoter for producing resilient transgenic crop varieties.

Abstract Antimicrobial peptides (AMPs) represent a versatile and innovative class of biomolecules with unique mechanisms of action, including membrane disruption, immunomodulation, and multi-target synergy, positioning them as promising alternatives to conventional antibiotics in combating drug-resistant pathogens. Their broad-spectrum activity and low resistance development have enabled transformative applications across medicine, agriculture, and food industries. In healthcare, AMPs show potential in treating multidrug-resistant infections and eradicating biofilms, while their role as natural preservatives extends food shelf life by targeting spoilage microorganisms. Agricultural advancements include transgenic crops expressing AMPs for disease resistance and livestock feed additives enhancing immune responses. Emerging technologies such as AI-driven peptide design, nanotechnology-based delivery systems, and CRISPR-engineered production platforms are addressing challenges in stability, scalability, and targeted action. Despite these strides, hurdles remain in large-scale synthesis, cost-effectiveness, and clinical translation. Collaborative efforts integrating computational biology, material science, and regulatory frameworks will be pivotal in harnessing AMPs’ full potential, offering sustainable solutions to global health crises, food security challenges, and antimicrobial resistance in the post-antibiotic era.

Insecticidal proteins derived from Bacillus thuringiensis (Bt) have been effectively employed in controlling lepidopteran pests, notably in transgenic crops targeting Spodoptera species. However, concerns have arisen regarding the long-term efficacy due to the emergence of tolerant and resistant insect populations. Prior research suggested that repeated exposures to Bt, which contains a mixture of spores and crystals, may contribute to the development of tolerance; however, the specific effects of sequential exposure to purified Cry1 and Vip3Aa proteins remain unclear. This study aimed to assess whether prior exposure of Spodoptera exigua neonate larvae to sublethal concentrations of Cry1Ab, Cry1Ca or Vip3Aa proteins would heighten their tolerance upon subsequent exposure, and whether such effects would extend to their offspring. Pre-exposure to Cry1Ab or Vip3Aa did not affect larval responses to the toxin. For Cry1Ca, a slight increase was observed under one treatment condition, but the effect was not considered biologically relevant. Transgenerational analysis revealed no enhancement of tolerance; rather, there was a negative impact on the offspring's response in some cases. These findings indicate that although previous studies have documented that sublethal contact with bacterial preparations may significantly affect insect tolerance, exposure to sublethal doses of purified Cry1 and Vip3Aa proteins is unlikely to lead to the development of tolerance in S. exigua.

Endophyte-engineered plant immunity: A post-GMO strategy for programmable crop defense.