Genome editing for resistance against plant pests and pathogens

From sequences to sustainability: Exploring dipterocarp genomes for oleoresin production, timber quality, and conservation

Dipterocarp species dominate tropical forest ecosystems and provide key ecological and economic value through their use of aromatic resins, medicinal chemicals, and high-quality timber. However, habitat loss and unsustainable logging have endangered many Dipterocarpaceae species. Genomic strategies provide new opportunities for both elucidating the molecular pathways underlying these desirable traits and informing conservation efforts for at-risk taxa. This review summarizes the progress in dipterocarp genomics analysis and applications. We describe 16 recently published Dipterocarpaceae genome sequences, representing crucial genetic blueprints. Phylogenetic comparisons delineate evolutionary relationships among species and provide frameworks for pinpointing functional changes underlying specialized metabolism and wood development patterns. We also discuss connections revealed thus far between specific gene families and both oleoresin biosynthesis and wood quality traits-including the identification of key terpenoid synthases and cellulose synthases likely governing pathway flux. Moreover, the characterization of adaptive genomic markers offers vital resources for supporting conservation practices prioritizing resilient genotypes displaying valuable oleoresin and timber traits. Overall, progress in dipterocarp functional and comparative genomics provides key tools for addressing the intertwined challenges of preserving biodiversity in endangered tropical forest ecosystems while sustainably deriving aromatic chemicals and quality lumber that support diverse human activities.

Symphony of survival: Insights into cross-talk mechanisms in plants, bacteria, and fungi for strengthening plant immune responses

Plants coexist with a diverse array of microorganisms, predominantly bacteria and fungi, in both natural and agricultural environments. While some microorganisms positively influence plant development and yield, others can cause harm to the host, leading to significant adverse impacts on the environment and the economy. Plant growth-promoting microorganisms (PGPM), including plant growth-promoting bacteria, arbuscular mycorrhizal fungus (AMF), and rhizobia, have been found to increase plant biomass production by synthesizing hormones, fixing nitrogen, and solubilizing phosphate and potassium. Numerous studies have contributed to unraveling the complex process of plant-microbe interactions in recent decades. In light of the increasing global challenges such as population growth, climate change, and resource scarcity, it has become imperative to explore the potential of plant-bacteria-fungi crosstalk in promoting sustainability. This review aims to bridge existing knowledge gaps, providing a roadmap for future research in this dynamic field by synthesizing current knowledge and identifying emerging trends.

Advancements in genetic studies of mushrooms: a comprehensive review

Genetic studies in mushrooms, driven by innovations such as CRISPR-Cas9 genome editing and RNA interference, transform our understanding of these enigmatic fungi and their multifaceted roles in agriculture, medicine, and conservation. This comprehensive review explores the rationale and significance of genetic research in mushrooms, delving into the ethical, regulatory, and ecological dimensions of this field. CRISPR-Cas9 emerges as a game-changing technology, enabling precise genome editing, targeted gene knockouts, and pathway manipulation. RNA interference complements these efforts by downregulating genes for improved crop yield and enhanced pest and disease resistance. Genetic studies also contribute to the conservation of rare species and developing more robust mushroom strains, fostering sustainable cultivation practices. Moreover, they unlock the potential for discovering novel medicinal compounds, offering new horizons in pharmaceuticals and nutraceuticals. As emerging technologies and ethical considerations shape the future of mushroom research, these studies promise to revolutionize our relationship with these fungi, paving the way for a more sustainable and innovative world.

Present status of insecticide impacts and eco-friendly approaches for remediation-a review

Insecticides are indispensable for modern agriculture to ensuring crop protection and optimal yields. However, their excessive use raises concerns regarding their adverse effects on agriculture and the environment. This study examines the impacts of insecticides on agriculture and proposes remediation strategies. Excessive insecticide application can lead to the development of resistance in target insects, necessitating higher concentrations or stronger chemicals, resulting in increased production costs and disruption of natural pest control mechanisms. In addition, non-target organisms, such as beneficial insects and aquatic life, suffer from the unintended consequences of insecticide use, leading to ecosystem imbalances and potential food chain contamination. To address these issues, integrated pest management (IPM) techniques that combine judicious insecticide use with biological control and cultural practices can reduce reliance on chemicals. Developing and implementing selective insecticides with reduced environmental persistence is crucial. Promoting farmer awareness of responsible insecticide use, offering training and resources, and adopting precision farming technologies can minimize overall insecticide usage.

