Search

Paper-based electrochemical analytical devices (ePADs) have gained significant interest as promising analytical units in recent years because they can be fabricated in simple ways, are low-cost, portable, and disposable platforms that can be applied in various fields. In this sense, paper-based electrochemical biosensors are attractive analytical devices since they can promote diagnose several diseases and potentially allow decentralized analysis. Electrochemical biosensors are versatile, as the measured signal can be improved by using mainly molecular technologies and nanomaterials to attach biomolecules, resulting in an increase in their sensitivity and selectivity. Additionally, they can be implemented in microfluidic devices that drive and control the flow without external pumping and store reagents, and improve the mass transport of analytes, increasing sensor sensitivity. In this review, we focus on the recent developments in electrochemical paper-based devices for viruses' detection, including COVID-19, Dengue, Zika, Hepatitis, Ebola, AIDS, and Influenza, among others, which have caused impacts on people's health, especially in places with scarce resources. Also, we discuss the advantages and disadvantages of the main electrode's fabrication methods, device designs, and biomolecule immobilization strategies. Finally, the perspectives and challenges that need to be overcome to further advance paper-based electrochemical biosensors' applications are critically presented. [ABSTRACT FROM AUTHOR]

Rupert Jethro Best (1903–91), working alone at the Waite Agricultural Research Institute in Adelaide between 1934 and 1937, was among the first to purify tobacco mosaic virus (TMV) and to propose that it was a complex macromolecule containing protein and another reactive group that was responsible for infectivity of the virus. However, his research was completely overshadowed by that of Wendell Stanley and the duo of Frederick Bawden and Norman (aka Bill) Pirie, working in the United States of America and Great Britain, respectively, to the point where Best is not even mentioned in modern histories of TMV. Many factors have contributed to this lack of recognition for Best. Professor James Prescott, a soil scientist and Best's supervisor at the Waite Institute, failed to appreciate the significance of his research, leading to critical delays in publication that prevented him from claiming precedence for purifying TMV. When Best's research was eventually published, it was in Australian journals that were not broadly distributed, resulting in minimal international exposure for his research. The plant virology community within which he worked in Australia was very small and entirely focused on plant disease control, and not concerned with fundamental questions about the composition of viruses. Communication with similarly interested scientists in the Northern Hemisphere was hindered by the great distances involved. In this paper, pioneering research done by Best on TMV is reviewed, and placed in context with that undertaken by Stanley and by Bawden and Pirie, who are best remembered for purifying TMV and characterising its physicochemical properties. Rupert Jethro Best, working alone in Adelaide at the Waite Agricultural Research Institute, was among the first to purify tobacco mosaic virus and to provide evidence that it was a heterogeneous macromolecule, composed mainly of protein but also small prosthetic groups with the properties of a weak acid, wherein lay the activity of the virus. This paper describes the contributions of Rupert Best to early theories on the material nature and mode of reproduction of viruses. Photographer unknown, State Library of South Australia. [ABSTRACT FROM AUTHOR]

This review describes the enhanced classification of polyphenols into flavonoids, lignans, phenolic acids, stilbenes, and tannins. Its focus is the natural sources of polyphenols and an in-depth discussion of their antibacterial, antifungal, and antiviral activity. Besides a broad literature overview, this paper contains authors' experimental data according to some daily consumed vegetables such as tomatoes, different varieties of onion, garlic, parsley, and cayenne pepper and the probable relation of these activities to polyphenols. The isolation of polyphenols via conventional and ultrasonic, pressurized liquids and pulse-field extractions, as well as their methods for detection and determination, are interpreted as well. The main mechanisms by which polyphenols inhibit the growth of bacteria, fungi, and viruses, such as protein synthesis, cell membrane destabilization, and ROS production induction, are in focus. Data on polyphenol concentrations and their respective MIC or the inhibition zone diameters of different bacterial and fungal species and suppressing viral replication are depicted. The toxicity of polyphenols in vitro, ex vivo, and in vivo towards microorganisms and human/animal cells, and the safety of the polyphenols applied in clinical and industrial applications are expanded. This review also characterizes the antimicrobial effects of some chemically synthesized polyphenol derivatives. Biotechnological advances are also reported, especially the entrapment of polyphenols in biocompatible nanoparticles to enhance their bioavailability and efficacy. Polyphenols are promising for exploring molecules' novel antimicrobial substances and paving the path for effective novel antimicrobial agents' discovery, taking into consideration their positives and negatives. [ABSTRACT FROM AUTHOR]

In an attempt of reducing the cost of tissue blot immunoassay (TBIA), some kinds of papers as alternative solid phases in place of nitrocellulose membrane (NCM), were tested for detection of three viruses: Cowpea mosaic virus (CPMV), Tomato mosaic virus (ToMV) and Zucchini yellow mosaic virus (ZYMV). Most of the examined papers developed positive reaction with all tested viruses. Canson paper (150g/m² and 300g/m²) were sensitive for detection of the tested viruses as NCM and persist in good condition during the processing. Filter paper (Whatman No. 1), local drawing paper (60g/m2), photocopy paper (80g/m²), (56g/m²) and (70g/m²) were very weak and need to taking care in handling. High glossy photo paper (200g/m²) was not effective however, it did not show any infected or healthy tissue print. Good results were obtained when both faces of NCM and Canson paper (300g/m-2) were printed with all tested viruses. TBIA could detect CPMV in infected leaves using the unused face of NCM previously processed with 7 or 11 years ago. CPMV, ToMV and ZYMV were detected 2, 4, 6, 8 and16 days after inoculation with NCM and Canson paper (300g/m-2). Also, the tested viruses were detected in leaf, petiole, stem and root of infected plants. ToMV could be detected using NCM and Canson paper (300g/m-2) in naturally infected tomato plant samples. [ABSTRACT FROM AUTHOR]

Food security is a basic human right that guarantees humans an adequate amount of nutritious food. However, plant viruses and agricultural pests cause real damage to food sources, leading to negative impacts on meeting the human right of obtaining a sufficient amount of food. Understanding infectious disease dynamics can help us to design appropriate control and prevention strategies. Although cassava is among the most produced and consumed crops and greatly contributes to food security, cassava mosaic disease causes a decrease in photosynthesis and reduces cassava yield, resulting in a lack of crops. This paper developed a fractional model for cassava mosaic disease (CMD) dynamics based on the Caputo–Fabrizio (CF) fractional derivative to decrease cassava plant infection. We used fixed-point theory to study the existence of a unique solution in the form of the CMD model. A stability analysis of the model was conducted by using fixed-point theory and the Picard technique. A new numerical scheme was proposed for solving the nonlinear system of a fractional model in the sense of the CF-derivative and applied to obtain numerical simulations for a fractional model of the dynamics of CMD. The obtained results are described using figures that show the dynamics and behaviors of the compartments of CMD, and it is concluded that decreasing the population of whitefly vectors can prevent cassava plants from becoming infected better than increasing the recovery rate of the infected cassava plants. [ABSTRACT FROM AUTHOR]

