Exigency of Plant-Based Vaccine against COVID-19 Emergence as Pandemic Preparedness

After two years since the declaration of COVID-19 as a pandemic by the World Health Organization (WHO), more than six million deaths have occurred due to SARS-CoV-2, leading to an unprecedented disruption of the global economy. Fortunately, within a year, a wide range of vaccines, including pathogen-based inactivated and live-attenuated vaccines, replicating and non-replicating vector-based vaccines, nucleic acid (DNA and mRNA)-based vaccines, and protein-based subunit and virus-like particle (VLP)-based vaccines, have been developed to mitigate the severe impacts of the COVID-19 pandemic. These vaccines have proven highly effective in reducing the severity of illness and preventing deaths. However, the availability and supply of COVID-19 vaccines have become an issue due to the prioritization of vaccine distribution in most countries. Additionally, as the virus continues to mutate and spread, questions have arisen regarding the effectiveness of vaccines against new strains of SARS-CoV-2 that can evade host immunity. The urgent need for booster doses to enhance immunity has been recognized. The scarcity of “safe and effective” vaccines has exacerbated global inequalities in terms of vaccine coverage. The development of COVID-19 vaccines has fallen short of the expectations set forth in 2020 and 2021. Furthermore, the equitable distribution of vaccines at the global and national levels remains a challenge, particularly in developing countries. In such circumstances, the exigency of plant virus-based vaccines has become apparent as a means to overcome supply shortages through fast manufacturing processes and to enable quick and convenient distribution to millions of people without the reliance on a cold chain system. Moreover, plant virus-based vaccines have demonstrated both safety and efficacy in eliciting robust cellular immunogenicity against COVID-19 pathogens. This review aims to shed light on the advantages and disadvantages of different types of vaccines developed against SARS-CoV-2 and provide an update on the current status of plant-based vaccines in the fight against the COVID-19 pandemic

Dissecting Diagnostic and Management Strategies for Plant Viral Diseases: What Next?

Recent advancements in molecular biology have revolutionized plant disease diagnosis and management. This review focuses on disease diagnosis through serological techniques, isothermal amplification methods, CRISPR-based approaches, and management strategies using RNA-based methods. Exploring high-throughput sequencing and RNA interference (RNAi) technologies like host-induced gene silencing (HIGS) and spray-induced gene silencing (SIGS), this review delves into their potential. Despite the precision offered by RNAi in pest and pathogen management, challenges such as off-target effects and efficient dsRNA delivery persist. This review discusses the significance of these strategies in preventing aphid-mediated plant virus transmission, emphasizing the crucial role of meticulous dsRNA design for effective viral RNA targeting while minimizing harm to plant RNA. Despite acknowledged challenges, including off-target effects and delivery issues, this review underscores the transformative potential of RNA-based strategies in agriculture. Envisaging reduced pesticide dependency and enhanced productivity, these strategies stand as key players in the future of sustainable agriculture

Precision Genome Editing Toolbox: Applications and Approaches for Improving Rice’s Genetic Resistance to Pathogens

In the present scenario of a looming food crisis, improving per hectare rice productivity at a greater pace is among the topmost priorities of scientists and breeders. In the past decades, conventional, mutational, and marker-assisted breeding techniques have played a significant role in developing multiple desired rice varieties. However, due to certain limitations, these techniques cannot furnish the projected food security of the 2050 population’s aching stomachs. One of the possible options would be precise crop genome editing using various tools, viz., TALENs and CRISPR/Cas9 to resolve this multifaceted crisis. Initially, the potentiality of these technologies was tested only in the rice protoplasts. Later, the techniques were employed to edit calli with help of modified vectors, CRISPR variants, cassette cloning systems, and delivery methods. With the continuous technological advancements such as base editing, multiplexing, etc., the precision, rapidness, efficiency, reliability, potency, and range of applications of these platforms have increased and even been used for gene function studies. This leads to a revolution in the field of the rice improvement program, especially the stress tolerance against various pests and pathogens in which the susceptibility factors located within the rice genome are targeted through genome editing tools. Therefore, in this current article, we have summarized the advancements in the rice genome editing tools during the last decade concerning enhanced biotic stress tolerance. Additionally, we have focused on the regulatory aspects of genome editing with associated risks and limitations, and the prospects to reshape the rice genome for durable resistance to complex biotic stress

Precision Genome Editing Toolbox: Applications and Approaches for Improving Rice’s Genetic Resistance to Pathogens

In the present scenario of a looming food crisis, improving per hectare rice productivity at a greater pace is among the topmost priorities of scientists and breeders. In the past decades, conventional, mutational, and marker-assisted breeding techniques have played a significant role in developing multiple desired rice varieties. However, due to certain limitations, these techniques cannot furnish the projected food security of the 2050 population’s aching stomachs. One of the possible options would be precise crop genome editing using various tools, viz., TALENs and CRISPR/Cas9 to resolve this multifaceted crisis. Initially, the potentiality of these technologies was tested only in the rice protoplasts. Later, the techniques were employed to edit calli with help of modified vectors, CRISPR variants, cassette cloning systems, and delivery methods. With the continuous technological advancements such as base editing, multiplexing, etc., the precision, rapidness, efficiency, reliability, potency, and range of applications of these platforms have increased and even been used for gene function studies. This leads to a revolution in the field of the rice improvement program, especially the stress tolerance against various pests and pathogens in which the susceptibility factors located within the rice genome are targeted through genome editing tools. Therefore, in this current article, we have summarized the advancements in the rice genome editing tools during the last decade concerning enhanced biotic stress tolerance. Additionally, we have focused on the regulatory aspects of genome editing with associated risks and limitations, and the prospects to reshape the rice genome for durable resistance to complex biotic stress

Major viral diseases in grain legumes: designing disease resistant legumes from plant breeding and OMICS integration

Grain legumes play a crucial role in human nutrition and as a staple crop for low-income farmers in developing and underdeveloped nations, contributing to overall food security and agroecosystem services. Viral diseases are major biotic stresses that severely challenge global grain legume production. In this review, we discuss how exploring naturally resistant grain legume genotypes within germplasm, landraces, and crop wild relatives could be used as promising, economically viable, and eco-environmentally friendly solution to reduce yield losses. Studies based on Mendelian and classical genetics have enhanced our understanding of key genetic determinants that govern resistance to various viral diseases in grain legumes. Recent advances in molecular marker technology and genomic resources have enabled us to identify genomic regions controlling viral disease resistance in various grain legumes using techniques such as QTL mapping, genome-wide association studies, whole-genome resequencing, pangenome and ‘omics’ approaches. These comprehensive genomic resources have expedited the adoption of genomics-assisted breeding for developing virus-resistant grain legumes. Concurrently, progress in functional genomics, especially transcriptomics, has helped unravel underlying candidate gene(s) and their roles in viral disease resistance in legumes. This review also examines the progress in genetic engineering-based strategies, including RNA interference, and the potential of synthetic biology techniques, such as synthetic promoters and synthetic transcription factors, for creating viral-resistant grain legumes. It also elaborates on the prospects and limitations of cutting-edge breeding technologies and emerging biotechnological tools (e.g., genomic selection, rapid generation advances, and CRISPR/Cas9-based genome editing tool) in developing virus-disease-resistant grain legumes to ensure global food security