Plants Developed by New Genetic Modification Techniques-Comparison of Existing Regulatory Frameworks in the EU and Non-EU Countries

Suitability of Real-Time PCR Methods for New Genomic Technique Detection in the Context of the European Regulations: A Case Study in Arabidopsis

PCR methods are widely applied for the detection of genetically modified organisms (GMOs) in Europe, facilitating compliance with stringent regulatory requirements and enabling the accurate identification and quantification of genetically modified traits in various crops and foodstuffs. This manuscript investigates the suitability of real-time PCR methods for detecting organisms generated through new genomic techniques (NGTs), specifically focusing on a case study using Arabidopsis thaliana as a model gene-edited plant. Given the complexities of European regulations regarding genetically modified organisms (GMOs) and the classification of gene-edited plants, there is a pressing need for robust detection methods. Our study highlights the development and validation of a novel single-plex real-time PCR method targeting a specific single nucleotide polymorphism (SNP) in the grf1-3 gene modified using CRISPR-Cas9 technology. We emphasize the effectiveness of locked nucleic acid (LNA)-modified primers in improving specificity. The results demonstrate that while the grf1-3 LNA method successfully detected and quantified gene-edited Arabidopsis DNA, achieving absolute specificity remains a challenge. This study also addresses the significance of the cross-laboratory method for validation, demonstrating that the method developed for an SNP-modified allele can be performed in accordance with the precision and trueness criteria established by the European Network of GMO Laboratories (ENGL). Furthermore, we call for continued collaboration among regulatory agencies, academia, and industry stakeholders to refine detection strategies. This proactive approach is essential not only for regulatory compliance but also for maintaining public trust in the safe integration of gene-edited organisms into food products.

Environmental Applications of GM Microorganisms: Tiny Critters Posing Huge Challenges for Risk Assessment and Governance

In recent years, the interest in developing genetically modified microorganisms (GMMs), including GMMs developed by genome editing, for use in the environment has significantly increased. However, the scientific knowledge on the ecology of such GMMs is severely limited. There is also little experience at the hands of regulators on how to evaluate the environmental safety of GMMs and on how to assess whether they provide sustainable alternatives to current (agricultural) production systems. This review analyzes two different GMM applications, GM microalgae for biofuel production and nitrogen-fixing GM soil bacteria for use as biofertilizers. We assess the challenges posed by such GMMs for regulatory environmental risk assessment (ERA) against the background of the GMO legislation existing in the European Union (EU). Based on our analysis, we present recommendations for ERA and the monitoring of GMM applications, and in particular for the improvement of the existing EU guidance. We also explore whether existing approaches for technology assessment can provide a framework for the broader assessment of GMM applications. To this end, we recommend developing and implementing an evidence-based sustainability analysis and other methods of technology assessment to support decision making and to address broader societal concerns linked to the use of GMM applications in the environment.

Emerging applications of gene editing technologies for the development of climate-resilient crops

Climate change threatens global crop yield and food security due to rising temperatures, erratic rainfall, and increased abiotic stresses like drought, heat, and salinity. Gene editing technologies, including CRISPR/Cas9, base editors, and prime editors, offer precise tools for enhancing crop resilience. This review explores the mechanisms of these technologies and their applications in developing climate-resilient crops to address future challenges. While CRISPR/enables targeted modifications of plant DNA, the base editors allow for direct base conversion without inducing double-stranded breaks, and the prime editors enable precise insertions, deletions, and substitutions. By understanding and manipulating key regulator genes involved in stress responses, such as DREB, HSP, SOS, ERECTA, HsfA1, and NHX; crop tolerance can be enhanced against drought, heat, and salt stress. Gene editing can improve traits related to root development, water use efficiency, stress response pathways, heat shock response, photosynthesis, membrane stability, ion homeostasis, osmotic adjustment, and oxidative stress response. Advancements in gene editing technologies, integration with genomics, phenomics, artificial intelligence (AI)/machine learning (ML) hold great promise. However, challenges such as off-target effects, delivery methods, and regulatory barriers must be addressed. This review highlights the potential of gene editing to develop climate-resilient crops, contributing to food security and sustainable agriculture.

Translocation of green fluorescent protein in homo- and hetero-transgrafted plants

Transgrafting, a technique involving the use of genetically modified (GM) plants as grafting partners with non-genetically modified (non-GM) crops, presents non-GM edible harvests from transgrafted crops, often considered as non-GM products. However, the classification of the non-GM portions from transgrafted crops as non-GM foods remains uncertain, therefore it is critical to investigate the potential translocation of substances from GM portions to non-GM edible portions in transgrafted plants. In this study, we explored the translocation of exogenous proteins (luciferase and green fluorescent protein) in model transgrafted plants consisting of GM plant rootstocks and non-GM tomato scions. Our results suggest that exogenous proteins accumulated in the stem tissues of non-GM tomato scions in all cases investigated. The levels and patterns of exogenous protein accumulation in the non-GM tomato stem tissues varied among the individual transgrafted plants and rootstock plant species used. However, exogenous proteins were not detected in the fruits, the edible part of the tomato, and in mature leaves in non-GM tomato scions under the current experimental conditions. Our results provide basic knowledge for understanding exogenous protein translocation in transgrafted plants.

An Isoflavone Synthase Gene in Arachis hypogea Responds to Phoma arachidicola Infection Causing Web Blotch

Peanut web blotch is an important leaf disease caused by Phoma arachidicola, which seriously affects the quality and yield of peanuts. However, the molecular mechanisms of peanut resistance to peanut web blotch are not well understood. In this study, a transcriptome analysis of the interaction between peanut (Arachis hypogaea) and P. arachidicola revealed that total 2989 (779 up- and 2210 down-regulated) genes were all differentially expressed in peanut leaves infected by P. arachidicola at 7, 14, 21 days post inoculation. The pathways that were strongly differentially expressed were the flavone or isoflavone biosynthesis pathways. In addition, two 2-hydroxy isoflavanone synthase genes, IFS1 and IFS2, were strongly induced by P. arachidicola infection. Overexpression of the two genes enhanced resistance to Phytophthora parasitica in Nicotiana benthamiana. Knockout of AhIFS genes in peanut reduced disease resistance to P. arachidicola. These findings demonstrated that AhIFS genes play key roles in peanut resistance to P. arachidicola infection. Promoter analysis of the two AhIFS genes showed several defense-related cis-elements distributed in the promoter region. This study improves our understanding of the molecular mechanisms behind resistance of peanut infection by P. arachidicola, and provides important information that could be used to undertake greater detailed characterization of web blotch resistance genes in peanut.

Drought stress mitigation through bioengineering of microbes and crop varieties for sustainable agriculture and food security

Climate change and agriculture are intrinsically connected and sudden changes in climatic conditions adversely impact global food production and security. The climate change-linked abiotic stressors like drought and high temperatures are resulting in crop failure. The most severe abiotic stress drought significantly affect the stomatal closure, production of reactive oxygen species, transpiration, photosynthesis or other physiological processes and plant morphology, and adversely affect plant growth and crop yield. Therefore, there is an exigent need for cost effective and eco-friendly modern technologies to induce drought tolerance in crop plants leading to climate-adapted sustainable agricultural practices for sustained food production. Among many options being pursued in this regard, the use of plant growth promoting microbes (PGPMs) is the most sustainable approach to promote drought stress resilience in crop plants leading to better plant growth and crop productivity. These PGPMs confer drought resistance via various direct or indirect mechanisms including production of antioxidants, enzymes, exopolysaccharides, modulation of phytohormones level, osmotic adjustment by inducing the accumulation of sugars, along with increases in nutrients, water uptake and photosynthetic pigments. However, several technological and ecological challenges limit their use in agriculture and sometimes treatment with plant beneficial microbes fails to produce desired results under field conditions. Thus, development of synthetic microbial communities or host mediated microbiome engineering or development of transgenic plants with the capacity to express desired traits may promote plant survival and growth under drought stress conditions. The present review critically assesses research evidence on the plant growth and stress resilience promoting potentials of PGPMs and their genes as an approach to develop drought resilient plants leading to increased crop productivity. Effective collaboration among scientific communities, policymakers and regulatory agencies is needed to create strong frameworks that both promote and regulate the utilization of synthetic microbial communities and transgenic plants in agriculture.