Transforming agriculture into a sustainable system includes innovative, safe, and sustainable management of virus diseases. Advances in cutting-edge biotechnological tools, such as CRISPR/Cas9 genome editing (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9), environmental RNA interference (RNAi), and the application of natural antiviral compounds, present promising new strategies for effective virus control. Highly sensitive and validated diagnostic tools allow early detection and targeted management strategies. The 56th meeting of the Deutsche Phytomedizinische Gesellschaft (DPG) working group on "Viruskrankheiten der Pflanzen" tackled the latest developments and challenges in the field of plant virology in Germany, covering topics on genomic technologies, diagnostics and quarantine regulations, virus–host interaction, virus diversity, plant immunity, and more. A special emphasis lay on the applied side of plant virology, as here, pressing agricultural challenges have to be met. In this perspectives paper, we give a summary on the conference's findings and highlight possibilities to derive novel strategies for disease control. [ABSTRACT FROM AUTHOR]

In 2022, the outbreak of the monkeypox virus occurred in many non-endemic countries, and the World Health Organization (WHO) assessed that this outbreak was "atypical". The establishment of a rapid and effective assay that can be used for the early diagnosis of monkeypox virus infection is crucial for outbreak prevention and control. In this study, the monkeypox virus A29 protein and the homologous vaccinia virus A27 protein and cowpox virus 162 protein were expressed in Escherichia coli BL21 for screening. We synthesized the monkeypox virus A2917–49 peptide as the immunogen and obtained 25 monoclonal antibodies (mAbs) against the A29 protein using mouse hybridoma techniques. Then an immunochromatographic test strip method for detecting A29 was established. The strips utilizing mAb-7C5 and 5D8 showed the best sensitivity and lowest limit of detection: 50 pg mL−1 for purified A29 and specificity tests showed that the strips did not cross-react with other orthopox viruses (vaccinia virus or cowpox virus) as well as common respiratory pathogens (SARS-CoV-2, influenza A and influenza B). Therefore, this method can be used for early and rapid diagnosis of monkeypox virus infection by antigen detection. [ABSTRACT FROM AUTHOR]

The second paper in this series [[2]] concerned an examination of two subgroups of the cytorhabdovirus lettuce necrotic yellows virus (LNYV), a virus apparently endemic to the Australia/New Zealand region. The Special Issue "State-of-the-Art Plant Virus Research in Australasia" in I Viruses i provided a fascinating snapshot of plant and fungus virus research being undertaken in Australasia during the final year of the official COVID-19 pandemic. In contrast to papers 2 and 3, where indigenous viruses were adapting to new hosts, in this paper, exotic viruses were shown to be evolving in exotic hosts under selection pressures present in their new geographical location of Tasmania. Paper seven [[7]] reported research into mycoviruses (viruses that infect fungi), not plant viruses as such, although in this case, the virus-infected fungus originated from inside the root of an Australian indigenous orchid. [Extracted from the article]

Soybean pests are one of the major factors limiting yield improvement. With the expansion of area and changes in cropping patterns, a number of new pests have been identified in the main soybean production areas of China. The common brown leafhopper, Orosius orientalis, is a new pest associated with soybean stay-green virus that has been discovered on cultivated soybean crop in the Yellow-Huai-hai region of China in recent years. The polyphagous insect has a wide feeding range and infests a variety of important grain and cash crops. This paper presents the basic information, geographical distribution, hosts, damage characteristics, plant virus transmission, occurrence patterns, and prevention and control measures O. orientalis. This review also provides insights into integrated prevention and control of the genus Orosius as an insect vector. [ABSTRACT FROM AUTHOR]

Plant viruses pose a significant threat to global agriculture, resulting in economic losses and threatening food security. High-throughput sequencing and molecular techniques are advancing our understanding of these viruses, allowing for their detection, characterization, and control. The 55th meeting of the DPG Working Group "Viruskrankheiten der Pflanzen" showcased these advancements, encouraging international collaboration and idea exchange to tackle plant virus challenges. The perspectives paper we present summarizes this conference's findings, highlighting the potential of these technologies in revolutionizing plant virus research. [ABSTRACT FROM AUTHOR]

A chance discovery early in 1980 led to a body of work on a virus and a rare species that lasted until the end of the decade. The discovery and characterisation of turnip yellow mosaic virus (TYMV-Cd) infecting one-fifth of the fragmented population of Cardamine robusta at Mt Kosciuszko, New South Wales, revealed a puzzle that remains unresolved. There is no clear explanation as to why there is a population of TYMV here in the Southern Hemisphere whose sequence has only diverged from Northern Hemisphere TYMV by a few percent. Adding to the mystery is the fact that TYMV-Cd only infects one of the rarest and geographically most restricted species in Australia, while it is surrounded by potential hosts known to be infected in the Northern Hemisphere. This article reviews research published on TYMV at Mt Kosciuszko during the 1980s and 1990s. While human agency cannot be ruled out, indications are that TYMV established without human intervention. The work is set in a historical context and highlights some of the changes around how plant virology is done. A chance discovery in alpine Australia in 1980 led to the discovery of a virus in a remote and rare species of plant. The virus has clear connections with a virus in the Northern Hemisphere. The way we study plant virology has changed over the intervening years but the mystery as to how the virus got there remains. Photograph by: PL Guy 2004. [ABSTRACT FROM AUTHOR]

Research into the biology of plant viruses, their mechanisms of pathogenicity, and the induction of host resistance has laid a solid foundation for the discovery of antiviral agents and their targets and the development of effective control technologies. Additionally, recent advancements in fields such as chemical biology, cheminformatics, bioinformatics, and synthetic biology have provided valuable methods and tools for the design of antiviral drugs, the synthesis of drug molecules, assessment of their activity, and investigation of their modes of action. Compared with drug development for human viral diseases, the control of plant viral diseases presents greater challenges, including the cost-benefit of agents, simplification of control technologies, and the effectiveness of treatments. Therefore, in the current context of complex outbreaks and severe damage caused by plant viral diseases, it is crucial to delve deeper into the research and development of antiviral agents. This review provides a detailed overview of the biological characteristics of current targets for antiviral agents, the mode of interaction between plant virus targets and antivirals, and insights for future drug development. We believe this review will not only facilitate the in-depth analysis of the development of antivirals for crops but also offer valuable perspectives for the development of antiviral agents for use in human and veterinary medicine. [ABSTRACT FROM AUTHOR]

Simple Summary: Plant–aphid interactions are complex, involving a series of defense mechanisms. When aphids feed on plants, they trigger plant defenses that are mediated by phytohormones, secondary metabolites, lectins, protease inhibitors, and resistance genes that can disrupt aphid growth and reproduction. On the other hand, aphids counter the host plant defense with salivary effectors that suppress plant immunity. Understanding these interactions between plants and aphids can guide the development of aphid-resistant crops through conventional breeding and genetic engineering, offering sustainable pest management strategies and reducing reliance on the application of chemical pesticides. Aphids are small, notorious insect pests that negatively impact plant health and agricultural productivity through direct damage, such as sap-sucking, and indirectly as vectors of plant viruses. Plants respond to aphid feeding with a variety of molecular mechanisms to mitigate damage. These responses are diverse and highly dynamic, functioning either independently or in combination. Understanding plant–aphid interactions is crucial for revealing the full range of plant defenses against aphids. When aphids infest, plants detect the damage via specific receptor proteins, initiating a signaling cascade that activates defense mechanisms. These defenses include a complex interaction of phytohormones that trigger defense pathways, secondary metabolites that deter aphid feeding and reproduction, lectins and protease inhibitors that disrupt aphid physiology, and elicitors that activate further defense responses. Meanwhile, aphids counteract plant defenses with salivary effectors and proteins that suppress plant defenses, aiding in their successful colonization. This review offers a detailed overview of the molecular mechanisms involved in plant–aphid interactions, emphasizing both established and emerging plant defense strategies. Its uniqueness lies in synthesizing the recent progress made in plant defense responses to aphids, along with aphids' countermeasures to evade such defenses. By consolidating current knowledge, this review provides key insights for developing sustainable strategies to achieve crop protection and minimize dependence on chemical pesticides. [ABSTRACT FROM AUTHOR]

