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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]

We improved a multiple rapid immunofilter paper assay (multi-RIPA) to simultaneously detect three major viruses of cucumber, Cucumber mosaic virus, Melon yellow spot virus and Zucchini yellow mosaic virus. When we increased the concentration of bovine serum albumin (BSA) in the extraction buffer, a positive band for each virus developed in the multi-RIPA, regardless of the order that the three sensitized white latex particles were immobilized on the strip. The increase in BSA concentration also strengthened the sensitivity of each RIPA. In addition, using a mixture of commercially available, red and blue, sensitized latex solutions as a tracer, purple bands could be produced on the strips. Because each virus yielded an unique color for a positive reaction, the three viruses were easy to distinguish. [ABSTRACT FROM AUTHOR]

The rapid immunofilter paper assay (RIPA) was developed to detect Tomato spotted wilt virus (TSWV), Groundnut ringspot virus (GRSV), and Tomato chlorotic spot virus (TCSV) using antisera against recombinant nucleocapsid (N) proteins of each tospovirus. The two-step RIPA was sensitive enough to detect each pecies specifically in only 30 min. This technique is proposed as an excellent tool for routine Tospovirus diagnosis and field epidemiological studies. [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]

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]

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]

The coronavirus is caused by the infection of the SARS-CoV-2 virus: it represents a complex and new condition, considering that until the end of December 2019 this virus was totally unknown to the international scientific community. The clinical management of patients with the coronavirus disease has undergone an evolution over the months, thanks to the increasing knowledge of the virus, symptoms and efficacy of the various therapies. Currently, however, there is no specific therapy for SARS-CoV-2 virus, know also as Coronavirus disease 19, and treatment is based on the symptoms of the patient taking into account the overall clinical picture. Furthermore, the test to identify whether a patient is affected by the virus is generally performed on sputum and the result is generally available within a few hours or days. Researches previously found that the biomedical imaging analysis is able to show signs of pneumonia. For this reason in this paper, with the aim of providing a fully automatic and faster diagnosis, we design and implement a method adopting deep learning for the novel coronavirus disease detection, starting from computed tomography medical images. The proposed approach is aimed to detect whether a computed tomography medical images is related to an healthy patient, to a patient with a pulmonary disease or to a patient affected with Coronavirus disease 19. In case the patient is marked by the proposed method as affected by the Coronavirus disease 19, the areas symptomatic of the Coronavirus disease 19 infection are automatically highlighted in the computed tomography medical images. We perform an experimental analysis to empirically demonstrate the effectiveness of the proposed approach, by considering medical images belonging from different institutions, with an average time for Coronavirus disease 19 detection of approximately 8.9 s and an accuracy equal to 0.95. [ABSTRACT FROM AUTHOR]

A major goal of chemical ecology is to understand the ecological function and evolutionary significance of secondary metabolites. Indeed, a recent explosion of papers on plant-microbe-insect interactions demonstrate that suitability and utilization are often impacted by both individual microbes and microbial consortia, or "microbiomes." Second, microorganisms can alter utilization of hosts by plants and insects, by changing apparency or adding novel physiological functions More recently, studies have begun to explore the roles of insect-associated microorganisms in conferring expanded functions. [Extracted from the article]

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]

In this paper, we report on the utilization of micro-technology based tools to fight viral infections. Inspired by various hemoperfusion and immune-affinity capture systems, a blood virus depletion device has been developed that offers highly efficient capture and removal of the targeted virus from the circulation, thus decreasing virus load. Single-domain antibodies against the Wuhan (VHH-72) virus strain produced by recombinant DNA technology were immobilized on the surface of glass micro-beads, which were then utilized as stationary phase. For feasibility testing, the virus suspension was flown through the prototype immune-affinity device that captured the viruses and the filtered media left the column. The feasibility test of the proposed technology was performed in a Biosafety Level 4 classified laboratory using the Wuhan SARS-CoV-2 strain. The laboratory scale device actually captured 120,000 virus particles from the culture media circulation proving the feasibility of the suggested technology. This performance has an estimated capture ability of 15 million virus particles by using the therapeutic size column design, representing three times over-engineering with the assumption of 5 million genomic virus copies in an average viremic patient. Our results suggested that this new therapeutic virus capture device could significantly lower virus load thus preventing the development of more severe COVID-19 cases and consequently reducing mortality rate. [ABSTRACT FROM AUTHOR]

