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The amount of viroid RNA required for sequence analysis can be reduced by five to six orders of magnitude when a modified 'polymerase chain reaction' (PCR) is used for the amplification of the reversely transcribed, overlapping viroid cDNAs. By applying this procedure it is possible to establish the molecular structure also of those viroids which are present only in extremely low amounts in various crop plants and ornamentals. [ABSTRACT FROM AUTHOR]

The efficiency of viroid cloning can be increased by three to four orders of magnitude when the synthesis of viroid cDNA is primed in such a way that it carries identical sticky ends on both termini and when the multiion transformation is applied. [ABSTRACT FROM AUTHOR]

Summary: The controlled change of plant genomes by homologous recombination (HR) is still difficult to achieve. We previously developed the in planta gene targeting (ipGT) technology which depends on the simultaneous activation of the target locus by a double‐strand break and the excision of the target vector. Whereas the use of SpCas9 resulted in low ipGT frequencies in Arabidopsis, we were recently able to improve the efficiency by using egg cell‐specific expression of the potent but less broadly applicable SaCas9 nuclease. In this study, we now tested whether we could improve ipGT further, by either performing it in cells with enhanced intrachromosomal HR efficiencies or by the use of Cas12a, a different kind of CRISPR/Cas nuclease with an alternative cutting mechanism. We could show before that plants possess three kinds of DNA ATPase complexes, which all lead to instabilities of homologous genomic repeats if lost by mutation. As these proteins act in independent pathways, we tested ipGT in double mutants in which intrachromosomal HR is enhanced 20–80‐fold. However, we were not able to obtain higher ipGT frequencies, indicating that mechanisms for gene targeting (GT) and chromosomal repeat‐induced HR differ. However, using LbCas12a, the GT frequencies were higher than with SaCas9, despite a lower non‐homologous end‐joining (NHEJ) induction efficiency, demonstrating the particular suitability of Cas12a to induce HR. As SaCas9 has substantial restrictions due to its longer GC rich PAM sequence, the use of LbCas12a with its AT‐rich PAM broadens the range of ipGT drastically, particularly when targeting in CG‐deserts like promoters and introns. Significance Statement: The introduction of pre‐designed changes in the plant genome by homologous recombination (HR) ('gene targeting' GT) still has room for improvement. Although we were recently able to improve the technology by egg cell‐specific expression of SaCas9, the number of addressable genomic sites was limited. Here we demonstrate that LbCas12a, which is able to target more and different sites than SaCas9, can be used efficiently for in planta GT, making the technology more efficient and widely applicable. [ABSTRACT FROM AUTHOR]

Using the CRISPR-Cas system, it has been possible to introduce different kinds of mutations in single or multiple genes for trait improvement in crops. Last year, for the first time, the CRISPR-Cas-mediated induction of different kinds of targeted heritable chromosomal rearrangements has been achieved in plants. This novel application has the potential to revolutionize plant breeding as genetic exchange and linkage drag are now becoming controllable in a targeted manner. [ABSTRACT FROM AUTHOR]

Soil salinity is a major threat to global agriculture, limiting plant growth and lowering crop yields. Recent advances in CRISPR/Cas9 genome editing technology provide unprecedented precision and efficiency for addressing these challenges by directly modifying the central dogma (CD) of molecular biology in plants. The CD naturally lends itself to tighter multi-level regulation, where transcription and translation are both under control at the same time. A multilayer component of CD such as epigenetic modification, transcription, post-transcriptional modification, translation, and post-translational modification contributes significantly to stress tolerance. Strict control of CD components by Clustered Regularly Interspaced Short Palindromic Repeats, CRISPR-associated protein 9 (CRISPR/Cas9) might lead to the generation of climate smart crops. This review delves into the latest developments in the CRISPR toolbox that improve plant salt tolerance. By targeting key genes involved in transcription and translation, CRISPR/Cas9 makes it easier to modify critical components of the central dogma, allowing plants to better manage salt stress. We explore various CRISPR-based strategies, including base editing, prime editing, transcription regulation, multiplexing, RNA and many more, that reprogram gene expression and protein function to improve salt tolerance. In addition, we discuss how CRISPR can be combined with transcriptional regulation and epigenetic modifications to provide a comprehensive approach to salinity resistance for plants. The review also addresses the issues of off-target effects and efficient delivery systems, recommending novel solutions to improve the precision and applicability of CRISPR technology. This review emphasizes the transformative potential of CRISPR in modifying the central dogma to develop salt-tolerant crops, thereby contributing to sustainable agriculture and global food security. [ABSTRACT FROM AUTHOR]

