Transgenic Crops Research Articles

Fields of contestation and contamination: Maize seeds, agroecology and the (de)coloniality of agriculture in Malawi and South Africa

Farmer-managed seed systems and the conservation of agrobiodiversity are increasingly recognized as important components of food and seed sovereignty. In contrast, hybrid, genetically modified (GM), and, increasingly, gene-edited crops continue to be promoted by Green Revolution proponents as a “climate smart” package that includes fertilizers, pesticides, purchased seeds, and links to global markets. Influencing seed laws and policies to support the uptake of modern crop varieties has been a key entry point in many countries, facilitated by networks of foreign donors, philanthropists, governments, and multinational companies. Using the case of South Africa, where GM crops have been grown for several decades, we provide insights on implications for Malawi, which passed a Seed Act in 2022, implicitly supporting GM crops. Both countries have histories of colonial agriculture with strong policy support for modern, hybrid varieties of maize, and the replacement (and displacement) of local, open-pollinated maize varieties. In South Africa, several studies have revealed the contamination of smallholder fields and seed systems. Through a political ecology lens, we explore how maize and its cotechnologies were commodified in South Africa and Malawi, and what South African experiences of GM crop adoption in smallholder farming systems can tell us about the challenges to be faced by smallholder Malawian farmers. We reveal how colonial histories and ongoing colonialities of power, knowledge, being, and nature continue to shape the character and form of agriculture in both countries, running counter to the needs of agroecological smallholder farmers and their ways of knowing and being. We conclude by envisioning what reimagined, transformed and decolonial approaches for food and agriculture might look like on the African continent, and how they might contribute toward the attainment of food and seed sovereignty and an agroecological future.

Reply to Berry, C. Factors Related to Bacillus thuringiensis and Gut Physiology. Comment on "Rajan, V. An Alkaline Foregut Protects Herbivores from Latex in Forage, but Increases Their Susceptibility to Bt Endotoxin. Life 2023, 13, 2195".

The comment titled "Factors related to Bacillus thuringiensis and gut physiology" disputes some of the inferences in the paper "An Alkaline Foregut Protects Herbivores from Latex in Forage, but Increases Their Susceptibility to Bt Endotoxin" published in this journal. The key points in the dissent are the following: 1. Bt is generally safe to non-target species. 2. Transgenic Bt crops provide additional ecological benefits due to reductions in conventional pesticide use. 3. Susceptibility to Bt does not indicate alkalinity, nor vice versa. My response is summarized as follows: 1. Bt can form non-specific pores at concentrations of 100 ng/mL in culture, and so is potentially unsafe for animals with gut environments in which Bt persists at or above this level. 2. Initial reductions in insecticide applications have not been sustained and are even increasing in areas planted with transgenic Bt cotton. 3. Acidic guts degrade Bt more efficiently, but I concede that gut alkalinity does not imply susceptibility to Bt due to many factors including resistance in target species, toxin heterogeneity and variable modes of action. However, the susceptibility of foregut-fermenting herbivores with alkaline guts to Bt intoxication cannot be invalidated without further study.

Bacillus thuringiensis translocation in citrus scion/rootstock combinations and binding of cry toxins with the Asian citrus psyllid gut receptors

Bacillus thuringiensis (Bt) can be effective in controlling insect pests either in spray products or by their toxins expressed in transgenic crops. The discovery of Bt as endophytic in citrus opened new perspectives for the control of Diaphorina citri Kuwayama, the vector of the bacteria Candidatus Liberibacter spp. associated with Huanglongbing. In this study, the endophytic translocation of Bt in citrus seedlings (small and large plants) and in different scion-rootstock combinations were investigated. We also assessed the lethal concentration of D. citri nymphs caused by systemic Bt in citrus and, moreover, the binding of Cry toxins with the Asian citrus psyllid (ACP) gut receptors. Endophytic translocation of Bt in citrus seedlings and nursery trees was confirmed by colony isolation, PCR detection, and Btk-GFP microscopy analyses, which demonstrated that, after Bt inoculation into the substrate, the bacteria enter through lateral root emergence sites and are localized in stem xylem vessel elements. Mean lethal concentrations for D. citri third instar nymphs were 4.92 × 104 and 2.19 × 104 spores mL−1 for S1450 and S1302 strains, respectively. Nymphal mortality induced by the bacteria was higher in citrus seedlings than in citrus nursery trees. All Cry-toxins tested were able to bind to D. citri brush border membrane vesicles, suggesting the potential pathogenicity of Bt strains against psyllid. This study clearly demonstrates the penetration and Bt translocation in the xylem of small and large citrus plants and the potential of the bacteria to cause ACP nymphs mortality that fed on shoots from Bt-treated citrus.