Coronavirus disease so called as COVID-19 is an infectious disease and its spread takes place due to human interaction by their pathogen materials during coughing and sneezing. COVID-19 is basically a respiratory disease as evidence proved that a large number of infected people died due to short breathing. Most widely and uncontrollably spreading unknown viral genome infecting people worldwide was announced to be 2019–2020 nCoV by WHO on January 30, 2020. Based on the seriousness of its spread and unavailability of vaccination or any form of treatment, it was an immediate health-emergency of concern of international-level. The paper analyses effects of this virus in countries, such as India and United States on day-to-day basis because of their greater variability. In this study, various performance measures, such as root mean square error (RMSE), mean absolute error (MAE), coefficient of determination (R 2) , mean absolute standard error (MASE) and mean absolute percentage error (MAPE) which characterize models' performances. R 2 value has been achieved to be closest to 1, i.e., 0.999 from Wavelet Neuronal Network Fuzzified Inferences' Layered Multivariate Adaptive Regression Spline (WNNFIL–MARS) for both the countries' data. It is important to capture the essence of this pandemic affecting millions of the population daily ever since its spread began from January, 2020. [ABSTRACT FROM AUTHOR]

Changes to virus taxonomy and the International Code of Virus Classification and Nomenclature ratified by the International Committee on Taxonomy of Viruses (2019). Over the past 30 years, VDN has kept its relevance among virologists as a reference for reliable virus taxonomy-related information provided in a timely fashion by the ICTV. This initial year of VDN concluded with a paper recommending the definition of the virus species as a "polythetic class of viruses", which was soon adopted by the ICTV [[11]]. Finally, the decision to establish the species rank as the basic level of virus taxonomy was published in a VDN article reporting the outcomes of the 20 SP th sp meeting of the EC held in Atlanta, GA in April 1991 [[10]]. [Extracted from the article]

Here we report a novel method to extract nucleic acids for virus detection. Plant tissue in a filter paper sandwich was hit with a hammer, and the crude sap was adsorbed by the filter paper, as in hammer blotting for tissue-print immunodetection of plant viruses. Nucleic acids were extracted from the paper with a guanidine-containing buffer and purified through standard extraction and precipitation. Both viral and cellular RNAs in the extracted RNA were detectable by RT-PCR. The blots can be stored at 4 °C for more than a few days to detect viral RNA, but not cellular RNA. [ABSTRACT FROM AUTHOR]

Cumulatively, these studies highlight some critical considerations to be made when performing diagnoses of plant diseases such as: a) Are there genetic variants of a causal agent that may be missed by standard molecular disease assays due to genetic variability of the causal agent? C) Can symptoms of a biotic disease be confused for other biotic or abiotic diseases? I savastanoi i causing the olive knot disease with epiphytic and endophytic bacteria " by Dokosozi and Bozkurt is an interesting contribution from Turkey that describes a promising biological control against the olive knot bacterium I Pseudomonas savastanoi i pv. [Extracted from the article]

An amendment to this paper has been published and can be accessed via a link at the top of the paper. [ABSTRACT FROM AUTHOR]

Clarifies the link between the International Committee on Taxonomy of Viruses (ICTV) and the papers that apear in the "Virology Division News" (VDN) concerning virus taxonomy. Primary purpose of the ICTV; Entitlement of the ICTV to use the pages of "Archives of Virology" for use as VDN; Titles of VDN since 1990 that have been related to taxonomic matters including "Potyviridae, a proposed family of plant viruses".

The proviral roles of phosphatidic acid in (+)ssRNA plant virus replication Viral replication organelles (VROs) are virus-induced membranous structures in which the synthesis of progeny viral RNA occurs. However, an emerging picture from recent studies is that ROS can act as proviral molecules and that some plant viruses can even trick the host ROS-generating machinery into facilitating virus replication (Hyodo and Okuno [5]). This article is an abstract of the paper presented by a winner of the Young Scientist Award at the 2021 Annual Meeting of the Phytopatho logical Society of Japan in Mie (online). The need for RBOHB-derived ROS in the replication of other (+)ssRNA plant viruses, including BMV, bamboo mosaic virus, and turnip mosaic virus, has been proposed (Hyodo et al. [8], [9]; Lee et al. [12]; Otulak-Koziel et al. [13]). [Extracted from the article]

The reconstruction of the evolutionary history of a set of species is an important problem in classification and phylogenetics. Phylogenetic networks are a generalization of evolutionary trees that are used to represent histories for species that have undergone reticulate evolution, an important evolutionary force for many organisms (e.g. plants or viruses). In this paper, we present a novel approach to understanding the structure of networks that are not necessarily binary. More specifically, we define the concept of a closed set and show that the collection of closed sets of a network forms a hierarchy, and that this hierarchy can be deduced from either the subtrees or subnetworks on all 3-subsets. This allows us to also show that closed sets generalize the concept of the SN-sets of a binary network, sets which have proven very useful in elucidating the structure of binary networks. We also characterize the minimal closed sets (under set inclusion) for a special class of networks (2-terminal networks). Taken together, we anticipate that our results should be useful for the development of new phylogenetic network reconstruction algorithms. [ABSTRACT FROM AUTHOR]