Chlamydomonas reinhardtii, a model organism for unicellular green microalgae, is widely used in basic and applied research. Nonetheless, proceeding towards synthetic biology requires a full set of manipulation techniques for inserting, removing, or editing genes. Despite recent advancements in CRISPR/Cas9, still significant limitations in producing gene knock-outs are standing, including (i) unsatisfactory genome editing (GE) efficiency and (ii) uncontrolled DNA random insertion of antibiotic resistance markers. Thus, obtaining efficient gene targeting without using marker genes is instrumental in developing a pipeline for efficient engineering of strains for biotechnological applications. We developed an efficient DNA-free gene disruption strategy, relying on phenotypical identification of mutants, to (i) precisely determine its efficiency compared to marker-relying approaches and (ii) establish a new DNA-free editing tool. This study found that classical CRISPR Cas9-based GE for gene disruption in Chlamydomonas reinhardtii is mainly limited by DNA integration. With respect to previous results achieved on synchronized cell populations, we succeeded in increasing the GE efficiency of single gene targeting by about 200 times and up to 270 times by applying phosphate starvation. Moreover, we determined the efficiency of multiplex simultaneous gene disruption by using an additional gene target whose knock-out did not lead to a visible phenotype, achieving a co-targeting efficiency of 22%. These results expand the toolset of GE techniques and, additionally, lead the way to future strategies to generate complex genotypes or to functionally investigate gene families. Furthermore, the approach provides new perspectives on how GE can be applied to (non-) model microalgae species, targeting groups of candidate genes of high interest for basic research and biotechnological applications. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) has been shown to be sensitive to temperature deviations, influencing its yield potential. The development of new maize hybrids resilient to unfavourable weather is a desirable aim for crop breeders. In this paper, we showcase the development of a multimodal deep learning model using RGB images, phenotypic, and weather data under temporal effects to predict the yield potential of maize before or during anthesis and silking stages. The main objective of this study was to assess if the inclusion of historical weather data, maize growth captured through imagery, and important phenotypic traits would improve the predictive power of an established multimodal deep learning model. Evaluation of the model performance when training from scratch showed its ability to accurately predict ~89% of hybrids with high-yield potential and demonstrated enhanced explanatory power compared with previously published models. Shapley Additive explanations (SHAP) analysis indicated the top influential features include plant density, hybrid placement in the field, date to anthesis, parental line, temperature, humidity, and solar radiation. Including weather historical data was important for model performance, significantly enhancing the predictive and explanatory power of the model. For future research, the use of the model can move beyond maize yield prediction by fine-tuning the model on other crop data, serving as a potential decision-making tool for crop breeders to determine high-performing individuals from diverse crop types. [ABSTRACT FROM AUTHOR]

Forests worldwide are under increasing pressure from climate change and emerging diseases, threatening their vital ecological and economic roles. Traditional breeding approaches, while valuable, are inherently slow and limited by the long generation times and existing genetic variation of trees. CRISPR technologies offer a transformative solution, enabling precise and efficient genome editing to accelerate the development of climate-resilient and productive forests. This review provides a comprehensive overview of CRISPR applications in forestry, exploring its potential for enhancing disease resistance, improving abiotic stress tolerance, modifying wood properties, and accelerating growth. We discuss the mechanisms and applications of various CRISPR systems, including base editing, prime editing, and multiplexing strategies. Additionally, we highlight recent advances in overcoming key challenges such as reagent delivery and plant regeneration, which are crucial for successful implementation of CRISPR in trees. We also delve into the potential and ethical considerations of using CRISPR gene drive for population-level genetic alterations, as well as the importance of genetic containment strategies for mitigating risks. This review emphasizes the need for continued research, technological advancements, extensive long-term field trials, public engagement, and responsible innovation to fully harness the power of CRISPR for shaping a sustainable future for forests. [ABSTRACT FROM AUTHOR]

Myostatin is a member of the TGF-ß superfamily and functions as a negative regulator for skeletal muscle development and growth. It has become the most targeted gene in aquaculture that used for selective breeding. Previous studies involved in genome editing in several fish species confirmed that CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) system was highly efficient with lower off-target effect, however, no reports were raised in Culter alburnus. In this study, we employed CRISPR/Cas9 gene editing system to successfully disrupt mstn gene by co-injection with Cas9 protein and the targeted sgRNA in C. alburnus. Various Indel mutations were obtained with 82% knockout efficiency in the F0 generation by PCR sequencing. In addition, mutations in mstn that induced by CRISPR/Cas9 were detected in the F1 generation by individually mating the wild-type female with the F0 generation of mstn-KO male at sexual maturity. More importantly, the body weight and length were significantly elevated in mstn ± group when compared to those of the control. As expected in mstn ± group, the expression level of mstn was sharply reduced, whereas a slight increase was observed in two growth-related genes (myod and myog). Moreover, higher numbers of muscle fibers were observed in mstn ± group, meaning that growth performance in mstn ± individuals might be represented by increasing the number of muscle fibers. Taken together, our current study successfully obtained a site-specific modification of mstn using CRISPR/Cas9 technology, and these results provided a new insight for facilitating topmouth culter genetic studies and breeding. [ABSTRACT FROM AUTHOR]

Evolutionary dynamics of inversion and its impact on biochemical traits are a puzzling question. Here, we show abundance of inversions in three Curcuma species (turmeric, hidden ginger and Siam tulip). Genes within inversions display higher long terminal repeat content and lower expression level compared with genomic background, suggesting inversions in Curcuma experience relaxed genetic constraints. It is corroborated by depletion of selected SNPs and enrichment of deleterious mutations in inversions detected among 56 Siam tulip cultivars. Functional verification of tandem duplicated terpene synthase (TPS) genes reveals that genes within inversions become pseudogenes, while genes outside retain catalytic function. Our findings suggest that inversions act as a counteracting force against tandem duplication in balancing birth and death of TPS genes and modulating terpenoid contents in Curcuma. This study provides an empirical example that inversions are likely not adaptive but affect biochemical traits. Evolutionary dynamics of inversions and their impact on biochemical traits are unclear. Here, the authors report the genome assemblies of three Curcuma species and find that terpene synthase genes quite often become pseudogenes inside an inversion, indicating inversions act as a counteracting force against gene tandem duplication. [ABSTRACT FROM AUTHOR]