Establishment of an indirect competitive immunoassay for the detection of dicamba based on a highly specific nanobody

Dicamba, a traditional highly effective and low toxicity herbicide, has gained new life with the development of dicamba-tolerant transgenic crops in recent years. However, dicamba is highly volatile and therefore easy to cause drift damage to sensitive crops. The development of efficient and sensitive detection methods is essential for monitoring of trace dicamba in the environment. Nanobody-based immunoassay plays an important role in on-site detection of pesticides. However, now rapid and sensitive immunoassay methods based on nanobody for dicamba detection were lacking. In this study, the nanobodies specifically recognizing dicamba were successfully obtained by immunising camels and phage display library construction, and then an indirect competitive immunoassay based on Nb-242 was constructed with IC50 of 0.93 μg/mL and a linear range of 0.11–8.01 μg/mL. Nb-242 had good specificity with no cross-reactivities against the dicamba analogs other than 2,3,6-trichlorobenzoic acid and the developed immnoassay had a good correlation with the standard HPLC in the spike-recovery studies. Finally, the key amino acid Ala 123, Tyr 55, Tyr 59 and Arg 72 of Nb-242 that specifically recognizing and binding with dicamba were identified by homologous modeling and molecular docking, laying an important foundation for further structural modification of Nb-242. This study has important guiding significance for constructing immunoassay method of dicamba based on nanobody and provides a sensitive, specific, and reliable detection method that is suitable for the detection of dicamba in the environment.

Improving regulatory efficiency for biotechnology products.

Small procedural changes in how regulatory agencies implement biotech policies can make significant differences in improving regulatory efficiency. This paper discusses how science based, crop specific guidance documents can improve dossier content and the review and approval of biotech varieties. In addition, we describe how the adoption of established risk assessment methodology and applying policy-linked decision making at the agency level can boost both efficiency and developer, public and government confidence in agency decision making and in biotech crops.

Identification of transgenic crops by CRISPR/Cas12a-assisted magnetic surface-enhanced resonance Raman spectroscopy

Rapid and reliable identification of genetically modified (GM) and non-GM crops is in urgent demand and remains a significant challenge in food safety. Here, a new and reliable Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-mediated magnetic surface-enhanced resonance Raman scattering (SERRS) biosensing is reported to identify specific gene sequences of transgenic crops (CaMV 35 S promoter and Nos terminator). This assay mainly combines the gene-specific recognition ability of CRISPR, the ultra-high sensitivity due to the Raman resonance effect, and the simple separation property of magnetic nanomaterials. A multifunctional SERRS-active nanoprobe was designed by decorating a gold-coated magnetic bead with the G-triplet deoxyribonucleic acid (DNA) sequences that enable a high loading of Raman reporters (methylene blue) inserted in G-triplet DNAs. The assay is achieved by the recognition of the CRISPR/Cas12a protein for bound target DNAs and the activation of the unlimited trans-cleavage action on the G-triplet DNAs, which causes a release of methylene blue above the nanoprobes and a reduction of the SERRS signal. Gel electrophoresis experiments imply that the designed crRNAs have good recognition and cleavage function for target DNAs and verify the feasibility of the experimental scheme. This SERRS assay exhibits a linear response of 4.15 × 10−12 M to 4.15 × 10−9 M with a pM detection level. Tests of the GM and non-GM crops of actual crop samples have been realized, which implies that this CRISPR-mediated magnetic SERRS method is available for assessing natural samples and working for GM crop regulation.

