Policy Considerations Regarding Genome Editing

Application of new breeding techniques in fruit trees

Climate change and rapid adaption of invasive pathogens pose a constant pressure on the fruit industry to develop improved varieties. Aiming to accelerate the development of better-adapted cultivars, new breeding techniques have emerged as a promising alternative to meet the demand of a growing global population. Accelerated breeding, cisgenesis, and CRISPR/Cas genome editing hold significant potential for crop trait improvement and have proven to be useful in several plant species. This review focuses on the successful application of these technologies in fruit trees to confer pathogen resistance and tolerance to abiotic stress and improve quality traits. In addition, we review the optimization and diversification of CRISPR/Cas genome editing tools applied to fruit trees, such as multiplexing, CRISPR/Cas-mediated base editing and site-specific recombination systems. Advances in protoplast regeneration and delivery techniques, including the use of nanoparticles and viral-derived replicons, are described for the obtention of exogenous DNA-free fruit tree species. The regulatory landscape and broader social acceptability for cisgenesis and CRISPR/Cas genome editing are also discussed. Altogether, this review provides an overview of the versatility of applications for fruit crop improvement, as well as current challenges that deserve attention for further optimization and potential implementation of new breeding techniques.

Processes for regulating genetically modified and gene edited plants

Innovation in agriculture has been essential in improving productivity of crops and forages to support a growing population, improving living standards while contributing toward maintaining environment integrity, human health, and wellbeing through provision of more nutritious, varied, and abundant food sources. A crucial part of that innovation has involved a range of techniques for both expanding and exploiting the genetic potential of plants. However, some techniques used for generating new variation for plant breeders to exploit are deemed higher risk than others despite end products of both processes at times being for all intents and purposes identical for the benefits they provide. As a result, public concerns often triggered by poor communication from innovators, resulting in mistrust and suspicion has, in turn, caused the development of a range of regulatory systems. The logic and motivations for modes of regulation used are reviewed and how the benefits from use of these technologies can be delivered more efficiently and effectively is discussed.

3Bs of CRISPR-Cas mediated genome editing in plants: exploring the basics, bioinformatics and biosafety landscape

The recent thrust in research has projected the type II clustered regularly interspaced short palindromic repeats and associated protein 9 (CRISPR-Cas9) system as an avant-garde plant genome editing tool. It facilitates the induction of site-specific double-stranded DNA cleavage by the RNA-guided DNA endonuclease (RGEN), Cas9. Elimination, addition, or alteration of sections in DNA sequence besides the creation of a knockout genotype (CRISPRko) is aided by the CRISPR-Cas9 system in its wild form (wtCas9). The inactivation of the nuclease domain generates a dead Cas9 (dCas9), which is capable of targeting genomic DNA without scissoring it. The dCas9 system can be engineered by fusing it with different effectors to facilitate transcriptional activation (CRISPRa) and transcriptional interference (CRISPRi). CRISPR-Cas thus holds tremendous prospects as a genome-manipulating stratagem for a wide gamut of crops. In this article, we present a brief on the fundamentals and the general workflow of the CRISPR-Cas system followed by an overview of the prospects of bioinformatics in propelling CRISPR-Cas research with a special thrust on the available databases and algorithms/web-accessible applications that have aided in increasing the usage and efficiency of editing. The article also provides an update on the current regulatory landscape in different countries on the CRISPR-Cas edited plants to emphasize the far-reaching impact of the genomic editing technology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01397-3.

Parameters, practices, and preferences for regulatory review of emerging biotechnology products in food and agriculture

This paper evaluates the U.S. regulatory review of three emerging biotechnology products according to parameters, practices, and endpoints of assessments that are important to stakeholders and publics. First, we present a summary of the literature on variables that are important to non-expert publics in governing biotech products, including ethical, social, policy process, and risk and benefit parameters. Second, we draw from our USDA-funded project results that surveyed stakeholders with subject matter expertise about their attitudes towards important risk, benefit, sustainability, and societal impact parameters for assessing novel agrifood technologies, including biotech. Third, we evaluate the regulatory assessments of three food and agricultural biotechnology case studies that have been reviewed under U.S. regulatory agencies and laws of the Coordinated Framework for the Regulation of Biotechnology, including gene-edited soybeans, beef cattle, and mustard greens. Evaluation of the regulatory review process was based on parameters identified in steps 1 and 2 which were deemed important to both publics and stakeholders. Based on this review, we then propose several policy options for U.S. federal agencies to strengthen their oversight processes to better align with a broader range of parameters to support sustainable agrifood products that rely on novel technologies. These policy options include 1) those that would not require new institutions or legal foundations (such as conducting Environmental Impact Statements and/or requiring a minimal level of safety data), 2) those that would require a novel institutional or cross-institutional framework (such as developing a publicly-available website and/or performing holistic sustainability assessments), and 3) those that would require the agencies to have additional legal authorities (such as requiring agencies to review biotech products according to a minimal set of health, environmental, and socio-economic parameters). Overall, the results of this analysis will be important for guiding policy practice and formulation in the regulatory assessment of emerging biotechnology products that challenge existing legal and institutional frameworks.