Among the cultivated crop species, the economically and culturally important grapevine plays host to the greatest number of distinctly characterized viruses. A critical component of the management and containment of these viral diseases in grapevine is both the identification of infected vines and the characterization of new pathogens. Next-generation high-throughput sequencing technologies, i.e., HTS technologies, have been widely adopted for their ability to quickly, broadly and directly characterize molecular sequences associated with potential pathogens. We empirically analyze the performance of HTS as a diagnostic tool in a phytosanitary context and make recommendations on its deployment for detecting known and novel viruses in grapevine. Three popular and widely used modalities for analyzing HTS data are characterized and compared using the standard diagnostic performance criteria of sensitivity (the true positive rate), specificity (the true negative rate) and analytical sensitivity (dilution series). [ABSTRACT FROM AUTHOR]

Plant viruses are endocellular, and they multiply inside their host plant cells. Outside of the host cells, they are acellular and cannot multiply and move to their hosts for reproduction. Plant virus use insect vectors to transmit and distribute from the infected farm to the next health plant or farms—especially the orders of Hemiptera, Thysanoptera, and Coleoptera are the vectors of plant viruses from infected to healthy plants. For instance, the hemipterans such as aphids, whiteflies, cicadas, spittle bugs, leafhoppers, assassin bugs, stink bugs, lygaeid bugs, and Thysanoptera (e.g., thrips) are the major vectors of plant viruses. Furthermore, the Aleyrodidae, Aphididae, Cicadellidae, and Delphacidae families of Hemiptera, the Chrysomelidae family of Coleoptera, and the Thripidae family of Thysanoptera were the most intriguing families of insects that vector plant viruses due to their behavior, short life cycles, easy interactions with their hosts, reproduction rapidly, and their feeding habits on a wide variety of host plants. The occurrence of these insect vectors in host plants decreased yield and led to malnutrition, reduced income, and reduced the marketability of the crops. Understanding the interactions between insect vectors, plant viruses, and crops is benefiting farmers in general for managing plant viruses and by managing insect vectors at large. Therefore, the objectives of this review are to address the insect vectors of plant viruses, host interactions, their effects, and put forward future opportunities. Finally, this review concluded that managing insect vectors at desirable stages, times, and places by available methods can manage plant viruses. [ABSTRACT FROM AUTHOR]

The diverse rhabdoviruses infecting plants and animals have conserved genome organizations, and the functions of viral structural proteins have been extensively studied. However, increasing number of rhabdoviruses have been found to encode various accessory proteins, whose specific roles during viral infection remain poorly understood. In this study, we investigated the function of the X proteins encoded by several members of the genus Alphanucleorhabdovirus. Using the recently established eggplant mottled dwarf virus (EMDV) reverse genetics system, we found that recombinant EMDV lacking the X gene was able to systemically infect Nicotiana benthamiana plants, albeit with reduced efficiency. However, this deletion mutant was largely restricted to the veinal tissues and caused asymptomatic infections. The EMDV X protein, which localized to the cytoplasm when expressed alone, was translocated to the nucleus via a specific interaction with the nucleocapsid (N) protein. Through analyzing the interactions of the X deletion mutants and the infection phenotypes of the derived EMDV deletion mutants, we demonstrated that the carboxyl-terminal region of the X protein (amino acids 71–83) is crucial for its interaction with the N protein and for viral pathogenesis. Moreover, the X proteins encoded by related alphanucleorhabdoviruses could fully or partially complement the functions of EMDV X in viral infection. These findings provide new insights into the roles of accessory proteins in plant rhabdovirus infection. [ABSTRACT FROM AUTHOR]

Background: Nanotechnology has been recognized as a viable technology for enhancing agriculture, particularly in the plant pathogen management area. Alfalfa mosaic virus (AMV) is a global pathogen that affects many plant species, especially economically valuable crops. Currently, there is less data on the interaction of nanoparticles with phytopathogens, particularly viruses. The current study looked into how copper oxide nanoparticles (CuO-NPs)-mediated Haloxylon salicornicum aqueous extract can fight AMV infections on tobacco plants. Results: Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed that CuO-NPs have a spherical and hexagonal structure ranging from 20 to 70 nm in size. Fourier transform infrared spectroscopy (FTIR) analysis showed that the produced CuO-NPs have many functional groups and a lot of secondary plant metabolites. Under greenhouse conditions, the foliar application of CuO-NPs (100 ppm) enhanced tobacco growth and decreased viral symptoms. Treatment with CuO-NPs 48 h before (protective treatment) or 48 h after (curative treatment) AMV infection significantly reduced AMV accumulation levels by 97%. Additionally, the levels of total chlorophyll, phenolic, and flavonoid contents, as well as DPPH, exhibited a significant increase in tobacco leaves 30 days after inoculation in comparison to untreated plants. Moreover, considerable differences in levels of different antioxidant enzymes, including SOD, PPO, POX, and CAT, were also observed. On the other hand, the oxidative stress markers (MDA and H2O2) were significantly reduced in CuO-NPs-treated plants compared with non-treated plants. It was also found that the protective treatment increased the expression levels of genes involved in the jasmonic pathway (JERF3 and WRKY1). On the other hand, the curative treatment increased the expression levels of polyphenolic pathway acid (CHI and HQT) and the SA-signaling pathway genes (PR-2 and POD). The study of molecular docking interactions with four AMV target proteins showed that CuO-NPs had high binding energy with the viral replication protein 1a, measured at -3.2 kcal/mol. The binding with these proteins can suppress AMV replication and spread, potentially clarifying the mechanism behind the antiviral effect. Conclusions: The overall analysis results indicate that the curative treatment is more influential and successful than the protective treatment in combating AMV infection. Consequentially, CuO-NPs could potentially be employed in foliar sprays for the effective and environmentally friendly management of plant virus infections. [ABSTRACT FROM AUTHOR]

Chitosan is a natural biopolymer that is industrially produced from chitin via deacetylation. Due to its unique properties and a plethora of biological activities, chitosan has found application in diverse areas from biomedicine to agriculture and the food sector. Chitosan is regarded as a biosafe, biodegradable, and biocompatible compound that was demonstrated to stimulate plant growth and to induce a general plant defense response, enhancing plant resistance to various pathogens, including bacteria, fungi, nematodes, and viruses. Here, we focus on chitosan application as an antiviral agent for plant protection. We review both the pioneer studies and recent research that report the effect of plant treatment with chitosan and its derivatives on viral infection. Special attention is paid to aspects that affect the biological activity of chitosan: polymer length and, correspondingly, its molecular weight; concentration; deacetylation degree and charge; application protocol; and experimental set-up. Thus, we compare the reported effects of various forms and derivatives of chitosan as well as chitosan-based nanomaterials, focusing on the putative mechanisms underlying chitosan-induced plant resistance to plant viruses. [ABSTRACT FROM AUTHOR]