The choice of a modeling approach is a critical decision in the modeling process, as it determines the complexity of the model and the phenomena that the model captures. In this paper, we developed an individual-based model (IBM) and compared it to a previously published ordinary differential equation (ODE) model, both developed to describe the same biological system although with slightly different emphases given the underlying assumptions and processes of each modeling approach. We used both models to examine the effect of insect vector life history and behavior traits on the spread of a vector-borne plant virus, and determine how choice of approach affects the results and their biological interpretation. A non-random distribution of insect vectors across plant hosts emerged in the IBM version of the model and was not captured by the ODE. This distribution led simultaneously to a slower-growing vector population and a faster spread of the pathogen among hosts. The IBM model also enabled us to test the effect of potential control measures to slow down virus transmission. We found that removing virus-infected hosts was a more effective strategy for controlling infection than removing vector-infested hosts. Our findings highlight the need to carefully consider possible modeling approaches before constructing a model. [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]

Maize lethal necrosis (MLN) is a viral disease caused by co-infection of Maize chlorotic mottle virus (MCMV) and a potyvirus mostly Sugarcane mosaic virus (SCMV). MLN is one of the most important maize production constraints in East Africa including Ethiopia. In this study molecular characterization was used to determine potential insect vectors that transmit MLN causing viruses in Ethiopia. Suspected insect vectors of MLN causing viruses collected from maize fields were initially identified to a genus/species level based on the morphological features. Further taxonomic determination was carried out using DNA sequencing from cytochrome oxidase primers. Pre-identified insect vectors of MLN-causing viruses were separately tested in the greenhouse for potential transmission of MCMV and SCMV. Accordingly, maize thrips, Franklinella sp. (Thysanoptera: Thripidae) and cereal leaf beetle, Oulema sp. (Coleoptera: Chrysomelidae) transmitted MCMV, whereas corn leaf aphids, Rhopalosiphum maidis Fich (Hemiptera: Aphididae) transmitted SCMV. Out of 86 maize fields surveyed, Franklinella sp. were widely distributed in 22 (25.6%) fields, mostly in Arsi and West Shewa zones of Oromia region. R. maidis was abundant in all the areas assessed, suggesting that this insect spp. is a vector for SCMV in Ethiopia. The presence of insects as vectors of MLN causing viruses on maize plants is believed to contribute to the widespread of MLN viruses from plant to plant, field to field and to new geographical areas. Thus, managing these vectors through appropriate control measures can reduce maize yield losses caused by MLN disease. [ABSTRACT FROM AUTHOR]

Wastewater surveillance has proven a cost-effective key public health tool to understand a wide range of community health diseases and has been a strong source of information on community levels and spread for health departments throughout the SARS- CoV-2 pandemic. Studies spanning the globe demonstrate the strong association between virus levels observed in wastewater and quality clinical case information of the population served by the sewershed. Few of these studies incorporate the temporal dependence present in sampling over time, which can lead to estimation issues which in turn impact conclusions. We contribute to the literature for this important public health science by putting forward time series methods coupled with statistical process control that (1) capture the evolving trend of a disease in the population; (2) separate the uncertainty in the population disease trend from the uncertainty due to sampling and measurement; and (3) support comparison of sub-sewershed population disease dynamics with those of the population represented by the larger downstream treatment plant. Our statistical methods incorporate the fact that measurements are over time, ensuring correct statistical conclusions. We provide a retrospective example of how sub-sewersheds virus levels compare to the upstream wastewater treatment plant virus levels. An on-line algorithm supports real-time statistical assessment of deviations of virus level in a population represented by a sub-sewershed to the virus level in the corresponding larger downstream wastewater treatment plant. This information supports public health decisions by spotlighting segments of the population where outbreaks may be occurring. [ABSTRACT FROM AUTHOR]

Wisteria vein mosaic virus (WVMV) is a potyvirus infecting Wisteria spp. worldwide, making these largely used ornamental plants unattractive and even unsalable. In 2021, nine Wisteria sinensis plants in Sarzana (Liguria, Italy) showing WVMV symptoms like vein mosaic with irregular patterns, mottling, deformation and twisting margin on leaves were reported. This work describes research on symptomatic and asymptomatic leaves to confirm the identity of the virus infection. All plants tested resulted positive to WVMV. Sequencing of NIb/CP genomic region and comparison on GenBank revealed the presence of eight new genetic variants named Sar 5–12. The eight nucleotide sequences alignments revealed identity ranging between 87.13 and 99.85%. Negative selection (dN/dS < 1) was detected suggesting well adaptation in the area here examined and stability in population. Through a phylogenetic tree, WVMV isolates were grouped in four clades with high bootstrap values, two of which included the eight Italian variants here identified. Since the late 1950 and 1960s, the present study represents the first additional report of WVMV in Italy, as well as its first molecular characterization ever. Further research is required to strengthen our understanding of the movement and transmission of WVMV. Examining how virus infected plants can disseminate this pathogen could help forestall potential risks that neighbouring species may face in their environments. [ABSTRACT FROM AUTHOR]

