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Journal of Visualized Experiments : JoVE May 2021Most plant viruses in nature are transmitted from one plant to another by hemipteran insects. A high population density of the vector insects that are highly efficient...
Most plant viruses in nature are transmitted from one plant to another by hemipteran insects. A high population density of the vector insects that are highly efficient at virus transmission plays a key role in virus epidemics in fields. Studying virus-insect vector interactions can advance our understanding of virus transmission and epidemics with the aim of designing novel strategies to control plant viruses and their vector insects. Immunofluorescence labeling has been widely used to analyze interactions between pathogens and hosts and is used here in the white-backed planthopper (WBPH, Sogatella furcifera), which efficiently transmits the southern rice black streaked dwarf virus (SRBSDV, genus Fijivirus, family Reoviridae), to locate the virions and insect proteins in the midgut epithelial cells. Using laser scanning confocal microscopy, we studied the morphological characteristics of midgut epithelial cells, cellular localization of insect proteins, and the colocalization of virions and an insect protein. This protocol can be used to study virus activities in insects, functions of insect proteins, and interactions between virus and vector insect.
Topics: Animals; Hemiptera; Insect Proteins; Insect Vectors; Microscopy, Fluorescence; Oryza; Plant Diseases; Plant Viruses
PubMed: 34057437
DOI: 10.3791/62605 -
Phytopathology Sep 2023Seed transmission is a major mode for plant virus persistence and dispersal, as it allows for virus survival within the seed in unfavorable conditions and facilitates...
Seed transmission is a major mode for plant virus persistence and dispersal, as it allows for virus survival within the seed in unfavorable conditions and facilitates spread when they become more favorable. To access these benefits, viruses require infected seeds to remain viable and germinate in altered environmental conditions, which may also be advantageous for the plant. However, how environmental conditions and virus infection affect seed viability, and whether these effects modulate seed transmission rate and plant fitness, is unknown. To address these questions, we utilized turnip mosaic virus, cucumber mosaic virus, and as model systems. Using seeds from plants infected by these viruses, we analyzed seed germination rates, as a proxy of seed viability, and virus seed transmission rate under standard and altered temperature, CO, and light intensity. With these data, we developed and parameterized a mathematical epidemiological model to explore the consequences of the observed alterations on virus prevalence and persistence. Altered conditions generally reduced overall seed viability and increased virus transmission rate compared with standard conditions, which indicated that under environmental stress, infected seeds are more viable. Hence, virus presence may be beneficial for the host. Subsequent simulations predicted that enhanced viability of infected seeds and higher virus transmission rate may increase virus prevalence and persistence in the host population under altered conditions. This work provides novel information on the influence of the environment in plant virus epidemics. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Topics: Plant Diseases; Plant Viruses; Seeds; Plants; Arabidopsis
PubMed: 36880795
DOI: 10.1094/PHYTO-11-22-0448-V -
Annual Review of Virology Sep 2019Viral diseases provide a major challenge to twenty-first century agriculture worldwide. Climate change and human population pressures are driving rapid alterations in... (Review)
Review
Viral diseases provide a major challenge to twenty-first century agriculture worldwide. Climate change and human population pressures are driving rapid alterations in agricultural practices and cropping systems that favor destructive viral disease outbreaks. Such outbreaks are strikingly apparent in subsistence agriculture in food-insecure regions. Agricultural globalization and international trade are spreading viruses and their vectors to new geographical regions with unexpected consequences for food production and natural ecosystems. Due to the varying epidemiological characteristics of diverent viral pathosystems, there is no one-size-fits-all approach toward mitigating negative viral disease impacts on diverse agroecological production systems. Advances in scientific understanding of virus pathosystems, rapid technological innovation, innovative communication strategies, and global scientific networks provide opportunities to build epidemiologic intelligence of virus threats to crop production and global food security. A paradigm shift toward deploying integrated, smart, and eco-friendly strategies is required to advance virus disease management in diverse agricultural cropping systems.
Topics: Agriculture; Animals; Commerce; Ecosystem; Food Supply; Humans; Internationality; Plant Diseases; Plant Viruses
PubMed: 31283443
DOI: 10.1146/annurev-virology-092818-015606 -
Bioconjugate Chemistry Sep 2023Toll-like receptors (TLRs) are promising targets in cancer immunotherapy due to their role in activating the immune system; therefore, various small-molecule TLR...