Soil microbes from conservation agriculture systems reduce growth of Bt-resistant western corn rootworm larvae

Sustainable agricultural management practices aimed at improving soil health can alter the soil microbiome, which can influence plant health and defenses against insects. The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major belowground pest of corn. Pest management relies heavily on the planting of transgenic crops expressing Bacillus thuringiensis (Bt) toxins. In this study, we ask how corn-WCR interactions via the soil microbiome are affected by a conservation management system (extended corn-soybean-wheat rotation with cover crops under no-till) compared with a conventional management system (corn-soybean rotation under mulch tillage and no cover crops) when combined with transgenic Bt corn. To do this, we applied soil microbes from the conservation and conventional management systems to two corn lines, one producing Bt and one non-Bt. We then reared Bt-resistant and Bt-susceptible WCR on inoculated seedlings to examine plant and insect changes in fitness. We found that Bt was effective against susceptible larvae in both soil treatments. Bt-resistant larvae were ~ 20% smaller when reared in the presence of soil microbes from the conservation management system. Thus, control of Bt-resistant WCR may be improved in a conservation system without sacrificing Bt effectiveness in susceptible insects. Comparing the microbial communities using 16S rRNA sequencing revealed that management practices influenced the microbiomes associated with the soil and the plant rhizosphere, but not WCR. Our findings suggest value for growers in utilizing conservation management practices, such as no-till and cover crops, in agricultural systems through bottom-up changes to plant–insect interactions via the soil microbiome.

Enhancement of salt tolerance of alfalfa: Physiological and molecular responses of transgenic alfalfa plants expressing Syntrichia caninervis-derived ScABI3

Alfalfa (Medicago sativa L.), a perennial forage plant, is a rich source of nutrients such as vitamins, minerals, and proteins. Salt stress, however, impedes its growth. The plant-specific transcription factor abscisic acid insensitive 3 (ABI3) has a critical contribution to the control of abscisic acid (ABA) signaling pathway and abiotic stress response. The gene ScABI3 from Syntrichia caninervis, a moss species tolerant to desiccation, could be considered a potential candidate gene to modify alfalfa's nutritional and growth aspects. However, it remains unclear how ScABI3 affects the salt stress response of transgenic alfalfa. Therefore, we elucidated the role and molecular mechanism of ScABI3 from S. caninervis as an ABA signaling factor in transgenic alfalfa. Our findings demonstrate that ScABI3 overexpression in transgenic alfalfa improves salt tolerance by promoting relative water content, antioxidant enzyme activity, and photosynthetic parameters. Furthermore, the key genes of plant hormone signaling and the classical salt tolerance pathway were activated in ScABI3 transgenic lines under salt stress. Based on these results, ScABI3 could be considered a potentially critical candidate gene to alleviate salt stress in alfalfa. The present study provides valuable insights for developing transgenic crop breeding strategies for saline-alkaline soils.

Factors driving the acceptance of genetically modified food crops in Ghana

AbstractCrops produced using recombinant DNA technology have invaluable food security roles but are not broadly accepted. Food insecurity affects between 45% and 50% of the Ghanaian populace, while the debate to adopt, accept, use, and commercialize genetically modified (GM) crops is ongoing. In this study, a choice‐based conjoint experimental design was adopted to investigate factors driving the acceptance or rejection of GM crops in Ghana. Results from average marginal component effect estimation suggest that safety concern is the major driver for accepting or rejecting GM crops. This was further confirmed using predicted probabilities and marginal means estimation of community acceptance especially when it possesses certain attributes. The safer the GM crop is perceived for human consumption, health, and environment, the more likely the Ghanaian populace will accept it. In addition, yield and taste were observed to be other key driving factors to accept GM crops. Importantly, the country of patency was also observed to be a critical driving factor for whether or not a GM crop is accepted in Ghana. There is a need for active and greater engagement with the Ghanaian populace to put proper legislation, regulations, policies, and knowledge co‐creation process to ensure the proper use of GM crops.