Exogenous Uniconazole promotes physiological metabolism and grain yield of rice under salt stress

Introduction

Salt stress severely inhibit plant growth and development. Uniconazole has been considered to significantly increase plant stress tolerance. However, the mechanism by which Uniconazole induces salt tolerance in rice seedlings and its impact on yield is still unclear.

Methods

In this study, the effects of exogenous Uniconazole on morphogenesis, physiological metabolism, and yield of rice seedlings under salt stress were analyzed using the salt-tolerant rice variety HD961 and the salt-sensitive rice variety 9311.

Results

The results showed that salt stress significantly inhibited rice growth, disrupted the antioxidant system and pigment accumulation, and reduced photosynthesis, and yield. There were corresponding percent decreases of 13.0% and 24.1% in plant height, 31.6% and 55.8% in leaf area, 65.7% and 85.3% in root volume, respectively for HD961 and 9311. spraying However, compared to salt stress, the US treatment increased the percentage to 4.7% and 139.0% in root volume, 7.5% and 38.0% in total chlorophyll, 4.5% and 14.3% in peroxidase (POD) of leaves, 14.4% and 54.2% in POD of roots, 18.7% and 22.7% in catalase (CAT) of leaves, and 22.6% and 53.9% in CAT of roots, respectively, for HD961 and 9311. In addition, it also significantly enhanced photosynthesis at the reproductive stage, promoted the transport of carbohydrate to grains. And US treatment significantly increased the percentage to 9.0% in panicle length, 28.0% in panicle number per hole, 24.0% in filled grain number, 3.0% in 1000-grain weight, and 26.0% in yield per plant, respectively, for HD961, compared to salt stress.

Discussion

In summary, applying Uniconazole at the seedling stage can alleviate the damage induced by NaCl stress on rice by regulating the physiological metabolism of rice plants. This reduces the negative effects of salt stress, enhance salt tolerance, and boost rice production.

CRISPR/Cas9-mediated genome editing technique to control fall armyworm (Spodoptera frugiperda) in crop plants with special reference to maize

Fall Armyworm imposes a major risk to agricultural losses. Insecticides have historically been used to manage its infestations, but it eventually becomes resistant to them. To combat the pest, a more recent strategy based on the use of transgenic maize that expresses Bt proteins such as Cry1F from the bacteria has been used. Nonetheless, there have been numerous reports of Cry1F maize resistance in FAW populations. Nowadays, the more effective and less time-consuming genome editing method known as CRISPR/Cas9 technology has gradually supplanted these various breeding techniques. This method successfully edits the genomes of various insects, including Spodoptera frugiperda. On the other hand, this new technique can change an insect's DNA to overcome its tolerance to specific insecticides or to generate a gene drive. The production of plant cultivars resistant to fall armyworms holds great potential for the sustainable management of this pest, given the swift advancement of CRISPR/Cas9 technology and its varied uses. Thus, this review article discussed and critically assessed the use of CRISPR/Cas9 genome-editing technology in long-term fall armyworm pest management. However, this review study focuses primarily on the mechanism of the CRISPR-Cas9 system in both crop plants and insects for FAW management.

Horizon scanning of potential environmental applications of terrestrial animals, fish, algae and microorganisms produced by genetic modification, including the use of new genomic techniques

With scientific progress and the development of new genomic techniques (NGTs), the spectrum of organisms modified for various purposes is rapidly expanding and includes a wide range of taxonomic groups. An improved understanding of which newly developed products may be introduced into the market and released into the environment in the near and more distant future is of particular interest for policymakers, regulatory authorities, and risk assessors. To address this information need, we conducted a horizon scanning (HS) of potential environmental applications in four groups of organisms: terrestrial animals (excluding insects and applications with gene drives), fish, algae and microorganisms. We applied a formal scoping review methodology comprising a structured search of the scientific literature followed by eligibility screening, complemented by a survey of grey literature, and regulatory websites and databases. In all four groups of organisms we identified a broad range of potential applications in stages of basic as well as advanced research, and a limited number of applications which are on, or ready to be placed on, the market. Research on GM animals including fish is focused on farmed animals and primarily targets traits which increase performance, influence reproduction, or convey resistance against diseases. GM algae identified in the HS were all unicellular, with more than half of the articles concerning biofuel production. GM algae applications for use in the environment include biocontrol and bioremediation, which are also the main applications identified for GM microorganisms. From a risk assessor's perspective these potential applications entail a multitude of possible pathways to harm. The current limited level of experience and limited amount of available scientific information could constitute a significant challenge in the near future, for which risk assessors and competent authorities urgently need to prepare.

Adoption of CRISPR-Cas for crop production: present status and future prospects

Background

Global food systems in recent years have been impacted by some harsh environmental challenges and excessive anthropogenic activities. The increasing levels of both biotic and abiotic stressors have led to a decline in food production, safety, and quality. This has also contributed to a low crop production rate and difficulty in meeting the requirements of the ever-growing population. Several biotic stresses have developed above natural resistance in crops coupled with alarming contamination rates. In particular, the multiple antibiotic resistance in bacteria and some other plant pathogens has been a hot topic over recent years since the food system is often exposed to contamination at each of the farm-to-fork stages. Therefore, a system that prioritizes the safety, quality, and availability of foods is needed to meet the health and dietary preferences of everyone at every time.

Methods

This review collected scattered information on food systems and proposes methods for plant disease management. Multiple databases were searched for relevant specialized literature in the field. Particular attention was placed on the genetic methods with special interest in the potentials of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and Cas (CRISPR associated) proteins technology in food systems and security.

Results

The review reveals the approaches that have been developed to salvage the problem of food insecurity in an attempt to achieve sustainable agriculture. On crop plants, some systems tend towards either enhancing the systemic resistance or engineering resistant varieties against known pathogens. The CRISPR-Cas technology has become a popular tool for engineering desired genes in living organisms. This review discusses its impact and why it should be considered in the sustainable management, availability, and quality of food systems. Some important roles of CRISPR-Cas have been established concerning conventional and earlier genome editing methods for simultaneous modification of different agronomic traits in crops.

Conclusion

Despite the controversies over the safety of the CRISPR-Cas system, its importance has been evident in the engineering of disease- and drought-resistant crop varieties, the improvement of crop yield, and enhancement of food quality.

A comparative analysis of attitudes toward genome-edited food among Japanese public and scientific community

Genome editing technologies such as CRISPR/Cas9 have been developed in the last decade and have been applied to new food technologies. Genome-edited food (GEF) is a crucial issue with those new food technologies. Thus, each country has established GEF governance systems to maximize benefits and minimize risks. These emphasize the importance of communicating about GEF to the public. The key concerns are understanding various viewpoints and value perspectives (framings) in science and technology and encouraging and opening communication with the public. Thus, it is essential to understand differences between the public and experts' interests and discuss various framings and effective communication with regard to GEF. Accordingly, this study involved administering a questionnaire to analyze the public's attitudes in Japan and identify gaps between these and expert opinions on GEF. A total of 4000 responses from the public and 398 responses from GEF experts were collected. The study found that the Japanese public has a "wait-and-watch" attitude toward GEF, and the demand for basic information on it is quite high. Moreover, they are apprehensive about proper risk governance systems for GEF. This is despite experts' emphasis on the adequacy of the mechanism, necessity of technology, and trust in the scientific community. Understanding gaps between the public and experts' opinions on and interests in GEF provides essential insight for effective communication and acts as the basis for appropriate governance of emerging science and technology.

