History, Evolution, And Diversity Of Mycoviruses
Mycoviruses are significant widespread viruses found to be infecting all major groups of plant pathogenic fungi. Mycoviruses require living cells to replicate like other animal and plant viruses. These viruses are transmitted through cell division or during spore formation. Most of the mycoviruses have double strand RNA genome, and few are known to have positive single strand RNA genome, DNA genomes are rear among mycoviruses with one exception of Sclerotinia sclerotiorum hypovirulence-associated DNA mycovirus 1 having DNA genome. Some Mycoviruses have been reported which are responsible for causing abnormal pigmentation, irregular growth and some are involved in altering their host sexual reproduction. These viruses are thought be evolved from plant viruses and so their diversity is classified in taxonomic groups like other viruses. The importance of mMycoviruses arises due to their most significant ability that is they reduced virulence of their host (hypovirulence). In this review, weI explored different aspects of mMycoviruses.
Mycoviruses usually infect the fungal species or they are found in association with pathogenic fungal species. These viruses are most commonly recognized in all major phyla of the fungi. These viruses are mostly present in then in latent stage and rarely cause disease . Few mycoviruses are found to cause considerable changes in the host fungi like irregular growth, mutated sexual reproduction and abnormal pigmentation. The most important feature they exhibit is hypovirulence (ability to reduce the virulence of pathogenic fungi) [1-4]. The presence of mycoviruses adds a new dimension in experimental mycology.
History of mycoviruses goes back to As as early as 1950 when a disease was reported by Siden and Hauser  in cultivated mushroom Agaricus bisporus. This mushroom produced misshaped fruiting bodies, premature distortion of mushroom tissue and consequently reduction in yield . Hollings and coworkers subsequently isolated tghree more morphologically distant viruses associated with diseased mushroom [6,7,8]. In years between 1962 and 1965, considerable evidence for mycoviruses in A.bisporus were reported. Prior to 1968, evidence for the mycoviruses other than that of A.bisporus had been reported. Presumptive evidence for yeast virus was published as early as 1936 . Many other viruses were discovered in fungal groups. These mycoviruses were discovered in two species of Penicilium (Penicilium stoloniferum and Penicilium funiculosum). Mycoviruses are found to share their characteristics with both animal and plants but they also show some distinct feature or their own such as they lack an extracellular route of infection, sporulation, transmission through cell division(intracellularly) and absence of movement proteins which essential for animal and plant viruses to complete their life cycle.
Several reports by taxonomists showed that the genome of most mycoviruses consist of double stranded RNA (dsRNA) while 30% of genome of mycoviruses is positive single stranded RNA (+ssRNA) . Gemini group virus related to mycoviruses have been recently reported .
Mycoviruses have been detected in major phyla of the fungi including Ascomycota, Basidiomycota, Zygomycota, Deuteromycota and Chytridiomycota. Viruses in Basidiomycota During 1950s, an epidemic disorder of mushrooms was seen by mushroom growers and was called as “The disease in the crop”. The infected mushroom showed distorted shape and their yields were greatly reduced. Blattny and Pilate  described in Czechosovakia a sporophore abnormality of Laccaria laccata and its form amethystina. Filtrate obtained from infected sporophore were watered on normal growing sporophore, it induced abnormal sporophores in next years.
Whereas normal sporophore continued to grow and produce normal yielding fruiting bodies . Similar abnormalities were noticed in Cantharellus infundibuliformis, C.cibarius, and Armillaria mellea, but no virus particles were seemed .
An important soilborne necrotrophic fungal pathogen Rhizoctonia solani belongs to basidiomycetes. However different-sized dsRNA factors were found in natural populations from AG1 to AG-13, the sequences of only four mycoviruses were characterized. Two dsRNA (M1 and M2; 6.4 kb and 3.6 kb in size, respectively) were isolated from strain Rbs 1A1 of R.solacni AG-3. M1 is phylogenetically related to Bromoviruses of plants and found to be associated with enhanced vigor and virulence. While M2 is related to Mitoviruses and associated with hypovirulence [86,87]. The Rhs 717 virus which was islolated from Rhs 717 strain of R.solacni AG-2 was a Partitivirus .
The first dsRNA element in R.solani was initially described by Butler and Castano. Since then numerous studies were performed to discover the diverse world of viruses infecting R. solani.
This group of fungi is very important because of their importance in antibiotic production. Antiviral properties are found in extracts obtained from several species during past decades for example Penicilium stoloniferum, P.funiculosum, P.cyclopium, P.cyaneo-fulvom, and Aspergillus niger. Lampson et al  identified virus like particles in P.funiculosum in some statolon preparation . Department of Biochemistry imperial College London showed that Penicilium stoloniferum and P.funiculosum were infected by virus containing dsRNA that was found to induce interferon production in mice .
With exceptions of mushroom virus, all the other discussed viruses are isometric. The only rod- shaped particles were found in ascomycetes Peziza astracoderna . Some purified preparation obtained from apothecia contained rigid rods 17×350 nm, resembling to tobacco mosaic virus TMV. But their inoculation did not produce TMV symptoms. The virus was serologically different from TMV . The virus like particles were also seen in abnormal yeast . They were 100 nm in diameter with double membrane. They are different from any other fungal virus.