Editing the genome of common cereals (Rice and Wheat): techniques, applications, and industrial aspects

Gene editing techniques have made a significant contribution to the development of better crops. Gene editing enables precise changes in the genome of crops, which can introduce new possibilities for altering the crops' traits. Since the last three decades, various gene editing techniques such as meganucleases, zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and clustered regularly interspersed short palindromic repeats (CRISPR)/Cas (CRISPR-associated proteins) have been discovered. In this review, we discuss various gene editing techniques and their applications to common cereals. Further, we elucidate the future of gene-edited crops, their regulatory features, and industrial aspects globally. To achieve this, we perform a comprehensive literature survey using databases such as PubMed, Web of Science, SCOPUS, Google Scholar etc. For the literature search, we used keywords such as gene editing, crop genome modification, CRISPR/Cas, ZFN, TALEN, meganucleases etc. With the advent of the CRISPR/Cas technology in the last decade, the future of gene editing has transitioned into a new dimension. The functionality of CRISPR/Cas in both DNA and RNA has increased through the use of various Cas enzymes and their orthologs. Constant research efforts in this direction have improved the gene editing process for crops by minimizing its off-target effects. Scientists also use computational tools, which help them to design experiments and analyze the results of gene editing experiments in advance. Gene editing has diverse potential applications. In the future, gene editing will open new avenues for solving more agricultural issues and boosting crop production, which may have great industrial prospects.

Animal Transgenesis and Cloning: Combined Development and Future Perspectives

The revolution in animal transgenesis began in 1981 and continues to become more efficient, cheaper, and faster to perform. New genome editing technologies, especially CRISPR-Cas9, are leading to a new era of genetically modified or edited organisms. Some researchers advocate this new era as the time of synthetic biology or re-engineering. Nonetheless, we are witnessing advances in high-throughput sequencing, artificial DNA synthesis, and design of artificial genomes at a fast pace. These advances in symbiosis with animal cloning by somatic cell nuclear transfer (SCNT) allow the development of improved livestock, animal models of human disease, and heterologous production of bioproducts for medical applications. In the context of genetic engineering, SCNT remains a useful technology to generate animals from genetically modified cells. This chapter addresses these fast-developing technologies driving this biotechnological revolution and their association with animal cloning technology.

Gene-Editing Technologies and Applications in Legumes: Progress, Evolution, and Future Prospects

Legumes are rich in protein and phytochemicals and have provided a healthy diet for human beings for thousands of years. In recognition of the important role they play in human nutrition and agricultural production, the researchers have made great efforts to gain new genetic traits in legumes such as yield, stress tolerance, and nutritional quality. In recent years, the significant increase in genomic resources for legume plants has prepared the groundwork for applying cutting-edge breeding technologies, such as transgenic technologies, genome editing, and genomic selection for crop improvement. In addition to the different genome editing technologies including the CRISPR/Cas9-based genome editing system, this review article discusses the recent advances in plant-specific gene-editing methods, as well as problems and potential benefits associated with the improvement of legume crops with important agronomic properties. The genome editing technologies have been effectively used in different legume plants including model legumes like alfalfa and lotus, as well as crops like soybean, cowpea, and chickpea. We also discussed gene-editing methods used in legumes and the improvements of agronomic traits in model and recalcitrant legumes. Despite the immense opportunities genome editing can offer to the breeding of legumes, governmental regulatory restrictions present a major concern. In this context, the comparison of the regulatory framework of genome editing strategies in the European Union and the United States of America was also discussed. Gene-editing technologies have opened up new possibilities for the improvement of significant agronomic traits in legume breeding.

Regulatory and Policy Considerations Around Genome Editing in Agriculture

The increasingly widespread use of genome editing brought with it a fierce debate about the most adequate regulation of this latest innovation in modern biotechnology and the products resulting from it. In almost all cases, this debate has become a repetition or continuation of the deliberations concerning genetically modified organisms (GMOs) of the 1990s and early 2000s.This chapter aims to untangle the historically influenced and often biased arguments of the debates by addressing the complex question of the correct interpretation of relevant underlying law and its applicability. In doing so, the chapter considers 25 countries and regions that have published results or ongoing investigations and discussions pertaining to the governance of genome editing in their jurisdictions: 16 have published policies or signed statements that exempt gene edited plants from GMO-regulations, as long as no foreign DNA or transgene remained in the final product. Such exemptions are based on the widely supported acceptance that the products of the underlying genome editing processes resemble those of "conventional breeding" techniques. These policies and statements often refer to the important role that modern precision biotechnologies, of which genome editing is one, play in addressing some of the world's overarching challenges, such as the loss of biodiversity, pest and disease control, and climate change; they are furthermore shown to exhibit an adherence to the four universal principles of good regulation: (a) proportionality, (b) non-discrimination, (c) predictability, and (d) enforceability. And while it is the right of jurisdictions to develop their own regulations independent from that of their neighbors, it is specifically the principle of "enforceability" that may become the ultimate litmus test of those regulations that do not grant exemptions from GMO-regulations.

