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Viruses Nov 2016The endoplasmic reticulum (ER) is central to plant virus replication, translation, maturation, and egress. Ubiquitin modification of ER associated cellular and viral... (Review)
Review
The endoplasmic reticulum (ER) is central to plant virus replication, translation, maturation, and egress. Ubiquitin modification of ER associated cellular and viral proteins, alongside the actions of the 26S proteasome, are vital for the regulation of infection. Viruses can arrogate ER associated ubiquitination as well as cytosolic ubiquitin ligases with the purpose of directing the ubiquitin proteasome system (UPS) to new targets. Such targets include necessary modification of viral proteins which may stabilize certain complexes, or modification of Argonaute to suppress gene silencing. The UPS machinery also contributes to the regulation of effector triggered immunity pattern recognition receptor immunity. Combining the results of unrelated studies, many positive strand RNA plant viruses appear to interact with cytosolic Ub-ligases to provide novel avenues for controlling the deleterious consequences of disease. Viral interactions with the UPS serve to regulate virus infection in a manner that promotes replication and movement, but also modulates the levels of RNA accumulation to ensure successful biotrophic interactions. In other instances, the UPS plays a central role in cellular immunity. These opposing roles are made evident by contrasting studies where knockout mutations in the UPS can either hamper viruses or lead to more aggressive diseases. Understanding how viruses manipulate ER associated post-translational machineries to better manage virus-host interactions will provide new targets for crop improvement.
Topics: Endoplasmic Reticulum; Host-Pathogen Interactions; Plant Diseases; Plant Viruses; Proteasome Endopeptidase Complex; Ubiquitination; Viral Proteins
PubMed: 27869775
DOI: 10.3390/v8110314 -
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 -
Plant Biotechnology Journal Apr 2018Plant virus infectious clones are important tools with wide-ranging applications in different areas of biology and medicine. Their uses in plant pathology include the... (Review)
Review
Plant virus infectious clones are important tools with wide-ranging applications in different areas of biology and medicine. Their uses in plant pathology include the study of plant-virus interactions, and screening of germplasm as part of prebreeding programmes for virus resistance. They can also be modified to induce transient plant gene silencing (Virus Induced Gene Silencing - VIGS) and as expression vectors for plant or exogenous proteins, with applications in both plant pathology and more generally for the study of plant gene function. Plant viruses are also increasingly being investigated as expression vectors for in planta production of pharmaceutical products, known as molecular farming. However, plant virus infectious clones may pose a risk to the environment due to their ability to reconstitute fully functional, transmissible viruses. These risks arise from both their inherent pathogenicity and the effect of any introduced genetic modifications. Effective containment measures are therefore required. There has been no single comprehensive review of the biosafety considerations for the contained use of genetically modified plant viruses, despite their increasing importance across many biological fields. This review therefore explores the biosafety considerations for working with genetically modified plant viruses in contained environments, with focus on plant growth facilities. It includes regulatory frameworks, risk assessment, assignment of biosafety levels, facility features and working practices. The review is based on international guidance together with information provided by plant virus researchers.
Topics: Containment of Biohazards; Equipment and Supplies; Genetic Vectors; Laboratories; Microorganisms, Genetically-Modified; Plant Viruses; Plasmids; Risk Assessment; Virology
PubMed: 29271098
DOI: 10.1111/pbi.12876 -
Virus Research Sep 2017Understanding host-pathogen interactions requires analyses to address the multiplicity of scales in heterogeneous landscapes. Anthropogenic influence on plant... (Review)
Review
Understanding host-pathogen interactions requires analyses to address the multiplicity of scales in heterogeneous landscapes. Anthropogenic influence on plant communities, especially cultivation, is a major cause of environmental heterogeneity. We have approached the analysis of how environmental heterogeneity determines plant-virus interactions by studying virus infection in a wild plant currently undergoing incipient domestication, the wild pepper or chiltepin, across its geographical range in Mexico. We have shown previously that anthropogenic disturbance is associated with higher infection and disease risk, and with disrupted patterns of host and virus genetic spatial structure. We now show that anthropogenic factors, species richness, host genetic diversity and density in communities supporting chiltepin differentially affect infection risk according to the virus analysed. We also show that in addition to these factors, a broad range of abiotic and biotic variables meaningful to continental scales, have an important role on the risk of infection depending on the virus. Last, we show that natural virus infection of chiltepin plants in wild communities results in decreased survival and fecundity, hence negatively affecting fitness. This important finding paves the way for future studies on plant-virus co-evolution.