Toll-like receptors (TLRs) are promising targets in cancer immunotherapy due to their role in activating the immune system; therefore, various small-molecule TLR agonists have been tested in clinical applications. However, the clinical use of TLR agonists is hindered by their non-specific side effects and poor pharmacokinetics. To overcome these limitations, we used plant virus nanoparticles (VNPs) and bacteriophage virus-like particles (VLPs) as drug delivery systems. We conjugated TLR3 or TLR7 agonists to cowpea mosaic virus (CPMV) VNPs, cowpea chlorotic mottle virus (CCMV) VNPs, and bacteriophage Qβ VLPs. The conjugation of TLR7 agonist, 2-methoxyethoxy-8-oxo-9-(4-carboxybenzyl)adenine (1V209), resulted in the potent activation of immune cells and promoted the production of pro-inflammatory cytokine interleukin 6. We found that 1V209 conjugated to CPMV, CCMV, and Qβ reduced tumor growth in vivo and prolonged the survival of mice compared to those treated with free 1V209 or a simple admixture of 1V209 and viral particles. Nucleic acid-based TLR3 agonist, polyinosinic acid with polycytidylic acid (poly(I:C)), was also delivered by CPMV VNPs, resulting in enhanced mice survival. All our data suggest that coupling and co-delivery are required to enhance the anti-tumor efficacy of TLR agonists and simple mixing of the VLPs with the agonists does not confer a survival benefit. The delivery of 1V209 or poly(I:C) conjugated to VNPs/VLPs probably enhances their efficacy due to the multivalent presentation, prolongation of tumor residence time, and targeting of the innate immune cells mediated by the VNP/VLP carrier.
Topics: Animals; Mice; Toll-Like Receptor 3; Toll-Like Receptor 7; Plant Viruses; Adjuvants, Immunologic; Bromovirus; Immunotherapy; Bacteriophages; Neoplasms
PubMed: 37611278
DOI: 10.1021/acs.bioconjchem.3c00271 -
Viruses Sep 2019Small RNAs (sRNAs), including microRNAs (miRNAs) and short interfering RNAs (siRNAs), are non-coding but powerful RNA molecules of 20-30 nucleotides in length. sRNAs... (Review)
Review
Small RNAs (sRNAs), including microRNAs (miRNAs) and short interfering RNAs (siRNAs), are non-coding but powerful RNA molecules of 20-30 nucleotides in length. sRNAs play crucial regulatory roles in diverse plant biological processes. Recently, many studies on sRNAs have been reported. We summarize new findings of sRNAs in virus-plant interactions to accelerate the function analysis of sRNAs. The main content of this review article includes three parts: virus-responsive sRNAs, function analysis of sRNAs in virus pathogenicity or host resistance, and some sRNAs-mediated underlying mechanisms in virus-plant interactions. New findings of sRNAs deepen our understanding about sRNAs' roles, which might contribute to the design of novel control measures against plant viruses.
Topics: Gene Expression Regulation, Plant; Host-Pathogen Interactions; MicroRNAs; Plant Diseases; Plant Viruses; Plants; RNA, Plant; RNA, Small Interfering
PubMed: 31491987
DOI: 10.3390/v11090827 -
Cells Jan 2021Vector transmission of plant viruses is basically of two types that depend on the virus helper component proteins or the capsid proteins. A number of plant viruses... (Review)
Review
Vector transmission of plant viruses is basically of two types that depend on the virus helper component proteins or the capsid proteins. A number of plant viruses belonging to disparate groups have developed unusual capsid proteins providing for interactions with the vector. Thus, cauliflower mosaic virus, a plant pararetrovirus, employs a virion associated p3 protein, the major capsid protein, and a helper component for the semi-persistent transmission by aphids. Benyviruses encode a capsid protein readthrough domain (CP-RTD) located at one end of the rod-like helical particle, which serves for the virus transmission by soil fungal zoospores. Likewise, the CP-RTD, being a minor component of the luteovirus icosahedral virions, provides for persistent, circulative aphid transmission. Closteroviruses encode several CPs and virion-associated proteins that form the filamentous helical particles and mediate transmission by aphid, whitefly, or mealybug vectors. The variable strategies of transmission and evolutionary 'inventions' of the unusual capsid proteins of plant RNA viruses are discussed.
Topics: Animals; Aphids; Capsid Proteins; Evolution, Molecular; Plant Viruses; RNA, Viral
PubMed: 33430410
DOI: 10.3390/cells10010090 -
International Journal of Biological... Jun 2023Patatavirales is the largest order of plant RNA viruses and exclusively contains the family Potyviridae, accounting for 30 % of all known plant viruses. The composition...
Patatavirales is the largest order of plant RNA viruses and exclusively contains the family Potyviridae, accounting for 30 % of all known plant viruses. The composition bias of animal RNA viruses and several plant RNA viruses has been determined. However, the comprehensive nucleic acid composition, codon pair usage patterns, dinucleotide preference and codon pair preference of plant RNA viruses have not been investigated to date. In this study, integrated analysis and discussion of the nucleic acid composition, codon usage patterns, dinucleotide composition and codon pair bias of potyvirids were performed using 3732 complete genome coding sequences. The nucleic acid composition of potyvirids was significantly enriched in A/U. Interestingly, the A/U-rich nucleotide composition of Patatavirales is essential for determining the preferred A-ended and U-ended codons and the overexpression of UpG and CpA dinucleotides. The codon usage patterns and codon pair bias of potyvirids were significantly correlated with their nucleic acid composition. Additionally, the codon usage pattern, dinucleotide composition and codon-pair bias of potyvirids are more dependent on the classification of the virus compared with their hosts. Our analysis provides a better understanding of future research on the origin and evolution patterns of the order Patatavirales.
