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Advances in Virus Research 1966
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Microbial Pathogenesis Aug 2019RNA viruses are the most diverse phytopathogens which cause severe epidemics in important agricultural crops and threaten the global food security. Being obligatory... (Review)
Review
RNA viruses are the most diverse phytopathogens which cause severe epidemics in important agricultural crops and threaten the global food security. Being obligatory intracellular pathogens, these viruses have developed fine-tuned evading mechanisms and are non-responsive to most of the prophylactic treatments. Additionally, their sprint ability to overcome host defense demands a broad-spectrum and durable mechanism of resistance. In context of CRISPR-Cas discoveries, some variants of Cas effectors have been characterized as programmable RNA-guided RNases in the microbial genomes and could be reprogramed in mammalian and plant cells with guided RNase activity. Recently, the RNA variants of CRISPR-Cas systems have been successfully employed in plants to engineer resistance against RNA viruses. Some variants of CRISPR-Cas9 have been tamed either for directly targeting plant RNA viruses' genome or through targeting the host genes/factors assisting in viral proliferation. The new frontiers in CRISPR-Cas discoveries, and more importantly shifting towards RNA targeting will pyramid the opportunities in plant virus research. The current review highlights the probable implications of CRISPR-Cas system to confer the pathogen-derived or host-mediated resistance against phytopathogenic RNA viruses. Furthermore, a multiplexed CRISPR-Cas13a methodology is proposed here to combat Potato virus Y (PVY); a globally diverse phytopathogen infecting multiple crops.
Topics: CRISPR-Cas Systems; Clustered Regularly Interspaced Short Palindromic Repeats; Crops, Agricultural; Disease Resistance; Gene Editing; Gene Targeting; Genes, Plant; Genome, Viral; Models, Theoretical; Plant Diseases; Plant Viruses; Plants; Plants, Genetically Modified; Potyvirus; RNA Viruses; Ribonucleases
PubMed: 31125685
DOI: 10.1016/j.micpath.2019.103551 -
Viruses Nov 2022Based on analyses of recent open-source data, this paper describes novel horizons in the diversity and taxonomy of beny-like viruses infecting hosts of the plant kingdom...
Based on analyses of recent open-source data, this paper describes novel horizons in the diversity and taxonomy of beny-like viruses infecting hosts of the plant kingdom (Plantae or Archaeplastida). First, our data expand the known host range of the family to include red algae. Second, our phylogenetic analysis suggests that the evolution of this virus family may have involved cross-kingdom host change events and gene recombination/exchanges between distant taxa. Third, the identification of gene blocks encoding known movement proteins in beny-like RNA viruses infecting non-vascular plants confirms other evidence that plant virus genomic RNAs may have acquired movement proteins simultaneously or even prior to the evolutionary emergence of the plant vascular system. Fourth, novel data on plant virus diversity highlight that molecular evolution gave rise to numerous provisional species of land-plant-infecting viruses, which encode no known potential movement genetic systems.
Topics: Phylogeny; RNA Viruses; Plants; Genome, Viral; Evolution, Molecular; Plant Viruses
PubMed: 36560684
DOI: 10.3390/v14122680 -
Trends in Plant Science Jan 2012Viruses infecting higher plants are among the smallest viruses known and typically have four to ten protein-encoding genes. By contrast, many viruses that infect algae... (Review)
Review
Viruses infecting higher plants are among the smallest viruses known and typically have four to ten protein-encoding genes. By contrast, many viruses that infect algae (classified in the virus family Phycodnaviridae) are among the largest viruses found to date and have up to 600 protein-encoding genes. This brief review focuses on one group of plaque-forming phycodnaviruses that infect unicellular chlorella-like green algae. The prototype chlorovirus PBCV-1 has more than 400 protein-encoding genes and 11 tRNA genes. About 40% of the PBCV-1 encoded proteins resemble proteins of known function including many that are completely unexpected for a virus. In many respects, chlorovirus infection resembles bacterial infection by tailed bacteriophages.
Topics: Biological Evolution; Chlorophyta; Genome, Viral; Phycodnaviridae; Plant Viruses; Viral Proteins
PubMed: 22100667
DOI: 10.1016/j.tplants.2011.10.005 -
Annual Review of Phytopathology 2011RNA-RNA recombination is one of the strongest forces shaping the genomes of plant RNA viruses. The detection of recombination is a challenging task that prompted the... (Review)
Review
RNA-RNA recombination is one of the strongest forces shaping the genomes of plant RNA viruses. The detection of recombination is a challenging task that prompted the development of both in vitro and in vivo experimental systems. In the divided genome of Brome mosaic virus system, both inter- and intrasegmental crossovers are described. Other systems utilize satellite or defective interfering RNAs (DI-RNAs) of Turnip crinkle virus, Tomato bushy stunt virus, Cucumber necrosis virus, and Potato virus X. These assays identified the mechanistic details of the recombination process, revealing the role of RNA structure and proteins in the replicase-mediated copy-choice mechanism. In copy choice, the polymerase and the nascent RNA chain from which it is synthesized switch from one RNA template to another. RNA recombination was found to mediate the rearrangement of viral genes, the repair of deleterious mutations, and the acquisition of nonself sequences influencing the phylogenetics of viral taxa. The evidence for recombination, not only between related viruses but also among distantly related viruses, and even with host RNAs, suggests that plant viruses unabashedly test recombination with any genetic material at hand.
