GM crops: science, politics and communication

Tracing scientific and technological development in genetically modified crops

Genetically Modified (GM) Organisms have been used in various domains since their introduction in the 1980s. According to ISAAA data, the use of GM crops in agriculture has also increased significantly in the past 30 years. However, even after 3 decades of commercialisation, GM crops are still surrounded with controversies with different countries adopting varying approaches to their introduction in the consumer markets, owing to different stances of various stakeholders. Motivated by this multitude of opinions, and absence of knowledge mapping, this study has undertaken scientometric analysis of the publication (Web of Science) and patent (Lens.org) data about genetically modified technology use in agriculture to explore the changing knowledge patterns and technological advancements in the area. It explores both scientific and technological perspectives regarding the use of Genetically Modified Crops, by using publication as well as patent data. The findings of this study highlight the major domains of research, technology development, and leading actors in the ecosystem. These findings can be helpful in taking effective policy decisions, and furthering the research activities. It presents a composite picture using both publications and patent data. Further, it will be of utility to explore the other technologies which are replacing GM technology in agriculture in future studies.

Factors Affecting Social Media Users' Emotions Regarding Food Safety Issues: Content Analysis of a Debate among Chinese Weibo Users on Genetically Modified Food Security

Social media is gradually building an online information environment regarding health. This environment is filled with many types of users' emotions regarding food safety, especially negative emotions that can easily cause panic or anger among the population. However, the mechanisms of how it affects users' emotions have not been fully studied. Therefore, from the perspective of communication and social psychology, this study uses the content analysis method to analyze factors affecting social media users' emotions regarding food safety issues. In total, 371 tweet samples of genetically modified food security in Sina Weibo (similar to Twitter) were encoded, measured, and analyzed. The major findings are as follows: (1) Tweet account type, tweet topic, and emotion object were all significantly related to emotion type. Tweet depth and objectivity were both positively affected by emotion type, and objectivity had a greater impact. (2) Account type, tweet topic, and emotion object were all significantly related to emotion intensity. When the depths were the same, emotion intensity became stronger with the decrease in objectivity. (3) Account type, tweet topic, emotion object, and emotion type were all significantly related to a user's emotion communication capacity. Tweet depth, objectivity, and user's emotion intensity were positively correlated with emotion communication capacity. Positive emotions had stronger communication capacities than negative ones, which is not consistent with previous studies. These findings help us to understand both theoretically and practically the changes and dissemination of user's emotions in a food safety and health information environment.

Cell-envelope proteinases from lactic acid bacteria: Biochemical features and biotechnological applications

Proteins displayed on the cell surface of lactic acid bacteria (LAB) perform diverse and important biochemical roles. Among these, the cell-envelope proteinases (CEPs) are one of the most widely studied and most exploited for biotechnological applications. CEPs are important players in the proteolytic system of LAB, because they are required by LAB to degrade proteins in the growth media into peptides and/or amino acids required for the nitrogen nutrition of LAB. The most important area of application of CEPs is therefore in protein hydrolysis, especially in dairy products. Also, the physical location of CEPs (i.e., being cell-envelope anchored) allows for relatively easy downstream processing (e.g., extraction) of CEPs. This review describes the biochemical features and organization of CEPs and how this fits them for the purpose of protein hydrolysis. It begins with a focus on the genetic organization and expression of CEPs. The catalytic behavior and cleavage specificities of CEPs from various LAB are also discussed. Following this, the extraction and purification of most CEPs reported to date is described. The industrial applications of CEPs in food technology, health promotion, as well as in the growing area of water purification are discussed. Techniques for improving the production and catalytic efficiency of CEPs are also given an important place in this review.

Plant Molecular Farming - Integration and Exploitation of Side Streams to Achieve Sustainable Biomanufacturing

Plants have unique advantages over other systems such as mammalian cells for the production of valuable small molecules and proteins. The benefits cited most often include safety due to the absence of replicating human pathogens, simplicity because sterility is not required during production, scalability due to the potential for open-field cultivation with transgenic plants, and the speed of transient expression potentially providing gram quantities of product in less than 4 weeks. Initially there were also significant drawbacks, such as the need to clarify feed streams with a high particle burden and the large quantities of host cell proteins, but efficient clarification is now readily achieved. Several additional advantages have also emerged reflecting the fact that plants are essentially biodegradable, single-use bioreactors. This article will focus on the exploitation of this concept for the production of biopharmaceutical proteins, thus improving overall process economics. Specifically, we will discuss the single-use properties of plants, the sustainability of the production platform, and the commercial potential of different biomass side streams. We find that incorporating these side streams through rational process integration has the potential to more than double the revenue that can currently be achieved using plant-based production systems.