Topics: Animals; RNA, Plant; Genome, Viral; Codon; RNA Viruses; Plant Viruses; Evolution, Molecular
PubMed: 37076075
DOI: 10.1016/j.ijbiomac.2023.124403 -
International Journal of Molecular... Jan 2022Small RNAs are significant regulators of gene expression, which play multiple roles in plant development, growth, reproductive and stress response. It is generally... (Review)
Review
Small RNAs are significant regulators of gene expression, which play multiple roles in plant development, growth, reproductive and stress response. It is generally believed that the regulation of plants' endogenous genes by small RNAs has evolved from a cellular defense mechanism for RNA viruses and transposons. Most small RNAs have well-established roles in the defense response, such as viral response. During viral infection, plant endogenous small RNAs can direct virus resistance by regulating the gene expression in the host defense pathway, while the small RNAs derived from viruses are the core of the conserved and effective RNAi resistance mechanism. As a counter strategy, viruses evolve suppressors of the RNAi pathway to disrupt host plant silencing against viruses. Currently, several studies have been published elucidating the mechanisms by which small RNAs regulate viral defense in different crops. This paper reviews the distinct pathways of small RNAs biogenesis and the molecular mechanisms of small RNAs mediating antiviral immunity in plants, as well as summarizes the coping strategies used by viruses to override this immune response. Finally, we discuss the current development state of the new applications in virus defense based on small RNA silencing.
Topics: Gene Expression Regulation, Plant; Host-Pathogen Interactions; MicroRNAs; Models, Biological; Plant Viruses; RNA Interference
PubMed: 35054880
DOI: 10.3390/ijms23020696 -
Molecular Biology Reports Mar 2021Plant viruses affect crop production both quantitatively and qualitatively. The viral genome consists of either DNA or RNA. However, most plant viruses are positive... (Review)
Review
Plant viruses affect crop production both quantitatively and qualitatively. The viral genome consists of either DNA or RNA. However, most plant viruses are positive single-strand RNA viruses. MicroRNAs are involved in gene regulation and affect development as well as host-virus interaction. They are non-coding short with 20-24 nucleotides long capable of regulating gene expression. The miRNA gene is transcribed by RNA polymerase II to form pri-miRNA which will later cleaved by Dicer-like 1 to produce pre-miRNA with the help of HYPONASTIC LEAVES1 and SERRATE which finally methylated and exported via nucleopore with the help of HASTY. The outcome of plant virus interaction depends on the effectiveness of host defense and the ability of a virus counter-defense mechanism. In plants, miRNAs are involved in the repression of gene expression through transcript cleavage. On the other hand, viruses use viral suppressors of RNA silencing (VSRs) which affect RISC assembly and subsequent mRNA degradation. Passenger strands, miRNA*, have a significant biological function in plant defense response as well as plant development.
Topics: Databases, Genetic; Gene Silencing; Host-Pathogen Interactions; MicroRNAs; Plant Viruses; Plants
PubMed: 33772417
DOI: 10.1007/s11033-021-06290-4 -
Plant Cell Reports Feb 2022The genome of most plant viruses consists of a single positive-strand of RNA (+ ssRNA). Successful replication of these viruses is fully dependent on the endomembrane... (Review)
Review
The genome of most plant viruses consists of a single positive-strand of RNA (+ ssRNA). Successful replication of these viruses is fully dependent on the endomembrane system of the infected cells, which experiences a massive proliferation and a profound reshaping that enables assembly of the macromolecular complexes where virus genome replication occurs. Assembly of these viral replicase complexes (VRCs) requires a highly orchestrated interplay of multiple virus and co-opted host cell factors to create an optimal microenvironment for efficient assembly and functioning of the virus genome replication machinery. It is now widely accepted that VRC formation involves the recruitment of high levels of sterols, but the specific role of these essential components of cell membranes and the precise molecular mechanisms underlying sterol enrichment at VRCs are still poorly known. In this review, we intend to summarize the most relevant knowledge on the role of sterols in ( +)ssRNA virus replication and discuss the potential of manipulating the plant sterol pathway to help plants fight these infectious agents.
Topics: Cell Membrane; Genome, Viral; Host-Pathogen Interactions; Phytosterols; Plant Diseases; Plant Viruses; Plants; RNA Viruses; Virus Replication
PubMed: 34665312
DOI: 10.1007/s00299-021-02799-x