Cucurbit crops are cultivated throughout the world. Melon (Cucumis melo L.), cucumber (Cucumis sativus L.), watermelon (Citrullus lanatus (Thumb.) Mat. et Nak.), squash and pumpkin (Cucurbita spp.) are the major crops. In Latin America and the Caribbean islands (LAC) cucurbits are consumed as a part of the daily diet since pre-Columbian times, when some species such as Cucurbita pepo L., Cucurbita moschata Duch. and Cucurbita maxima Duch. were domesticated by American Indians. In LAC, cucurbit crops have become export commodities and a source of income for several countries, in addition to their role in local consumption. The increase of area devoted to cucurbit crops and the intensification of production has led to the emergence of severe viral epidemics that threaten the sustainability of these cultures. This paper reviews the cucurbit viruses described in the region and their impact. In addition, the potential of different measures to control the most frequent cucurbit viruses in LAC is discussed. [ABSTRACT FROM AUTHOR]

Over the last 15 years, interest in plant virus evolution has re-emerged, as shown by the increasing number of papers published on this subject. In recent times, research in plant virus evolution has been viewed from a molecular, rather than populational, standpoint, and there is a need for work aimed at understanding the processes involved in plant virus evolution. However, accumulated data from analyses of experimental and natural populations of plant viruses are beginning to delineate some trends that often run contrary to accepted opinion: (1) high mutation rates are not necessarily adaptive, as a large fraction of the mutations are deleterious or lethal; (2) in spite of high potential for genetic variation, populations of plant viruses are not highly variable, and genetic stability is the rule rather than the exception; (3) the degree of constriction of genetic variation in virus-encoded proteins is similar to that in their eukaryotic hosts and vectors; and (4) in spite of huge census sizes of plant virus populations, selection is not the sole factor that shapes their evolution, and genetic drift may be important. Here, we review recent advances in understanding plant virus evolution, and describe the experimental and analytical methods most suited to this purpose.

The wheat curl mite (WCM), Aceria tosichella, and the plant viruses it transmits represent an invasive mite-virus complex that has affected cereal crops worldwide. The main damage caused by WCM comes from its ability to transmit and spread multiple damaging viruses to cereal crops, with Wheat streak mosaic virus (WSMV) and Wheat mosaic virus (WMoV) being the most important. Although WCM and transmitted viruses have been of concern to cereal growers and researchers for at least six decades, they continue to represent a challenge. In older affected areas, for example in North America, this mite-virus complex still has significant economic impact. In Australia and South America, where this problem has only emerged in the last decade, it represents a new threat to winter cereal production. The difficulties encountered in making progress towards managing WCM and its transmitted viruses stem from the complexity of the pathosystem. The most effective methods for minimizing losses from WCM transmitted viruses in cereal crops have previously focused on cultural and plant resistance methods. This paper brings together information on biological and ecological aspects of WCM, including its taxonomic status, occurrence, host plant range, damage symptoms and economic impact. Information about the main viruses transmitted by WCM is also included and the epidemiological relationships involved in this vectored complex of viruses are also addressed. Management strategies that have been directed at this mite-virus complex are presented, including plant resistance, its history, difficulties and advances. Current research perspectives to address this invasive mite-virus complex and minimize cereal crop losses worldwide are also discussed. [ABSTRACT FROM AUTHOR]

An abstract of the research paper "Studies on Genome Structure and Function of Fruit Tree Viruses," by Nobuyuki Yoshikawa is presented.

Virus-like symptoms—red ringspots on stems and leaves, circular blotches or pale spots on fruit—were found on commercial highbush blueberry ( Vaccinium corymbosum) cultivars Blueray, Weymouth, Duke and Sierra in Japan. In PCR testing, single DNA fragments were amplified from total nucleic acid samples of the diseased blueberry bushes using primers specific to Blueberry red ringspot virus (BRRV). Sequencing analysis of the amplified products revealed 95.7–97.7% nucleotide sequence identity with the BRRV genome. This paper is the first report of blueberry red ringspot disease caused by BRRV in Japan. [ABSTRACT FROM AUTHOR]

A new grapevine leafroll-associated virus isolate (GLRaV-Pr) from Greek grapevines was recently reported. This virus, along with the genetically related GLRaV-4, -5, -6 and -9, form a separate diverse lineage within the genus Ampelovirus. In this paper, the complete nucleotide sequence of GLRaV-Pr was determined, making it the first fully sequenced virus of this lineage. Its genome is 13,696 nt long and contains seven open reading frames, which potentially encode a 253-kDa polyprotein containing papain-like protease, methyltransferase, AlkB and helicase domains, a 58.2-kDa RNA-dependent RNA polymerase, a 5.2-kDa hydrophobic protein, a 58.5-kDa heat shock 70 protein homologue, a 60-kDa protein, a 30-kDa coat protein (CP) and a 23-kDa protein. A virus-specific antibody was raised against the recombinant CP of GLRaV-Pr and was applied in western blot analysis. The genomic, serological and phylogenetic data reported here confirm that GLRaV-Pr is a member of a distinct Ampelovirus species. Comparisons of GLRaV-Pr with the only available genetically related, fully sequenced virus, PMWaV-1, PBNSPaV and the partially sequenced GLRaV-9 revealed that this lineage, including GLRaV-4, -5, -6, -9 and -De, exhibits a high uniformity of genome organization and includes the smallest and simplest viruses within the family Closteroviridae. [ABSTRACT FROM AUTHOR]