The kinetochore complex, an important protein assembly situated on the centromere, plays a pivotal role in chromosome segregation during cell division. Like in animals and fungi, the plant kinetochore complex is important for maintaining chromosome stability, regulating microtubule attachment, executing error correction mechanisms, and participating in signaling pathways to ensure accurate chromosome segregation. This review summarizes the composition, function, and regulation of the plant kinetochore complex, emphasizing the interactions of kinetochore proteins with centromeric DNAs (cenDNAs) and RNAs (cenRNAs). Additionally, the applications of the centromeric histone H3 variant (the core kinetochore protein CENH3, first identified as CENPA in mammals) in the generation of ploidy-variable plants and synthesis of plant artificial chromosomes (PACs) are discussed. The review serves as a comprehensive roadmap for researchers delving into plant kinetochore exploration, highlighting the potential of kinetochore proteins in driving technological innovations in synthetic genomics and plant biotechnology. [ABSTRACT FROM AUTHOR]

Background: Oilseed plants of the Brassicaceae plant family are cultivated for food, feed and industrial purposes on large-scale in Europe. This review gives an overview of current market-oriented applications of new genomic techniques (NGTs) in relevant Brassicaceae oilseed crops based on a literature survey. In this respect, changes in oil quality, yield, growth and resistance to biotic and abiotic stress are under development in oilseed rape (Brassica napus), camelina (Camelina sativa), and pennycress (Thlaspi arvense). Main findings: Environmental risk scenarios starting with hazard identification are developed for specific NGT applications in Brassicaceae oilseed crops with either a changed oil composition or with fitness-related traits. In case of a changed oil composition, an increase or decrease of polyunsaturated fatty acids (PUFA) may lead to risks for health and survival of pollinators. Regarding fitness-related traits, other risks were identified, i.e. an increased spread and persistence of NGT plants. Furthermore, there are indications for potential disturbance of interactions with the environment, involving signalling pathways and reaction to stress conditions. Conclusion: It is shown that for environmental risk scenarios of the technological specificities of NGTs, the plants' biology and the scale of releases have to be considered in combination. Therefore, the release of NGT plants into the environment for agricultural purposes will, also in future, require risk assessment and monitoring of individual traits as well as of combinatorial and long-term cumulative effects. In addition, risk management should develop concepts and measures to control and potentially limit the scale of releases. This is especially relevant for NGT Brassicaceae in Europe, which is a centre of diversity of this plant family. [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether the plant DNA damage levels and DNA damage response (DDR) are regulated during Agrobacterium infection and potentially manipulated by Agrobacterium to facilitate T-DNA integration. We investigated the plant genomic response to Agrobacterium infection by measuring gamma H2AX levels, which reflect the levels of double-strand DNA breaks (DSBs), and by characterizing transcription of three major DNA repair marker genes NAC82, KU70, and AGO2. These experiments revealed that, globally, Agrobacterium infection did not result in a major increase in DSB content in the host genome. The transcription of the DNA damage repair genes, on the other hand, was elevated upon the wild-type Agrobacterium infection. This transcriptional outcome was largely negated by a mutation in the bacterial virB5 gene which encodes the virulence (Vir) protein B5, a minor component of Agrobacterium pilus necessary for the translocation of Vir effector proteins into the host cell, suggesting that the transcriptional activation of the cellular DNA damage repair machinery requires the transport into the host cell of the Agrobacterium effectors, i.e., the VirD2, VirD5, VirE2, VirE3, and VirF proteins. Most likely, a combination of several of these Vir effectors is required to activate the host DNA repair as their individual loss- or gain-of-function mutants did not significantly affect this process. [ABSTRACT FROM AUTHOR]

The stress that the space environment can induce on plant physiology is of both abiotic and biotic nature. The abiotic space environment is characterized by ionizing radiation and altered gravity, geomagnetic field (GMF), pressure, and light conditions. Biotic interactions include both pathogenic and beneficial interactions. Here, we provide an overall picture of the effects of abiotic and biotic space-related factors on plant physiology. The knowledge required for the success of future space missions will lead to a better understanding of fundamental aspects of plant physiological responses, thus providing useful tools for plant breeding and agricultural practices on Earth. A review summarizes the effects of abiotic (ionizing radiation, altered gravity, geomagnetic field, pressure, and light conditions) and both beneficial and pathogenic biotic space-related factors on plant physiology. [ABSTRACT FROM AUTHOR]

Summary: Epistasis refers to nonallelic interaction between genes that cause bias in estimates of genetic parameters for a phenotype with interactions of two or more genes affecting the same trait. Partitioning of epistatic effects allows true estimation of the genetic parameters affecting phenotypes. Multigenic variation plays a central role in the evolution of complex characteristics, among which pleiotropy, where a single gene affects several phenotypic characters, has a large influence. While pleiotropic interactions provide functional specificity, they increase the challenge of gene discovery and functional analysis. Overcoming pleiotropy‐based phenotypic trade‐offs offers potential for assisting breeding for complex traits. Modelling higher order nonallelic epistatic interaction, pleiotropy and non‐pleiotropy‐induced variation, and genotype × environment interaction in genomic selection may provide new paths to increase the productivity and stress tolerance for next generation of crop cultivars. Advances in statistical models, software and algorithm developments, and genomic research have facilitated dissecting the nature and extent of pleiotropy and epistasis. We overview emerging approaches to exploit positive (and avoid negative) epistatic and pleiotropic interactions in a plant breeding context, including developing avenues of artificial intelligence, novel exploitation of large‐scale genomics and phenomics data, and involvement of genes with minor effects to analyse epistatic interactions and pleiotropic quantitative trait loci, including missing heritability. [ABSTRACT FROM AUTHOR]