CRISPR/Cas9-mediated genome editing efficiently creates specific mutations at multiple loci using one sgRNA in Brassica napus

CRISPR/Cas9 is a valuable tool for both basic and applied research that has been widely applied to different plant species. Nonetheless, a systematical assessment of the efficiency of this method is not available for the allotetraploid Brassica napus-an important oilseed crop. In this study, we examined the mutation efficiency of the CRISPR/Cas9 method for 12 genes and also determined the pattern, specificity and heritability of these gene modifications in B. napus. The average mutation frequency for a single-gene targeted sgRNA in the T0 generation is 65.3%. For paralogous genes located in conserved regions that were targeted by sgRNAs, we observed mutation frequencies that ranged from 27.6% to 96.6%. Homozygotes were readily found in T0 plants. A total of 48.2% of the gene mutations, including homozygotes, bi-alleles, and heterozygotes were stably inherited as classic Mendelian alleles in the next generation (T1) without any new mutations or reversions. Moreover, no mutation was found in the putative off-target sites among the examined T0 plants. Collectively, our results demonstrate that CRISPR/Cas9 is an efficient tool for creating targeted genome modifications at multiple loci that are stable and inheritable in B. napus. These findings open many doors for biotechnological applications in oilseed crops.

Transgenic Crops and Sustainable Agriculture in the European Context

The rapid adoption of transgenic crops in the United States, Argentina, and Canada stands in strong contrast to the situation in the European Union (EU), where a de facto moratorium has been in place since 1998. This article reviews recent scientific literature relevant to the problematic introduction of transgenic crops in the EU to assess if there are specific reasons why transgenic crops have a potentially greater adverse impact on sustainable agriculture in the EU context than elsewhere. Sustainable agriculture integrates three main goals: environmental health, economic profitability, and socioeconomic equity. Transgenic crops do not appear a suitable tool for sustainable agriculture in the EU due to specific environmental, economic, and socioeconomic reasons. Therefore, a moratorium on transgenic crops based on the precautionary principle should be officially adopted until proper risk assessment. In addition, agroecological alternatives to transgenic crops fit better the EU vision of agriculture.

Integrated pest management and weed management in the United States and Canada

There is interest in more diverse weed management tactics because of evolved herbicide resistance in important weeds in many US and Canadian crop systems. While herbicide resistance in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate-tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. There are many tactics that help to mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides, often to the exclusion of alternative tactics. Application of integrated pest management for weeds is better characterized as integrated weed management, and more typically integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds, and the relief provided by different herbicide use practices is generally short-lived at best. More diversity of tactics for weed management must be incorporated in crop systems.

Genetically modified crops: detection strategies and biosafety issues

Genetically modified (GM) crops are increasingly gaining acceptance but concurrently consumers' concerns are also increasing. The introduction of Bacillus thuringiensis (Bt) genes into the plants has raised issues related to its risk assessment and biosafety. The International Regulations and the Codex guidelines regulate the biosafety requirements of the GM crops. In addition, these bodies synergize and harmonize the ethical issues related to the release and use of GM products. The labeling of GM crops and their products are mandatory if the genetically modified organism (GMO) content exceeds the levels of a recommended threshold. The new and upcoming GM crops carrying multiple stacked traits likely to be commercialized soon warrant sensitive detection methods both at the DNA and protein levels. Therefore, traceability of the transgene and its protein expression in GM crops is an important issue that needs to be addressed on a priority basis. The advancement in the area of molecular biology has made available several bioanalytical options for the detection of GM crops based on DNA and protein markers. Since the insertion of a gene into the host genome may even cause copy number variation, this may be uncovered using real time PCR. Besides, assessing the exact number of mRNA transcripts of a gene, correlation between the template activity and expressed protein may be established. Here, we present an overview on the production of GM crops, their acceptabilities, detection strategies, biosafety issues and potential impact on society. Further, overall future prospects are also highlighted.