Epigenome editing for targeted DNA (de)methylation: a new perspective in modulating gene expression

Traditionally, it has been believed that inheritance is driven as phenotypic variations resulting from changes in DNA sequence. However, this paradigm has been challenged and redefined in the contemporary era of epigenetics. The changes in DNA methylation, histone modification, non-coding RNA biogenesis, and chromatin remodeling play crucial roles in genomic functions and regulation of gene expression. More importantly, some of these changes are inherited to the next generations as a part of epigenetic memory and play significant roles in gene expression. The sum total of all changes in DNA bases, histone proteins, and ncRNA biogenesis constitutes the epigenome. Continuous progress in deciphering epigenetic regulations and the existence of heritable epigenetic/epiallelic variations associated with trait of interest enables to deploy epigenome editing tools to modulate gene expression. DNA methylation marks can be utilized in epigenome editing for the manipulation of gene expression. Initially, genome/epigenome editing technologies relied on zinc-finger protein or transcriptional activator-like effector protein. However, the discovery of clustered regulatory interspaced short palindromic repeats CRISPR)/deadCRISPR-associated protein 9 (dCas9) enabled epigenome editing to be more specific/efficient for targeted DNA (de)methylation. One of the major concerns has been the off-target effects, wherein epigenome editing may unintentionally modify gene/regulatory element which may cause unintended change/harmful effects. Moreover, epigenome editing of germline cell raises several ethical/safety issues. This review focuses on the recent developments in epigenome editing tools/techniques, technological limitations, and future perspectives of this emerging technology in therapeutics for human diseases as well as plant improvement to achieve sustainable developmental goals.

Strategies for Traceability to Prevent Unauthorised GMOs (Including NGTs) in the EU: State of the Art and Possible Alternative Approaches

The EU's regulatory framework for genetically modified organisms (GMOs) was developed for "classical" transgenic GMOs, yet advancements in so-called "new genomic techniques (NGTs)" have led to implementation challenges regarding detection and identification. As traceability can complement detection and identification strategies, improvements to the existing traceability strategy for GMOs are investigated in this study. Our results are based on a comprehensive analysis of existing traceability systems for globally traded agricultural products, with a focus on soy. Alternative traceability strategies in other sectors were also analysed. One focus was on traceability strategies for products with characteristics for which there are no analytical verification methods. Examples include imports of "conflict minerals" into the EU. The so-called EU Conflict Minerals Regulation requires importers of certain raw materials to carry out due diligence in the supply chain. Due diligence regulations, such as the EU's Conflict Minerals Regulation, can legally oblige companies to take responsibility for certain risks in their supply chains. They can also require the importer to prove the regional origin of imported goods. The insights from those alternative traceability systems are transferred to products that might contain GMOs. When applied to the issue of GMOs, we propose reversing the burden of proof: All companies importing agricultural commodities must endeavour to identify risks of unauthorised GMOs (including NGTs) in their supply chain and, where appropriate, take measures to minimise the risk to raw material imports. The publication concludes that traceability is a means to an end and serves as a prerequisite for due diligence in order to minimise the risk of GMO contamination in supply chains. The exemplary transfer of due diligence to a company in the food industry illustrates the potential benefits of mandatory due diligence, particularly for stakeholders actively managing non-GMO supply chains.

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.

CRISPR Variants for Gene Editing in Plants: Biosafety Risks and Future Directions

The CRISPR genome editing technology is a crucial tool for enabling revolutionary advancements in plant genetic improvement. This review shows the latest developments in CRISPR/Cas9 genome editing system variants, discussing their benefits and limitations for plant improvement. While this technology presents immense opportunities for plant breeding, it also raises serious biosafety concerns that require careful consideration, including potential off-target effects and the unintended transfer of modified genes to other organisms. This paper highlights strategies to mitigate biosafety risks and explores innovative plant gene editing detection methods. Our review investigates the international biosafety guidelines for gene-edited crops, analyzing their broad implications for agricultural and biotechnology research and advancement. We hope to provide illuminating and refined perspectives for industry practitioners and policymakers by evaluating CRISPR genome enhancement in plants.

Plant breeding for harmony between sustainable agriculture, the environment, and global food security: an era of genomics-assisted breeding

MAIN CONCLUSION

Genomics-assisted breeding represents a crucial frontier in enhancing the balance between sustainable agriculture, environmental preservation, and global food security. Its precision and efficiency hold the promise of developing resilient crops, reducing resource utilization, and safeguarding biodiversity, ultimately fostering a more sustainable and secure food production system. Agriculture has been seriously threatened over the last 40 years by climate changes that menace global nutrition and food security. Changes in environmental factors like drought, salt concentration, heavy rainfalls, and extremely low or high temperatures can have a detrimental effects on plant development, growth, and yield. Extreme poverty and increasing food demand necessitate the need to break the existing production barriers in several crops. The first decade of twenty-first century marks the rapid development in the discovery of new plant breeding technologies. In contrast, in the second decade, the focus turned to extracting information from massive genomic frameworks, speculating gene-to-phenotype associations, and producing resilient crops. In this review, we will encompass the causes, effects of abiotic stresses and how they can be addressed using plant breeding technologies. Both conventional and modern breeding technologies will be highlighted. Moreover, the challenges like the commercialization of biotechnological products faced by proponents and developers will also be accentuated. The crux of this review is to mention the available breeding technologies that can deliver crops with high nutrition and climate resilience for sustainable agriculture.

GMOs or non-GMOs? The CRISPR Conundrum

CRISPR-Cas9, the "genetic scissors", is being presaged as a revolutionary technology, having tremendous potential to create designer crops by introducing precise and targeted modifications in the genome to achieve global food security in the face of climate change and increasing population. Traditional genetic engineering relies on random and unpredictable insertion of isolated genes or foreign DNA elements into the plant genome. However, CRISPR-Cas based gene editing does not necessarily involve inserting a foreign DNA element into the plant genome from different species but introducing new traits by precisely altering the existing genes. CRISPR edited crops are touching markets, however, the world community is divided over whether these crops should be considered genetically modified (GM) or non-GM. Classification of CRISPR edited crops, especially transgene free crops as traditional GM crops, will significantly affect their future and public acceptance in some regions. Therefore, the future of the CRISPR edited crops is depending upon their regulation as GM or non-GMs, and their public perception. Here we briefly discuss how CRISPR edited crops are different from traditional genetically modified crops. In addition, we discuss different CRISPR reagents and their delivery tools to produce transgene-free CRISPR edited crops. Moreover, we also summarize the regulatory classification of CRISPR modifications and how different countries are regulating CRISPR edited crops. We summarize that the controversy of CRISPR-edited plants as GM or non-GM will continue until a universal, transparent, and scalable regulatory framework for CRISPR-edited plants will be introduced worldwide, with increased public awareness by involving all stakeholders.

