Introduction
Potato virus X (PVX) is a plant RNA virus. Its infection cycle includes invasion of the host plant, RNA replication, translation of viral proteins, cell-to-cell movement and release of new virions. Upon infection, PVX releases its plus-strand RNA genome from the virion and produces a viral replicase using host translation machinery. The replicase synthesizes minus-strand RNA. Subsequently new plus-strand genomic RNA (gRNA) and subgenomic RNAs (sgRNAs) are produced. Movement and coat proteins are translated from the sgRNAs for encapsidation and movement through plasmodesmata. In this mini-review, all aspects of the virus infection cycle of PVX are discussed.
Classification
Potato virus X (PVX) is a small non-enveloped virus, which has a monopartite plus-strand RNA genome. Therefore it belongs to class IV of the Baltimore system. PVX is a member of the Potexvirus genus. Along with eight other genera, this genus belongs to the Alphaflexiviridae family [1].
Virion morphology and content
PVX forms small filamentous virions which have a deeply grooved surface [2]. The flexuous filaments consist of a single plus-strand genomic RNA coated with viral coat protein (CP). The helical structure has a pitch of 3.6nm and contains 8 7/8 CP subunits per turn [3]. The full-length filaments have a model length of 515nm with a diameter of 13nm [4].
CP consists of a single domain with high α-helical content [4]. The N-terminal part this domain is surface exposed whereas the C-terminal region buried in the virion. Several experiments indicate the CP is an O-glycoprotein. Equal amounts of galactose and fructose residues are O-linked to an acetylated serine residue at the N-terminal region [2]. This mediates the formation of a structured...
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...ut 10%. This is despite of obtaining high virus titers. Symptomless plants are regarded as carriers of PVX and are an important source of infection. Under more severe conditions, necrotic streaks and severe mosaic, crinkling and rugosity of the leaves can occur. Especially upon mixed infections with potato virus Y (PVY), the yield loss can be up to 50%.
Several potato plants carry resistance genes against PVX. Up to date two resistance genes have been identified. One gene product mediates salicylic acid systemic defense responses, whereas the other encodes the Rx protein. This protein has a nucleotide binding-site (NBS) and a leucine-rich repeat (LRR). The native fold of Rx confers an inactive conformation. Upon interactions with the viral CP, Rx partially unfolds, thereby its NBS-LRR domain [27]. This activates the signaling cascade mediating virus resistance.
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The Panic Virus: A True Story of Medicine, Science, and Fear written by Seth Mnookin offers something for all potential readers. For those who are anti-vaccine, Mnookin offers valid science, testimony, history, and excerpts that demonstrate that vaccinating a child can be more beneficial than not. Instead of simply dismissing those who do not vaccinate their children, Mnookin offers valid points to counter argue in this debate. Mnookin offers thought, logic, reasoning, and research into his arguments, showing that his opinion is rooted in fact, rather than opinion or belief. Those who are on the fence about vaccination may find this book useful in that Mnookin not only offers plenty valid points about pro-vaccination, however, he also provides
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Like other negative-stranded RNA viruses, the G protein of rabies virus binds to the host cell membranes and penetrates into the host cytoplasm by pinocytosis. The virions are composed of cytoplasmic vesicles, fuse to cytoplasmic membrane and release RNP into the cytoplasm. The core starts primary transcription of the five complementary monocistronic messenger RNAs by using the virion-associated RNA-dependent RNA polymerase. Each mRNA is translated to an individual viral protein. After synthesis and replication of the genomic RNA, the full length, positive-stranded RNA is completed and becomes the template for the next negative-stranded RNA. In the assembly process, the N-P-L complex encapsulates negative-stranded genomic RNA to be made up of RNP core and the M protein consists of a capsule or matrix that su...
In the 1995 film 'Outbreak' directed by Wolfgang Petersen a deadly virus has appeared in different parts of the United States. A team combining of the Center for Disease Control and Army Medical Research Institute of Infection Diseases took the lead on the Motaba virus. Sam the Colonel of the institute took his team to a village in Africa where the disease had been located. The disease wiped most of the village out in a matter of two to three days and they found the possible host. Returning back to the United States Sam and his team came to the conclusion the disease is not airborne and cannot spread. The disease was created 27 years before but destroyed the Army decided to bomb the whole infected area.
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Nguyen, Bianca. "AP Biology/BN: Bacteria vs. Virus vs. Prion." AP Biology/BN: Bacteria vs. Virus vs. Prion. N.p., 16 Dec. 2011. Web. 18 Apr. 2014. .
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The issue written in this article is regarding the banning and lack of approval for blight-resistant potatoes in the european union. Late potato blight, a potato disease caused by the the eukaryotic microorganism phytophthora infestans, is a significant cause for loss of crop and yield by potato farmers. Looking back to the past, the blight was responsible for the catastrophic Irish Great Famine of the 1840s causing eradication of their main food source, potatoes. As a result of the blight, potatoes become rotten and unsafe for human consumption. Late potato blight today is still a serious issue because it has caused the loss of $5.9 billion dollars of potatoes worldwide annually.By engineering blight resistance into potatoes, scientists have hoped to increase the yield and productivity of potato crops affected by this devastating disease. However, the attempts of the scientists are met with strong resistance by anti-GMO activists and lobbying groups, who are intent on food as naturally pure as possible. In consequence of not using genetically modified potatoes, the farmers are forced to use costly pesticides in an attempt to control the blight. With the human population rapidly increasing, it is essential that all measures be taken to increase food/crop yield in order to prevent starvation and hunger caused by the overpopulation. The battle between agricultural researchers like Simplot and the anti-GMO lobbying group GeneWatch is a controversial one that must be addressed by this generation and future generations.
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Most plant diseases will be destroyed. However, some heat resistant viruses will not be affected (e.g. the tobacco mosaic virus).
Using microarray gene-chip technology, we monitor RNA levels produced by 10,000 genes in both normal and mutant plants. "In the mutant plants, we found one gene, called DMI3, which produced extremely low levels of RNA. The normal version of the DMI3 gene produces a protein that is remarkably similar to tobacco plant proteins that are known to modulate their behaviors in response to calcium."
...ound in our bodies. The trick is that the virus “gets confused” and incorporates the fatal molecule into its growing RNA strands which leads to the prevention of RNA synthesis and thus the entire viral replication.
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