Genome editing for healthy crops: traits, tools and impacts

Crop cultivars in commercial use have often been selected because they show high levels of resistance to pathogens. However, widespread cultivation of these crops for many years in the environments favorable to a pathogen requires durable forms of resistance to maintain "healthy crops". Breeding of new varieties tolerant/resistant to biotic stresses by incorporating genetic components related to durable resistance, developing new breeding methods and new active molecules, and improving the Integrated Pest Management strategies have been of great value, but their effectiveness is being challenged by the newly emerging diseases and the rapid change of pathogens due to climatic changes. Genome editing has provided new tools and methods to characterize defense-related genes in crops and improve crop resilience to disease pathogens providing improved food security and future sustainable agricultural systems. In this review, we discuss the principal traits, tools and impacts of utilizing genome editing techniques for achieving of durable resilience and a "healthy plants" concept.

CRISPR/Cas-mediated plant genome editing: outstanding challenges a decade after implementation

The discovery of the CRISPR/Cas genome-editing system has revolutionized our understanding of the plant genome. CRISPR/Cas has been used for over a decade to modify plant genomes for the study of specific genes and biosynthetic pathways as well as to speed up breeding in many plant species, including both model and non-model crops. Although the CRISPR/Cas system is very efficient for genome editing, many bottlenecks and challenges slow down further improvement and applications. In this review we discuss the challenges that can occur during tissue culture, transformation, regeneration, and mutant detection. We also review the opportunities provided by new CRISPR platforms and specific applications related to gene regulation, abiotic and biotic stress response improvement, and de novo domestication of plants.

Editing of TOM1 gene in tobacco using CRISPR/Cas9 confers resistance to Tobacco mosaic virus

BACKGROUND

Genome editing technology has become one of the excellent tools for precise plant breeding to develop novel plant germplasm. The Tobacco mosaic virus (TMV) is the most prominent pathogen that infects several Solanaceae plants, such as tobacco, tomato, and capsicum, which requires critical host factors for infection and replication of its genomic RNA in the host. The Tobamovirus multiplication (TOM) genes, such as TOM1, TOM2A, TOM2B, and TOM3, are involved in the multiplication of Tobamoviruses. TOM1 is a transmembrane protein necessary for efficient TMV multiplication in several plant species. The TOM genes are crucial recessive resistance genes that act against the tobamoviruses in various plant species.

METHODS AND RESULTS

The single guided RNA (sgRNA) was designed to target the first exon of the NtTOM1 gene and cloned into the pHSE401 vector. The pHSE401-NtTOM1 vector was introduced into Agrobacterium tumefaciens strain LBA4404 and then transformed into tobacco plants. The analysis on T0 transgenic plants showed the presence of the hptII and Cas9 transgenes. The sequence analysis of the NtTOM1 from T0 plants showed the indels. Genotypic evaluation of the NtTOM1 mutant lines displayed the stable inheritance of the mutations in the subsequent generations of tobacco plants. The NtTOM1 mutant lines successfully conferred resistance to TMV.

CONCLUSIONS

CRISPR/Cas genome editing is a reliable tool for investigating gene function and precision breeding across different plant species, especially the species in the Solanaceae family.

CRISPR/Cas- and Topical RNAi-Based Technologies for Crop Management and Improvement: Reviewing the Risk Assessment and Challenges Towards a More Sustainable Agriculture

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated gene (Cas) system and RNA interference (RNAi)-based non-transgenic approaches are powerful technologies capable of revolutionizing plant research and breeding. In recent years, the use of these modern technologies has been explored in various sectors of agriculture, introducing or improving important agronomic traits in plant crops, such as increased yield, nutritional quality, abiotic- and, mostly, biotic-stress resistance. However, the limitations of each technique, public perception, and regulatory aspects are hindering its wide adoption for the development of new crop varieties or products. In an attempt to reverse these mishaps, scientists have been researching alternatives to increase the specificity, uptake, and stability of the CRISPR and RNAi system components in the target organism, as well as to reduce the chance of toxicity in nontarget organisms to minimize environmental risk, health problems, and regulatory issues. In this review, we discuss several aspects related to risk assessment, toxicity, and advances in the use of CRISPR/Cas and topical RNAi-based technologies in crop management and breeding. The present study also highlights the advantages and possible drawbacks of each technology, provides a brief overview of how to circumvent the off-target occurrence, the strategies to increase on-target specificity, the harm/benefits of association with nanotechnology, the public perception of the available techniques, worldwide regulatory frameworks regarding topical RNAi and CRISPR technologies, and, lastly, presents successful case studies of biotechnological solutions derived from both technologies, raising potential challenges to reach the market and being social and environmentally safe.