Ascomycetes fungus Cryphonectria parasitica caused chestnut blight which has been a disaster for American chestnut (Castanea dentata) in both North America and Europe . CHV1 is hypovirulence-associated mycovirus of the C.parasitica and it was firstly analyzed in 1991 . Keeping in view the biological feature of CHV1, International Committee on Taxonomy of Viruses (ICTV) established a new family Hypoviridae . Hypoviridae contains just a single Hypovirus genus. Family Hypoviridae contains four species isolated from C.parasitica that belong to genus hypovirus; Cryphonectria hypovirus 1 (CHV1) , Cryphonectria hypovirus 2 (CHV2) , Cryphonectria hypovirus 3 (CHV3)  ans Cryphonectria hypovirus 4 (CHV4) . The impact on the virulence of C.parasitica by these species was different. Three viruses other than these hypoviruses were isolated from C.parasitica. Cryphonectria parasitica mitovirus 1 (CpMV1) belonging to genus mitovirus of family Nanoviridae, was isolated from hypovirulent strain NB631 . The other two viruses Cryphonectria parasitica mycoreovirus 1 (CpMyRV1) and Cryphonectria parasitica mycoreovirus 2 (CpMyRV2) were isolated from two hypovirulent strains 9B21 and C18 respectively .
The rapid spread of severe acute respiratory syndrome (SARS) in early 2003 was accepted by a number of governments as a challenge to their national security because of its adverse effects on their economies, including their hospital systems.The SARS epidemic is one of the beneficial case study for evaluating national and international capabilities to deal with disease outbreaks, both naturally occurring and deliberate. This appendix examines the course, impact and important of the epidemic, including the lessons learned regarding the...
Viruses’ evolutionary history has been an interesting but challenging topic for the cell biologists and virologist. Due to their great variety, it has been difficult for biologists to classify them and how they connect to the traditional tree of life. It can express genetic elements that can move between cells. They can represent organisms that lived freely before becoming parasites. It is also alleged they can be precursors of life (David R. Wessner, 2010) Recently, it was proposed that the...
Infections are minute creatures that exist wherever on earth. They can contaminate creatures, plants, organisms, and even microscopic organisms. Here and there an infection can cause an illness so savage that it is lethal. Other viral contaminations trigger no discernible response. An infection may likewise have one impact on one kind of creature, yet an alternate impact on another. This clarifies how an infection that influences a feline may not influence a canine. Infections fluctuate in multifaceted nature. They comprise...
Introduction Measles virus (MEV)- induced neurologic disease is associated with the community acquired infection of disease, whereas most important rubella virus (RV)-induced neurologic disease is associated with congenital disease. There are lots of safe and effective vaccines exists. Mev, the etiologic agent of measles, is a member of the Morbillivirus genus of the Paramyxoviridae family of non-segmented, negative -stranded, enveloped RNA viruses. There are several morbilliviruses and each has a relatively restricted host range. Morbilliviruses have six structural proteins. MeV...
Abstract There are seven types of coronaviruses appeared till now and they are different in their pathogenicity and the degree of the severity of the symptoms they cause. Phylogenetic analysis should be conducted in order to know the origin of the lethal viruses to be able to find treatments for them. In this essay, what have been found so far about the evolutionary origins of SARS-CoV-1, MERS-CoV and SARS-CoV-2 will be discussed. Furthermore, the animal hosts that are similar to...
Viruses have continuously challenged our perception of what ‘living’ means. The scientific community have constantly debated whether viruses are classified as living or non-living organisms. Viruses are very important complexes of biochemical that influence all types of living organisms including bacteria, yeast, plants and animal cells. Viruses are blobs of RNA or DNA surrounded by a coat of protein. They do not consist of organelles and therefore cannot make copies of their selves. Living organisms also are assumed to compel...
Introduction COVID-19 is a worldwide pandemic involving the vast spread of a type of viruses called the Corona virus. These viruses are positive-stranded RNA viruses having a crown-like appearance when viewed an electron microscope. It belongs to the subfamily Orthocoronavirinae of the Coronaviridae family (order Nidovirales) and is divided into four genera of CoVs: Alphacoronavirus (alphaCoV), Betacoronavirus (betaCoV), Deltacoronavirus (deltaCoV), and Gammacoronavirus (gammaCoV). Then, the betaCoV genus divides into five sub-genera. Genomic studies have proven that bats and rodents are...
Though many people may believe that there are other major factors that are a threat to mankind and viruses are not even a major issue, they actually are. I totally agree that they are one of the biggest threats to mankind as they can be extremely harmful based on the type and they are the cause for hundreds of deaths nowadays. The following are worldwide statistics on this issue. “Worldwide, these annual epidemics are estimated to result in about 3...
Viruses a foe which has affected the past and has now turned modern-day living into an almost apocalyptic like state due to the appearance of Covid-19. Along with being one of the most heavily studied areas within science, although a conclusive answer on whether viruses can be considered apart of the living or nonliving is still being debated. The virus does challenge the concept of what is considering living as a whole, due to the fact that it is considered...
01 / 09
Fair Use Policy
EduBirdie considers academic integrity to be the essential part of the learning process and does not support any violation of the academic standards. Should you have any questions regarding our Fair Use Policy or become aware of any violations, please do not hesitate to contact us via firstname.lastname@example.org.
We are here 24/7 to write your paper in as fast as 3 hours.