Fusarium oxysporum: Difference between revisions
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Interesting features of cell structure; how it gains energy; what important molecules it produces. | Interesting features of cell structure; how it gains energy; what important molecules it produces. | ||
[[Image:Fusarium3.jpg|thumb|This image shows the microconidia of ''F. oxysporum''. These are the tiny asexual fungal spores that function as its mode of reproduction. [2]]] | [[Image:Fusarium3.jpg|thumb|This image shows the microconidia of ''F. oxysporum''. These are the tiny asexual fungal spores that function as its mode of reproduction. [2]]] | ||
''F. oxysporum'' is a rapidly growing colony, which can expand to 4.5 cm in a few days. | ''F. oxysporum'' is a rapidly growing colony, which can expand to 4.5 cm in a few days. <br> | ||
In terms of life cycle, ''F. oxysporum'' has three types of asexual spores: | |||
*'''Microconidia''' - The smaller sized conidia, one or two celled, more abundant and frequently produced by the fungus under all conditions. It is also the type of spore most frequently produced within the vessels of infected plants. | |||
*'''Macroconidia''' - The larger conidia, which are three to five celled, gradually pointed and curved toward the ends. These spores are commonly found on the surface of plants killed by this pathogen as well as in sporodochia-like groups. | |||
*'''Chlamydospores''' - Have one or two cells, are round, thick-walled spores, produced either terminally or intercalary on older mycelium or in macroconidia. [11] | |||
==Ecology and Pathogenesis== | ==Ecology and Pathogenesis== |
Revision as of 01:44, 15 April 2011
Classification
Superkingdom: Eukaryota; Kingdom: Fungi; Phylum: Ascomycota; Class: Sordariomycetes; Order: Hypocreales; Genus: Fusarium
Species
NCBI: Taxonomy |
Fusarium oxysporum
Description and Significance
Describe the appearance, habitat, etc. of the organism, and why you think it is important.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces.
F. oxysporum is a rapidly growing colony, which can expand to 4.5 cm in a few days.
In terms of life cycle, F. oxysporum has three types of asexual spores:
- Microconidia - The smaller sized conidia, one or two celled, more abundant and frequently produced by the fungus under all conditions. It is also the type of spore most frequently produced within the vessels of infected plants.
- Macroconidia - The larger conidia, which are three to five celled, gradually pointed and curved toward the ends. These spores are commonly found on the surface of plants killed by this pathogen as well as in sporodochia-like groups.
- Chlamydospores - Have one or two cells, are round, thick-walled spores, produced either terminally or intercalary on older mycelium or in macroconidia. [11]
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Fusarium oxysporum has many Formae speciales (special forms) that exist as plant pathogens, causing storage, root, stem, and fruit rot, as well as vascular wilt. They are also important mycotoxin (toxic metabolite) producers. These various special forms infect certain crops.
- F. oxysporum f.sp. cubense causes Banana wilt
- F. oxysporum f.sp. vasinfectum causes wilt of cotton
- F. oxysporum f.sp. batatas causes wilt of sweet potatoes and stem rot
- F. oxysporum f.sp. lycopersici causes tomato wilt
In general, the fungi manages to infect the vascular system of the plant, where it wreaks havoc. The outward signs of fusarium wilt is the plant's leaves turning yellow or brown, and then falling off. As the disease progresses, the fungi will eventually reach the fruit and alter the natural color to a yellowish hue. Often, the plant dies before reaching its mature stage. [4]
Although much more well known for the aforementioned plant pathogenicity, Fusarium oxysporum has also been shown to be pathogenic to humans and animals. [2]. The diseases associated with Fusarium include:
- Fungal keratitis - The fungal infection of the cornea that can infect the eyeball and causes abscesses to form on it. [5]
- Onychomycosis - The fungal infection of the nail that can cause fingernails or toenails to thicken, discolor, disfigure, and split. [6]
- Hyalohyphomycosis - A fungal infection of the skin that can result in an extreme rash or penetrate the dermis and cause infection or internal bleeding. [7]
References
[1] http://www-unix.oit.umass.edu/~psoil120/images/fusarium.jpg
[2] http://www.mycology.adelaide.edu.au/Fungal_Descriptions/Hyphomycetes_%28hyaline%29/Fusarium/
[3] http://platforms.inibap.org/xanthomonaswilt/index.php?option=com_content&view=article&id=74&Itemid=94&lang=english
[4] http://www.oisat.org/pests/diseases/fungal/fusarium_wilt.html
[5] http://medical-dictionary.thefreedictionary.com/mycotic+keratitis
[6] http://www.emedicinehealth.com/onychomycosis/article_em.htm
[7] http://www.mycology.adelaide.edu.au/Mycoses/Opportunistic/Hyalohyphomycosis/
[8] http://www.uveitis.org/medical/articles/case/fungal_keratitis.html
[9] http://www.myfootshop.com/detail.asp?Condition=Onychomycosis
[10] http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2800%2902774-4/fulltext
Author
Page authored by Andrew Smith and Andrew Smedley, students of Prof. Jay Lennon at Michigan State University.
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