Losses incurred by introduction of efficient vectors and phytoviruses into non-endemic areas and climate change are threatening food and nutritional security globally. Insect vectors transmit numerous viruses that affect high value vegetable crops. These viruses are diverse, and their transmission modes vary. Often, more than one virus is transmitted by the same vector, and many viruses can infect the same host. Even under conventional agriculture, it is challenging to reduce losses and maintain sustainability. The challenge becomes even more grave in organic production. However, it is critical to address this issue, as organic production is gaining traction for desirable reasons. Typically, organic farms are smaller and vulnerable to landscape effects. The threshold for vectors that transmit plant viruses is zero, it is impossible to achieve such stringent control, especially when super vectors such as thrips and whiteflies reach explosive populations. Nevertheless, significant progress could be achieved by integrating multiple management options. There is no 'silverbullet' option, but host resistance comes close to it. Host resistance governed by single dominant genes could be highly valuable. Unfortunately, that is often not the case and there are drawbacks. Partial resistance conferred by semi-dominant and multiple genes also is available. Cultivars with complete or partial resistance can be effectively integrated with cultural, biological (augmentative), and chemical management options. This review attempts to highlight the seriousness of insecttransmitted viruses in organic vegetable production, provide an update on management options and limitations, and discuss knowledge gaps and future research areas aimed at enhancing sustainability. [ABSTRACT FROM AUTHOR]

Plant viral infections cause significant economic losses, totalling $350 billion USD in 2021. With no treatment for virus-infected plants, accurate and efficient diagnosis is crucial to preventing and controlling these diseases. High-throughput sequencing (HTS) enables cost-efficient identification of known and unknown viruses. However, existing diagnostic pipelines face challenges. First, many methods depend on subjectively chosen parameter values, undermining their robustness across various data sources. Second, artifacts (e.g. false peaks) in the mapped sequence data can lead to incorrect diagnostic results. While some methods require manual or subjective verification to address these artifacts, others overlook them entirely, affecting the overall method performance and leading to imprecise or labour-intensive outcomes. To address these challenges, we introduce IIMI, a new automated analysis pipeline using machine learning to diagnose infections from 1583 plant viruses with HTS data. It adopts a data-driven approach for parameter selection, reducing subjectivity, and automatically filters out regions affected by artifacts, thus improving accuracy. Testing with in-house and published data shows IIMI's superiority over existing methods. Besides a prediction model, IIMI also provides resources on plant virus genomes, including annotations of regions prone to artifacts. The method is available as an R package (iimi) on CRAN and will integrate with the web application www.virtool.ca , enhancing accessibility and user convenience. [ABSTRACT FROM AUTHOR]

Phytopathogens are a significant challenge to agriculture and food security. In this regard, methods for the early diagnosis of plant diseases, including optical methods, are being actively developed. This review focuses on one of the optical diagnostic methods, chlorophyll fluorescence (ChlF) imaging. ChlF reflects the activity of photosynthetic processes and responds subtly to environmental factors, which makes it an excellent tool for the early detection of stressors, including the detection of pathogens at a pre-symptomatic stage of disease. In this review, we analyze the peculiarities of changes in ChlF parameters depending on the type of pathogen (viral, bacterial, or fungal infection), the terms of disease progression, and its severity. The main mechanisms responsible for the changes in ChlF parameters during the interaction between pathogen and host plant are also summarized. We discuss the advantages and limitations of ChlF imaging in pathogen detection compared to other optical methods and ways to improve the sensitivity of ChlF imaging in the early detection of pathogens. [ABSTRACT FROM AUTHOR]

Virus attacks have had devastating effects on mankind. The prominent viruses such as Ebola virus (2012), SARS-CoV or Severe acute respiratory syndrome, Middle East respiratory syndrome-related coronavirus called as the MERS (EMC/2012), Spanish flu (H1N1 virus-1918) and the most recent COVID-19(SARS-CoV-2) are the ones that have created a difficult situation for the survival of the human race. Currently, throughout the world, a global pandemic situation has put economy, livelihood and human existence in a very pathetic situation. Most of the above-mentioned viruses exhibit some similar characteristics and genetic pattern. Analysing such characteristics and genetic pattern can help the researchers to get a deeper insight into the viruses and helps in finding appropriate medicine or cure. To address these issues, this paper proposes an experimental analysis of the above-mentioned viruses data using correlation methods. The virus data considered for the experimental analysis include the distribution of various amino acids, protein sequences, 3D modelling of viruses, pairwise alignment of proteins that comprise the DNA genome of the viruses. Furthermore, this comparative analysis can be used by the researchers and organizations like WHO(World Health Organization), computational biologists, genetic engineers to frame a layout for studying the DNA sequence distribution, percentage of GC (guanine–cytosine) protein which determines the heat stability of viruses. We have used the Biopython to illustrate the gene study of prominent viruses and have derived results and insights in the form of 3D modelling. The experimental results are more promising with an accuracy rate of 96% in overall virus relationship calculation. [ABSTRACT FROM AUTHOR]

The document discusses the current state of plant virus research in China, highlighting advancements in areas such as virus discovery, plant-virus interactions, and virus detection technology. Various studies are presented, including the identification of novel viruses in rice plants, the development of detection methods, and the role of translation initiation factors in viral resistance. The document aims to provide an updated understanding of plant-virus interactions and to support further research in virology and related fields. [Extracted from the article]

Summary: In the world of intelligent agriculture, agricultural disease picture detection plays a critical role. Plant disease identification must be efficient if agricultural production is to be increased sustainably. Anomalies in plants affected by viruses, insects, nutritional deficiencies, or poor weather conditions have traditionally been diagnosed by human experts. Deep learning (DL) and transfer learning, two sophisticated machine learning techniques synonymous with the advancement of artificial intelligence technologies in recent years, have started to be used for the identification of agricultural diseases. However, a variety of significant obstacles exist in the way of widespread use of these approaches. This paper looks at DL and transfer learning in particular, and discusses recent developments in using these advanced technologies to recognize agricultural disease images. Many DL architectures have recently been adopted, along with visualization tools, which are critical for identifying signs and classifying plant diseases. The analysis and evaluation of these two approaches show that transfer learning is the better choice given existing agricultural disease data tools. The paper then looks at the key problems that need to be addressed for research in this area to advance, such as image dataset creation, the collection of big data auxiliary domains, and the optimization of the transfer learning process. The construction of technically feasible agricultural disease image recognition systems requires the creation of image datasets collected under real cultivation conditions. This survey aims to learn more about DL capabilities in plant disease detection to increase device efficiency and accuracy in future research. [ABSTRACT FROM AUTHOR]