Potentials of genotypes, morpho-physio-biochemical traits, and growing media on shelf life and future prospects of gene editing in tomatoes

Background: To study the genetic basis of the impact of genotypes and morpho-physio-biochemical traits under different organic and inorganic fertilizer doses on the shelf life attribute of tomatoes, field experiments were conducted in randomized block designs during the rabi seasons of 2018-2019 and 2019-2020. The experiment comprised three diverse nutrient environments [T1-organic; T2-inorganic; T3-control (without any fertilizers)] and five tomato genotypes with variable growth habits, specifically Angoorlata (Indeterminate), Avinash-3 (semi-determinate), Swaraksha (semi-determinate), Pusa Sheetal (semi-determinate), and Pusa Rohini (determinate). Results: The different tomato genotypes behaved apparently differently from each other in terms of shelf life. All the genotypes had maximum shelf life when grown in organic environments. However, the Pusa Sheetal had a maximum shelf life of 8.35 days when grown in an organic environment and showed an increase of 12% over the control. The genotype Pusa Sheetal, organic environment and biochemical trait Anthocyanin provides a promise as potential contributor to improve the keeping quality of tomatoes. Conclusion: The genotype Pusa Sheetal a novel source for shelf life, organic environment, and anthocyanin have shown promises for extended shelf life in tomatoes. Thus, the identified trait and genotype can be utilized in tomato improvement programs. Furthermore, this identified trait can also be targeted for its quantitative enhancement in order to increase tomato shelf life through a genome editing approach. A generalized genome editing mechanism is consequently suggested.

Product safety aspects of plant molecular farming

Plant molecular farming (PMF) has been promoted since the 1990s as a rapid, cost-effective and (most of all) safe alternative to the cultivation of bacteria or animal cells for the production of biopharmaceutical proteins. Numerous plant species have been investigated for the production of a broad range of protein-based drug candidates. The inherent safety of these products is frequently highlighted as an advantage of PMF because plant viruses do not replicate in humans and vice versa. However, a more nuanced analysis of this principle is required when considering other pathogens because toxic compounds pose a risk even in the absence of replication. Similarly, it is necessary to assess the risks associated with the host system (e.g., the presence of toxic secondary metabolites) and the production approach (e.g., transient expression based on bacterial infiltration substantially increases the endotoxin load). This review considers the most relevant host systems in terms of their toxicity profile, including the presence of secondary metabolites, and the risks arising from the persistence of these substances after downstream processing and product purification. Similarly, we discuss a range of plant pathogens and disease vectors that can influence product safety, for example, due to the release of toxins. The ability of downstream unit operations to remove contaminants and process-related toxic impurities such as endotoxins is also addressed. This overview of plant-based production, focusing on product safety aspects, provides recommendations that will allow stakeholders to choose the most appropriate strategies for process development.

Synergistic effects of biofilm-producing PGPR strains on wheat plant colonization, growth and soil resilience under drought stress

Drought stress substantially impedes crop productivity throughout the world. Microbial based approaches have been considered a potential possibility and are under study. Based on our prior screening examination, two distinct and novel biofilm-forming PGPR strains namely Bacillus subtilis-FAB1 and Pseudomonas azotoformans-FAP3 are encompassed in this research. Bacterial biofilm development on glass surface, microtiter plate and seedling roots were assessed and characterized quantitatively and qualitatively by light and scanning electron microscopy. Above two isolates were further evaluated for their consistent performance by inoculating on wheat plants in a pot-soil system under water stresses. Bacterial moderate tolerance to ten-day drought was recorded on the application of individual strains with wheat plants; however, the FAB1 + FAP3 consortium expressively improved wheat survival during drought. The strains FAB1 and FAP3 displayed distinct and multifunctional plant growth stimulating attributes as well as effective roots and rhizosphere colonization in combination which could provide sustained wheat growth during drought. FAB1 and FAP3-induced alterations cooperatively conferred improved plant drought tolerance by controlling physiological traits (gs, Ci, E, iWUE and P_N), stress indicators (SOD, CAT, GR, proline and MDA content) and also maintained physico-chemical attributes and hydrolytic enzymes including DHA, urease, ALP, protease, ACP and β glucosidase in the soil. Our findings could support future efforts to enhance plant drought tolerance by engineering the rhizobacterial biofilms and associated attributes which requires in-depth exploration and exploiting potential native strains for local agricultural application.

Recommendations for the Assessment of Potential Environmental Effects of Genome-Editing Applications in Plants in the EU

The current initiative of the European Commission (EC) concerning plants produced using certain new genomic techniques, in particular, targeted mutagenesis and cisgenesis, underlines that a high level of protection for human and animal health and the environment needs to be maintained when using such applications. The current EU biosafety regulation framework ensures a high level of protection with a mandatory environmental risk assessment (ERA) of genetically modified (GM) products prior to the authorization of individual GMOs for environmental release or marketing. However, the guidance available from the European Food Safety Authority (EFSA) for conducting such an ERA is not specific enough regarding the techniques under discussion and needs to be further developed to support the policy goals towards ERA, i.e., a case-by-case assessment approach proportionate to the respective risks, currently put forward by the EC. This review identifies important elements for the case-by-case approach for the ERA that need to be taken into account in the framework for a risk-oriented regulatory approach. We also discuss that the comparison of genome-edited plants with plants developed using conventional breeding methods should be conducted at the level of a scientific case-by-case assessment of individual applications rather than at a general, technology-based level. Our considerations aim to support the development of further specific guidance for the ERA of genome-edited plants.

From Transgenesis to Genome Editing in Crop Improvement: Applications, Marketing, and Legal Issues

The biotechnological approaches of transgenesis and the more recent eco-friendly new breeding techniques (NBTs), in particular, genome editing, offer useful strategies for genetic improvement of crops, and therefore, recently, they have been receiving increasingly more attention. The number of traits improved through transgenesis and genome editing technologies is growing, ranging from resistance to herbicides and insects to traits capable of coping with human population growth and climate change, such as nutritional quality or resistance to climatic stress and diseases. Research on both technologies has reached an advanced stage of development and, for many biotech crops, phenotypic evaluations in the open field are already underway. In addition, many approvals regarding main crops have been granted. Over time, there has been an increase in the areas cultivated with crops that have been improved through both approaches, but their use in various countries has been limited by legislative restrictions according to the different regulations applied which affect their cultivation, marketing, and use in human and animal nutrition. In the absence of specific legislation, there is an on-going public debate with favorable and unfavorable positions. This review offers an updated and in-depth discussion on these issues.

Genome editing for improving nutritional quality, post-harvest shelf life and stress tolerance of fruits, vegetables, and ornamentals

Agricultural production relies on horticultural crops, including vegetables, fruits, and ornamental plants, which sustain human life. With an alarming increase in human population and the consequential need for more food, it has become necessary for increased production to maintain food security. Conventional breeding has subsidized the development of improved verities but to enhance crop production, new breeding techniques need to be acquired. CRISPR-Cas9 system is a unique and powerful genome manipulation tool that can change the DNA in a precise way. Based on the bacterial adaptive immune system, this technique uses an endonuclease that creates double-stranded breaks (DSBs) at the target loci under the guidance of a single guide RNA. These DSBs can be repaired by a cellular repair mechanism that installs small insertion and deletion (indels) at the cut sites. When equated to alternate editing tools like ZFN, TALENs, and meganucleases, CRISPR- The cas-based editing tool has quickly gained fast-forward for its simplicity, ease to use, and low off-target effect. In numerous horticultural and industrial crops, the CRISPR technology has been successfully used to enhance stress tolerance, self-life, nutritional improvements, flavor, and metabolites. The CRISPR-based tool is the most appropriate one with the prospective goal of generating non-transgenic yields and avoiding the regulatory hurdles to release the modified crops into the market. Although several challenges for editing horticultural, industrial, and ornamental crops remain, this new novel nuclease, with its crop-specific application, makes it a dynamic tool for crop improvement.