Summary: Sugarcane (Saccharum spp. hybrid) is a prime feedstock for commercial production of biofuel and table sugar. Optimizing canopy architecture for improved light capture has great potential for elevating biomass yield. LIGULELESS1 (LG1) is involved in leaf ligule and auricle development in grasses. Here, we report CRISPR/Cas9‐mediated co‐mutagenesis of up to 40 copies/alleles of the putative LG1 in highly polyploid sugarcane (2n = 100–120, x = 10–12). Next generation sequencing revealed co‐editing frequencies of 7.4%–100% of the LG1 reads in 16 of the 78 transgenic lines. LG1 mutations resulted in a tuneable leaf angle phenotype that became more upright as co‐editing frequency increased. Three lines with loss of function frequencies of ~12%, ~53% and ~95% of lg1 were selected following a randomized greenhouse trial and grown in replicated, multi‐row field plots. The co‐edited LG1 mutations were stably maintained in vegetative progenies and the extent of co‐editing remained constant in field tested lines L26 and L35. Next generation sequencing confirmed the absence of potential off targets. The leaf inclination angle corresponded to light transmission into the canopy and tiller number. Line L35 displaying loss of function in ~12% of the lg1 NGS reads exhibited an 18% increase in dry biomass yield supported by a 56% decrease in leaf inclination angle, a 31% increase in tiller number, and a 25% increase in internode number. The scalable co‐editing of LG1 in highly polyploid sugarcane allows fine‐tuning of leaf inclination angle, enabling the selection of the ideotype for biomass yield. [ABSTRACT FROM AUTHOR]

The African continent is vulnerable to food insecurity. Increased food costs, job losses, and climate change force Africans to chronic hunger. Biotechnology can be used to mitigate this by using techniques such as CRISPR/Cas9 systems, TALENs, and ZFNs. Biotechnology can utilize geminiviruses to deliver the necessary reagents for precise genome alteration. Additionally, plants infected with geminiviruses can withstand harsher weather conditions such as drought. Therefore, this article discusses geminivirus replication and its use as beneficial plant DNA viruses. It focuses explicitly on genome editing to increase plant resistance by manipulating plants' salicylic acid and jasmonic acid pathways. [ABSTRACT FROM AUTHOR]

Sequence‐specific endonucleases have been key to the study of the mechanisms and control of DNA double‐strand break (DSB) repair and recombination, and the availability of CRISPR‐Cas nucleases over the last decade has driven rapid progress in the understanding and application of targeted recombination in many organisms, including plants. We present here an analysis of recombination at targeted chromosomal 5′ overhang DSB generated by the FnCas12a endonuclease in the plant, Arabidopsis thaliana. The much‐studied Cas9 nuclease cleaves DNA to generate blunt‐ended DSBs, but relatively less is known about the repair of other types of breaks, such as those with 5′‐overhanging ends. Sequencing the repaired breaks clearly shows that the majority of repaired DSB carry small deletions and are thus repaired locally by end‐joining recombination, confirmed by Nanopore sequencing of larger amplicons. Paired DSBs generate deletions at one or both cut‐sites, as well as deletions and reinsertions of the deleted segment between the two cuts, visible as inversions. While differences are seen in the details, overall the deletion patterns are similar between repair at single‐cut and double‐cut events, notwithstanding the fact that only the former involve cohesive DNA overhangs. A strikingly different repair pattern is however observed at breaks flanked by direct repeats. This change in sequence context results in the presence of a major alternative class of repair events, corresponding to highly efficient repair by single‐strand annealing recombination. [ABSTRACT FROM AUTHOR]

Food security is the situation in which all people around the globe, in all circumstances must maintain constant physical and financial access to adequate nutritious, clean, and safe food. This is why food security is regarded as a major global issue. Domestically and internationally, many factors affect food production and quality; these include environmental climate change conditions, disasters, emerging new diseases, political issues, and shifts in the global economy. Additionally, rapid population growth necessitates adjustments to food and crop production. The current agricultural production strategies negatively affect soil fertility and cause many defects such as desertification, deforestation, and increased soil salinity. Additionally, the high use of chemical fertilizers and pesticides affects human health and food production. The production of numerous strategic crops, including rice, maize, soybeans, and wheat, was reduced due to the aforementioned factors. The global hunger index increased, and millions of people were placed in the food insecurity red zone. Governments and societies attempted to address the problem by creating a new one: a higher yield of low-quality main food crops, which can give rise to hidden hunger, a serious issue that violates people's rights to a healthy and nutritious diet and inevitably causes food insecurity. In an attempt to end hunger, the Green Revolution produced high-yielding varieties of crops; however, this came at the expense of massive amounts of chemical pesticides, fertilizers, and other agricultural activities and practices that ignored the negative effects on the environment and nutritional value. Yet, billions of people worldwide suffer from iron, zinc, iodine, and vitamin A deficiency, making hidden hunger, malnutrition, and micronutrient deficiencies a severe and widespread nutritional issue in developing nations. The most common nutritional condition affecting poor and rural populations, especially those in low-income developing countries, is iron and zinc deficiency. To decrease and close the gap between crop production and food consumption, there is a need to increase agricultural productivity. Here we discussed the current status of food insecurity and malnutrition status where many research efforts and developments to enhance food quality and production for food crops with the help of genome editing tools and applications for sustainable food production. [ABSTRACT FROM AUTHOR]