Topics: Biodiversity; Capsicum; Ecosystem; Genetic Variation; Host-Pathogen Interactions; Mexico; Plant Diseases; Plant Viruses
PubMed: 28554561
DOI: 10.1016/j.virusres.2017.05.015 -
Annual Review of Phytopathology Aug 2017During the past decade, knowledge of pathogen life history has greatly benefited from the advent and development of molecular epidemiology. This branch of epidemiology... (Review)
Review
During the past decade, knowledge of pathogen life history has greatly benefited from the advent and development of molecular epidemiology. This branch of epidemiology uses information on pathogen variation at the molecular level to gain insights into a pathogen's niche and evolution and to characterize pathogen dispersal within and between host populations. Here, we review molecular epidemiology approaches that have been developed to trace plant virus dispersal in landscapes. In particular, we highlight how virus molecular epidemiology, nourished with powerful sequencing technologies, can provide novel insights at the crossroads between the blooming fields of landscape genetics, phylogeography, and evolutionary epidemiology. We present existing approaches and their limitations and contributions to the understanding of plant virus epidemiology.
Topics: Molecular Epidemiology; Phylogeography; Plant Diseases; Plant Viruses
PubMed: 28525307
DOI: 10.1146/annurev-phyto-080516-035616 -
Virus Research Jun 2014This review focuses on new or improved technologies currently being applied, or likely to be applied in the future, to worldwide research on plant virus epidemiology.... (Review)
Review
This review focuses on new or improved technologies currently being applied, or likely to be applied in the future, to worldwide research on plant virus epidemiology. Recent technological advances and innovations provide many opportunities to improve understanding of the way diverse types of plant virus epidemics develop and how to manage them. The review starts at the macro level by considering how recent innovations in remote sensing and precision agriculture can provide valuable information about (i) virus epidemics occurring at continental, regional or district scales (via satellites) and within individual crops (mostly via lightweight unmanned aerial vehicles), and (ii) exactly where to target control measures. It then considers recent improvements in information systems and innovations in modelling that improve (i) understanding of virus epidemics and ability to predict them, and (ii) delivery to end-users of critical advice on control measures, such as Internet-based Decision Support Systems. The review goes on to discuss how advances in analysis of spatiotemporal virus spread patterns within crops can help to enhance understanding of how virus epidemics develop and validate potentially useful virus control measures. At the micro level, the review then considers the many insights that advances in molecular epidemiology can provide about genetic variation within plant virus populations involved in epidemics, and how this variation drives what occurs at the macro level. Next, it describes how recent innovations in virus detection technologies are providing many opportunities to collect and analyse new types, and ever increasing amounts, of data about virus epidemics, and the genetic variability of the virus populations involved. Finally, the implications for plant virus epidemiology of technologies likely to be important in the future are considered. To address looming world food insecurity and threats to plant biodiversity resulting from climate change and rapid population growth, it is important that new and improved technologies that help understand and control epidemics of damaging plant viruses are adopted as smoothly and speedily as possible.
Topics: Agriculture; Aviation; Crops, Agricultural; Information Systems; Molecular Epidemiology; Molecular Typing; Plant Diseases; Plant Viruses; Plants; Remote Sensing Technology; Spatio-Temporal Analysis
PubMed: 24275610
DOI: 10.1016/j.virusres.2013.11.003 -
Methods in Molecular Biology (Clifton,... 2008Plant viruses spread from the initially infected cells to the rest of the plant in several distinct stages. First, the virus (in the form of virions or nucleic acid... (Review)
Review
Plant viruses spread from the initially infected cells to the rest of the plant in several distinct stages. First, the virus (in the form of virions or nucleic acid protein complexes) moves intracellularly from the sites of replication to plasmodesmata (PD, plant-specific intercellular membranous channels), the virus then transverses the PD to spread intercellularly (cell-to-cell movement). Long-distance movement of virus occurs through phloem sieve tubes. The processes of plant virus movement are controlled by specific viral movement proteins (MPs). No extensive sequence similarity has been found in MPs belonging to different plant virus taxonomic groups. Moreover, different MPs were shown to use different pathways and mechanisms for virus transport. Some viral transport systems require a single MP while others require additional virus-encoded proteins to transport viral genomes. In this review, we focus on the functions and properties of different classes of MPs encoded by RNA containing plant viruses.