CRISPR-Cas: A robust technology for enhancing consumer-preferred commercial traits in crops

The acceptance of new crop varieties by consumers is contingent on the presence of consumer-preferred traits, which include sensory attributes, nutritional value, industrial products and bioactive compounds production. Recent developments in genome editing technologies provide novel insight to identify gene functions and improve the various qualitative and quantitative traits of commercial importance in plants. Various conventional as well as advanced gene-mutagenesis techniques such as physical and chemical mutagenesis, CRISPR-Cas9, Cas12 and base editors are used for the trait improvement in crops. To meet consumer demand, breakthrough biotechnologies, especially CRISPR-Cas have received a fair share of scientific and industrial interest, particularly in plant genome editing. CRISPR-Cas is a versatile tool that can be used to knock out, replace and knock-in the desired gene fragments at targeted locations in the genome, resulting in heritable mutations of interest. This review highlights the existing literature and recent developments in CRISPR-Cas technologies (base editing, prime editing, multiplex gene editing, epigenome editing, gene delivery methods) for reliable and precise gene editing in plants. This review also discusses the potential of gene editing exhibited in crops for the improvement of consumer-demanded traits such as higher nutritional value, colour, texture, aroma/flavour, and production of industrial products such as biofuel, fibre, rubber and pharmaceuticals. In addition, the bottlenecks and challenges associated with gene editing system, such as off targeting, ploidy level and the ability to edit organelle genome have also been discussed.

Are null segregants new combinations of heritable material and should they be regulated?

Through genome editing and other techniques of gene technology, it is possible to create a class of organism called null segregants. These genetically modified organisms (GMOs) are products of gene technology but are argued to have no lingering vestige of the technology after the segregation of chromosomes or deletion of insertions. From that viewpoint regulations are redundant because any unique potential for the use of gene technology to cause harm has also been removed. We tackle this question of international interest by reviewing the early history of the purpose of gene technology regulation. The active ingredients of techniques used for guided mutagenesis, e.g., site-directed nucleases, such as CRISPR/Cas, are promoted for having a lower potential per reaction to create a hazard. However, others see this as a desirable industrial property of the reagents that will lead to genome editing being used more and nullifying the promised hazard mitigation. The contest between views revolves around whether regulations could alter the risks in the responsible use of gene technology. We conclude that gene technology, even when used to make null segregants, has characteristics that make regulation a reasonable option for mitigating potential harm. Those characteristics are that it allows people to create more harm faster, even if it creates benefits as well; the potential for harm increases with increased use of the technique, but safety does not; and regulations can control harm scaling.

Managers' attitudes toward gene-editing technology and companies' R&D investment in gene-editing: the case of Chinese seed companies

The Chinese government has issued a series of new policies to make it easier to industrialize gene-edited crops. However, whether technological advantages will eventually translate into industrial advantages and whether farmers will soon have access to gene-edited varieties partly depends on seed companies' willingness to produce and sell gene-edited varieties to farmers and to invest in developing their own gene-edited varieties. This study utilizes data from a survey of 111 seed companies collected in 2019 before the implementation of new regulations. This study provides empirical evidence on whether gene-edited crops will be available to farmers. The results show that the number of companies conducting research on gene-edited crops is limited, mostly to large companies. Approximately 55% of seed company managers would consider developing and selling gene-edited crops modified by SDN-1 and SDN-2 site-directed nuclease genome editing without external genetic material, whereas 46% support crops modified by SDN-3, which require gene replacement or foreign deoxyribonucleic acid (DNA) insertion and are regulated as genetically modified organisms (GMOs). The regression results show that large companies and companies with well-educated researchers are more likely to support and develop gene-editing technology. Past GM investment experience and collaboration with public institutions in gene-editing research increases the probability of company investment in gene editing R&D. These results suggest that gene-edited cultivars are more likely to be produced and sold to farmers in the future than GMOs, and that gene-edited agricultural products could have a significant market share of the seed market in the future.

Genome editing for vegetable crop improvement: Challenges and future prospects

Vegetable crops are known as protective foods due to their potential role in a balanced human diet, especially for vegetarians as they are a rich source of vitamins and minerals along with dietary fibers. Many biotic and abiotic stresses threaten the crop growth, yield and quality of these crops. These crops are annual, biennial and perennial in breeding behavior. Traditional breeding strategies pose many challenges in improving economic crop traits. As in most of the cases the large number of backcrosses and stringent selection pressure is required for the introgression of the useful traits into the germplasm, which is time and labour-intensive process. Plant scientists have improved economic traits like yield, quality, biotic stress resistance, abiotic stress tolerance, and improved nutritional quality of crops more precisely and accurately through the use of the revolutionary breeding method known as clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 (Cas9). The high mutation efficiency, less off-target consequences and simplicity of this technique has made it possible to attain novel germplasm resources through gene-directed mutation. It facilitates mutagenic response even in complicated genomes which are difficult to breed using traditional approaches. The revelation of functions of important genes with the advancement of whole-genome sequencing has facilitated the CRISPR-Cas9 editing to mutate the desired target genes. This technology speeds up the creation of new germplasm resources having better agro-economical traits. This review entails a detailed description of CRISPR-Cas9 gene editing technology along with its potential applications in olericulture, challenges faced and future prospects.

Genetically modified organisms: adapting regulatory frameworks for evolving genome editing technologies

Genetic modification of living organisms has been a prosperous activity for research and development of agricultural, industrial and biomedical applications. Three decades have passed since the first genetically modified products, obtained by transgenesis, become available to the market. The regulatory frameworks across the world have not been able to keep up to date with new technologies, monitoring and safety concerns. New genome editing techniques are opening new avenues to genetic modification development and uses, putting pressure on these frameworks. Here we discuss the implications of definitions of living/genetically modified organisms, the evolving genome editing tools to obtain them and how the regulatory frameworks around the world have taken these technologies into account, with a focus on agricultural crops. Finally, we expand this review beyond commercial crops to address living modified organism uses in food industry, biomedical applications and climate change-oriented solutions.

Towards social acceptability of genome-edited plants in industrialised countries? Emerging evidence from Europe, United States, Canada, Australia, New Zealand, and Japan

The agricultural biotechnology world has been divided into two blocks; countries adopting GM crops for commercial cultivation (adopters) and others without any or without relevant cultivation of such crops (non-adopters). Meanwhile, an increasing number of adopter countries have exempted certain genome-edited (GE) crops from legal GMO pre-market approval and labelling requirements. Among them are major exporters of agricultural commodities such as United States, Canada, and Australia. Due to the relaxed legislation more GE plants are expected to enter the market soon. Many countries in the non-adopter group, however, depend on import of large volumes of agricultural commodities from adopter countries. Unlike first generation GM, certain GE crops cannot be identified as unambiguously originating from genome editing using available techniques. Consequently, pressure is mounting on non-adopter jurisdictions to reconsider their policies and legislations. Against this backdrop, the paper explores recent developments relevant for social acceptability in selected non-adopters, Japan, New Zealand, the EU, Norway, and Switzerland in contrast to United States, Canada, and Australia. While Japan is already opening-up and Norway and Switzerland are discussing revisions of their policies, the EU and New Zealand are struggling with challenges resulting from high court decisions. In an attempt to take a closer look into the inner dynamics of these developments, the concept of social acceptability proposed by Wüstenhagen et al. (Energy Policy, 2007, 35(5), 2683-2691) is employed. This aids the understanding of developments in the jurisdictions considered and identifies specific or cross-cutting challenges.