CRISPR/Cas9-mediated gene editing requires high efficiency to be routinely implemented, especially in species which are laborious and slow to transform. This requirement intensifies further when targeting multiple genes simultaneously, which is required for genetic screening or more complex genome engineering. Species in the Citrus genus fall into this category. Here we describe a series of experiments with the collective aim of improving multiplex gene editing in the Carrizo citrange cultivar using tRNA-based sgRNA arrays. We evaluate a range of promoters for their efficacy in such experiments and achieve significant improvements by optimizing the expression of both the Cas9 endonuclease and the sgRNA array. In the case of the former we find the UBQ10 or RPS5a promoters from Arabidopsis driving the zCas9i endonuclease variant useful for achieving high levels of editing. The choice of promoter expressing the sgRNA array also had a large impact on gene editing efficiency across multiple targets. In this respect Pol III promoters perform especially well, but we also demonstrate that the UBQ10 and ES8Z promoters from Arabidopsis are robust alternatives. Ultimately, this study provides a quantitative insight into CRISPR/Cas9 vector design that has practical application in the simultaneous editing of multiple genes in Citrus, and potentially other eudicot plant species. [ABSTRACT FROM AUTHOR]

Bioengineered/genome-edited carbon capture and sequestration (BE/GEd-CCS) crops are being developed to mitigate climate change. This paper explores how technology, regulation, funding, and social implications, could shape the development and deployment of these crops. We conclude that some of the technological efforts to create BE/GEd-CCS crops may work. Still, stakeholders must agree on generally accepted methods of measuring how much carbon is captured in the soil and its value. The regulatory space for BE/GEd-CCS crops remains fluid until the first crops are reviewed. BE/GEd-CCS crops have received considerable initial funding and may benefit financially more from other federal programs and voluntary carbon markets. BE/GEd-CCS crops may continue perpetuating social equity concerns about agricultural biotechnology due to a lack of oversight. We argue that stakeholders need to pursue a multidisciplinary view of BE/GEd-CCS crops that draw in varying perspectives for effective development and deployment. Communication is needed between researchers and policymakers involved in either developing BE/GEd-CCS crops or developing voluntary carbon markets. We argue for the start of a conversation both across disciplines and between researchers and policymakers about the development and deployment of BE/GEd-CCS crops. [ABSTRACT FROM AUTHOR]

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Simple Summary: Rice production is strongly affected by environmental stresses such as drought, heat and salt. Rice plants have developed intricate molecular mechanisms to deal with these challenges. Researchers have identified crucial genes, proteins and metabolic pathways involved in these responses through transcriptomic and proteomic studies. Understanding these molecular mechanisms can help in developing new stress-resistant varieties, thus ensuring stable production under adverse environmental conditions. This review aims to provide a straightforward summary of the progress in understanding the molecular mechanisms of rice's response to various environmental stresses through transcriptomic and proteomic studies. Rice (Oryza sativa L.) is grown nearly worldwide and is a staple food for more than half of the world's population. With the rise in extreme weather and climate events, there is an urgent need to decode the complex mechanisms of rice's response to environmental stress and to breed high-yield, high-quality and stress-resistant varieties. Over the past few decades, significant advancements in molecular biology have led to the widespread use of several omics methodologies to study all aspects of plant growth, development and environmental adaptation. Transcriptomics and proteomics have become the most popular techniques used to investigate plants' stress-responsive mechanisms despite the complexity of the underlying molecular landscapes. This review offers a comprehensive and current summary of how transcriptomics and proteomics together reveal the molecular details of rice's response to environmental stresses. It also provides a catalog of the current applications of omics in comprehending this imperative crop in relation to stress tolerance improvement and breeding. The evaluation of recent advances in CRISPR/Cas-based genome editing and the application of synthetic biology technologies highlights the possibility of expediting the development of rice cultivars that are resistant to stress and suited to various agroecological environments. [ABSTRACT FROM AUTHOR]

Plant viral diseases constitute a major contributor to agricultural production losses, significantly impacting the economies of exporting countries by more than USD 30 billion annually. Understanding and researching the biology and genomics of viruses is crucial for developing virus-resistant genetically edited or genetically modified plants. Genetic modifications can be targeted to specific regions within genes of target plants which are important or essential for the virus to establish a systemic infection, thus fostering resistance or enabling plants to effectively respond to invading agents while preserving their yield. This review provides an overview of viral incidence and diversity in tropical fruit crops and aims to examine the current state of the knowledge on recent research efforts aimed at reducing or eliminating the damage caused by viral diseases, with emphasis on genetically edited products that have reached the market in recent years. [ABSTRACT FROM AUTHOR]

The advent of Clustered Regularly Interspaced Palindromic Repeat (CRISPR)/CRISPR-associated (Cas) proteins as a revolutionary innovation in genome editing has greatly promoted targeted modification and trait improvement in most plant species. For grapevine (Vitis vinifera L.), a perennial woody plant species, CRISPR/Cas genome editing is an extremely promising technique for genetic improvement in a short period. Advances in grapevine genome editing have been achieved by using CRISPR technology in recent years, which promises to accelerate trait improvement in grapevine. In this review, we describe the development and advances in CRISPR/Cas9 and its orthologs and variants. We summarize the applications of genome editing in grapevine and discuss the challenges facing grapevine genome editing as well as the possible strategies that could be used to improve genome editing in grapevine. In addition, we outline future perspectives for grapevine genome editing in a model system, precise genome editing, accelerated trait improvement, and transgene-free genome editing. We believe that CRISPR/Cas will play a more important role in grapevine genome editing, and an exciting and bright future is expected in this economically significant species. [ABSTRACT FROM AUTHOR]