Potatoes are developed vegetatively from tubers, and therefore potato virus transmission is always a possibility. The potato leafroll virus (PLRV) is a highly devastating virus of the genus Polerovirus and family Luteoviridae and is regarded as the second-most destructive virus after Potato virus Y. Multiple species of aphids are responsible for the persistent and non-propagating transmission of PLRV. Due to intrinsic tuber damage (net necrosis), the yield and quality are drastically diminished. PLRV is mostly found in phloem cells and in extremely low amounts. Therefore, we have attempted to detect PLRV in both potato tuber and leaves using a highly sensitive, reliable and cheap method of one-step reverse transcription-recombinase polymerase amplification (RT-RPA). In this study, an isothermal amplification and detection approach was used for efficient results. Out of the three tested primer sets, one efficiently amplified a 153-bp product based on the coat protein gene. In the present study, there was no cross-reactivity with other potato viruses and the optimal amplification reaction time was thirty minutes. The products of RT-RPA were amplified at a temperature between 38 and 42 °C using a simple heating block/water bath. The present developed protocol of one-step RT-RPA was reported to be highly sensitive for both leaves and tuber tissues equally in comparison to the conventional reverse transcription-polymerase chain reaction (RT-PCR) method. By using template RNA extracted employing a cellular disc paper-based extraction procedure, the method was not only simplified but it detected the virus as effectively as purified total RNA. The simplified one-step RT-RPA test was proven to be successful by detecting PLRV in 129 samples of various potato cultivars (each consisting of leaves and tubers). According to our knowledge, this is the first report of a one-step RT-RPA performed using simple RNA extracted from cellular disc paper that is equally sensitive and specific for detecting PLRV in potatoes. In terms of versatility, durability and the freedom of a highly purified RNA template, the one-step RT-RPA assay exceeds the RT-PCR assay, making it an effective alternative for the certification of planting materials, breeding for virus resistance and disease monitoring. [ABSTRACT FROM AUTHOR]

A mathematical analysis by computations performed in [[4]] succeeded to predict that the RNA editing mechanism by a conformational switch in HDV genotype 3 occurs in HDV genotype 7 as well. Mathematical and computational biology of viruses at the molecular or cellular levels are more difficult to accurately address than at the population level. The HDV paper in [[4]] already mentions addressing HDV viral kinetics across the different genotypes through the use of a simple differential equation model (transitioning from the molecular to the cellular level), and from here on, the Special Issue is devoted to the cellular level. 32422927 6 Casey J.L. RNA editing in hepatitis delta virus genotype III requires a branched double-hairpin RNA structure. [Extracted from the article]

Simple Summary: As COVID-19 shifts from pandemic to endemic, emerging variants may be more or less virulent. Predicting whether an emerging COVID-19 variant has of high risk of causing severe disease is needed to plan for potential burdens on hospital capacity and protecting vulnerable populations. However, it takes time to do laboratory and animal experiments to determine whether a new genetic variant might be more severe, and the results may not be representative of when the virus infects humans. By the time there is epidemiological data on the severity of disease associated with a new variant, it can be too late for designing an optimal public health response. There is a critical need for computer models that can predict severe disease risk from genetic sequence data, which can be obtained from just the first few infections in a potential incoming wave. Two key challenges make computer modeling difficult: (1) sequence changes are complex, and (2) using historical data to predict future disease requires accounting for the confounding effects of changing patient demographics, improving therapeutics, and increased vaccination. In this paper, we introduce a novel interpretable deep learning architecture to solve this problem, demonstrating that it can make robust predictions for emerging variants. Through the COVID-19 pandemic, SARS-CoV-2 has gained and lost multiple mutations in novel or unexpected combinations. Predicting how complex mutations affect COVID-19 disease severity is critical in planning public health responses as the virus continues to evolve. This paper presents a novel computational framework to complement conventional lineage classification and applies it to predict the severe disease potential of viral genetic variation. The transformer-based neural network model architecture has additional layers that provide sample embeddings and sequence-wide attention for interpretation and visualization. First, training a model to predict SARS-CoV-2 taxonomy validates the architecture's interpretability. Second, an interpretable predictive model of disease severity is trained on spike protein sequence and patient metadata from GISAID. Confounding effects of changing patient demographics, increasing vaccination rates, and improving treatment over time are addressed by including demographics and case date as independent input to the neural network model. The resulting model can be interpreted to identify potentially significant virus mutations and proves to be a robust predctive tool. Although trained on sequence data obtained entirely before the availability of empirical data for Omicron, the model can predict the Omicron's reduced risk of severe disease, in accord with epidemiological and experimental data. [ABSTRACT FROM AUTHOR]

Background: The rapid production of influenza vaccines is crucial to meet increasing pandemic response demands. Here, we developed plant-made vaccines comprising centralized consensus influenza hemagglutinin (HA-con) proteins (H1 and H3 subtypes) conjugated to a modified plant virus, tobacco mosaic virus (TMV) nanoparticle (TMV-HA-con). Methods: We compared immune responses and protective efficacy against historical H1 or H3 influenza A virus infections among TMV-HA-con, HA-con protein combined with AddaVax™ adjuvant, and whole-inactivated virus vaccine (Fluzone®). Results: Immunogenicity studies demonstrated robust IgG, IgM, and IgA responses in the TMV-HA-con and HA-con protein vaccinated groups, with relatively low induction of interferon (IFN)-γ+ T-cell responses across all vaccinated groups. The TMV-HA-con and HA-con protein groups displayed partial protection (100% and 80% survival) with minimal weight loss following challenge with two H1N1 strains. The HA-con protein group exhibited 80% and 100% survival against two H3 strains, whereas the TMV-HA-con groups showed reduced protection (20% survival). The Fluzone® group conferred 20–100% survival against two H1N1 strains and one H3N1 strain, but did not protect against H3N2 infection. Conclusions: Our findings indicate that TMV-HA and HA-con protein vaccines with adjuvant induce protective immune responses against influenza A virus infections. Furthermore, our results underscore the potential of plant-based production using TMV-like nanoparticles for developing influenza A virus candidate vaccines. [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]

The virions of plant viruses and their structurally modified particles (SP) represent valuable platforms for recombinant vaccine epitopes and antitumor agents. The possibility of modifying their surface with biological compounds makes them a tool for developing medical biotechnology applications. Here, we applied a new type of SP derived from virions and virus-like particles (VLP) of Alternanthera mosaic virus (AltMV) and well-studied SP from Tobacco mosaic virus (TMV). We have tested the ability of SP from AltMV (AltMV SPV) and TMV virions also as AltMV VLP to bind to and penetrate Ewing sarcoma cells. The adsorption properties of AltMV SPV and TMV SP are greater than those of the SP from AltMV VLP. Compared to normal cells, AltMV SPV adsorbed more effectively on patient-derived sarcoma cells, whereas TMV SP were more effective on the established sarcoma cells. The AltMV SPV and TMV SP were captured by all sarcoma cell lines. In the established Ewing sarcoma cell line, the effectiveness of AltMV SPV penetration was greater than that of TMV SP. The usage of structurally modified plant virus particles as a platform for drugs and delivery systems has significant potential in the development of anticancer agents. [ABSTRACT FROM AUTHOR]

