Applications Of Genetic Modification Research Articles

Melatonin: A Potential Agent in Delaying Leaf Senescence

Delaying early leaf senescence is important for improving photosynthetic efficiency and crop productivity. Melatonin, a multitasking bio-stimulator, participates widely in plant development and stress responses. In recent years, the cumulative researches show that melatonin has the ability to delay senescence in plants. This review covers the most recent advances on the mechanisms of melatonin-mediated leaf senescence. Melatonin biosynthesis in senescing leaves employs an alternative pathway and is significantly regulated by light. Melatonin increases the thickness of leaf cuticle, wax accumulation and the ratio of palisade/spongy of senescing leaves to maintain intact leaf structure. Melatonin eliminates free radicals through a scavenging cascade reaction and induces antioxidants and antioxidant enzymes; and provides better protection against lipid peroxidation via arranging parallel to the bilayers at high concentration. Meanwhile, melatonin’s ability to ensure high photosynthetic efficiency is predominantly attributed to the reduction of chlorophylls and chloroplast proteins degradation, and the acceleration of chlorophyll de novo synthesis. The dual role of melatonin-regulated autophagy is beneficial for maintaining cellular homeostasis. NACs, WRKYs and DREBs play essential roles in melatonin-controlled transcriptional reprogramming of senescing leaves. Additionally, melatonin improves the activity of cytokinin and auxin; and inhibits the action of abscisic acid, ethylene and jasmonic acid to impact indirectly leaf senescence. Epigenetic modification may be part of mechanisms of melatonin-mediated alterations in gene expression. Moreover, selection of germplasms rich in melatonin and application of genetic modification in agriculture are extensively discussed. Further studies are needed to detail the mechanisms of melatonin-mediated signaling transduction in leaf senescence.

Application of genetic modification and genome editing for developing climate‐smart banana

AbstractBanana is a major staple food crop feeding more than 500 million people in tropical and subtropical countries. Its production is largely constrained by diseases and pests in addition to other factors such as declining soil fertility, narrow genetic diversity in germplasm, and inadequate availability of clean planting material. The impact of climate change, particularly a rise in temperature and drought, is predicted to affect production adversely due to direct effect on plant agronomy and also influence on pathogens, pests, and their interactions with host plants. There is need to develop climate‐smart varieties of banana with multiple and durable resistance to combat abiotic stresses such as extreme temperature and drought, and biotic stresses such as pathogens and pests. Modern breeding tools, including genetic modification and genome editing, can be applied for the improvement of banana bypassing the natural bottlenecks of traditional breeding. Intensive efforts using genetic modification have been made to develop improved banana varieties with resistance to biotic stresses; however, these need to be coupled with tolerance to abiotic stresses. Genome editing, an emerging powerful tool, can be applied for developing sustainable solutions to adapt to climate change by resisting biotic and abiotic stresses. CRISPR/Cas9‐based genome editing has been lately established for banana, paving the way for functional genomics allowing identification of genes associated with stress‐tolerant traits, which could be used for the improvement of banana for adaptation to a changing climate. This article presents an overview of recent advancements and prospective on the application of genetic modification and genome editing for developing climate‐smart banana.

Development of a Double Nuclear Gene-Targeting Method by Two-Step Transformation Based on a Newly Established Chloramphenicol-Selection System in the Red Alga Cyanidioschyzon merolae.

The unicellular red alga Cyanidioschyzon merolae possesses a simple cellular architecture that consists of one mitochondrion, one chloroplast, one peroxisome, one Golgi apparatus, and several lysosomes. The nuclear genome content is also simple, with very little genetic redundancy (16.5 Mbp, 4,775 genes). In addition, molecular genetic tools such as gene targeting and inducible gene expression systems have been recently developed. These cytological features and genetic tractability have facilitated various omics analyses. However, only a single transformation selection marker URA has been made available and thus the application of genetic modification has been limited. Here, we report the development of a nuclear targeting method by using chloramphenicol and the chloramphenicol acetyltransferase (CAT) gene. In addition, we found that at least 200-bp homologous arms are required and 500-bp arms are sufficient for a targeted single-copy insertion of the CAT selection marker into the nuclear genome. By means of a combination of the URA and CAT transformation systems, we succeeded in producing a C. merolae strain that expresses HA-cyclin 1 and FLAG-CDKA from the chromosomal CYC1 and CDKA loci, respectively. These methods of multiple nuclear targeting will facilitate genetic manipulation of C. merolae.

Ethical Issues and Potential Stakeholder Priorities Associated with the Application of Genomic Technologies Applied to Animal Production Systems

This study considered the range of ethical issues and potential stakeholder priorities associated with the application of genomic technologies applied to animal production systems, in particular those which utilised genomic technologies in accelerated breeding rather than the application of genetic modification. A literature review was used to inform the development of an ethical matrix, which was used to scope the potential perspectives of different agents regarding the acceptability of genomic technologies, as opposed to genetic modification (GM) techniques applied to animal production systems. There are very few studies carried out on stakeholder (including consumer) attitudes regarding the application of genomics to animal production in the human food chain and it may be that this technology is perceived as no more than an extension of traditional breeding techniques. While this is an area which needs more research, it would appear from this study that genomics, because it avoids many of the disadvantages and consumer perceptions associated with GM, is likely to prove a more publicly acceptable route than is GM for the development of healthier and more productive animals. However, stakeholders also need to have an approach to the moral status of the animals involved that finds credibility and acceptability with civil society.

