| Oomycetes | |
|---|---|
| |
| Asexual (A: sporangia, B: zoospores, C: chlamydospores) and sexual (D: oospores) reproductive structures of Phytophthora infestans (Peronosporales) | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Clade: | Diaphoretickes |
| Clade: | SAR |
| Clade: | Stramenopiles |
| Phylum: | Gyrista |
| Subphylum: | Pseudofungi |
| Class: | Oomycetes Winter, 1880[1] |
| Orders and families | |
| Synonyms | |
| |
The Oomycetes (/ˌoʊ.əˈmaɪsiːts/),[3] or Oomycota, form a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms within the Stramenopiles. They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the result of contact between hyphae of male antheridia and female oogonia; these spores can overwinter and are known as resting spores.[4]: 409 Asexual reproduction involves the formation of chlamydospores and sporangia, producing motile zoospores.[4] Oomycetes occupy both saprophytic and pathogenic lifestyles, and include some of the most notorious pathogens of plants, causing devastating diseases such as late blight of potato and sudden oak death. One oomycete, the mycoparasite Pythium oligandrum, is used for biocontrol, attacking plant pathogenic fungi.[5] The oomycetes are also often referred to as water molds (or water moulds), although the water-preferring nature which led to that name is not true of most species, which are terrestrial pathogens.
Oomycetes were originally grouped with fungi due to similarities in morphology and lifestyle. However, molecular and phylogenetic studies revealed significant differences between fungi and oomycetes which means the latter are now grouped with the stramenopiles (which include some types of algae). The Oomycota have a very sparse fossil record; a possible oomycete has been described from Cretaceous amber.[6]
- ^ Winter, G. Rabenhorst’s Kryptogamen-Flora, 2nd ed., vol. 1, part 1, p. 32 Archived 2014-12-13 at the Wayback Machine, 1880 [1879].
- ^ Dick, M. W. (2001). Straminipilous fungus. Dordrecht, the Netherlands: Kluwer Academic Publishers, p. 289.
- ^ "oomycete". CollinsDictionary.com. HarperCollins. Retrieved 5 September 2023.
- ^ a b Agrios, George. Plant Pathology (5 ed.). Academic Press. ISBN 978-0120445653.
- ^ Vallance, J.; Le Floch, G.; Deniel, F.; Barbier, G.; Levesque, C. A.; Rey, P. (2009). "Influence of Pythium oligandrum Biocontrol on Fungal and Oomycete Population Dynamics in the Rhizosphere". Applied and Environmental Microbiology. 75 (14): 4790–800. Bibcode:2009ApEnM..75.4790V. doi:10.1128/AEM.02643-08. PMC 2708430. PMID 19447961.
- ^ "Introduction to the Oomycota". Archived from the original on 2003-10-09. Retrieved 2014-07-07.