The development of cross-reactive vaccines is one of the central aims of modern vaccinology. Continuous mutation and the emergence of new SARS-CoV-2 variants and subvariants create the problem of universal coronavirus vaccine design. Previously, the authors devised three recombinant coronavirus antigens, which were based on the sequence collected in 2019 (the Wuhan variant) and produced in an E. coli bacterial expression system. The present work has shown, for the first time, that these recombinant antigens induce the production of antibodies that clearly interact with produced in CHO full-length S-protein of the Omicron variant. The immunogenicity of these recombinant antigens was studied in formulations with different adjuvants: Freund's adjuvant, Al(OH)3 and an adjuvant based on spherical particles (SPs), which are structurally modified plant virus. All adjuvanted formulations effectively stimulated Omicron-specific IgG production in mice. These universal coronavirus antigens could be considered the main component for the further development of broad-spectrum coronavirus vaccines for the prevention of SARS-CoV-2 infection. The present work also provides evidence that the synthetic biology approach is a promising strategy for the development of highly cross-reactive vaccines. Moreover, it is important to note that the bacterial expression system might be appropriate for the production of antigenically active universal antigens. [ABSTRACT FROM AUTHOR]

Tobacco mosaic virus (TMV) is one of the most persistent and infectious plant viruses. The substantial economic losses caused by TMV in the production of tobacco and vegetables (especially in the Solanaceae family) are prompting the introduction of innovative solutions that effectively inhibit infection by this pathogen. Biological control agents based on bacteria of the genera Pseudomonas, Bacillus, Pantoea and actinomycetes are becoming increasingly popular in the fight against TMV. Some fungi, including Fusarium spp., Trichoderma spp., Alternaria spp. and Sepedonium spp., as well as wood-rotting fungi, also exhibit high anti-TMV activity. This article presents a comprehensive review of recent scientific advances in the bioprotection of selected solanaceous crops against TMV. It provides information on the structure of the virus, its host range, pathogenicity and the severity of losses caused in pepper, tomato and tobacco production. The review characterises environmentally safe techniques involving biological control agents naturally occurring in the environment and the bioactive compounds extracted from them. It also identifies their effects on crops at the morphological, physiological and molecular levels. In addition, the manuscript outlines prospects for the future applications of beneficial micro-organisms and active compounds derived from them in the protection against TMV. [ABSTRACT FROM AUTHOR]

Whitefly (Bemisia tabaci Gennadius) (Hemiptera: Aleyrodidae) is a serious pest of several summer crops in hot and dry climates with diverse cryptic species complex worldwide. Cotton is one of the favorite hosts of B. tabaci, where it feeds and spread different plant viruses. The major clade of B. tabaci; Asia-II is predominant in the cotton zone of Punjab-Pakistan. The control of B. tabaci in cotton ecosystem mostly depends upon the sprays of synthetic insecticides in Pakistan. Monitoring of insecticidal resistance is an essential tool in effective management of B. tabaci. Different cotton field strains were collected from the four major cotton growing districts of South Punjab to assess their genetic mitotype and resistance levels compared with the laboratory susceptible population against most commonly used insecticides during 2020 and 2021. Leaf-dip bioassays were performed on 2nd instar nymphal (N2) stage; while adult bioassays were conducted on field collected populations. Genetic analysis of mtCOI revealed that all the populations were belonged to Asia II-1 clade. A mixture of three haplotypes of Asia II-I including haplotypes-2, haplotype-3 and haplotype-4 was identified from Jampur and Bahawalpur samples. However, haplotype-4 and haplotype-3 were identified from Multan population while Vehari samples comprised of haplotype-4 and haplotype-2. Buprofezin (RR ranged 25.75–36.71), pyriproxyfen (RR ranged 7.98–12.78) and diafenthiuron (RR ranged 20.59–28.12) were least efficient products in adult bioassays and had moderate to low level of resistance. However, spirotetramat and flonicamid both were relatively effective against adults with low to very low resistance during both the years. Pyriproxyfen demonstrated least efficacy for reducing adult emergence followed by flonicamid and buprofezin with moderate to very low resistance ratio respectively. In contrast spirotetramat (RR ranged 2.20–4.01), was highly effective against nymphs followed by diafenthiuron (RR ranged 4.63–7.68), having very low resistance ratio. However an upward trend of resistance development was observed against all the five tested insecticides during both the monitoring years. It can be concluded that, in the aftermath of the emergence of resistance to old conventional insecticides, various chemistries with unique modes of action having no, very low, or low levels of resistance can be substituted in rotation. [ABSTRACT FROM AUTHOR]

Potato virus Y (PVY) is a major tobacco (Nicotiana tabacum L.) pathogen that causes severe crop losses. We studied the influence of meteorological factors and a population of twelve aphid species on the development of PVY in field-grown tobacco from 1996 to 2010 in Poland. Three PVY-susceptible tobacco varieties were used in the study. The mean virus incidence ranged from 18% in 2010 to almost 99% in 1996, 2004, and 2009. For determining the relationship between tobacco plant infection and meteorological conditions and aphid populations, logistic regression analysis was used. It was found that the probability of PVY infection is significantly dependent on the average air temperature, relative humidity, number of days with an average temperature of at least 25 °C, and the abundance of Aphis fabae and Brachycaudus helichrysi. The probability of infection of tobacco plants with potato virus Y decreased with increasing air temperature and relative humidity. In addition, with each subsequent day with a temperature of at least 25 °C, the risk of infection decreased by 24%. Furthermore, it was often observed that high populations of Aphis fabae and Brachycaudus helichrysi were associated with a high incidence of virus infection in tobacco plants. [ABSTRACT FROM AUTHOR]

Endogenous viral elements (EVEs) have been reported to exist widely in the genomes of eukaryotic organisms, and they are closely associated with the growth, development, genetics, adaptation, and evolution of their hosts. In this study, two methods—homologous sequence search and genome alignment—were used to explore the endogenous viral sequences in the genomes of Fragaria species. Results revealed abundant endogenous pararetroviruses (EPRVs) in the genomes of Fragaria species, including 786 sequences belonging to five known taxa such as Caulimovirus and other unclassified taxa. Differences were observed in the detected EPRVs between the two methods, with the homologous sequence search having a greater number of EPRVs. On the contrary, genome alignment identified various types and sources of virus-like sequences. Furthermore, through genome alignment, a 267-bp sequence with 95% similarity to the gene encoding the aphid-transmitted protein of Strawberry vein banding virus (Caulimovirus venafragariae) was discovered in the F. chiloensis genome, which was likely a recent insertion. In addition, the statistical analysis of the genome alignment results indicated a remarkably higher abundance of virus-like sequences in the genomes of polyploid strawberries compared with diploid ones. Moreover, the differences in virus-like sequences were observed between the genomes of Fragaria species and those of their close relatives. This study enriched the diversity of viruses that infect strawberries, and laid a theoretical foundation for further research on the origin of endogenous viruses in the strawberry genome, host–virus interactions, adaptation, evolution, and their functions. [ABSTRACT FROM AUTHOR]

Modern diagnostic techniques based on DNA sequence similarity are currently the gold standard for the detection of existing and emerging pathogens. Whilst individual assays are inexpensive to use, assay development is costly and carries risks of not being sensitive or specific enough to capture an increasingly diverse range of targets. Sequencing can provide the entire nucleic acid content of a sample and may be used to identify all pathogens present in the sample when the depth of coverage is sufficient. Targeted enrichment techniques have been used to increase sequence coverage and improve the sensitivity of detection within virus samples, specifically, to capture sequences for a range of different viruses or increase the number of reads from low-titre virus infections. Vertebrate viruses have been well characterised using in-solution hybridisation capture to target diverse virus families. The use of probes for genotyping and strain identification has been limited in plants, and uncertainty around sensitivity is an impediment to the development of a large-scale virus panel to use within regulatory settings and diagnostic pipelines. This review aims to compare significant studies that have used targeted enrichment of viruses to identify approaches to probe design and potential for use in plant virus detection and characterisation. [ABSTRACT FROM AUTHOR]