Implications and Lessons From the Introduction of Genome-Edited Food Products in Japan

Japan clarified its regulatory approaches for products derived from genome editing technologies in 2019. Consequently, Japan has become a pioneer in the social implementation of such technologies, as to date, the notification process for three products, GABA-enriched tomato, fleshier red sea bream, and high-growth tiger puffer, has been completed. However, this has led to questions about how this was achieved, given the poor consumer acceptance and low public support for genetically modified (GM) foods in the past. This paper describes Japan’s regulatory approaches and their implementation guidelines for products created using genome editing technologies. It explains the governance of genome editing technologies and how the derived products have been introduced into society. The three factors that made this possible include: 1) improved R&D environments as a result of government-led innovation policy and regulations which have sought a balance between science and social demand 2) changes in the players (i.e. university startups), that engage in R&D and the strategies used for social introduction, and 3) social value changes—the recent rise in momentum for sustainable development goals (SDGs) and environmental, social, and governance (ESG) investing. The lessons and challenges in terms of R&D policy development and regulation from these analyses are presented. As the market size and social impact of genome-edited food products is limited, it is too early to fully assess this topic for Japan and thus, the analysis in this study is preliminary and must be revisited in the coming years.

Cytokinin and Its Key Role to Enrich the Plant Nutrients and Growth Under Adverse Conditions-An Update

Among the field crops, wheat is regarded as one of the most paramount cereal crops because it is widely grown, consumed as food across the world, and also known as the staple food for nearly 35 per cent of the world population. However, it is threatened by spot blotch disease causing considerable yield loss, with existing genotypes lacking the resistance and the necessary nutrients. Cytokinins (CKs) are key phytohormones that not only regulate the plant growth/development but also play an important role during stress and in the nutrient metabolic pathway of crop plants. Deficiency of important nutrients like zinc, iron, and vitamin A causes irreparable damage to the body, pressing the need to increase the accumulation of such micronutrients in the edible parts of the plant. Crop bio-fortification is one of the emerging approaches through which the quantities of these nutrients could be increased to an advisable amount. Cytokinin is observed to have a pivotal role in managing environmental stress/climate change and defense systems of plants, and apart from this, it is also found that it has an impact over Zn accumulation in cereal crops. Manipulation of the cytokine dehydrogenase (CKX) enzyme that degrades cytokinin could affect the yield, root growth, and important nutrients. Several instances revealed that an increment in the contents of Zn, S, Fe, and Mn in the seeds of cereals is a reflection of increasing the activity of CKX enzyme resulting the enhancement of the root system which not only helps in the absorption of water in a drought prone area but is also beneficial for scavenging nutrients to the deeper ends of the soil. Exploring micronutrients from the lithosphere via the root system helps in the uptake of the micronutrients and transporting them via the vascular system to the sink of crop plants, therefore, identification and incorporation of CKs/CKX linked gene(s) into targeted crop plants, exploring a bio-fortification approach including CRISPR-Cas9 through conventional and molecular breeding approaches could be the most paramount job for improving the important traits and stress management in order to enhance the plant growth, productivity, and nutritional value of the wheat crops, which would be useful for mankind.

Exploring Consumers’ Attitudes towards Food Products Derived by New Plant Breeding Techniques

New plant breeding techniques (NPBTs) are seen as promising and innovative tools to achieve food security and food safety. Biotechnological innovations have great potential to address sustainable food development, and they are expected in the near future to play a critical role in feeding a growing population without exerting added pressure on the environment. There is, however, a considerable debate as to how these new techniques should be regulated and whether some or all of them should fall within the scope of EU legislation on genetically modified organisms (GMOs), despite the product obtained being free from genes foreign to the species. In the EU, the adoption of these methods does not rely only on the scientific community but requires social acceptance and a political process that leads to an improved regulatory framework. In this paper, we present the results of an online survey carried out in Italy with 700 randomly selected participants on consumer attitudes towards food obtained by NPBTs. By applying the decision tree machine learning algorithm J48 to our dataset, we identified significant attributes to predict the main drivers of purchasing such products. A classification model accuracy assessment has also been developed to evaluate the overall performance of the classifier. The result of the model highlighted the role of consumers’ self-perceived knowledge and their trust in the European approval process for NPBT, as well as the need for a detailed label. Our findings may support decision makers and underpin the development of NPBT products in the market.

Green Revolution to Gene Revolution: Technological Advances in Agriculture to Feed the World

Technological applications in agriculture have evolved substantially to increase crop yields and quality to meet global food demand. Conventional techniques, such as seed saving, selective breeding, and mutation breeding (variation breeding), have dramatically increased crop production, especially during the 'Green Revolution' in the 1990s. However, newer issues, such as limited arable lands, climate change, and ever-increasing food demand, pose challenges to agricultural production and threaten food security. In the following 'Gene Revolution' era, rapid innovations in the biotechnology field provide alternative strategies to further improve crop yield, quality, and resilience towards biotic and abiotic stresses. These innovations include the introduction of DNA recombinant technology and applications of genome editing techniques, such as transcription activator-like effector (TALEN), zinc-finger nucleases (ZFN), and clustered regularly interspaced short palindromic repeats/CRISPR associated (CRISPR/Cas) systems. However, the acceptance and future of these modern tools rely on the regulatory frameworks governing their development and production in various countries. Herein, we examine the evolution of technological applications in agriculture, focusing on the motivations for their introduction, technical challenges, possible benefits and concerns, and regulatory frameworks governing genetically engineered product development and production.

Genome Editing Technology for Genetic Amelioration of Fruits and Vegetables for Alleviating Post-Harvest Loss

Food security and crop production are challenged worldwide due to overpopulation, changing environmental conditions, crop establishment failure, and various kinds of post-harvest losses. The demand for high-quality foods with improved nutritional quality is also growing day by day. Therefore, production of high-quality produce and reducing post-harvest losses of produce, particularly of perishable fruits and vegetables, are vital. For many decades, attempts have been made to improve the post-harvest quality traits of horticultural crops. Recently, modern genetic tools such as genome editing emerged as a new approach to manage and overcome post-harvest effectively and efficiently. The different genome editing tools including ZFNs, TALENs, and CRISPR/Cas9 system effectively introduce mutations (In Dels) in many horticultural crops to address and resolve the issues associated with post-harvest storage quality. Henceforth, we provide a broad review of genome editing applications in horticulture crops to improve post-harvest stability traits such as shelf life, texture, and resistance to pathogens without compromising nutritional value. Moreover, major roadblocks, challenges, and their possible solutions for employing genome editing tools are also discussed.

Whole-Genome Transformation of Yeast Promotes Rare Host Mutations with a Single Causative SNP Enhancing Acetic Acid Tolerance

Whole-genome (WG) transformation (WGT) with DNA from the same or another species has been used to obtain strains with superior traits. Very few examples have been reported in eukaryotes—most apparently involving integration of large fragments of foreign DNA into the host genome. We show that WGT of a haploid acetic acid-sensitive Saccharomyces cerevisiae strain with DNA from a tolerant strain, but not from nontolerant strains, generated many tolerant transformants, some of which were stable upon subculturing under nonselective conditions. The most tolerant stable transformant contained no foreign DNA but only seven nonsynonymous single nucleotide polymorphisms (SNPs), of which none was present in the donor genome. The SNF4 mutation c.[805G→T], generating Snf4^E269*, was the main causative SNP. Allele exchange of SNF4^E269* or snf4Δ in industrial strains with unrelated genetic backgrounds enhanced acetic acid tolerance during fermentation under industrially relevant conditions. Our work reveals a surprisingly small number of mutations introduced by WGT, which do not bear any sequence relatedness to the genomic DNA (gDNA) of the donor organism, including the causative mutation. Spontaneous mutagenesis under protection of a transient donor gDNA fragment, maintained as extrachromosomal circular DNA (eccDNA), might provide an explanation. Support for this mechanism was obtained by transformation with genomic DNA of a yeast strain containing NatMX and selection on medium with nourseothricin. Seven transformants were obtained that gradually lost their nourseothricin resistance upon subculturing in nonselective medium. Our work shows that WGT is an efficient strategy for rapidly generating and identifying superior alleles capable of improving selectable traits of interest in industrial yeast strains.