Isolation of the Atlantic salmon β-actin promoter and its use to drive expression in salmon cells in culture and in transgenic zebrafish

The application of genetic modification offers considerable opportunities for more efficient and more effective fish aquaculture. Susceptibility to infectious diseases and limitations in growth rates could be successfully tackled by the application of transgenic technology. Acceptance of transgenic technology applied to commercial fish has to surmount technical difficulties, regulatory barriers and public acceptance concerns. It seems desirable to implement transgenesis strategies that cause the least qualitative and quantitative alterations in the genetic composition of the resulting enhanced fish. With Atlantic salmon being the most important farmed fish worldwide, it seemed of interest to obtain genomic sequences from this species capable of directing autogenic expression of selected transgenes. We now report the isolation of the β-actin promoter from genomic DNA of Atlantic salmon locally produced in Chile. The activity of the promoter was demonstrated ex vivo in cultured salmon cells, as well as in vivo in transgenic fish. Transiently transfected CHSE-214 cells exhibited constitutive expression of reporter constructs driven by the cloned salmon β-actin genomic region. The suitability of the Atlantic salmon β-actin promoter to drive expression of the fluorescent protein EGFP in transgenic zebrafish was demonstrated. Germline transmission of the transgenes suggests that this promoter could be safely applied into fish transgenesis without health concerns. The isolation of functionally competent β-actin promoter from Atlantic salmon opens the way for its use in autogenic transgenesis in this commercially important salmonid species.

Consumer attitudes toward genetic modification and sustainability: implications for the future of biorenewables

AbstractConsumers are increasingly interested in sustainability and more sustainable production methods but, especially in Europe, they have been quite critical toward particular applications of genetic modification (GM). While there is little doubt that the sustainability issue entails substantial opportunities for biorenewables, the GM issue –posing either a threat or an opportunity –is less straightforward. Although initial findings suggest that European consumers feel positive about biotechnology applications for biofuel production, consumer attitudes toward and acceptance of GM, specifically in the production of biorenewables, have not been investigated in depth, leaving numerous questions unresolved and calling for further social sciences research in this area. A particularly interesting path to explore is to what extent the consumer's belief that GM is tampering with nature, and therefore is ethically wrong, might be outweighed by the perception that GM in biorenewables production contributes to re‐establishing the balance in nature and therefore is beneficial overall. Further challenges pertain to communication, providing tangible benefits to consumers, and monitoring consumer acceptance and adoption of biorenewables. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd

Ethical Tools to Support Systematic Public Deliberations about the Ethical Aspects of Agricultural Biotechnologies

This special issue of the Journal of Agricultural and Environmental Ethics presents so-called ethical tools that are developed to support systematic public deliberations about the ethical aspects of agricultural biotechnologies. This paper firstly clarifies the intended connotations of the term “ethical tools” and argues that such tools can support liberal democracies to cope with the issues that are raised by the application of genetic modification and other modern biotechnologies in agriculture and food production. The paper secondly characterizes the societal discussion on agricultural biotechnology and defends the thesis that normative perspectives fuel this discussion, so one cannot come to grips with this discussion if one neglects these perspectives. The paper thirdly agrues that no such thing exists as “one” societal debate in which these issues should be discussed. There are several interwined debates, and different actors participate in different discourses. Some practical instruments are necessary in order to include the right issues in these debates. These instruments will be coined as “ethical tools,” since they are practical instruments that can be used (tools) in order to support debates and deliberative structures for a systematic engagement with ethical issues (hence, ethical tools). Finally, the paper clarifies the ethics of these ethical tools and presents the tools as discussed in the remainder of this special issue: 1) tools to include ethical issues in public consulation and involvement; 2) tools to support systematic reflection upon ethical issues in decision-making; and 3) tools to support explicit communication about values in the food chain.

Consumer perceptions of food products involving genetic modification—results from a qualitative study in four Nordic countries

Product descriptions of cheese, candy and salmon products were presented to samples of respondents in four Nordic countries. The descriptions represented various applications of genetic modification (GM), varied along a ‘distance’ dimension and a ‘what is modified’ dimension, and were presented along with a conventionally produced product. Respondents ranked the products according to preference, and their perceptions were ascertained by the laddering method. Results indicate that respondents regard ‘non-GM’ as a value in itself, and associate the use of GM with a host of negative consequences and risks, but mostly with uncertainty and unhealthiness. Benefits of the use of GM were perceived and regarded as relevant, but could not compensate for the negative associations. The ‘distance’ dimension had a clear impact on consumer preferences, whereas the ‘what is modified’ dimension had effects which were product specific.

Food biotechnology: current developments and the need for awareness

Discusses some current and future applications of genetic modification of food production, and describes some of the initiatives under way to raise awareness of these developments among industry and consumer groups.

Working Group VII: Food Products

The working group recognised that many international and national organisations had developed strategies for evaluating the safety of new food products produced by the application of genetic modification. These strategies were necessarily fairly general and the group agreed that it should focus its attention on the pathogenicity and toxicity of live microorganisms used in food.