Global agricultural production must quadruple by 2050 to fulfil the needs of a growing global population, but climate change exacerbates the difficulty. Cereals are a very important source of food for the world population. Improved cultivars are needed, with better resistance to abiotic stresses like drought, salt, and increasing temperatures, and resilience to biotic stressors like bacterial and fungal infections, and pest infestation. A popular, versatile, and helpful method for functional genomics and crop improvement is genome editing. Rapidly developing genome editing techniques including clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) are very important. This review focuses on how CRISPR/Cas9 genome editing might enhance cereals' agronomic qualities in the face of climate change, providing important insights for future applications. Genome editing efforts should focus on improving characteristics that confer tolerance to conditions exacerbated by climate change (e.g. drought, salt, rising temperatures). Improved water usage efficiency, salt tolerance, and heat stress resilience are all desirable characteristics. Cultivars that are more resilient to insect infestations and a wide range of biotic stressors, such as bacterial and fungal diseases, should be created. Genome editing can precisely target genes linked to disease resistance pathways to strengthen cereals' natural defensive systems. The world population is increasing day by day. Cereals are a good source of energy for this increasing population. Climate changes exert pressure on agriculture and hinder overall production. Genome editing techniques such as CRISPR/Cas have been extensively used to improve crops. In this review, we summarise the different genome editing techniques, their advantages, and disadvantages. This article belongs to the Collection Functional Genomics for Developing Climate Resilient Crops. [ABSTRACT FROM AUTHOR]

Agriculture plays a fundamental role in ensuring global food security, yet plant diseases remain a significant threat to crop production. Traditional methods to manage plant diseases have been extensively used, but they face significant drawbacks, such as environmental pollution, health risks and pathogen resistance. Similarly, biopesticides are eco-friendly, but are limited by their specificity and stability issues. This has led to the exploration of novel biotechnological approaches, such as the development of synthetic proteins, which aim to mitigate these drawbacks by offering more targeted and sustainable solutions. Similarly, recent advances in genome editing techniques—such as meganucleases (MegNs), zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)—are precise approaches in disease management, but are limited by technical challenges and regulatory concerns. In this realm, nanotechnology has emerged as a promising frontier that offers novel solutions for plant disease management. This review examines the role of nanoparticles (NPs), including organic NPs, inorganic NPs, polymeric NPs and carbon NPs, in enhancing disease resistance and improving pesticide delivery, and gives an overview of the current state of nanotechnology in managing plant diseases, including its advantages, practical applications and obstacles that must be overcome to fully harness its potential. By understanding these aspects, we can better appreciate the transformative impact of nanotechnology on modern agriculture and can develop sustainable and effective strategies to mitigate plant diseases, ensuring enhanced agricultural productivity. [ABSTRACT FROM AUTHOR]

In plants three different approaches have been used to study homologous DNA recombination; extrachromosomal recombination (ECR) between transfected DNA molecules, intrachromosomal recombination (ICR) between repeated genes integrated into and resident at the genome and recombination between introduced DNA and homologous sequences in the genome (gene targeting). ECR is efficient (10 to 10) and occurs mainly during a limited time period early after transfection. It proceeds predominantly via nonconservative single-strand annealing. ICR, which in most cases is described best by the double-strand break repair model of recombination, occurs at frequencies of one event in 10 to 10 cells. ICR takes place throughout the whole life-cycle of a plant, in all organs and at different developmental stages. As there exists no predetermined germline in plants, somatic recombination events can be transferred to the next generation. Recombination frequencies are enhanced by DNA damage. Gene targeting, like ICR, occurs at low rates in plant cells. Almost nothing is known about the enzymes involved in homologous recombination in plants. [ABSTRACT FROM AUTHOR]

Gene-editing tools, such as Zinc-fingers, TALENs, and CRISPR-Cas, have fostered a new frontier in the genetic improvement of plants across the tree of life. In eukaryotes, genome editing occurs primarily through two DNA repair pathways: non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ is the primary mechanism in higher plants, but it is unpredictable and often results in undesired mutations, frameshift insertions, and deletions. Homology-directed repair (HDR), which proceeds through HR, is typically the preferred editing method by genetic engineers. HR-mediated gene editing can enable error-free editing by incorporating a sequence provided by a donor template. However, the low frequency of native HR in plants is a barrier to attaining efficient plant genome engineering. This review summarizes various strategies implemented to increase the frequency of HDR in plant cells. Such strategies include methods for targeting double-strand DNA breaks, optimizing donor sequences, altering plant DNA repair machinery, and environmental factors shown to influence HR frequency in plants. Through the use and further refinement of these methods, HR-based gene editing may one day be commonplace in plants, as it is in other systems. [ABSTRACT FROM AUTHOR]

