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Pospiviroid Plvd
''Pospiviroid'' is a genus of ssRNA viroids that infects plants, most commonly tubers. It belongs to the family ''Pospiviroidae The Pospiviroidae are a ''incertae sedis'' family of ssRNA viroids with 5 genera and 39 species, including the first viroid to be discovered, PSTVd, which is part of genus Pospiviroid. Their secondary structure is key to their biological act ...''. The first viroid discovered was a pospiviroid, the PSTVd species (potato spindle tuber viroid). Taxonomy Pospiviroid has 10 virus species References External links ICTV Report: ''Pospiviroidae'' Viroids Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrysanthemum Stunt Viroid
Chrysanthemums ( ), sometimes called mums or chrysanths, are flowering plants in the Asteraceae family. They are native plant, native to East Asia and northeastern Europe. Most species originate from East Asia, and the center of diversity is in China. Countless horticultural varieties and cultivars exist. Description The genus ''Chrysanthemum'' are perennial herbaceous flowering plants, sometimes subshrubs. The leaves are alternate, divided into leaflets and may be pinnatisect, lobed, or serrate (toothed) but rarely entire; they are connected to stalks with indumentum, hairy bases. The compound inflorescence is an array of several pseudanthium, flower heads, or sometimes a solitary head. The head has a base covered in layers of bract, phyllaries. The simple row of ray florets is white, yellow, or red. The disc florets are yellow. Pollen grains are approximately 34 microns. The fruit is a ribbed achene. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomato Planta Macho Viroid
The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originated from and was domesticated in western South America. It was introduced to the Old World by the Spanish in the Columbian exchange in the 16th century. Tomato plants are vines, largely annual and vulnerable to frost, though sometimes living longer in greenhouses. The flowers are able to self-fertilise. Modern varieties have been bred to ripen uniformly red, in a process that has impaired the fruit's sweetness and flavor. There are thousands of cultivars, varying in size, color, shape, and flavor. Tomatoes are attacked by many insect pests and nematodes, and are subject to diseases caused by viruses and by mildew and blight fungi. The tomato has a strong savoury umami flavor, and is an important ingredient in cuisines around the world. It is used in pizza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSTVd
The potato spindle tuber viroid (PSTVd, ''Pospiviroid fusituberis'') was the first viroid to be identified.Discovery of Viroids PSTVd is a small, single stranded molecule closely related to the chrysanthemum stunt viroid. Present within the viroidal RNA is the common to its genus. The natural hosts are |
Pospiviroidae
The Pospiviroidae are a ''incertae sedis'' family of ssRNA viroids with 5 genera and 39 species, including the first viroid to be discovered, PSTVd, which is part of genus Pospiviroid. Their secondary structure is key to their biological activity. The classification of this family is based on differences in the conserved central region sequence. ''Pospiviroidae'' replication occurs in an asymmetric fashion via host cell RNA polymerase, RNase, and RNA ligase. Its hosts are plants, specifically dicotyledons and some monocotyledons. The severity of the infection can vary from no effect to devastating and widespread damage to a population. This can also depend on the virus-host combination. Genome Members of the family Pospiviroidae have circular ssRNA of 246–375 nt. They assume rod-like or quasi-rod-like conformations containing a central conserved region (CCR) and a terminal conserved hairpin (TCH) or a terminal conserved region (TCR). The genome of viroids does not encode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuber
Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate (survive winter or dry months), provide energy and nutrients, and are a means of asexual reproduction. Stem tubers manifest as thickened rhizomes (underground stems) or stolons (horizontal connections between organisms); examples include the potato and Yam (vegetable), yam. The term ''root tuber'' describes modified lateral roots, as in sweet potatoes, cassava, and dahlias. Terminology The term originates from the Latin , meaning 'lump, bump, or swelling'. Some writers limit the definition of ''tuber'' to structures derived from Plant stem, stems, while others also apply the term to structures derived from roots., p. 124 Stem tubers A stem tuber forms from thickened rhizomes or stolons. The top sides of the tuber produce shoots that grow into typical stems and leaves and the undersides produce roots. They tend to form at the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viroid
Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most cause diseases, whose respective economic importance to humans varies widely. A recent metatranscriptomics study suggests that the host diversity of viroids and viroid-like elements is broader than previously thought and that it would not be limited to plants, encompassing even the prokaryotes. The first discoveries of viroids in the 1970s triggered the historically third major extension of the biosphere—to include smaller lifelike entities—after the discoveries in 1675 by Antonie van Leeuwenhoek (of the "subvisible" microorganisms) and in 1892–1898 by Dmitri Iosifovich Ivanovsky and Martinus Beijerinck (of the "submicroscopic" viruses). The unique properties of viroids have been recognized by the International Committee on Taxonomy of Viruses, in creating a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SsRNA
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyribonucleic acid (DNA) are nucleic acids. The nucleic acids constitute one of the four major macromolecules essential for all known forms of life. RNA is assembled as a chain of nucleotides. Cellular organisms use messenger RNA (mRNA) to convey genetic information (using the nitrogenous bases of guanine, uracil, adenine, and cytosine, denoted by the letters G, U, A, and C) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome. Some RNA molecules play an active role within cells by catalyzing biological reactions, controlling gene expression, or sensing and communicating responses to cellular signals. One of these active processes is protein synthesis, a universal function in which RNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomato Chlorotic Dwarf Viroid
The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originated from and was domesticated in western South America. It was introduced to the Old World by the Spanish in the Columbian exchange in the 16th century. Tomato plants are vines, largely annual and vulnerable to frost, though sometimes living longer in greenhouses. The flowers are able to self-fertilise. Modern varieties have been bred to ripen uniformly red, in a process that has impaired the fruit's sweetness and flavor. There are thousands of cultivars, varying in size, color, shape, and flavor. Tomatoes are attacked by many insect pests and nematodes, and are subject to diseases caused by viruses and by mildew and blight fungi. The tomato has a strong savoury umami flavor, and is an important ingredient in cuisines around the world. It is used in pizza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrus Exocortis Viroid
''Citrus'' is a genus of flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, mandarins, lemons, grapefruits, pomelos, and limes. ''Citrus'' is native to South Asia, East Asia, Southeast Asia, Melanesia, and Australia. Indigenous people in these areas have used and domesticated various species since ancient times. Its cultivation first spread into Micronesia and Polynesia through the Austronesian expansion (–1500 BCE). Later, it was spread to the Middle East and the Mediterranean () via the incense trade route, and from Europe to the Americas. Renowned for their highly fragrant aromas and complex flavor, citrus are among the most popular fruits in cultivation. With a propensity to hybridize between species, making their taxonomy complicated, there are numerous varieties encompassing a wide range of appearance and fruit flavors. Evolution Evolutionary history The large citrus fruit of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomato Apical Stunt Viroid
The tomato (, ), ''Solanum lycopersicum'', is a plant whose fruit is an edible Berry (botany), berry that is eaten as a vegetable. The tomato is a member of the nightshade family that includes tobacco, potato, and chili peppers. It originated from and was domesticated in western South America. It was introduced to the Old World by the Spanish in the Columbian exchange in the 16th century. Tomato plants are vines, largely Annual plant, annual and vulnerable to frost, though sometimes living longer in greenhouses. The flowers are able to self-fertilise. Modern varieties have been bred to ripen uniformly red, in a process that has impaired the fruit's sweetness and flavor. There are thousands of cultivars, varying in size, color, shape, and flavor. Tomatoes are attacked by many insect pests and nematodes, and are subject to diseases caused by viruses and by mildew and blight fungi. The tomato has a strong savoury umami flavor, and is an important ingredient in cuisines around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