Benchmark study on glyphosate-resistant crop systems in the United States. Part 2: Perspectives

A six-state, 5 year field project was initiated in 2006 to study weed management methods that foster the sustainability of genetically engineered (GE) glyphosate-resistant (GR) crop systems. The benchmark study field-scale experiments were initiated following a survey, conducted in the winter of 2005-2006, of farmer opinions on weed management practices and their views on GR weeds and management tactics. The main survey findings supported the premise that growers were generally less aware of the significance of evolved herbicide resistance and did not have a high recognition of the strong selection pressure from herbicides on the evolution of herbicide-resistant (HR) weeds. The results of the benchmark study survey indicated that there are educational challenges to implement sustainable GR-based crop systems and helped guide the development of the field-scale benchmark study. Paramount is the need to develop consistent and clearly articulated science-based management recommendations that enable farmers to reduce the potential for HR weeds. This paper provides background perspectives about the use of GR crops, the impact of these crops and an overview of different opinions about the use of GR crops on agriculture and society, as well as defining how the benchmark study will address these issues.

Musings about the effects of environment on photosynthesis

Understanding of how plants respond to their environment, particularly to extreme conditions to which their metabolisms are not adapted, is advancing on many fronts. An enormous matrix of plant and environmental factors exists from which mechanisms and assessments of quantitative responses must be developed if further progress in understanding how to improve plant (and particularly crop) production is to be achieved. This Special Issue contains assessments of different areas of plant sciences, ranging from genome to field, but with a focus on photosynthesis. Photosynthesis is central to all aspects of plant biology as the provider of energy and assimilates for growth and reproduction, yet how it is regulated by abiotic stresses, such as salinity and water deficits, and by biotic stresses, such as insect herbivory, is still unclear. Differences in responses of C3, C4 and CAM plants are still uncertain and mechanisms unclarified. Gene distribution and transfer between chloroplasts and nucleus on an evolutionary time scale may reflect conditions in the cell and organelles relevant to the short-term effects of water deficits on photosynthetic rate and the function of ATP synthase. Regulation of conditions in tissues and cells depends not only on chloroplast functions but on mitochondrial activity, and their interaction and differences in responses have implications for understanding many aspects of cell metabolism. Adaptation of plant structure, such as stomatal frequency and composition of the photosynthetic machinery by changes to gene expression controlled by transcription factors, or arising from regulation of gene expression by redox state, is of major importance with implications for adaptation in the short- and long-term. The incisive and thought-provoking reviews in this Special Issue offer analyses of experimental information and develop concepts within the complex matrix, relating photosynthesis and associated metabolism to the environment and addressing mechanisms critically with a balanced assessment of the current state of the science.

Garden-variety vaccines: antigens derived from transgenic plants

The discovery of new vaccines can result from deletion of virulence determinants from a specific pathogen or from identification of target antigens that stimulate a protective immune response. Vaccine development will become less empirical as applications of genomics, proteomics and reverse vaccinology are exploited, and new protective antigens will emerge for inclusion in the vaccines of the future. However, production and purification of these new antigens for oral and parenteral use using traditional expression systems, will be expensive and unattractive to vaccine manufacturers who see the vaccine market as economically uninviting. Cost is one of the persistent barriers to deployment of new vaccines to populations that need them most urgently. This factor will inhibit the development and distribution of safe and effective new vaccines against high priority pathogens.

Safe and acceptable strategies for producing foreign molecules in plants

The ability to express foreign genes using transgenic technologies has opened up options for producing large quantities of commercially important industrial or pharmaceutical products in plants. These technologies have made it possible to use well-developed systems of commercial agriculture that were developed principally to produce raw material for large-scale food, feed or processing applications for the production of foreign molecules. The possibility of the novel industrial or pharmaceutical molecules produced in such plants, or components derived from them, contaminating the environment and food chains has become especially controversial. This potential contamination has prompted detailed consideration of how such crops and the molecules that they produce can be effectively isolated and contained. First, the crop can be completely isolated physically from its food or feed counterpart during every aspect of its development and commercialization. Second, genetic isolation systems or genetic barriers that prevent normal reproduction can be used to reduce the likelihood of the industrial or pharmaceutical crop entering the food chain.