Viroids

@article{Tsagris2008Viroids,
  title={Viroids},
  author={Efthimia Mina Tsagris and {\'A}ngel Emilio Mart{\'i}nez de Alba and M. Gozmanova and Kriton Kalantidis},
  journal={Cellular Microbiology},
  year={2008},
  volume={10}
}
Viroids are small, circular RNA pathogens, which infect several crop plants and can cause diseases of economic importance. They do not code for proteins but they contain a number of RNA structural elements, which interact with factors of the host. The resulting set of sophisticated and specific interactions enables them to use the host machinery for their replication and transport, circumvent its defence reactions and alter its gene expression. Although found in plants, viroids have a distant… 
What has been happening with viroids?
TLDR
Viroid sequences that are involved in pathogenicity through the RNA silencing system and the target of their viroid-specific small RNAs also have been identified and new viroids have also been discovered and characterized.
Current overview on viroid–host interactions
TLDR
The current understanding of the viroid–host interaction has been summarized with the goal of simplifying the complexity of viroid biology for future research.
Viroids: self‐replicating, mobile, and fast‐evolving noncoding regulatory RNAs
  • B. Ding
  • Biology
    Wiley interdisciplinary reviews. RNA
  • 2010
TLDR
The host range of many viroids is expanding, essentially as a result of continuing and fast evolution of noncoding sequences/structures to gain new biological functions.
Cytopathic Effects Incited by Viroid RNAs and Putative Underlying Mechanisms
TLDR
Early and more recent studies addressing the cytopathology and histopathology incited by a chloroplast-replicating viroid will be reviewed and reassessed in the light of recent advances in the regulatory roles of small RNAs.
Viroids and Viroid-like Circular RNAs: Do They Descend from Primordial Replicators?
TLDR
Although viroid-like replicators are unlikely to be direct descendants of primordial RNA replicators, the study of the diversity and evolution of these ultimate genetic parasites can yield insights into the earliest stages of the evolution of life.
Viroids: an Ariadne's thread into the RNA labyrinth
TLDR
Viroids are models for studying RNA evolution and for analysing RNA transport in plants, because they can move intracellularly, intercellularly through plasmodesmata and to distal parts of the plant through the vascular system.
Viroids as a Tool to Study RNA-Directed DNA Methylation in Plants
TLDR
A revised RdDM model is proposed based on the cumulative amount of evidence from viroid and non-viroid systems and the gradual elucidation through the years of the diverse array of RdDM’s mechanistic details.
olecular biology of viroid – host interactions and disease ontrol strategies
TLDR
Efforts to engineer viroid resistance into host species have been underway for several years, and include the use of antisense RNA, antisenseRNA plus ribozymes, a dsRNase, and siRNAs, among others.
Symptomatic plant viroid infections in phytopathogenic fungi
TLDR
The stable infection of three viroid species in different plant pathogenic filamentous fungi is demonstrated and it is shown that viroid infection can reduce the growth and virulence of fungi.
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References

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Virp1 Is a Host Protein with a Major Role in Potato Spindle Tuber Viroid Infection in Nicotiana Plants
TLDR
Transfection experiments with isolated protoplasts revealed that Virp1-suppressed cells were unable to sustain viroid replication, suggesting that resistance to viroid infection in Virp 1-suppression plants is likely the result of cell-autonomous events.
Viroid: a useful model for studying the basic principles of infection and RNA biology.
TLDR
The structural simplicity, functional versatility, and experimental tractability of viroid RNAs make viroid-host interactions an excellent model to investigate the basic principles of infection and further the general mechanisms of RNA-templated replication, intracellular and intercellular RNA trafficking, and RNA-based regulation of gene expression.
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TLDR
This chapter gives a brief review of possible mechanisms of viroid replication, summarizing the present knowledge of the synthesis ofViroid RNA, the processing reactions which form the mature circular RNA molecule, and the relationships between viroid structure and replicability.
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TLDR
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TLDR
A full-length copy of the gene encoding the 55-kDa PKV (protein kinase viroid)-induced protein has been isolated and sequence analysis revealed significant homologies to cyclic nucleotide-dependent protein kinases, suggesting that it is a putative member of the class of dual-specificityprotein kinases.
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TLDR
It is shown that preventing RNA silencing in tobacco, using a silencing suppressor, greatly reduces the symptoms caused by the Y satellite of cucumber mosaic virus, and viroid and satellite RNAs are significantly resistant to RNAsilencing-mediated degradation.
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TLDR
A genome-wide mutational analysis led to a genomic map of viroid RNA motifs that mediate single-cell replication and systemic trafficking, respectively, which provides a framework to enable high-throughput studies on the tertiary structures and functional mechanisms of RNA motifS that regulate viroid replication and trafficking.
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TLDR
The lack of infectivity observed in a series of transmission assays in carnation indicates that CarSV RNA, in spite of sharing structural similarities with viroid and viroid-like satellite RNAs from plants, does not belong to either of these two groups.
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TLDR
Experimental data concerning viroid-specific nucleic acids accumulating in tomato plants establish the major features of a replication cycle for viroid RNA in plant cells, and suggests a role for endogenous small RNA's in cellular development.
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