Geminivirus-Derived Vectors as Tools for Functional Genomics

A persistent issue in the agricultural sector worldwide is the intensive damage caused to crops by the geminivirus family of viruses. The diverse types of viruses, rapid virus evolution rate, and broad host range make this group of viruses one of the most devastating in nature, leading to millions of dollars' worth of crop damage. Geminiviruses have a small genome and can be either monopartite or bipartite, with or without satellites. Their ability to independently replicate within the plant without integration into the host genome and the relatively easy handling make them excellent candidates for plant bioengineering. This aspect is of great importance as geminiviruses can act as natural nanoparticles in plants which can be utilized for a plethora of functions ranging from vaccine development systems to geminivirus-induced gene silencing (GIGS), through deconstructed viral vectors. Thus, the investigation of these plant viruses is pertinent to understanding their crucial roles in nature and subsequently utilizing them as beneficial tools in functional genomics. This review, therefore, highlights some of the characteristics of these viruses that can be deemed significant and the subsequent successful case studies for exploitation of these potentially significant pathogens for role mining in functional biology.

Making Use of Plant uORFs to Control Transgene Translation in Response to Pathogen Attack

Reducing crop loss to diseases is urgently needed to meet increasing food production challenges caused by the expanding world population and the negative impact of climate change on crop productivity. Disease-resistant crops can be created by expressing endogenous or exogenous genes of interest through transgenic technology. Nevertheless, enhanced resistance by overexpressing resistance-produced genes often results in adverse developmental affects. Upstream open reading frames (uORFs) are translational control elements located in the 5' untranslated region (UTR) of eukaryotic mRNAs and may repress the translation of downstream genes. To investigate the function of three uORFs from the 5' -UTR of ACCELERATED CELL 11 (uORFsACD11), we develop a fluorescent reporter system and find uORFsACD11 function in repressing downstream gene translation. Individual or simultaneous mutations of the three uORFsACD11 lead to repression of downstream translation efficiency at different levels. Importantly, uORFsACD11-mediated translational inhibition is impaired upon recognition of pathogen attack of plant leaves. When coupled with the PATHOGENESIS-RELATED GENE 1 (PR1) promoter, the uORFsACD11 cassettes can upregulate accumulation of Arabidopsis thaliana LECTIN RECEPTOR KINASE-VI.2 (AtLecRK-VI.2) during pathogen attack and enhance plant resistance to Phytophthora capsici. These findings indicate that the uORFsACD11 cassettes can be a useful toolkit that enables a high level of protein expression during pathogen attack, while for ensuring lower levels of protein expression at normal conditions.

VIGE: virus-induced genome editing for improving abiotic and biotic stress traits in plants

Agricultural production is hampered by disease, pests, and environmental stresses. To minimize yield loss, it is important to develop crop cultivars with resistance or tolerance to their respective biotic and abiotic constraints. Transformation techniques are not optimized for many species and desirable cultivars may not be amenable to genetic transformation, necessitating inferior cultivar usage and time-consuming introgression through backcrossing to the preferred variety. Overcoming these limitations will greatly facilitate the development of disease, insect, and abiotic stress tolerant crops. One such avenue for rapid crop improvement is the development of viral systems to deliver CRISPR/Cas-based genome editing technology to plants to generate targeted beneficial mutations. Viral delivery of genomic editing constructs can theoretically be applied to span the entire host range of the virus utilized, circumventing the challenges associated with traditional transformation and breeding techniques. Here we explore the types of viruses that have been optimized for CRISPR/Cas9 delivery, the phenotypic outcomes achieved in recent studies, and discuss the future potential of this rapidly advancing technology.