Examining the Relationship between Biotech Crop Cultivation and Global Food Security Sustainable Index: A Comparative Analysis from 2012 to 2018

This study examines the dynamics between the cultivation of biotech plants and food protection on a global scale from 2012 to 2018 which will ensure sustainability in food. The use of facts from the worldwide food security Index (GFSI) and biotech crop cultivation regions, we analyze modifications in food security metrics alongside developments in biotech crop adoption across various international locations. Our findings reveal intriguing patterns, including extensive increases in biotech crop cultivation in Brazil and the United States, coinciding with terrific enhancements in GFSI scores in nations like Chile, Uruguay, and Argentina. Conversely, a few countries, such as Burkina Faso and Myanmar, exhibited high-quality shifts in GFSI despite stagnant biotech crop cultivation. Furthermore, simultaneous will increase or decreases in each biotech crop cultivation and GFSI rankings were observed in positive international locations, underscoring the complicated interaction between biotech crop adoption and food security effects. Moreover, we discuss the importance of considering food security at each national and household stages, highlighting the need for nuanced analyses of biotech crop contributions to general food security.

A point-of-care testing platform for on-site identification of genetically modified crops.

Genetically modified (GM) food is still highly controversial nowadays. Due to the disparate policies and attitudes worldwide, demands for a rapid, cost-effective and user-friendly GM crop identification method are increasingly significant for import administration, market supervision, etc. However, as the most-recognized methods, nucleic acid-based identification approaches require bulky instruments, long turn-around times and trained personnel, which are only suitable in laboratories. To fulfil the urgent needs of on-site testing, we develop a point-of-care testing platform that is able to identify 12 types of GM crops in less than 40 minutes without using laboratory settings. Our system integrates sample pre-treatment modules in a microfluidic chip, performs DNA amplification via a battery-powered portable kit, and presents results via eye-recognized colorimetric change. A paraffin-based reflow method and a slip plate-based fluid switch are developed to encapsulate and release amplification primers in individual microwells on demand, thus enabling identification of varied targets simultaneously. Our system offers an efficient, affordable and convenient tool for GM crop identification, thus it will not only benefit customs and market administration bureaus, but also satisfy demands of numerous consumers.

In silico-based Safety Assessment of the EPSPS CP4 single event expressed in genetically modified crops

In silico-based Safety Assessment of the EPSPS CP4 single event expressed in genetically modified crops

Research on Effects of Agricultural Activities and Transgenic Crops in Biodiversity in Bangladesh

Research on Effects of Agricultural Activities and Transgenic Crops in Biodiversity in Bangladesh

Impact of rutin on growth, development and oviposition of Bt‐susceptible and Bt‐resistant pink bollworm

AbstractThe evolution of pest resistance to insecticidal proteins from Bacillus thuringiensis (Bt) restricts the sustainable application of transgenic Bt crops, and exploring other ecofriendly insecticides to efficiently suppress Bt‐resistant populations is thus urgently needed. The plant secondary metabolite rutin possesses pest resistance effects and plays an important role in plant resistance to pests, but the effect of rutin on pink bollworms is unclear. We investigated the effects of rutin on two types (Bt‐susceptible and Bt‐resistant) of pink bollworms (Pectinophora gossypiella). Rutin had significant inhibitory effects on the growth, development, and oviposition of both Bt‐susceptible and Bt‐resistant strains. For both strains, rutin ingestion by larvae did not significantly affect larval survival at 7 days after treatment or egg hatching rate but significantly decreased pupation rate, eclosion rate, neonate‐to‐adult survival, pupal weight and eggs per female and significantly prolonged larval developmental periods, and the effect increased with increasing rutin content. The response to rutin ingestion was basically consistent between Bt‐resistant and Bt‐susceptible strains, indicating that the Bt‐resistant strain did not exhibit cross‐resistance to rutin. These results provide a reference basis for green control and resistance management of pink bollworms and may be used as a component of comprehensive management for this pest.

Detection and occurrence of genetically modified rice and potato in the Saudi food market.