RNA silencing is a sequence-specific defense mechanism against viruses. As a counterdefense, viruses evolved silencing suppressors to interfere with host silencing. In analyses using protoplasts prepared from cultured cells (BY-2) and mesophyll cells of Nicotiana tabacum and N. benthamiana, viral suppressors differentially functioned in different cell types. This phenomenon has not been discussed in earlier papers on protoplast systems and RNA silencing. In investigations of the cellular activities of viral suppressors and their role in the RNA-silencing pathway, assays with host protoplasts offer many advantages and can complement other in planta assays such as Agrobacterium-mediated transient expression. [ABSTRACT FROM AUTHOR]

Beet western yellows virus relies on the aphid M. persicae for its transmission in a persistent and circulative mode. To be transmitted, the virus must cross the midgut and the accessory salivary gland epithelial barriers by a transcytosis mechanism where vector receptors interact with virions. The aphid and the peptidic viral determinants implicated in this interaction mechanism have been studied. In this paper, we report that the coat and the readthrough proteins that constitute the capsid of this virus are glycosylated. Modification of the glucidic core of these structural viral proteins by oxidation with sodium metaperiodate or deglycosylation with N-glycosidase F or α-D-galactosidase abrogates the aphid transmission of the virus. Aphid transmission could also be inhibited by lectins directed against α-D-galactose when aphids were allowed to acquire virus on artificial membranes. These results suggest that the glucidic cores of the capsid proteins of beet western yellows virus contain α-D-galactose residues that are implicated in virus-aphid interaction and promote aphid transmission of the virus. [ABSTRACT FROM AUTHOR]

An enhanced attenuated strain of Pepper mild mottle virus (PMMoV) was constructed by incorporating mutations that affect viral attenuation from three reported attenuated strains of PMMoV, which causes serious economic losses in the production of green pepper in Japan. The new strain caused no symptoms on pepper plants and protected them from infection by a wild-type strain. The mutations responsible for viral attenuation were located in the intervening region (IR) of the 126-kDa/183-kDa proteins. The mutations had synergistic effects in terms of the attenuation of symptoms and decreased the accumulation of the viral coat protein in infected pepper plants. In this paper, we propose an efficient method for the improvement of attenuated viruses by reverse genetics in plant viruses. [ABSTRACT FROM AUTHOR]

Provides information on the German tobacco mosaic virus research group. Historical background; Contribution to the history of molecular biology; Significance of the research program developed by the group.

Summary. Tomato leaf curl Bangalore virus (ToLCBV-[Ban5]) from south India belongs to the genus Begomovirus of the family Geminiviridae. So far, only the DNA A component has been identified in this virus. In this paper we report the overexpression of ToLCBV-[Ban5] coat protein (CP) in E. coli and its characterization. The purified recombinant CP bound preferentially to ssDNA in a sequence non-specific manner. Deletion of 50 amino acids from the N-terminus, including a putative N-terminal α helix, did not result in the loss of binding to DNA. A search for motifs responsible for DNA binding indicated a conserved putative zinc finger motif in the CPs (corresponding to residues 65–85 in ToLCBV-[Ban 5] CP) of begomoviruses. The role of this motif in DNA binding was evaluated through site-directed mutagenesis of the conserved cysteines (C68, C72) and histidines (H81, H85) present within this motif to alanine. The results indicate that the zinc finger motif is indeed involved in binding to zinc and DNA. [ABSTRACT FROM AUTHOR]