Public Perceptions Regarding Genomic Technologies Applied to Breeding Farm Animals: A Qualitative Study

The societal acceptability of different applications of genomic technologies to animal production systems will determine whether their innovation trajectories will reach the commercialisation stage. Importantly, technological implementation and commercialisation trajectories, regulation, and policy development need to take account of public priorities and attitudes. More effective co-production practices will ensure the application of genomic technologies to animals aligns with public priorities and are acceptable to society. Consumer rejection of, and limited demand for, animal products developed using novel genomic technologies will determine whether they are integration into the food system. However, little is known about whether genomic technologies that accelerate breeding but do not introduce cross-species genetic changes are more acceptable to consumers than those that do. Five focus groups, held in the north east of England, were used to explore the perceptions of, and attitudes towards, the use of genomic technologies in breeding farm animals for the human food supply chain. Overall, study participants were more positive towards genomic technologies applied to promote animal welfare (e.g., improved disease resistance), environmental sustainability, and human health. Animal “disenhancement” was viewed negatively and increased food production alone was not perceived as a potential benefit. In comparison to gene editing, research participants were most negative about genetic modification and the application of gene drives, independent of the benefits delivered.

Biosafety of Genome Editing Applications in Plant Breeding: Considerations for a Focused Case-Specific Risk Assessment in the EU

An intensely debated question is whether or how a mandatory environmental risk assessment (ERA) should be conducted for plants obtained through novel genomic techniques, including genome editing (GE). Some countries have already exempted certain types of GE applications from their regulations addressing genetically modified organisms (GMOs). In the European Union, the European Court of Justice confirmed in 2018 that plants developed by novel genomic techniques for directed mutagenesis are regulated as GMOs. Thus, they have to undergo an ERA prior to deliberate release or being placed on the market. Recently, the European Food Safety Authority (EFSA) published two opinions on the relevance of the current EU ERA framework for GM plants obtained through novel genomic techniques (NGTs). Regarding GE plants, the opinions confirmed that the existing ERA framework is suitable in general and that the current ERA requirements need to be applied in a case specific manner. Since EFSA did not provide further guidance, this review addresses a couple of issues relevant for the case-specific assessment of GE plants. We discuss the suitability of general denominators of risk/safety and address characteristics of GE plants which require particular assessment approaches. We suggest integrating the following two sets of considerations into the ERA: considerations related to the traits developed by GE and considerations addressing the assessment of method-related unintended effects, e.g., due to off-target modifications. In conclusion, we recommend that further specific guidance for the ERA and monitoring should be developed to facilitate a focused assessment approach for GE plants.

An Editing-Site-Specific PCR Method for Detection and Quantification of CAO1-Edited Rice

Genome-edited plants created by genome editing technology have been approved for commercialization. Due to molecular characteristics that differ from classic genetically modified organisms (GMOs), establishing regulation-compliant analytical methods for identification and quantification of genome-edited plants has always been regarded as a challenging task. An editing-site-specific PCR method was developed based on the unique edited sequence in CAO1-edited rice plants. Test results of seven primer/probe sets indicated that this method can identify specific CAO1-edited rice from other CAO1-edited rice and wild types of rice with high specificity and sensitivity. The use of LNA (locked nucleic acid) in a probe can efficiently increase the specificity of the editing-site-specific PCR method at increased annealing temperature which can eliminate non-specific amplification of the non-target. The genome-edited ingredient content in blinded samples at the level of 0.1% to 5.0% was accurately quantified by this method on the ddPCR platform with RSD of <15% and bias in the range of ±17%, meeting the performance requirements for GMO detection method. The developed editing-site-specific PCR method presents a promising detection and quantification technique for genome-edited plants with known edited sequence.

Genome engineering for crop improvement and future agriculture

Feeding the ever-growing population is a major challenge, especially in light of rapidly changing climate conditions. Genome editing is set to revolutionize plant breeding and could help secure the global food supply. Here, I review the development and application of genome editing tools in plants while highlighting newly developed techniques. I describe new plant breeding strategies based on genome editing and discuss their impact on crop production, with an emphasis on recent advancements in genome editing-based plant improvements that could not be achieved by conventional breeding. I also discuss challenges facing genome editing that must be overcome before realizing the full potential of this technology toward future crops and food production.

Genome Edited Crops Touch the Market: A View on the Global Development and Regulatory Environment

Products of genome editing as the most promising "New Plant Breeding Technology" (NPBT) have made the transition from the lab to the market in a short time. Globally, research activities employing genome editing are constantly expanding and more and more plants with market-oriented traits are being developed, and companies have already released the first genome edited crops to the market. Few countries, most of which are located in the Americas, have adapted legislations to these technologies or released guidelines supporting the use of genome editing. Other countries are debating the path to come either because there is no clarity on the legal classification or due consensus is hampered by a renewed GMO debate. In recent years (2017-2020), eight countries have introduced guidelines clarifying the legal status of genome edited products and many of those are actively committed to international harmonization of their policies. In this publication we give an overview on the current and potentially future international regulatory environment and an update on plants derived by genome editing with market-oriented traits.