State-of-the-Art in CRISPR Technology and Engineering Drought, Salinity, and Thermo-tolerant crop plants

Our review has described principles and functional importance of CRISPR-Cas9 with emphasis on the recent advancements, such as CRISPR-Cpf1, base editing (BE), prime editing (PE), epigenome editing, tissue-specific (CRISPR-TSKO), and inducible genome editing and their potential applications in generating stress-tolerant plants. Improved agricultural practices and enhanced food crop production using innovative crop breeding technology is essential for increasing access to nutritious foods across the planet. The crop plants play a pivotal role in energy and nutrient supply to humans. The abiotic stress factors, such as drought, heat, and salinity cause a substantial yield loss in crop plants and threaten food security. The most sustainable and eco-friendly way to overcome these challenges are the breeding of crop cultivars with improved tolerance against abiotic stress factors. The conventional plant breeding methods have been highly successful in developing abiotic stress-tolerant crop varieties, but usually cumbersome and time-consuming. Alternatively, the CRISPR/Cas genome editing has emerged as a revolutionary tool for making efficient and precise genetic manipulations in plant genomes. Here, we provide a comprehensive review of the CRISPR/Cas genome editing (GE) technology with an emphasis on recent advances in the plant genome editing, including base editing (BE), prime editing (PE), epigenome editing, tissue-specific (CRISPR-TSKO), and inducible genome editing (CRISPR-IGE), which can be used for obtaining cultivars with enhanced tolerance to various abiotic stress factors. We also describe tissue culture-free, DNA-free GE technology, and some of the CRISPR-based tools that can be modified for their use in crop plants.

CRISPR-Cas-Led Revolution in Diagnosis and Management of Emerging Plant Viruses: New Avenues Toward Food and Nutritional Security

Plant viruses pose a serious threat to agricultural production systems worldwide. The world's population is expected to reach the 10-billion mark by 2057. Under the scenario of declining cultivable land and challenges posed by rapidly emerging and re-emerging plant pathogens, conventional strategies could not accomplish the target of keeping pace with increasing global food demand. Gene-editing techniques have recently come up as promising options to enable precise changes in genomes with greater efficiency to achieve the target of higher crop productivity. Of genome engineering tools, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) proteins have gained much popularity, owing to their simplicity, reproducibility, and applicability in a wide range of species. Also, the application of different Cas proteins, such as Cas12a, Cas13a, and Cas9 nucleases, has enabled the development of more robust strategies for the engineering of antiviral mechanisms in many plant species. Recent studies have revealed the use of various CRISPR-Cas systems to either directly target a viral gene or modify a host genome to develop viral resistance in plants. This review provides a comprehensive record of the use of the CRISPR-Cas system in the development of antiviral resistance in plants and discusses its applications in the overall enhancement of productivity and nutritional landscape of cultivated plant species. Furthermore, the utility of this technique for the detection of various plant viruses could enable affordable and precise in-field or on-site detection. The futuristic potential of CRISPR-Cas technologies and possible challenges with their use and application are highlighted. Finally, the future of CRISPR-Cas in sustainable management of viral diseases, and its practical utility and regulatory guidelines in different parts of the globe are discussed systematically.

In-Depth Characterization of greenflesh Tomato Mutants Obtained by CRISPR/Cas9 Editing: A Case Study With Implications for Breeding and Regulation

Gene editing has already proved itself as an invaluable tool for the generation of mutants for crop breeding, yet its ultimate impact on agriculture will depend on how crops generated by gene editing technologies are regulated, and on our ability to characterize the impact of mutations on plant phenotype. A starting operational strategy for evaluating gene editing-based approaches to plant breeding might consist of assessing the effect of the induced mutations in a crop- and locus-specific manner: this involves the analysis of editing efficiency in different cultivars of a crop, the assessment of potential off-target mutations, and a phenotypic evaluation of edited lines carrying different mutated alleles. Here, we targeted the GREENFLESH (GF) locus in two tomato cultivars ('MoneyMaker' and 'San Marzano') and evaluated the efficiency, specificity and mutation patterns associated with CRISPR/Cas9 activity for this gene. The GF locus encodes a Mg-dechelatase responsible for initiating chlorophyll degradation; in gf mutants, ripe fruits accumulate both carotenoids and chlorophylls. Phenotypic evaluations were conducted on two transgene-free T₂ 'MoneyMaker' gf lines with different mutant alleles (a small insertion of 1 nucleotide and a larger deletion of 123 bp). Both lines, in addition to reduced chlorophyll degradation, showed a notable increase in carotenoid and tocopherol levels during fruit ripening. Infection of gf leaves and fruits with Botrytis cinerea resulted in a significant reduction of infected area and pathogen proliferation compared to the wild type (WT). Our data indicates that the CRISPR/Cas9-mediated mutation of the GF locus in tomato is efficient, specific and reproducible and that the resulting phenotype is robust and consistent with previously characterized greenflesh mutants obtained with different breeding techniques, while also shedding light on novel traits such as vitamin E overaccumulation and pathogen resistance. This makes GF an appealing target for breeding tomato cultivars with improved features for cultivation, as well as consumer appreciation and health.

An Outlook on Global Regulatory Landscape for Genome-Edited Crops

The revolutionary technology of CRISPR/Cas systems and their extraordinary potential to address fundamental questions in every field of biological sciences has led to their developers being awarded the 2020 Nobel Prize for Chemistry. In agriculture, CRISPR/Cas systems have accelerated the development of new crop varieties with improved traits-without the need for transgenes. However, the future of this technology depends on a clear and truly global regulatory framework being developed for these crops. Some CRISPR-edited crops are already on the market, and yet countries and regions are still divided over their legal status. CRISPR editing does not require transgenes, making CRISPR crops more socially acceptable than genetically modified crops, but there is vigorous debate over how to regulate these crops and what precautionary measures are required before they appear on the market. This article reviews intended outcomes and risks arising from the site-directed nuclease CRISPR systems used to improve agricultural crop plant genomes. It examines how various CRISPR system components, and potential concerns associated with CRISPR/Cas, may trigger regulatory oversight of CRISPR-edited crops. The article highlights differences and similarities between GMOs and CRISPR-edited crops, and discusses social and ethical concerns. It outlines the regulatory framework for GMO crops, which many countries also apply to CRISPR-edited crops, and the global regulatory landscape for CRISPR-edited crops. The article concludes with future prospects for CRISPR-edited crops and their products.

An Outlook on Global Regulatory Landscape for Genome-Edited Crops

The revolutionary technology of CRISPR/Cas systems and their extraordinary potential to address fundamental questions in every field of biological sciences has led to their developers being awarded the 2020 Nobel Prize for Chemistry. In agriculture, CRISPR/Cas systems have accelerated the development of new crop varieties with improved traits—without the need for transgenes. However, the future of this technology depends on a clear and truly global regulatory framework being developed for these crops. Some CRISPR-edited crops are already on the market, and yet countries and regions are still divided over their legal status. CRISPR editing does not require transgenes, making CRISPR crops more socially acceptable than genetically modified crops, but there is vigorous debate over how to regulate these crops and what precautionary measures are required before they appear on the market. This article reviews intended outcomes and risks arising from the site-directed nuclease CRISPR systems used to improve agricultural crop plant genomes. It examines how various CRISPR system components, and potential concerns associated with CRISPR/Cas, may trigger regulatory oversight of CRISPR-edited crops. The article highlights differences and similarities between GMOs and CRISPR-edited crops, and discusses social and ethical concerns. It outlines the regulatory framework for GMO crops, which many countries also apply to CRISPR-edited crops, and the global regulatory landscape for CRISPR-edited crops. The article concludes with future prospects for CRISPR-edited crops and their products.