Topics: Biological Evolution; Bromovirus; Genetic Variation; Genome, Viral; Mutation; Plant Viruses; RNA; RNA, Viral; Recombination, Genetic; Virus Replication
PubMed: 21529157
DOI: 10.1146/annurev-phyto-072910-095351 -
Virologie (Montrouge, France) Feb 2021Plant virus ecology began to be explored at the end of the 19 century. Since then, major advances have revealed complex virus-host-vector interactions in a variety of... (Review)
Review
Plant virus ecology began to be explored at the end of the 19 century. Since then, major advances have revealed complex virus-host-vector interactions in a variety of environments. These advances have been accelerated by development of new technologies for virus detection and characterization, the latest of which being high-throughput sequencing (HTS). HTS technologies have proved to be effective for non-targeted characterization of all or nearly all viruses present in a sample without requiring prior information about virus identity, as would be needed for virus-targeted tests. Phytoviromic studies have thus made important advances, including characterization of the complex interactions between phytovirus dynamics and the structure of multi-species host communities, and documentation of the effects of anthropogenic ecosystem simplification on plant virus emergence and diversity. However, such studies must overcome challenges at every stage, from plant sampling to bioinformatics analysis. This review summarizes major advances in plant virus ecology, in association with technological developments, and presents key considerations for use of HTS in the study of the ecology of phytovirus communities.
Topics: DNA Viruses; Ecology; Ecosystem; Nucleotides; Plant Viruses
PubMed: 33650495
DOI: 10.1684/vir.2021.0879 -
BioEssays : News and Reviews in... Aug 1991In addition to their function in transport of water, ions, small metabolites, and growth factors in normal plant tissue, the plasmodesmata presumably serve as routes for... (Review)
Review
In addition to their function in transport of water, ions, small metabolites, and growth factors in normal plant tissue, the plasmodesmata presumably serve as routes for cell-to-cell movement of plant viruses in infected tissue. Virus cell-to-cell spread through plasmodesmata is an active process mediated by specialized virus encoded movement proteins; however, the mechanism by which these proteins operate is not clear. We incorporate recent information on the biochemical properties of plant virus movement proteins and their interaction with plasmodesmata in a model for transport of nucleic acids through plasmodesmatal channels. We propose that only single stranded (ss) nucleic acids can be transported efficiently through plasmodesmata, and that movement proteins function as molecular chaperones for ss nucleic acids to form unfolded movement protein-ss nucleic acid complexes. These complexes are targeted to plasmodesmata. Plasmodesmatal permeability is then increased following interaction with movement protein and the entire movement complex or its nucleic acid component is translocated across the plasmodesmatal channel.
Topics: DNA, Viral; Intercellular Junctions; Mosaic Viruses; Plant Physiological Phenomena; Plant Viruses; Plants; RNA, Viral; Viral Proteins
PubMed: 1953699
DOI: 10.1002/bies.950130802 -
Archives of Virology Feb 2013Orchid fleck virus (OFV) causes chlorotic or necrotic spots in many orchid species. Its particle morphology and cytopathic effects are similar to those of... (Review)
Review
Orchid fleck virus (OFV) causes chlorotic or necrotic spots in many orchid species. Its particle morphology and cytopathic effects are similar to those of nucleorhabdoviruses. Although OFV shares clear sequence similarities with rhabdoviruses, its taxonomic status is undetermined because its negative-sense RNA genome is bipartite. This review presents a general overview of classical and contemporary findings about etiology, serology, epidemiology, pathology, molecular biology, detection and prevention methods of orchid fleck virus. Because of the characteristics of OFV and viruses of the Rhabdoviridae and Mononegavirales, it is proposed that a new genus of negative-sense RNA plant viruses outside of the Mononegavirales be established with orchid fleck virus as the type species.
Topics: Genome, Viral; Orchidaceae; Plant Diseases; Plant Viruses; RNA Viruses; RNA, Viral
PubMed: 23070138
DOI: 10.1007/s00705-012-1506-5 -
Virology May 2015Positive-strand RNA viruses are the most common type of plant virus. Many aspects of the reproductive cycle of this group of viruses have been studied over the years and... (Review)
Review
Positive-strand RNA viruses are the most common type of plant virus. Many aspects of the reproductive cycle of this group of viruses have been studied over the years and this has led to the accumulation of a significant amount of insightful information. In particular, the identification and characterization of cis-acting RNA elements within these viral genomes have revealed important roles in many fundamental viral processes such as virus disassembly, translation, genome replication, subgenomic mRNA transcription, and packaging. These functional cis-acting RNA elements include primary sequences, secondary and tertiary structures, as well as long-range RNA-RNA interactions, and they typically function by interacting with viral or host proteins. This review provides a general overview and update on some of the many roles played by cis-acting RNA elements in positive-strand RNA plant viruses.
Topics: Genome, Viral; Host-Parasite Interactions; Nucleic Acid Conformation; Plant Viruses; Protein Biosynthesis; RNA Viruses; Regulatory Sequences, Ribonucleic Acid; Transcription, Genetic; Virus Assembly; Virus Replication; Virus Uncoating
PubMed: 25759098
DOI: 10.1016/j.virol.2015.02.032 -
Current Opinion in Virology Nov 2011Positive strand RNA viruses cause membrane modifications which are microenvironments or larger intracellular compartments, also called 'viroplasms'. These compartments... (Review)
Review
Positive strand RNA viruses cause membrane modifications which are microenvironments or larger intracellular compartments, also called 'viroplasms'. These compartments serve to concentrate virus and host factors needed to produce new genomes. Forming these replication sites often involves virus induced membrane synthesis, changes in fatty acid metabolism, and viral recruitment of cellular factors to subcellular domains. Interacting viral and host factors builds the physical scaffold for replication complexes. Such virus induced changes are a visible cytopathology that has been used by plant and mammalian virologists to describe virus disease. This article describes key examples of membrane modifications that are essential for plant virus replication and intercellular transport.
Topics: Intracellular Membranes; Plant Diseases; Plant Viruses; Plants; Virus Replication
PubMed: 22440840
DOI: 10.1016/j.coviro.2011.09.009