Early infections of the papaya ringspot virus-watermelon strain (PRSV-W) in summer squash Cucurbita pepo may cause marketable yield losses of up to 100%. Because control of the viral disease via management of vector insects is not efficient, incorporation of PRSV-W genetic resistance into C. pepo cultivars would be highly desirable. Although resistant accessions have been described in C. ecuadorensis, C. foetidissima, C. maxima and C. moschata, resistant accessions of C. pepo are rare. This paper reports on interspecific hybridization between C. pepo and a PRSV-W-resistant C. moschata squash accession, and on the early steps in introgression of this resistance into the former species. C. pepo cv. Asmara was crossed with two PRSV-W resistant C. moschata accessions. Immature F1 (C.pepo × C.moschata) embryos were excised 20 days after pollination, and cultured asseptically in two different culture media, each under two different light regimes. No adult plants could be recovered from immature embryos of the cross C. pepo cv. Asmara × C. moschata cv. Piramoita. From the cross C. pepo cv. Asmara × C. moschata cv. Duda, 4 seedlings were recovered from 6 embryos incubated in a growth chamber [25° to 28 °C, 16 hours of light with 1500–2000 lux/ 8 h dark period] immediately after excision and inoculation in a culture medium [= Murashige and Skoog (MS) + 0.01 mg/L of IAA (indolacetic acid) + 0.1 mg/L of Kinetin], without an intervening dark period. F1 (C. pepo × C. moschata) plants were fertile, and upon selfing yielded viable F2 seeds. PRSV-W resistance was assessed in the F2 (C. pepo × C. moschata) population, using C. pepo cv. Asmara and C. moschata cv. Duda, respectively, as the susceptible and resistant (tolerant) checks. Plants were mechanically inoculated with a known PRSV-W isolate. The F2 population showed a PRSV-W response intermediate between those of the parental accessions, and estimates of the mean degree of dominance indicates incomplete dominance in the direction of susceptibility. The mean broad-sense heritability estimate of PRSV-W resistance was 0.48, a medium to high value, indicating the likelihood of a significant response to selection for resistance. The introgression of the resistance to PRSV-W of C. moschata into C. pepo seems to be technically viable. [ABSTRACT FROM AUTHOR]

Summary. The three-dimensional structure of many non-enveloped spherical RNA viruses has been determined in great detail, mainly using X-ray crystallography. Great insight in the structure of the protein capsid has been obtained, but much less information is available about the secondary and tertiary structure of the RNA in situ, due to a number of methodological problems. In this paper the current knowledge about RNA–protein interactions and the folding of the RNA is reviewed, with a special emphasis on the plant virus Turnip yellow mosaic virus. A major characteristic of many spherical RNA viruses appears to be the positioning of A-type double helical segments of 7–9 basepairs at icosahedral symmetry axes, probably interacting via its phosphates with basic amino acid residues of the coat protein in a sequence-independent manner. It is only in the case of the RNA bacteriophages that we know in atomic detail how an RNA hairpin interacts with the coat protein. [ABSTRACT FROM AUTHOR]

Summary. In this paper we describe results obtained from screening field populations of begomoviruses from infected cassava from six countries in southern Africa. It was found that African cassava mosaic virus occurs in five of the six countries (except Angola), East African cassava mosaic virus is present in five countries (except Zambia) and South African cassava mosaic virus was detected only in South Africa and Swaziland. In addition, we report for the first time in southern Africa, the appearance of the Ugandan variant virus (UgV) which was found frequently in mixed infections with other cassava-infecting begomoviruses. [ABSTRACT FROM AUTHOR]

The structural diversity and tunability of the capsid proteins (CPs) of various icosahedral and rod-shaped viruses have been well studied and exploited in the development of smart hybrid nanoparticles. However, the potential of CPs of the wide-spread flexuous filamentous plant viruses remains to be explored. Here, we show that we can control the shape, size, RNA encapsidation ability, symmetry, stability and surface functionalization of nanoparticles through structure-based design of CP from potato virus Y (PVY). We provide high-resolution insight into CP-based self-assemblies, ranging from large polymorphic or monomorphic filaments to smaller annular, cubic or spherical particles. Furthermore, we show that we can prevent CP self-assembly in bacteria by fusion with a cleavable protein, enabling controlled nanoparticle formation in vitro. Understanding the remarkable structural diversity of PVY CP not only provides possibilities for the production of biodegradable nanoparticles, but may also advance future studies of CP's polymorphism in a biological context. Capsid proteins (CPs) of various icosahedral and rod-shaped viruses exhibit structural diversity and tunability as well as application in smart hybrid nanoparticles, however, the potential of CPs of filamentous plant viruses remains underexplored. Here, the authors exploit the structure-based design of CP from potato virus Y to tune the shape, size, RNA encapsidation ability, symmetry, stability, and surface functionalization of nanoparticles. [ABSTRACT FROM AUTHOR]

This document contains abstracts of presentations from the XXVIII Congress of the Italian Phytopathological Society. The presentations cover a wide range of topics related to plant pathology and microbiology, including the use of experimental evolution to select beneficial wound microbiomes, the application of commercial formulations and plant extracts to improve crop yield and quality, the control of various plant diseases, the importance of plant microbiomes in agriculture, the potential of bacterial strains as biological control agents, the genetic diversity of plant viruses, the use of organic fertilizers to control plant pathogens, the characteristics of newly recognized plant pathogens, the mycotoxigenic potential of Penicillium species, the diversity of Fusarium species and the contamination of mycotoxins in wheat, the detection and management of plant diseases, and the role of the microbiome in plant defense responses. These studies provide valuable insights into plant diseases and offer potential solutions for disease control and management. [Extracted from the article]

