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Hypoviridae
''Hypovirus'' is a genus of viruses, in the family ''Hypoviridae''. Fungi serve as natural hosts. There are four species in this genus. Infection reduces the virulence of its parasitic host, making it a hyperparasite useful for blight control. Species The following species are recognized by the ICTV, all of which were found with ''Cryphonectria parasitica'': *'' Cryphonectria hypovirus 1'' *'' Cryphonectria hypovirus 2'' *'' Cryphonectria hypovirus 3'' *'' Cryphonectria hypovirus 4'' There are numerous family members affecting other plant-pathogenic fungi not yet accepted into the ICTV nomenclature. A proposal reorganizes the family into three genera. The informal family '' Fusariviridae'' is the sister group. Structure The diameter is around 50–80 nm. Genomes are linear, around 9–13kb in length. The genome has 1 or 2 open reading frames, named OrfA (not always present) and OrfB. The genome contains no structural proteins. The virus accordingly does not bud out of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoviridae
''Hypovirus'' is a genus of viruses, in the family ''Hypoviridae''. Fungi serve as natural hosts. There are four species in this genus. Infection reduces the virulence of its parasitic host, making it a hyperparasite useful for blight control. Species The following species are recognized by the ICTV, all of which were found with ''Cryphonectria parasitica'': *'' Cryphonectria hypovirus 1'' *'' Cryphonectria hypovirus 2'' *'' Cryphonectria hypovirus 3'' *'' Cryphonectria hypovirus 4'' There are numerous family members affecting other plant-pathogenic fungi not yet accepted into the ICTV nomenclature. A proposal reorganizes the family into three genera. The informal family '' Fusariviridae'' is the sister group. Structure The diameter is around 50–80 nm. Genomes are linear, around 9–13kb in length. The genome has 1 or 2 open reading frames, named OrfA (not always present) and OrfB. The genome contains no structural proteins. The virus accordingly does not bud out of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Chestnut
The American chestnut (''Castanea dentata'') is a large, fast-growing deciduous tree of the beech family native to eastern North America. As is true of all species in genus Castanea, the American chestnut produces burred fruit with edible nuts. The American chestnut was one of the most important forest trees throughout its range and was considered the finest chestnut tree in the world.Davis, Donald E"Historical Significance of American Chestnut on Appalachian Culture and Ecology" ''www.ecosystem.psu.edu'', 2005. Retrieved October 28, 2015. During the early to mid 20th century, American chestnut trees were devastated by chestnut blight, a fungal disease that came from Chinese chestnut trees that were introduced into North America from East Asia. It is estimated that the blight killed between 3 and 4 billion American chestnut trees in the first half of the 20th century, beginning in 1904.Griffin, Gary"Recent advances in research and management of chestnut blight on American ches ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Replicase
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MEROPS
MEROPS is an online database for peptidases (also known as proteases, proteinases and proteolytic enzymes) and their inhibitors. The classification scheme for peptidases was published by Rawlings & Barrett in 1993, and that for protein inhibitors by Rawlings ''et al.'' in 2004.Rawlings, N.D., Tolle, D.P. & Barrett, A.J. (2004) "Evolutionary families of peptidase inhibitors." ''Biochem J'' 378, 705-716. The most recent version, MEROPS 12.3, was released in September 2020. Overview The classification is based on similarities at the tertiary and primary structural levels. Comparisons are restricted to that part of the sequence directly involved in the reaction, which in the case of a peptidase must include the active site, and for a protein inhibitor the reactive site. The classification is hierarchical: sequences are assembled into families, and families are assembled into clans. Each peptidase, family, and clan has a unique identifier. Classification Family The families of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chestnut
The chestnuts are the deciduous trees and shrubs in the genus ''Castanea'', in the beech family Fagaceae. They are native to temperate regions of the Northern Hemisphere. The name also refers to the edible nuts they produce. The unrelated horse chestnuts (genus ''Aesculus'') are not true chestnuts, but are named for producing nuts of similar appearance that are mildly poisonous to humans. True chestnuts should also not be confused with water chestnuts, which are tubers of an aquatic herbaceous plant in the sedge family Cyperaceae. Other species commonly mistaken for chestnut trees are the chestnut oak (''Quercus prinus'') and the American beech ('' Fagus grandifolia''),Chestnut Tree in chestnuttree.net. both of which are also in the Fagaceae family. |