Simple Summary: Interactions between insects and symbiotic bacteria affect the behavior or biological characteristics of host insects, which in turn affect the intraspecific and interspecific relationships of insects. In this paper, we review multi-trophic interactions among symbiotic bacteria, insects, and their mutualistic partners, and the known or suspected mechanisms that modulate these interactions. The nutritional-, antifungal- and semiochemical-producing functions of symbiotic bacteria in several mutualism systems, as well as the modes of transmission of these bacteria, are summarized in detail. Finally, we also try to provide insights into future research directions. Bacteria associated with insects potentially provide many beneficial services and have been well documented. Mutualism that relates to insects is widespread in ecosystems. However, the interrelation between "symbiotic bacteria" and "mutualism" has rarely been studied. We introduce three systems of mutualism that relate to insects (ants and honeydew-producing Hemiptera, fungus-growing insects and fungi, and plant persistent viruses and vector insects) and review the species of symbiotic bacteria in host insects, as well as their functions in host insects and the mechanisms underlying mutualism regulation. A deeper understanding of the molecular mechanisms and role of symbiotic bacteria, based on metagenomics, transcriptomics, proteomics, metabolomics, and microbiology, will be required for describing the entire interaction network. [ABSTRACT FROM AUTHOR]

As the second-largest cut flower plant globally and one of the top ten traditional flowers in China, chrysanthemums hold significant economic value, encompassing both ornamental and medicinal applications. However, aphids pose a considerable threat as one of the most critical pests affecting chrysanthemums. These pests not only diminish the ornamental value of chrysanthemums through feeding and reproduction but also transmit numerous plant viruses, causing irreversible damage. This review examines aphids' feeding and damage patterns as a starting point, highlighting the unique endogenous defense mechanisms that have evolved in chrysanthemums during their continuous struggle against aphids. These mechanisms include constitutive defense and induced defense. In addition, we enumerate aphid-resistance genes that have been reported in chrysanthemums. Furthermore, this paper compares and predicts the aphid-resistance genes of other species based on the published Chrysanthemum nankingense genome, aiming to provide a valuable reference for future research on aphid-resistance genes in chrysanthemums. [ABSTRACT FROM AUTHOR]

Viral infection, which entails synthesis of viral proteins and active reproduction of the viral genome, effects significant changes in the functions of many intracellular systems in plants. Along with these processes, a virus has to suppress cellular defense to create favorable conditions for its successful systemic spread in a plant. The virus exploits various cellular factors of a permissive host modulating its metabolism as well as local and systemic transport of macromolecules and photoassimilates. The Nicotiana benthamiana stress-induced gene encoding Kunitz peptidase inhibitor-like protein (KPILP) has recently been shown to be involved in chloroplast retrograde signaling regulation and stimulation of intercellular transport of macromolecules. In this paper we demonstrate the key role of KPILP in the development of tobamovius infection. Systemic infection of N. benthamiana plants with tobacco mosaic virus (TMV) or the closely related crucifer-infecting tobamovirus (crTMV) induces a drastic increase in KPILP mRNA accumulation. KPILP knockdown significantly reduces the efficiency of TMV and crTMV intercellular transport and reproduction. Plants with KPILP silencing become partially resistant to tobamovirus infection. Therefore, KPILP could be regarded as a novel proviral factor in the development of TMV and crTMV infection in N. benthamiana plants. [ABSTRACT FROM AUTHOR]

In this research work, coronavirus disease 2019 (COVID-19) has been considered to help mankind survive the present-day pandemic. This research is helpful to monitor the patients newly infected by the virus, and patients who have already recovered from the disease, and also to study the flow of virus from similar health issues. In this paper, an internet of things (IoT) framework has been developed for the early detection of suspected cases. This framework is used for collecting and uploading symptoms (data) through sensor devices to the physician, data analytics center, cloud, and isolation/health centers. The symptoms of the first wave, second wave, and omicron are used to identify the suspects. Five machine learning algorithms which are considered to be the best in the existing literature have been used to find the best machine learning classifier in this research work. The proposed framework is used for the rapid detection of COVID-19 cases from real-world COVID-19 symptoms to mitigate the spread in society. This model also monitors the affected patient who has undergone treatment and recovered. It also collects data for analysis to perform further improvements in algorithms based on daily updated information from patients to provide better solutions to mankind. [ABSTRACT FROM AUTHOR]

As a continuation of our previous work, in this paper, we examine in greater detail the genome organization and some protein properties of the members of a potential group named Reclovirids and belonging to Benyviridae-related viruses. It can be proposed that the single-component Reclovirid genomes encode previously undiscovered transport genes. Indeed, analysis of the coding potential of these novel viral genomes reveals one or more cistrons ranging in size from 40 to 80 to about 600 codons, located in the 3′-terminal region of the genomic RNA, encoding proteins with predicted hydrophobic segments that are structurally diverse among Reclovirids and have no analogues in other plant RNA viruses. Additionally, in many cases, the possible methyltransferase domain of Reclovirid replicases is preceded by membrane-embedded protein segments that are not present in annotated members of the Benyviridae family. These observations suggest a general association of most Reclovirid proteins with cell membranes. [ABSTRACT FROM AUTHOR]

The new power system information network has the security problem of computer virus attack, and the study of its transmission mechanism is helpful to discover the law and influence of virus transmission. In this paper, the research method of epidemic theory is introduced, and a new Susceptible-Exposed-Infectious-Recovered-Susceptible(SEIR-S) virus model is proposed. The immune time-delay parameter is introduced to simulate the evolution and mutation of the virus so that nodes immune to the virus can still be re-infected after a certain time interval. At the same time, the immune time of different nodes is different, and the distributed immune time delay is used to enhance the authenticity of the simulated virus transmission; and considering the influence of the scale-free characteristics of the information network, this paper establishes a continuous Markov chain based on time. The transmission process of the virus, and then deduce the theoretical analysis results of the virus infection rate threshold. Based on theoretical analysis, the propagation process of the SEIR-S virus model with distributed immune time delay was simulated by using the Monte Carlo method, and the accuracy of the threshold formula of virus infection rate was verified. The influence rule of the hysteresis parameter, that is, increasing the average immune time of nodes to viruses can reduce the infection density of the network in a steady, and at the same time, making the immune time of network nodes obey a normal distribution can effectively reduce the oscillation effect of viruses on the network. [ABSTRACT FROM AUTHOR]

"Frontiers in Virology" celebrates its 3rd anniversary with a focus on consolidating virus research through multidisciplinary approaches. The journal emphasizes understanding the complex nature of viruses, including their relationships with hosts and the environment. With specialty sections covering various aspects of virology, the journal aims to provide a platform for cutting-edge research on viruses, including those that are pathogenic to humans and animals. The editorial highlights the ongoing challenges posed by highly mutable viruses like IFV, HIV-1, SARS-CoV-2, and Mpox, and the importance of integrating data science and experimental virology to address these challenges effectively. [Extracted from the article]