The genetic information of many viruses is divided between separately encapsidated nucleic acid molecules. A simple evolutionary model is constructed to explain this phenomenon. All multicompartmental viruses infect plants, and most are RNA viruses. The former fact may be due to the high transmission multiplicities enjoyed by plant viruses. The latter may be due to the low replication fidelity of RNA, although another explanation is also offered. The logic of the analysis is contrasted with that of previous explanations. In particular, this paper proceeds from a 'selfish DNA' viewpoint. It is not necessary to suppose that the division of the genome fills any adaptive function for the virus. The theory makes testable predictions about the parameters of multicompartmental viruses. [ABSTRACT FROM AUTHOR]

Transmission of many plant viruses relies on phloem-feeding insect vectors. However, how plant viruses directly modulate insect behavior is largely unknown. Barley yellow striate mosaic virus (BYSMV) is transmitted by the small brown planthopper (SBPH, Laodelphax striatellus). Here, we show that BYSMV infects the central nervous system (CNS) of SBPHs, induces insect hyperactivity, and prolongs phloem feeding duration. The BYSMV accessory protein P6 interacts with the COP9 signalosome subunit 5 (LsCSN5) of SBPHs and suppresses LsCSN5-regulated de-neddylation from the Cullin 1 (CUL1), hereby inhibiting CUL1-based E3 ligases-mediated degradation of the circadian clock protein Timeless (TIM). Thus, virus infection or knockdown of LsCSN5 compromises TIM oscillation and induces high insect locomotor activity for transmission. Additionally, expression of BYSMV P6 in the CNS of transgenic Drosophila melanogaster disturbs circadian rhythm and induces high locomotor activity. Together, our results suggest the molecular mechanisms whereby BYSMV modulates locomotor activity of insect vectors for transmission. Most plant viruses are transmitted by insect vectors in finely regulatory mechanisms. Here, the authors show that a plant rhabdovirus can modify circadian rhythm of its insect vectors and enhances locomotor activity for efficient transmission. [ABSTRACT FROM AUTHOR]

The melon accession PI414723 carries the Zym-1 resistance locus, which is used in breeding programs to control the disease caused by zucchini yellow mosaic virus (ZYMV). We investigated the effects of Zym-1 on the phenotype and on viral titers of F2 plants derived from the cross between PI414723 and Védrantais. For that, we used the simple sequence repeat marker CMAG36, which is linked to Zym-1, and a developed quantitative PCR (qPCR) protocol based on the coat protein of ZYMV. PI414723 and F1 remained symptomless 21 days after inoculation (dai), whereas Védrantais displayed extreme susceptibility. At 8 dai ZYMV was not detected in the apical leaf of the resistant genotype but was in F1 plants at very low levels. Most plants homozygous for resistance (R) or susceptibility (S) alleles at Zym-1 were either symptomless or presented extreme symptoms, respectively. However, a few opposite cases were observed in the two genotypes. Different from the R and F1 plants, the reactions of heterozygotes (H) were more diverse, indicating a partial dominance of Zym-1 at the phenotypic level. ZYMV was detected on R and H plants in equivalent titers, but about 59 times lower than in S plants. This study illustrates the major effects of Zym-1 on the phenotype and viral multiplication or movement. It indicates that in the heterozygous state, Zym-1 may interact with the other resistance genes of PI414723 in an epistatic manner. [ABSTRACT FROM AUTHOR]

In 2021 in Kanagawa Prefecture, Japan, green pepper (Capsicum annuum L.) developed necrotic spots on leaves and necrosis of stems. The nucleotide sequence of the N gene of the virus, isolated through two-rounds of single-lesion isolation, shared 95% identity with that of tomato zonate spot virus (TZSV) reported in China. When green pepper plants were inoculated with the isolated virus, the original symptoms were reproduced, and RT-PCR confirmed the presence of the virus in the inoculated plants. This is the first report of TZSV in Japan. [ABSTRACT FROM AUTHOR]

Coronaviruses have been the causative agent of three epidemics and pandemics in the past two decades, including the ongoing COVID-19 pandemic. A broadly-neutralizing coronavirus therapeutic is desirable not only to prevent and treat COVID-19, but also to provide protection for high-risk populations against future emergent coronaviruses. As all coronaviruses use spike proteins on the viral surface to enter the host cells, and these spike proteins share sequence and structural homology, we set out to discover cross-reactive biologic agents targeting the spike protein to block viral entry. Through llama immunization campaigns, we have identified single domain antibodies (VHHs) that are cross-reactive against multiple emergent coronaviruses (SARS-CoV, SARS-CoV-2, and MERS). Importantly, a number of these antibodies show sub-nanomolar potency towards all SARS-like viruses including emergent CoV-2 variants. We identified nine distinct epitopes on the spike protein targeted by these VHHs. Further, by engineering VHHs targeting distinct, conserved epitopes into multi-valent formats, we significantly enhanced their neutralization potencies compared to the corresponding VHH cocktails. We believe this approach is ideally suited to address both emerging SARS-CoV-2 variants during the current pandemic as well as potential future pandemics caused by SARS-like coronaviruses. [ABSTRACT FROM AUTHOR]