Chestnut Blight
The pathogenic fungus ''Cryphonectria parasitica'' (formerly ''Endothia parasitica'') is a member of the Ascomycota (sac fungi). This necrotrophic fungus is native to East Asia and South East Asia and was introduced into Europe and North America in the early 1900s. The fungus spread rapidly and caused significant tree loss in both regions. Overview ''Cryphonectria parasitica'' is a parasitic fungus of chestnut trees. This disease came to be known as chestnut blight. Naturally found in South East Asia, accidental introductions led to invasive populations of ''C. parasitica'' in North America and Europe. The fungal disease has had a devastating economic and social impact on communities in the eastern United States. In the first half of the 20th century it killed an estimated four billion trees; or, by another count, 3.5 billion trees through 2013. Less severe impacts have occurred in Europe due to widespread CHV1-induced ''hypovirulence''. CHV1 is one of at least two viral pathog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicase
Helicases are a class of enzymes thought to be vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two hybridized nucleic acid strands (hence '' helic- + -ase''), using energy from ATP hydrolysis. There are many helicases, representing the great variety of processes in which strand separation must be catalyzed. Approximately 1% of eukaryotic genes code for helicases. The human genome codes for 95 non-redundant helicases: 64 RNA helicases and 31 DNA helicases. Many cellular processes, such as DNA replication, transcription, translation, recombination, DNA repair, and ribosome biogenesis involve the separation of nucleic acid strands that necessitates the use of helicases. Some specialized helicases are also involved in sensing of viral nucleic acids during infection and fulfill a immunological function. Function Helicases are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viruses
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virulence
Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to cause disease—is determined by its virulence factors. In the specific context of gene for gene systems, often in plants, virulence refers to a pathogen's ability to infect a resistant host. The noun ''virulence'' derives from the adjective ''virulent'', meaning disease severity. The word ''virulent'' derives from the Latin word ''virulentus'', meaning "a poisoned wound" or "full of poison." From an ecological standpoint, virulence is the loss of fitness induced by a parasite upon its host. Virulence can be understood in terms of proximate causes—those specific traits of the pathogen that help make the host ill—and ultimate causes—the evolutionary pressures that lead to virulent traits occurring in a pathogen strain. Virulen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryphonectria Hypovirus 3
''Cryphonectria'' is a fungal genus in the order Diaporthales. The most well-known and well-studied species in the genus is ''Cryphonectria parasitica'', the species which causes chestnut blight. The genus was, for a time, considered synonymous with '' Endothia'', but the two are now recognised as distinct. Taxonomic studies in 2006 limited the genus to four species, but a fifth, '' Cryphonectria naterciae'', was described in 2011 from Portugal. Species *'' Cryphonectria abscondita'' *'' Cryphonectria acaciarum'' *'' Cryphonectria cubensis'' *'' Cryphonectria decipiens'' *'' Cryphonectria japonica'' *'' Cryphonectria macrospora'' *'' Cryphonectria moriformis'' *'' Cryphonectria naterciae'' *'' Cryphonectria nitschkei'' *''Cryphonectria parasitica'' *'' Cryphonectria variicolor'' According to Murr) (And.et And.)Chestnut blight was first discovered in North America in 1904 on '' Castanea dentata''. By the 1940s it had killed most wild American chestnut trees, which were formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryphonectria Hypovirus 2
''Cryphonectria'' is a fungal genus in the order Diaporthales. The most well-known and well-studied species in the genus is ''Cryphonectria parasitica'', the species which causes chestnut blight. The genus was, for a time, considered synonymous with '' Endothia'', but the two are now recognised as distinct. Taxonomic studies in 2006 limited the genus to four species, but a fifth, '' Cryphonectria naterciae'', was described in 2011 from Portugal. Species *'' Cryphonectria abscondita'' *'' Cryphonectria acaciarum'' *'' Cryphonectria cubensis'' *'' Cryphonectria decipiens'' *'' Cryphonectria japonica'' *'' Cryphonectria macrospora'' *'' Cryphonectria moriformis'' *'' Cryphonectria naterciae'' *'' Cryphonectria nitschkei'' *''Cryphonectria parasitica'' *'' Cryphonectria variicolor'' According to Murr) (And.et And.)Chestnut blight was first discovered in North America in 1904 on '' Castanea dentata''. By the 1940s it had killed most wild American chestnut trees, which were formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