Generating CRISPR/Cas9-mediated mutants in tomato (Solanum lycopersicum L.) involves screening shoots regenerated fromcultured cells transformedwith a T-DNA harboring sequences encoding Cas9 and single guide RNAs (sgRNAs). Production of transformants can be inconsistent and obtaining transformants in large numbersmay be difficult, resulting in a limited variety of mutations. Here, I report a method for generating various types of mutations from one transgenic plant harboring the CRISPR/Cas9 system. In this method, a wild-type plant was crossed with a T0 biallelic mutant expressing two sgRNAs targeting the RIPENING INHIBITOR (RIN) gene, and the resulting F1 seedlings were classified using a kanamycin resistancemarker on the T-DNA. Genotyping of the RIN locus revealed that kanamycin-sensitive F1 seedlings, which carried no T-DNA, always harbored the wild-type allele and a mutant allele from the transgenic parent. Kanamycin-resistant F1 seedlings, which do carry the TDNA, harbored a variety of novel mutant alleles, but not the wild-type allele, suggesting that it was mutated during crossing. The novel mutations included one-base insertions or short deletions at each target site, or large deletions across the two target sites. Thismethod was also successfully applied to producemutations in Geranylgeranyl pyrophosphate synthase 2 (GGPS2). Because thismethod involves crossing rather than transformation, it can be readily scaled up to produce numerous novel mutations, even in plant species or cultivars for which transformation is inefficient. Therefore, when initial transgene experiments fail to induce the desired mutation, this method provides additional opportunities for generating mutants. [ABSTRACT FROM AUTHOR]

Introduction: Citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), is a devastating disease worldwide. Previously, we successfully generated cankerresistant Citrus sinensis cv. Hamlin lines in the T0 generation. This was achieved through the transformation of embryogenic protoplasts using the ribonucleoprotein (RNP) containing Cas12a and one crRNA to edit the canker susceptibility gene, CsLOB1, which led to small indels. Methods: Here, we transformed embryogenic protoplasts of Hamlin with RNP containing Cas12a and three crRNAs. Results: Among the 10 transgene-free genome-edited lines, long deletions were obtained in five lines. Additionally, inversionswere observed in three of the five edited lines with long deletions, but not in any edited lines with short indel mutations, suggesting long deletions maybe required for inversions. Biallelic mutations were observed for each of the three target sites in four of the 10 edited lines when three crRNAs were used, demonstrating that transformation of embryogenic citrus protoplasts with Cas12a and three crRNAs RNP can be very efficient for multiplex editing. Our analysis revealed the absence of off-target mutations in the edited lines. These cslob1 mutant lines were canker-resistant and no canker symptoms were observed after inoculation with Xcc and Xcc growth was significantly reduced in the cslob1 mutant lines compared to the wild type plants. Discussion: Taken together, RNP (Cas12a and three crRNAs) transformation of embryogenic protoplasts of citrus provides a promising solution for transgene-free multiplex genome editing with high efficiency and for deletion of long fragments. [ABSTRACT FROM AUTHOR]

Background: CRISPR Cas9 and Cas12a are the two most frequently used programmable nucleases reported in plant systems. There is now a wide range of component parts for both which likely have varying degrees of effectiveness and potentially applicability to different species. Our aim was to develop and optimise Cas9 and Cas12a based systems for highly efficient genome editing in the monocotyledons barley and wheat and produce a user-friendly toolbox facilitating simplex and multiplex editing in the cereal community. Results: We identified a Zea mays codon optimised Cas9 with 13 introns in conjunction with arrayed guides driven by U6 and U3 promoters as the best performer in barley where 100% of T0 plants were simultaneously edited in all three target genes. When this system was used in wheat > 90% of T0 plants were edited in all three subgenome targets. For Cas12a, an Arabidopsis codon optimised sequence with 8 introns gave the best editing efficiency in barley when combined with a tRNA based multiguide array, resulting in 90% mutant alleles in three simultaneously targeted genes. When we applied this Cas12a system in wheat 86% & 93% of T0 plants were mutated in two genes simultaneously targeted. We show that not all introns contribute equally to enhanced mutagenesis when inserted into a Cas12a coding sequence and that there is rationale for including multiple introns. We also show that the combined effect of two features which boost Cas12a mutagenesis efficiency (D156R mutation and introns) is more than the sum of the features applied separately. Conclusion: Based on the results of our testing, we describe and provide a GoldenGate modular cloning system for Cas9 and Cas12a use in barley and wheat. Proven Cas nuclease and guide expression cassette options found in the toolkit will facilitate highly efficient simplex and multiplex mutagenesis in both species. We incorporate GRF-GIF transformation boosting cassettes in wheat options to maximise workflow efficiency. [ABSTRACT FROM AUTHOR]

Forage maize is a versatile crop extensively utilized for animal nutrition in agriculture and holds promise as a valuable resource for the production of fermentable sugars in the biorefinery sector. Within this context, the carbohydrate fraction of the lignocellulosic biomass undergoes deconstruction during ruminal digestion and the saccharification process. However, the cell wall's natural resistance towards enzymatic degradation poses a significant challenge during both processes. This so-called biomass recalcitrance is primarily attributed to the presence of lignin and ferulates in the cell walls. Consequently, maize varieties with a reduced lignin or ferulate content or an altered lignin composition can have important beneficial effects on cell wall digestibility. Considerable efforts in genetic improvement have been dedicated towards enhancing cell wall digestibility, benefiting agriculture, the biorefinery sector and the environment. In part I of this paper, we review conventional and advanced breeding methods used in the genetic improvement of maize germplasm. In part II, we zoom in on maize mutants with altered lignin for improved digestibility and biomass processing. [ABSTRACT FROM AUTHOR]