This paper presents two viral infection models that describe dynamics of the virus under the effect of two distinct types of antibodies. The first model considers the population of five compartments, target cells, infected cells, free virus particles, antibodies type-1 and antibodies type-2. The presence of two types of antibodies can be a result of secondary viral infection. In the second model, we incorporate the latently infected cells. We assume that the antibody responsiveness is given by a combination of the self-regulating antibody response and the predator–prey-like antibody response. For both models, we verify the nonnegativity and boundedness of their solutions, then we outline all possible equilibria and prove the global stability by constructing proper Lyapunov functions. The stability of the uninfected equilibrium EQ 0 and infected equilibrium EQ * is determined by the basic reproduction number R 0 . The theoretical findings are verified through numerical simulations. According to the outcomes, the trajectories of the solutions approach EQ 0 and EQ * when R 0 ≤ 1 and R 0 > 1 , respectively. We study the sensitivity analysis to show how the values of all the parameters of the suggested model affect R 0 under the given data. The impact of including the self-regulating antibody response and latently infected cells in the viral infection model is discussed. We showed that the presence of the self-regulating antibody response reduces R 0 and makes the system more stabilizable around EQ 0 . Moreover, we established that neglecting the latently infected cells in the viral infection modeling leads to the design of an overflow of antiviral drug therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: The domestic donkey is an endangered equid species. There are 199 donkeys in the Special Nature Reserve "Zasavica", out of the estimated 1000 that are assumed to exist in Serbia. The aim of this study was to assess the exposure of donkeys in the Special Nature Reserve "Zasavica" to some of the most significant viral pathogens and establish the seroprevalence of equine infectious anemia, African horse sickness, equine herpesvirus type 1 infection, equine influenza and equine viral arteritis. In tested blood samples, antibodies against equine herpesvirus type 1 and equine influenza virus (subtype H3N8) were found, while all samples tested negative for African horse sickness virus, equine infectious anemia virus and equine arteritis virus. To our knowledge, this study represents the first results of detection of these pathogens in the population of domestic donkeys in Serbia. The paper presents the findings of specific antibodies in the blood sera of donkeys against the following viruses: equine infectious anemia virus (EIAV), African horse sickness virus (AHSV), equine herpesvirus type 1 (EHV-1), equine influenza virus subtype H3N8 (EIV) and equine arteritis virus (EAV). The analyses were conducted during the year 2022. From a total of 199 donkeys bred in "Zasavica", blood was sampled from 53 animals (2 male donkeys and 51 female donkeys), aged 3 to 10 years. Specific antibodies against EIAV were not detected in any of the tested animals using the agar-gel immunodiffusion (AGID) assay. No specific antibodies against AHSV, tested by enzyme-linked immunosorbent assay (ELISA), or antibodies against EAV, tested by the virus neutralization test (VNT) and ELISA were detected in any of these animals. A positive serological result for EHV-1 was determined by the VNT in all animals, with antibody titer values ranging from 1:2 to 1:128, while a very low antibody titer value for EIV (subtype H3N8) of 1:16 was determined in 18 donkeys using the hemagglutination inhibition test (HI test). [ABSTRACT FROM AUTHOR]

Plants evolved several mechanisms to protect themselves against viruses. Besides recessive resistance, where compatible host factors required for viral proliferation are absent or incompatible, there are (at least) two types of inducible antiviral immunity: RNA silencing (RNAi) and immune responses mounted upon activation of nucleotide-binding domain leucine-rich repeat (NLR) receptors. RNAi is associated with viral symptom recovery through translational repression and transcript degradation following recognition of viral double-stranded RNA produced during infection. NLR-mediated immunity is induced upon (in)direct recognition of a viral protein by an NLR receptor, triggering either a hypersensitive response (HR) or an extreme resistance response (ER). During ER, host cell death is not apparent, and it has been proposed that this resistance is mediated by a translational arrest (TA) of viral transcripts. Recent research indicates that translational repression plays a crucial role in plant antiviral resistance. This paper reviews current knowledge on viral translational repression during viral recovery and NLR-mediated immunity. Our findings are summarized in a model detailing the pathways and processes leading to translational arrest of plant viruses. This model can serve as a framework to formulate hypotheses on how TA halts viral replication, inspiring new leads for the development of antiviral resistance in crops. [ABSTRACT FROM AUTHOR]

Air pollution caused by SARS-CoV-2 and other viruses in human settlements will have a great impact on human health, but also a great risk of transmission. The transmission power of the virus can be represented by quanta number in the Wells-Riley model. In order to solve the problem of different dynamic transmission scenarios, only a single influencing factor is considered when predicting the infection rate, which leads to large differences in quanta calculated in the same space. In this paper, an analog model is established to define the indoor air cleaning index RL and the space ratio parameter. Based on infection data analysis and rule summary in animal experiments, factors affecting quanta in interpersonal communication were explored. Finally, by analogy, the factors affecting person-to-person transmission mainly include viral load of infected person, distance between individuals, etc., the more severe the symptoms, the closer the number of days of illness to the peak, and the closer the distance to the quanta. In summary, there are many factors that affect the infection rate of susceptible people in the human settlement environment. This study provides reference indicators for environmental governance under the COVID-19 epidemic, provides reference opinions for healthy interpersonal communication and human behavior, and provides some reference for accurately judging the trend of epidemic spread and responding to the epidemic. [ABSTRACT FROM AUTHOR]

One of the systems of plant defense against viral infection is RNA silencing, or RNA interference (RNAi), in which small RNAs derived from viral genomic RNAs and/or mRNAs serve as guides to target an Argonaute nuclease (AGO) to virus-specific RNAs. Complementary base pairing between the small interfering RNA incorporated into the AGO-based protein complex and viral RNA results in the target cleavage or translational repression. As a counter-defensive strategy, viruses have evolved to acquire viral silencing suppressors (VSRs) to inhibit the host plant RNAi pathway. Plant virus VSR proteins use multiple mechanisms to inhibit silencing. VSRs are often multifunctional proteins that perform additional functions in the virus infection cycle, particularly, cell-to-cell movement, genome encapsidation, or replication. This paper summarizes the available data on the proteins with dual VSR/movement protein activity used by plant viruses of nine orders to override the protective silencing response and reviews the different molecular mechanisms employed by these proteins to suppress RNAi. [ABSTRACT FROM AUTHOR]

COVID-19, which broke out globally in 2019, is an infectious disease caused by a novel strain of coronavirus, and its spread is highly contagious and concealed. Environmental vectors play an important role in viral infection and transmission, which brings new difficulties and challenges to disease prevention and control. In this paper, a type of differential equation model is constructed according to the spreading functions and characteristics of exposed individuals and environmental vectors during the virus infection process. In the proposed model, five compartments were considered, namely, susceptible individuals, exposed individuals, infected individuals, recovered individuals, and environmental vectors (contaminated with free virus particles). In particular, the re-positive factor was taken into account (i.e., recovered individuals who have lost sufficient immune protection may still return to the exposed class). With the basic reproduction number R 0 of the model, the global stability of the disease-free equilibrium and uniform persistence of the model were completely analyzed. Furthermore, sufficient conditions for the global stability of the endemic equilibrium of the model were also given. Finally, the effective predictability of the model was tested by fitting COVID-19 data from Japan and Italy. [ABSTRACT FROM AUTHOR]