The number of food products with genetically modified (GM) crops on the global market has increased due to advancements in genetic engineering technology. Legislation regulating the labeling and use of GM crops has increased considerably worldwide to provide consumers with health and safety assurance. It is still unclear whether genetically modified organisms (GMOs) are present in the food market of the Kingdom of Saudi Arabia due to a lack of scientific studies. This work was planned to detect GM rice and GM potatoes in the Saudi food market. One hundred non-labeled rice and rice product samples and 50 potato and potato samples were collected randomly from different market sites of Makkah, Riyadh and Jeddah during 2022-2023. The cetyl trimethyl ammonium bromide (CTAB) method was used to extract DNA. Viviants DNA extraction kit was used to extract DNA from rice starch and potato chips. To find GMOs in samples, CMOScreen 35S and NOS test kits were utilized. DNA-based qualitative and quantitative approaches were used to screen targets for PCR detection of GM rice sequences. The results indicated that 32 (32%) rice samples were positive for CaMV 35S promoter, while no positive result was detected for the NOS terminator. Besides, 30% of potato samples were positive for the CaMV 35S promoter, and the same samples were positive for the presence of the Cry V gene. It could be concluded that there were GM rice and potatoes in the Kingdom of Saudi Arabia's food markets. Establishing strong regulations and certified laboratories to monitor genetically modified foods (GMF) or crops in the Saudi market is recommended.

Sensitive detection of genetically modified maize based on a CRISPR/Cas12a system.

With the vigorous development of biotechnology, genetically modified organisms (GMOs) have become more and more common. In order to effectively supervise and administrate them, the rapid and accurate detection of GMOs is urgently demanded. Here, GMO gene-specific sensing methods based on colorimetry and surface-enhanced Raman scattering (SERS) were proposed based on the lateral branch cleavage function of the CRISPR/Cas12a system. Two transgenes, pCaMV35S and M810 Cry1Ab, were chosen as targets for transgenic crops. By using these methods, we performed transgenic detection on five types of maize leaves and successfully distinguished transgenic from non-transgenic samples. The colorimetric method is rapid, economical and available for field detection. The SERS approach, giving a higher sensitivity to 100 fM, is more suitable for laboratory application scenarios. This study explores practical transgenic detection approaches and will be valuable for the supervision of GMOs.

Long-term Sustainability of Bt Transgenic Crops in Agricultural Systems

Long-term Sustainability of Bt Transgenic Crops in Agricultural Systems

실질적 동등성에 근거한 유전자변형 벼의 안전성 평가

Genetically modified crops must undergo safety evaluation approval before commercial use, ensuring substantial equivalence compared to conventional crops. Safety assessment based on 'substantial equivalence' involves a stepwise approach, comparing GM crops with their non-GM counterparts, examining statistical differences or equivalence within the natural variability range for the desired attributes. For instance, if statistically significant differences are observed in safety test items between GM and control crops, additional analysis compares them to the commercially available varieties to determine inclusion within their compositional range. Further analysis involves biological or toxicological assessments if difference between GM crops and others are identified. Using data from insect-resistant genetically modified rice and its non-GM counterpart, available in the Rural Development Administration's crop component database, we applied statistical methods for substantial equivalence assessment. The substantial equivalence assessment of GM crops covers various evaluation aspects, including toxicological, allergenic, and nutritional attributes. In this study, statistical analysis was performed on rice's nutritional component data, integrating the results with theoretical contents.

GM CROPS AND GENETIC ENGINEERING

GM CROPS AND GENETIC ENGINEERING

Consumer Evaluations of and Attitudes towards New Genome Editing Techniques: An Italian Case Study

The ever-increasing development of assisted evolution technologies (AETs) in agriculture has boosted crop improvement. The commercialization of improved biotech crops can be promoted by modern gene editing instead of conventional genetic modification, which is a cheaper and faster approach that can help address future agriculture challenges, such as food security, environmental sustainability, and climate change. However, the use of these technologies is still sensitive and debated in many countries. Each region promotes a different approach, depending on regulatory policies, and adopting these technologies requires knowledge of consumer views and stakeholder acceptance. For this purpose, we conducted a survey of 564 Italians regarding their knowledge of genetic techniques, informational tools, purchase preferences, environmental sustainability, and food safety issues. The research aims are twofold: (a) to assess the level of knowledge and (b) to determine how consumer background, including social and demographic characteristics, affects their level of knowledge. Our findings emphasize the importance of communication and dissemination activities, in which clarity and a broad appeal are key.