Chikungunya virus (CHIKV) infection has been associated with severe cardiac manifestations, yet, how CHIKV infection leads to heart disease remains unknown. Here, we leveraged both mouse models and human primary cardiac cells to define the mechanisms of CHIKV heart infection. Using an immunocompetent mouse model of CHIKV infection as well as human primary cardiac cells, we demonstrate that CHIKV directly infects and actively replicates in cardiac fibroblasts. In immunocompetent mice, CHIKV is cleared from cardiac tissue without significant damage through the induction of a local type I interferon response from both infected and non-infected cardiac cells. Using mice deficient in major innate immunity signaling components, we found that signaling through the mitochondrial antiviral-signaling protein (MAVS) is required for viral clearance from the heart. In the absence of MAVS signaling, persistent infection leads to focal myocarditis and vasculitis of the large vessels attached to the base of the heart. Large vessel vasculitis was observed for up to 60 days post infection, suggesting CHIKV can lead to vascular inflammation and potential long-lasting cardiovascular complications. This study provides a model of CHIKV cardiac infection and mechanistic insight into CHIKV-induced heart disease, underscoring the importance of monitoring cardiac function in patients with CHIKV infections. Mosquito-borne viruses are serious global public health threats associated with severe atypical cardiovascular manifestations. Here, the authors dissect how chikungunya virus directly infects cardiac tissue leading to heart disease and define key host pathways involved in viral cardiac persistence and tissue damage. [ABSTRACT FROM AUTHOR]

Infectious African swine fever virus (ASFV) can cause the spread and morbidity of African swine fever, while the inactivated virus cannot. When they are not distinguished separately, the detection results will lack authenticity and cause unnecessary panic and detection cost. The detection technology based on cell culture is complex, high-cost, and time-consuming in practice, which is not conducive to the rapid detection of infectious ASFV. In this study, a propidium monoazide (PMA) qPCR detection method for rapid diagnosis of infectious ASFV was constructed. Parameters of PMA concentration, light intensity, and lighting time were under strict safety verification and comparative analysis for optimization. The results determined that the optimal condition for PMA to pretreat ASFV was the final concentration of PMA 100 μM. The light intensity was 40 W, the light duration was 20 min, the target fragment size of the optimal primer probe was 484 bp, and its detection sensitivity for infectious ASFV was 101.28 HAD50/mL. In addition, the method was innovatively applied to the rapid evaluation of disinfection effect. When ASFV concentration was less than 102.28 HAD50/mL, the method could still be effective for the evaluation of thermal inactivation effect, and the evaluation ability of chlorine-containing disinfectants was better, and the applicable concentration could reach 105.28 HAD50/mL. It is worth mentioning that this method can not only reflect whether the virus is inactivated, but also indirectly reflect the degree of damage to viral nucleic acid caused by disinfectants. In conclusion, the PMA-qPCR constructed in this study can be applied to laboratory diagnosis, disinfection effect evaluation, drug development, and other aspects of infectious ASFV and can provide new technical support for effective prevention and control of ASF. Key points: • A rapid detection method for infectious ASFV was developed • Provide a new scheme for rapid evaluation of disinfection effect of chlorine-containing disinfectants • PMA-qPCR can simultaneously show the survival status of the virus and the damage of nucleic acid [ABSTRACT FROM AUTHOR]

Prediction, prevention and treatment of virus infections require understanding of cell-to-cell variability that leads to heterogenous disease outcomes, but the source of this heterogeneity has yet to be clarified. To study the multimodal response of single human cells to herpes simplex virus type 1 (HSV-1) infection, we mapped high-dimensional viral and cellular state spaces throughout the infection using multiplexed imaging and quantitative single-cell measurements of viral and cellular mRNAs and proteins. Here we show that the high-dimensional cellular state scape can predict heterogenous infections, and cells move through the cellular state landscape according to infection progression. Spatial information reveals that infection changes the cellular state of both infected cells and of their neighbors. The multiplexed imaging of HSV-1-induced cellular modifications links infection progression to changes in signaling responses, transcriptional activity, and processing bodies. Our data show that multiplexed quantification of responses at the single-cell level, across thousands of cells helps predict infections and identify new targets for antivirals. The heterogeneity of single cell responses during infection have been reported to influence disease outcome. Here, Pietilä et al characterize cellular heterogeneity during Herpes Simplex Virus 1 infection using a multimodal approach that resolves gene expression, proteomic and spatial details at the single cell level. [ABSTRACT FROM AUTHOR]