|
Blueberry Mosaic Associated Ophiovirus
The ''Blueberry mosaic associated ophiovirus'' (B1MaV) is a plant virus which infects blueberry plants, causing a discoloration of the leaves of the plants in a mosaic-like pattern. The disease is found in blueberry plants in many regions of North America, as well as South America, Europe, New Zealand, and South Africa. Within these regions the virus is most often found in high blueberry-yielding areas, but can be spread to other locations. ''Blueberry mosaic associated'' ''ophiovirus'' is one of seven species in the genus ''Ophiovirus''. It is a member of the Aspiviridae family, in the Serpentovirales order, and in the Milnevircetes class. The ''Ophioviridae'' viruses are characterized by a flexible and elongated nucleocapsid that is composed mostly of filamentous structures and is helically symmetrical. It also has a non-enveloped protein capsid that is capable of coiling around itself allowing for a super-coiled structure and the helical symmetry. The virus has the potential to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Virus
Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses can be pathogenic to higher plants. Most plant viruses are rod-shaped, with protein discs forming a tube surrounding the viral genome; isometric particles are another common structure. They rarely have an envelope. The great majority have an RNA genome, which is usually small and single stranded (ss), but some viruses have double-stranded (ds) RNA, ssDNA or dsDNA genomes. Although plant viruses are not as well understood as their animal counterparts, one plant virus has become very recognizable: ''tobacco mosaic virus'' (TMV), the first virus to be discovered. This and other viruses cause an estimated US$60 billion loss in crop yields worldwide each year. Plant viruses are grouped into 73 genera and 49 families. However, these figures relate only to cultivated plants, which r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blueberry
Blueberries are a widely distributed and widespread group of perennial flowering plants with blue or purple berries. They are classified in the section ''Cyanococcus'' within the genus ''Vaccinium''. ''Vaccinium'' also includes cranberries, bilberries, huckleberries and Madeira blueberries. Commercial blueberries—both wild (lowbush) and cultivated (highbush)—are all native to North America. The highbush varieties were introduced into Europe during the 1930s. Blueberries are usually prostrate shrubs that can vary in size from to in height. In commercial production of blueberries, the species with small, pea-size berries growing on low-level bushes are known as "lowbush blueberries" (synonymous with "wild"), while the species with larger berries growing on taller, cultivated bushes are known as "highbush blueberries". Canada is the leading producer of lowbush blueberries, while the United States produces some 40% of the world supply of highbush blueberries. Origin and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiovirus
''Aspiviridae'', formerly ''Ophioviridae'', is a family of segmented negative-strand RNA viruses which infect plants. Member viruses are characterized by an elongated and highly filamentous and flexible nucleocapsid with helical symmetry. It is a monotypic taxon containing only one genus, ''Ophiovirus''. ''Aspiviridae'' is also the only family in the order ''Serpentovirales'', which in turn is the only order in the class ''Milneviricetes''. History The name ''Aspiviridae'' derives from the Latin (snake or viper), referring to the shape, along with the suffix for a virus family ''-viridae''. ''Ophiovirus'' derives from the Ancient Greek ''ophi''s, “snake”, with –''virus'' the suffix for a virus genus. Likewise, ''Serpentovirales'' is from "serpent" with ''-virales'' the suffix for a virus order. ''Milneviricetes'' is in honor of Robert G. Milne, the last author on the first paper describing ophioviruses. Virology Structure The protein capsid is non-enveloped and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspiviridae
''Aspiviridae'', formerly ''Ophioviridae'', is a family of segmented negative-strand RNA viruses which infect plants. Member viruses are characterized by an elongated and highly filamentous and flexible nucleocapsid with helical symmetry. It is a monotypic taxon containing only one genus, ''Ophiovirus''. ''Aspiviridae'' is also the only family in the order ''Serpentovirales'', which in turn is the only order in the class ''Milneviricetes''. History The name ''Aspiviridae'' derives from the Latin (snake or viper), referring to the shape, along with the suffix for a virus family ''-viridae''. ''Ophiovirus'' derives from the Ancient Greek ''ophi''s, “snake”, with –''virus'' the suffix for a virus genus. Likewise, ''Serpentovirales'' is from "serpent" with ''-virales'' the suffix for a virus order. ''Milneviricetes'' is in honor of Robert G. Milne, the last author on the first paper describing ophioviruses. Virology Structure The protein capsid is non-enveloped and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentovirales
''Aspiviridae'', formerly ''Ophioviridae'', is a family of segmented negative-strand RNA viruses which infect plants. Member viruses are characterized by an elongated and highly filamentous and flexible nucleocapsid with helical symmetry. It is a monotypic taxon containing only one genus, ''Ophiovirus''. ''Aspiviridae'' is also the only family in the order ''Serpentovirales'', which in turn is the only order in the class ''Milneviricetes''. History The name ''Aspiviridae'' derives from the Latin (snake or viper), referring to the shape, along with the suffix for a virus family ''-viridae''. ''Ophiovirus'' derives from the Ancient Greek ''ophi''s, “snake”, with –''virus'' the suffix for a virus genus. Likewise, ''Serpentovirales'' is from "serpent" with ''-virales'' the suffix for a virus order. ''Milneviricetes'' is in honor of Robert G. Milne, the last author on the first paper describing ophioviruses. Virology Structure The protein capsid is non-enveloped a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleocapsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The capsid and inner genome is called the nucleocapsid. Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while the helical shape resembles the shape of a spring, taking the space of a cylinder but not being a cylinder itself. The capsid faces may consist of one or more ... [...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] |
RNA-dependent RNA Polymerase
RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to typical DNA-dependent RNA polymerases, which all organisms use to catalyze the transcription of RNA from a DNA template. RdRp is an essential protein encoded in the genomes of most RNA-containing viruses with no DNA stage including SARS-CoV-2. Some eukaryotes also contain RdRps, which are involved in RNA interference and differ structurally from viral RdRps. History Viral RdRps were discovered in the early 1960s from studies on mengovirus and polio virus when it was observed that these viruses were not sensitive to actinomycin D, a drug that inhibits cellular DNA-directed RNA synthesis. This lack of sensitivity suggested that there is a virus-specific enzyme that could copy RNA from an RNA template and not from a DNA template. Distr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post Transcriptional Gene Silencing
RNA interference (RNAi) is a biological process in which RNA molecules are involved in sequence-specific suppression of gene expression by double-stranded RNA, through translational or transcriptional repression. Historically, RNAi was known by other names, including ''co-suppression'', ''post-transcriptional gene silencing'' (PTGS), and ''quelling''. The detailed study of each of these seemingly different processes elucidated that the identity of these phenomena were all actually RNAi. Andrew Fire and Craig C. Mello shared the 2006 Nobel Prize in Physiology or Medicine for their work on RNAi in the nematode worm ''Caenorhabditis elegans'', which they published in 1998. Since the discovery of RNAi and its regulatory potentials, it has become evident that RNAi has immense potential in suppression of desired genes. RNAi is now known as precise, efficient, stable and better than antisense therapy for gene suppression. Antisense RNA produced intracellularly by an expression vector may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodesma
Plasmodesmata (singular: plasmodesma) are microscopic channels which traverse the cell walls of plant cells and some algal cells, enabling transport and communication between them. Plasmodesmata evolved independently in several lineages, and species that have these structures include members of the Charophyceae, Charales, Coleochaetales and Phaeophyceae (which are all algae), as well as all embryophytes, better known as land plants. Unlike animal cell Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacter ...s, almost every plant cell is surrounded by a polysaccharide cell wall. Neighbouring plant cells are therefore separated by a pair of cell walls and the intervening middle lamella, forming an extracellular domain known as the apoplast. Although cell walls are permeable to small solu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus Psorosis Virus
''Citrus psorosis ophiovirus'' is a plant pathogenic virus infecting citrus plants worldwide. It is considered the most serious and detrimental virus pathogen of these trees. Psorosis disease Psorosis includes various graft-transmitted diseases all of which can be associated with different pathogenic strains including the more mild CPs-V-A and more severe CPsV-B. The virus is characterized by a single-stranded RNA molecule with a 48 kDa coat protein and a spiral filament structure. Common hosts of this disease are citrus and herbaceous plants like sweet orange, grapefruit, mandarin, and Mexican lime. Symptoms of infected hosts consist of interveinal chlorotic flecks and leaf mottling in younger tissues–in more severe cases these symptoms persist in older tissues. In mild cases, the bark of the trunk or limbs may exhibit scaling and flaking. Later in the disease cycle, gum can permeate into the wood and form an irregular circular pattern. In more severe cases symptoms include r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phloem
Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This transport process is called translocation. In trees, the phloem is the innermost layer of the bark (botany), bark, hence the name, derived from the Ancient Greek word (''phloiós''), meaning "bark". The term was introduced by Carl Nägeli in 1858. Structure Phloem tissue consists of conducting Cell (biology), cells, generally called sieve elements, Ground tissue#Parenchyma, parenchyma cells, including both specialized companion cells or albuminous cells and unspecialized cells and supportive cells, such as fibres and sclereids. Conducting cells (sieve elements) Sieve elements are the type of cell that are responsible for transporting sugars throughout the plant. At maturity they lack a Cell nucleus, nucleus and have very few organelles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.gif "Click for more on -> Nucleocapsid")