Meiosis is a critical process in sexual reproduction, and errors during this cell division can significantly impact fertility. Successful meiosis relies on the coordinated action of numerous genes involved in DNA replication, strand breaks, and subsequent rejoining. DNA topoisomerase enzymes play a vital role by regulating DNA topology, alleviating tension during replication and transcription. To elucidate the specific function of DNA topoisomerase 1α ($AtTOP1 \alpha$ A t T O P 1 α) in male reproductive development of Arabidopsis thaliana, we investigated meiotic cell division in Arabidopsis flower buds. Combining cytological and biochemical techniques, we aimed to reveal the novel contribution of $AtTOP1 \alpha$ A t T O P 1 α to meiosis. Our results demonstrate that the absence of $AtTOP1 \alpha$ A t T O P 1 α leads to aberrant chromatin behavior during meiotic division. Specifically, the top1α1 mutant displayed altered heterochromatin distribution and clustered centromere signals at early meiotic stages. Additionally, this mutant exhibited disruptions in the distribution of 45s rDNA signals and a reduced frequency of chiasma formation during metaphase I, a crucial stage for genetic exchange. Furthermore, the atm-2×top1α1 double mutant displayed even more severe meiotic defects, including incomplete synapsis, DNA fragmentation, and the presence of polyads. These observations collectively suggest that $AtTOP1 \alpha$ A t T O P 1 α plays a critical role in ensuring accurate meiotic progression, promoting homologous chromosome crossover formation, and potentially functioning in a shared DNA repair pathway with ATAXIA TELANGIECTASIA MUTATED (ATM) in Arabidopsis microspore mother cells. [ABSTRACT FROM AUTHOR]

Summary: Soybean is a typical short‐day crop, and most commercial soybean cultivars are restricted to a relatively narrow range of latitudes due to photoperiod sensitivity. Photoperiod sensitivity hinders the utilization of soybean germplasms across geographical regions. When grown in temperate regions, tropical soybean responds to prolonged day length by increasing the vegetative growth phase and delaying flowering and maturity, which often pushes the harvest window past the first frost date. In this study, we used CRISPR/LbCas12a to edit a North American subtropical soybean cultivar named 06KG218440 that belongs to maturity group 5.5. By designing one gRNA to edit the nuclear localization signal (NLS) regions of both E1 and E1Lb, we created a series of new germplasms with shortened flowering time and time to maturity and determined their favourable latitudinal zone for cultivation. The novel partial function alleles successfully achieve yield and early maturity trade‐offs and exhibit good agronomic traits and high yields in temperate regions. This work offers a straightforward editing strategy to modify subtropical and tropical soybean cultivars for temperate growing regions, a strategy that could be used to enrich genetic diversity in temperate breeding programmes and facilitate the introduction of important crop traits such as disease tolerance or high yield. [ABSTRACT FROM AUTHOR]

Summary: Eukaryotic translation initiation factors (eIFs) are important for mRNA translation but also pivotal for plant‐virus interaction. Most of these plant‐virus interactions were found between plant eIFs and the viral protein genome‐linked (VPg) of potyviruses. In case of lost interaction due to mutation or deletion of eIFs, the viral translation and subsequent replication within its host is negatively affected, resulting in a recessive resistance. Here we report the identification of the Beta vulgaris Bv‐eIF(iso)4E as a susceptibility factor towards the VPg‐carrying beet chlorosis virus (genus Polerovirus). Using yeast two‐hybrid and bimolecular fluorescence complementation assays, the physical interaction between Bv‐eIF(iso)4E and the putative BChV‐VPg was detected, while the VPg of the closely related beet mild yellowing virus (BMYV) was found to interact with the two isoforms Bv‐eIF4E and Bv‐eIF(iso)4E. These VPg‐eIF interactions within the polerovirus‐beet pathosystem were demonstrated to be highly specific, as single mutations within the predicted cap‐binding pocket of Bv‐eIF(iso)4E resulted in a loss of interaction. To investigate the suitability of eIFs as a resistance resource against beet infecting poleroviruses, B. vulgaris plants were genome edited by CRISPR/Cas9 resulting in knockouts of different eIFs. A simultaneous knockout of the identified BMYV‐interaction partners Bv‐eIF4E and Bv‐eIF(iso)4E was not achieved, but Bv‐eIF(iso)4EKO plants showed a significantly lowered BChV accumulation and decrease in infection rate from 100% to 28.86%, while no influence on BMYV accumulation was observed. Still, these observations support that eIFs are promising candidate genes for polerovirus resistance breeding in sugar beet. [ABSTRACT FROM AUTHOR]

RNA polymerase II (Pol II) dysfunction is frequently implied in human disease. Understanding its functional mechanism is essential for designing innovative therapeutic strategies. To visualize its supra-molecular interactions with genes and nascent RNA, we generated a human cell line carrying ~335 consecutive copies of a recombinant β-globin gene. Confocal microscopy showed that Pol II was not homogeneously concentrated around these identical gene copies. Moreover, Pol II signals partially overlapped with the genes and their nascent RNA, revealing extensive compartmentalization. Using a cell line carrying a single copy of the β-globin gene, we also tested if the binding of catalytically dead CRISPR-associated system 9 (dCas9) to different gene regions affected Pol II transcriptional activity. We assessed Pol II localization and nascent RNA levels using chromatin immunoprecipitation and droplet digital reverse transcription PCR, respectively. Some enrichment of transcriptionally paused Pol II accumulated in the promoter region was detected in a strand-specific way of gRNA binding, and there was no decrease in nascent RNA levels. Pol II preserved its transcriptional activity in the presence of DNA-bound dCas9. Our findings contribute further insight into the complex mechanism of mRNA transcription in human cells. [ABSTRACT FROM AUTHOR]