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Odontoglossum Ringspot Virus
''Odontoglossum ringspot virus'' (ORSV) is a plant pathogenic virus that belongs to the family ''Virgaviridae''. It is one of the most common viruses affecting cultivated orchids, perhaps second only to the ''Cymbidium mosaic virus ''Cymbidium mosaic virus'' (CymMV) is a plant pathogenic virus of the family ''Alphaflexiviridae''. ''Cymbidium mosaic virus'' and the '' Odontoglossum ringspot virus'' (ORSV) are two of the most common viruses affecting cultivated orchids world ...''. It causes spots on leaves and colored streaks on flowers. If a plant is also infected with the ''Cymbidium mosaic virus'', it can lead to a condition called blossom brown necrotic streak. Phylogenetics Its genome has been sequenced and contains approximately 6600 nucleotides organized into four open reading frames. Its similarity to other tobamoviruses can be seen from the genetic data and the (limited) ability of a '' Tobacco mosaic virus'' modified to contain ORSV movement protein to infect to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgaviridae
''Virgaviridae'' is a family of positive-strand RNA viruses. Plants serve as natural hosts.Adams MJ, Antoniw JF, Kreuze J (2009) Virgaviridae: a new family of rod-shaped plant viruses. Arch Virol 154(12):1967–1972 The name of the family is derived from the Latin word ''virga'' (rod), as all viruses in this family are rod-shaped. There are currently 59 species in this family, divided among seven genera. Structure Viruses in Virgaviridae are non-enveloped, with rigid helical rod geometries, and helical symmetry. The diameter is around 20-25 nm, and virions have a central "canal." Genomes are linear, single-stranded, positive sense RNA with a 3'-tRNA like structure and no polyA tail. They may be in one, two, or three segments, depending on the genus. Coat proteins are about 19–24 kiloDaltons. Life cycle Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orchid
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering plants. The Orchidaceae have about 28,000 currently accepted species, distributed in about 763 genera. (See ''External links'' below). The determination of which family is larger is still under debate, because verified data on the members of such enormous families are continually in flux. Regardless, the number of orchid species is nearly equal to the number of bony fishes, more than twice the number of bird species, and about four times the number of mammal species. The family encompasses about 6–11% of all species of seed plants. The largest genera are ''Bulbophyllum'' (2,000 species), ''Epidendrum'' (1,500 species), ''Dendrobium'' (1,400 species) and ''Pleurothallis'' (1,000 species). It also includes ''Vanilla'' (the genus of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cymbidium Mosaic Virus
''Cymbidium mosaic virus'' (CymMV) is a plant pathogenic virus of the family ''Alphaflexiviridae''. ''Cymbidium mosaic virus'' and the '' Odontoglossum ringspot virus'' (ORSV) are two of the most common viruses affecting cultivated orchids worldwide. Infected plants can have less desirable flowers or other problems, causing significant financial losses to orchid growers. The virus has not often been reported in wild orchid populations. It can be found in a wide variety of orchid genera but does not infect plants other than orchids. Once an orchid is infected, the virus spreads throughout the infected plant in a number of weeks. Control measures may include sanitizing pruning equipment between plants. There is an ELISA test available to test for presence of the virus. It is related to the '' Narcissus mosaic virus'' (NMV), the '' Scallion virus X'' (SVX), the ''Pepino mosaic virus'' (PepMV) and the '' Potato aucuba mosaic virus'' (PAMV). Importance Orchids are composed of ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP) and uridine triphosphate (UTP)—throughout the cell for the many cellular func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Reading Frame
In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames will be "open" (the "reading", however, refers to the RNA produced by transcription of the DNA and its subsequent interaction with the ribosome in translation). Such an ORF may contain a start codon (usually AUG in terms of RNA) and by definition cannot extend beyond a stop codon (usually UAA, UAG or UGA in RNA). That start codon (not necessarily the first) indicates where translation may start. The transcription termination site is located after the ORF, beyond the translation stop codon. If transcription were to cease before the stop codon, an incomplete protein would be made during translation. In eukaryotic genes with multiple exons, introns are removed and exons are then joined together after transcription to yield the final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobamovirus
''Tobamovirus'' is a genus of positive-strand RNA viruses in the family '' Virgaviridae.'' Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name ''Tobamovirus'' comes from the host and symptoms of the first virus discovered (''Tobacco mosaic virus''). There are four informal subgroups within this genus: these are the tobamoviruses that infect the brassicas, cucurbits, malvaceous, and solanaceous plants. The main differences between these groups are genome sequences, and respective range of host plants. There are 37 species in this genus. Structure Tobamoviruses are non-enveloped, with helical rod geometries, and helical symmetry. The diameter is around 18 nm, with a length of 300–310 nm. Genomes are linear and non-segmented, around 6.3–6.5kb in length. Genome The RNA genome encodes at least four polypeptides: these are the non-structural protein and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco Mosaic Virus
''Tobacco mosaic virus'' (TMV) is a positive-sense single-stranded RNA virus species in the genus ''Tobamovirus'' that infects a wide range of plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns, such as "mosaic"-like mottling and discoloration on the leaves (hence the name). TMV was the first virus to be discovered. Although it was known from the late 19th century that a non-bacterial infectious disease was damaging tobacco crops, it was not until 1930 that the infectious agent was determined to be a virus. It is the first pathogen identified as a virus. The virus was crystallised by W.M. Stanley. It has a similar size to the largest synthetic molecule, known as PG5 History In 1886, Adolf Mayer first described the tobacco mosaic disease that could be transferred between plants, similar to bacterial infections. In 1892, Dmitri Ivanovsky gave the first concrete evidence for the existence of a non-bacterial infect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Movement Protein
In order for a virus to infect a plant, it must be able to move between cells so it can spread throughout the plant. Plant cell walls make this moving/spreading quite difficult and therefore, for this to occur, movement proteins must be present. A movement protein (MP) is a specific virus-encoded protein that is considered to be a general feature of plant genomes. They allow for local and systemic viral spread throughout a plant. MPs were first studied in the Tobacco Mosaic Virus (TMV) where it was found that viruses were unable to spread without the presence of a specific protein. In general, the plant viruses first, move within the cell from replication sites to the plasmodesmata (PD). Then, the virus is able to go through the PD and spread to other cells. This process is controlled through MPs. Different MPs use different mechanisms and pathways to regulate this spread of some viruses. Nearly all plants express at least one MP, while some can encode many different MPs which help ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Plant Pathogens And Diseases
Viral means "relating to viruses" (small infectious agents). Viral may also refer to: Viral behavior, or virality Memetic behavior likened that of a virus, for example: * Viral marketing, the use of existing social networks to spread a marketing message * Viral phenomenon, relating to contagion theory or the "virality" of network culture, such as a meme * Viral video, a video that quickly attains a high popularity Titled works * ''Viral'' (2016 American film), a 2016 American science fiction horror drama * ''Viral'' (2016 Hindi film), an Indian Bollywood film based on social media * ''Viral'' (web series), a 2014 Brazilian comedy web series * '' V/H/S: Viral'', an American anthology horror film * '' Viral: The Search for the Origin of COVID-19'', a book by Alina Chand and Matt Ridley See also * ''Virals'', a novel series by Kathy Reichs * Virulence Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobamovirus
''Tobamovirus'' is a genus of positive-strand RNA viruses in the family '' Virgaviridae.'' Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name ''Tobamovirus'' comes from the host and symptoms of the first virus discovered (''Tobacco mosaic virus''). There are four informal subgroups within this genus: these are the tobamoviruses that infect the brassicas, cucurbits, malvaceous, and solanaceous plants. The main differences between these groups are genome sequences, and respective range of host plants. There are 37 species in this genus. Structure Tobamoviruses are non-enveloped, with helical rod geometries, and helical symmetry. The diameter is around 18 nm, with a length of 300–310 nm. Genomes are linear and non-segmented, around 6.3–6.5kb in length. Genome The RNA genome encodes at least four polypeptides: these are the non-structural protein and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