An Outlook on Global Regulatory Landscape for Genome-Edited Crops

The revolutionary technology of CRISPR/Cas systems and their extraordinary potential to address fundamental questions in every field of biological sciences has led to their developers being awarded the 2020 Nobel Prize for Chemistry. In agriculture, CRISPR/Cas systems have accelerated the development of new crop varieties with improved traits-without the need for transgenes. However, the future of this technology depends on a clear and truly global regulatory framework being developed for these crops. Some CRISPR-edited crops are already on the market, and yet countries and regions are still divided over their legal status. CRISPR editing does not require transgenes, making CRISPR crops more socially acceptable than genetically modified crops, but there is vigorous debate over how to regulate these crops and what precautionary measures are required before they appear on the market. This article reviews intended outcomes and risks arising from the site-directed nuclease CRISPR systems used to improve agricultural crop plant genomes. It examines how various CRISPR system components, and potential concerns associated with CRISPR/Cas, may trigger regulatory oversight of CRISPR-edited crops. The article highlights differences and similarities between GMOs and CRISPR-edited crops, and discusses social and ethical concerns. It outlines the regulatory framework for GMO crops, which many countries also apply to CRISPR-edited crops, and the global regulatory landscape for CRISPR-edited crops. The article concludes with future prospects for CRISPR-edited crops and their products.

Maize Transformation: From Plant Material to the Release of Genetically Modified and Edited Varieties

Over the past decades, advances in plant biotechnology have allowed the development of genetically modified maize varieties that have significantly impacted agricultural management and improved the grain yield worldwide. To date, genetically modified varieties represent 30% of the world's maize cultivated area and incorporate traits such as herbicide, insect and disease resistance, abiotic stress tolerance, high yield, and improved nutritional quality. Maize transformation, which is a prerequisite for genetically modified maize development, is no longer a major bottleneck. Protocols using morphogenic regulators have evolved significantly towards increasing transformation frequency and genotype independence. Emerging technologies using either stable or transient expression and tissue culture-independent methods, such as direct genome editing using RNA-guided endonuclease system as an in vivo desired-target mutator, simultaneous double haploid production and editing/haploid-inducer-mediated genome editing, and pollen transformation, are expected to lead significant progress in maize biotechnology. This review summarises the significant advances in maize transformation protocols, technologies, and applications and discusses the current status, including a pipeline for trait development and regulatory issues related to current and future genetically modified and genetically edited maize varieties.

Should we still worry about the safety of GMO foods? Why and why not? A review

Global population is increasing at an alarming rate, posing a threat on the supplies of basic needs and services. However, population increase does not seem to be a common agendum of the global scientists and political leaders. People in the developed countries are more concerned about new technologies and their products. Pseudo-threats related to the uncertainties of genetic engineering of crops and their outputs present on consumers are more audible and controversial than the real difficulties the world is experiencing at the moment and in the future. This review presents brief summaries of the real reasons to worry about and the uncertainties about genetically modified organisms. This article also presents the real uncertainties shared by consumers and scientists with respect to the past, present, and future of genetically engineered organisms. Developments in the field of precision genetics in the recent years and the implications on regulatory, breeding, and socio-cultural dimensions of the global settings are included.

Sustainable use of CRISPR/Cas in fish aquaculture: the biosafety perspective

Aquaculture is becoming the primary source of seafood for human diets, and farmed fish aquaculture is one of its fastest growing sectors. The industry currently faces several challenges including infectious and parasitic diseases, reduced viability, fertility reduction, slow growth, escapee fish and environmental pollution. The commercialization of the growth-enhanced AquAdvantage salmon and the CRISPR/Cas9-developed tilapia (Oreochromis niloticus) proffers genetic engineering and genome editing tools, e.g. CRISPR/Cas, as potential solutions to these challenges. Future traits being developed in different fish species include disease resistance, sterility, and enhanced growth. Despite these notable advances, off-target effect and non-clarification of trait-related genes among other technical challenges hinder full realization of CRISPR/Cas potentials in fish breeding. In addition, current regulatory and risk assessment frameworks are not fit-for purpose regarding the challenges of CRISPR/Cas notwithstanding that public and regulatory acceptance are key to commercialization of products of the new technology. In this study, we discuss how CRISPR/Cas can be used to overcome some of these limitations focusing on diseases and environmental release in farmed fish aquaculture. We further present technical limitations, regulatory and risk assessment challenges of the use of CRISPR/Cas, and proffer research strategies that will provide much-needed data for regulatory decisions, risk assessments, increased public awareness and sustainable applications of CRISPR/Cas in fish aquaculture with emphasis on Atlantic salmon (Salmo salar) breeding.

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.

CRISPR/Cas systems: opportunities and challenges for crop breeding

Increasing crop production to meet the demands of a growing population depends largely on crop improvement through new plant-breeding techniques (NPBT) such as genome editing. CRISPR/Cas systems are NPBTs that enable efficient target-specific gene editing in crops, which is supposed to accelerate crop breeding in a way that is different from genetically modified (GM) technology. Herein, we review the applications of CRISPR/Cas systems in crop breeding focusing on crop domestication, heterosis, haploid induction, and synthetic biology, and summarize the screening methods of CRISPR/Cas-induced mutations in crops. We highlight the importance of molecular characterization of CRISPR/Cas-edited crops, and pay special attentions to emerging highly specific genome-editing tools such as base editors and prime editors. We also discuss future improvements of CRISPR/Cas systems for crop improvement.

Novel plant breeding techniques to advance nitrogen use efficiency in rice: A review

Recently, there has been a remarkable increase in rice production owing to genetic improvement and increase in application of synthetic fertilizers. For sustainable agriculture, there is dire need to maintain a balance between profitability and input cost. To meet the steady growing demands of the farming community, researchers are utilizing all available resources to identify nutrient use efficient germplasm, but with very little success. Therefore, it is essential to understand the underlying genetic mechanism controlling nutrients efficiency, with the nitrogen use efficiency (NUE) being the most important trait. Information regarding genetic factors controlling nitrogen (N) transporters, assimilators, and remobilizers can help to identify candidate germplasms via high-throughput technologies. Large-scale field trials have provided morphological, physiological, and biochemical trait data for the detection of genomic regions controlling NUE. The functional aspects of these attributes are time-consuming, costly, labor-intensive, and less accurate. Therefore, the application of novel plant breeding techniques (NPBTs) with context to genome engineering has opened new avenues of research for crop improvement programs. Most recently, genome editing technologies (GETs) have undergone enormous development with various versions from Cas9, Cpf1, base, and prime editing. These GETs have been vigorously adapted in plant sciences for novel trait development to insure food quantity and quality. Base editing has been successfully applied to improve NUE in rice, demonstrating the potential of GETs to develop germplasms with improved resource use efficiency. NPBTs continue to face regulatory setbacks in some countries due to genome editing being categorized in the same category as genetically modified (GM) crops. Therefore, it is essential to involve all stakeholders in a detailed discussion on NPBTs and to formulate uniform policies tackling biosafety, social, ethical, and environmental concerns. In the current review, we have discussed the genetic mechanism of NUE and NPBTs for crop improvement programs with proof of concepts, transgenic and GET application for the development of NUE germplasms, and regulatory aspects of genome edited crops with future directions considering NUE.