Topics: Cell Movement; Comovirus; Nepovirus; Plant Diseases; Plant Viral Movement Proteins; Plant Viruses; Plasmodesmata; Potyvirus; RNA, Viral; Tobacco Mosaic Virus
PubMed: 18370246
DOI: 10.1007/978-1-59745-102-4_3 -
Annual Review of Phytopathology Aug 2018The first bacterial and viral avirulence ( avr) genes were cloned in 1984. Although virus and bacterial avr genes were physically isolated in the same year, the... (Review)
Review
The first bacterial and viral avirulence ( avr) genes were cloned in 1984. Although virus and bacterial avr genes were physically isolated in the same year, the questions associated with their characterization after discovery were very different, and these differences had a profound influence on the narrative of host-pathogen interactions for the past 30 years. Bacterial avr proteins were subsequently shown to suppress host defenses, leading to their reclassification as effectors, whereas research on viral avr proteins centered on their role in the viral infection cycle rather than their effect on host defenses. Recent studies that focus on the multifunctional nature of plant virus proteins have shown that some virus proteins are capable of suppression of the same host defenses as bacterial effectors. This is exemplified by the P6 protein of Cauliflower mosaic virus (CaMV), a multifunctional plant virus protein that facilitates several steps in the infection, including modulation of host defenses. This review highlights the modular structure and multifunctional nature of CaMV P6 and illustrates its similarities to other, well-established pathogen effectors.
Topics: Caulimovirus; Host-Pathogen Interactions; Plant Viruses; Viral Proteins
PubMed: 29852091
DOI: 10.1146/annurev-phyto-080417-050151 -
The New Phytologist Oct 2013This review discusses the varying roles that have been played by many plant-viral regulatory sequences and proteins in the creation of plant-based expression systems and... (Review)
Review
This review discusses the varying roles that have been played by many plant-viral regulatory sequences and proteins in the creation of plant-based expression systems and virus particles for use in nanotechnology. Essentially, there are two ways of expressing an exogenous protein: the creation of transgenic plants possessing a stably integrated gene construction, or the transient expression of the desired gene following the infiltration of the gene construct. Both depend on disarmed strains of Agrobacterium tumefaciens to deliver the created gene construction into cell nuclei, usually through the deployment of virus-derived components. The importance of efficient mRNA translation in the latter process is highlighted. Plant viruses replicate to sustain an infection to promote their survival. The major product of this, the virus particle, is finding increasing roles in the emerging field of bionanotechnology. One of the major products of plant-viral expression is the virus-like particle (VLP). These are increasingly playing a role in vaccine development. Similarly, many VLPs are suitable for the investigation of the many facets of the emerging field of synthetic biology, which encompasses the design and construction of new biological functions and systems not found in nature. Genetic and chemical modifications to plant-generated VLPs serve as ideal starter templates for many downstream synthetic biology applications.
Topics: Nanotechnology; Plant Diseases; Plant Viruses; Plants, Genetically Modified; RNA, Messenger; Synthetic Biology; Vaccines, Virus-Like Particle
PubMed: 23452220
DOI: 10.1111/nph.12204 -
Pesticide Biochemistry and Physiology Jan 2017Plant virus diseases, known as 'plant cancer', are the second largest plant diseases after plant fungal diseases, which have caused great damage to agricultural... (Review)
Review
Plant virus diseases, known as 'plant cancer', are the second largest plant diseases after plant fungal diseases, which have caused great damage to agricultural industry. Since now, the most direct and effective method for controlling viruses is chemotherapeutics, except for screening of anti-disease species. As the occurrence and harm of plant diseases intensify, production and consumption of pesticides have increased year by year, and greatly contributed to the fertility of agriculture, but also brought a series of problems, such as the increase of drug resistance of plant pathogens and the excessive pesticide residues. In recent years, biopesticide, as characterized by environmentally safe due to low residual, safe to non-target organism due to better specificity and not as susceptible to produce drug resistance due to diverse work ways, has gained more attention than ever before and exhibited great development potential. Now much progress has been made about researches on new biogenic anti-plant-virus substances. The types of active components include proteins, polysaccharides and small molecules (alkaloids, flavonoids, phenols, essential oils) from plants, proteins and polysaccharides from microorganisms, polysaccharides from algae and oligochitosan from animals. This study summarized the research advance of biogenic anti-plant-virus substances in recent years and put forward their further development in the future.
Topics: Animals; Antiviral Agents; Bacteria; Fungi; Phytochemicals; Plant Preparations; Plant Proteins; Plant Viruses; Plants
PubMed: 28043326
DOI: 10.1016/j.pestbp.2016.07.003