Alternaria brassicicola
Black Spot Disease
Black Spot (Alternaria brassiciciola) Credit: Elizabeth Bush, Virginia Polytechnic Institute
Habitat
The genus Alternaria is comprised of many common saprophytic (derive nutrients from dead and/or decaying organic matter) and plant pathogenic species. Alternaria spores can be typically found in the air, soil, decaying plant material, wood, and foods. Alternaria brassicicola (Schweinitz, Wiltshire) is a ubiquitous plant pathogenic fungus but also exists as a saprophyte.
Biology
A. brassicicola causes black spot disease (also called dark leaf spot) on virtually every important cultivated Brassica species including broccoli, cabbage, canola, and mustard. It is of worldwide economic importance resulting occasionally in 20-50% yield reductions in crops such as canola, mustard or rape. Like other diseases caused by Alternaria species, black spot appears on the leaves as necrotic lesions, which are often described as black and sooty with chlorotic yellow halos surrounding the lesion sites. A. brassicicola, however, is not limited to infection of leaves, and can infect all parts of the plant including pods, seeds, and stems, and is of particular importance as a post-harvest disease. A. brassicicola is considered a necrotrophic (causing death) plant pathogenic fungus and like other Alternaria species has been shown to secrete numerous toxic secondary metabolites and proteins that cause cell death via induction of apoptosis in plants or by directly damaging cells. A. brassicicola has routinely been used as a model necrotrophic fungal pathogen in studies with Arabidopsis thaliana, also a weedy member of the Brassicaceae plant family. From a human health perspective, A. brassicicola is representative of a genus of fungi that is considered one of the most potent sources of mold-derived allergens. Moreover, sensitization to Alternaria is also strongly associated with chronic respiratory diseases such as asthma and chronic rhinosinusitis.
Sequencing Plan
The Alternaria brassicicola isolate selected for sequencing, A. brassicicola ATCC 96866, is available from the American Type Culture Collection (Manassas, VA). This was originally isolated from infected Brassica oleracea (cabbage) seed by E.G. Simmons, designated as EGS 42-002, and deposited at ATCC. The genome was sequenced to a total of 6.4x whole genome coverage. A combination of whole genome shotgun plasmid, fosmid and BAC end sequences were used in the initial unfiltered assembly. The combined sequence reads were assembled using the PCAP software (Genome Res. 13(9):2164-70 2003). Further sequence improvement is anticipated. A BAC fingerprint map has been constructed and will be compared to the final assembly for further refinement of both the sequencing assembly and the fingerprint map. This project is funded by USDA-CSREES as part of the NSF-USDA Interagency Microbial Genome Sequencing Program.
Contacts
| Name | Affiliation |
|---|---|
| Patrick Minx | The Genome Institute, Washington University School of Medicine |
| Christopher Lawrence | Virginia Bioinformatics Institute, Virginia Tech |
Sequences & Maps
Assemblies
| Name | Date | Description | Blast DBs |
| Alternaria_brassicicola-1.0 | Feb 20, 2006 | 6.4X | contigs |
Maps
| Name | Date | Type | Description |
| Alternaria brassicicola | Mar 06, 2006 | Physical | FPC |
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