Mycoviruses
As mycovirus ( ancient Greek μύκης mykes : Mushroom) refers to those viruses , the various fungi and yeasts have to host. The non-taxonomic group of mycoviruses includes virus species from nine very different virus families ( Barnaviridae , Chrysoviridae , Hypoviridae , Metaviridae , Narnaviridae , Partitiviridae , Pseudoviridae , Reoviridae and Totiviridae ) and the unclassified genus Rhizidiovizomyces (with virusis ) Rhizidioviruses .
The mycoviruses detectable in spores and hyphae mostly do not cause any disease in fungi ( hypovirulence ) and spread almost exclusively through cell division of the host cell (vertical transmission) or cell fusion. Most mycoviruses do not have an infection cycle that takes place outside the cell, and in some cases there are no extracellular virions . Only virus-like particles (VLPs) are found in the cytoplasm of the fungal cell as a sign of infection. Due to these properties of hypovirulence and the lack of virus particles outside the cell, the mycoviruses are also known as cryptoviruses (Greek κρύπτος: hidden).
discovery
The first indication of virus in fungi found in 1968 in studies on cultured cultivated mushrooms ( Agaricus bisporus ), which were affected by a severe growth disorder. VLPs could be identified in the hyphae of these mushrooms. In 1970 VLPs and a viral, double-stranded RNA were also found in hyphae of the Aspergillus foetidus mold . Since these first discoveries of viral infections in fungi were based on investigations into diseases of fungi, the vast majority of non-pathogenic mycoviruses were not discovered and characterized by nucleic acid hybridization and PCR studies until the 1980s and 1990s .
Occurrence
Mycovirus are represented in different fungal species taxonomic groups worldwide, including Ascomycota (Ascomycetes), Stand mushrooms (Basidiomycetes) and not part of the mushrooms oomycete (Peronosporomycetes). Mycoviruses are responsible for the synthesis of so-called “killer toxins” in various types of yeast, which, like brewer's yeast, are also of economic importance. These are glycoproteins produced by the virus-infected yeast cell , which have a toxic effect on non-infected yeast cells of other strains (but of the same type) by damaging the cell membrane or the DNA synthesis apparatus ( killer yeasts ).
swell
- M. Hollings: Mycoviruses: Viruses that Infect Fungi. In: Adv. Virus Res. 1978, Vol. 22, pp. 1-53 (Review), PMID 345774 .
- S. Tavantzis: Partitiviruses of Fungi . In: Brian WJ Mahy, Marc H. van Regenmortel (Eds.): Encyclopedia of Virology. Volume 4, 3rd edition, San Diego 2008, ISBN 978-0-12-373935-3 , pp. 63ff.
Individual evidence
- ↑ SIB: Narnaviridae , on: ViralZone
- ↑ SIB: Rhizidiovirus , on: ViralZone
- ↑ ICTV: ICTV Taxonomy history: Rhizidiomyces virus , Plenary session vote August 12, 1987 in Edmonton (MSL # 10)
- ↑ GT Banks, KW Buck, EB Chain, F. Himmelweit, JE Marks, JM Tyler, M. Hollings, FT Last, OM Stone: Viruses in fungi and interferon stimulation . In: Nature. 1968, Vol. 218, No. 5141, pp. 542-545, PMID 4967851 .
- ^ GT Banks et al. : Antiviral activity of double stranded RNA from a virus isolated from Aspergillus foetidus. In: Nature. 1970, Vol. 227, 5257, pp. 505-507, PMID 4316959 .