Abstract |
The hemibiotroph Colletotrichum graminicola is the causal agent of stem rot and leaf anthracnose on Zea mays. Following penetration of epidermal cells, the fungus enters a short biotrophic phase, followed by a destructive necrotrophic phase of pathogenesis. During both phases, secreted fungal proteins are supposed to determine progress and success of the infection. To identify genes encoding such proteins, we constructed a yeast signal sequence trap (YSST) cDNA-library from RNA extracted from mycelium grown in vitro on corn cell walls and leaf extract. Of the 103 identified unigenes, 50 showed significant similarities to genes with a reported function, 25 sequences were similar to genes without a known function, and 28 sequences showed no similarity to entries in the databases. Macroarray hybridization and quantitative reverse-transcriptase polymerase chain reaction confirmed that most genes identified by the YSST screen are expressed in planta. Other than some genes that were constantly expressed, a larger set showed peaks of transcript abundances at specific phases of pathogenesis. Another set exhibited biphasic expression with peaks at the biotrophic and necrotrophic phase. Transcript analyses of in vitro-grown cultures revealed that several of the genes identified by the YSST screen were induced by the addition of corn leaf components, indicating that host-derived factors may have mimicked the host milieu.
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Authors | Jorrit-Jan Krijger, Ralf Horbach, Michael Behr, Patrick Schweizer, Holger B Deising, Stefan G R Wirsel |
Journal | Molecular plant-microbe interactions : MPMI
(Mol Plant Microbe Interact)
Vol. 21
Issue 10
Pg. 1325-36
(Oct 2008)
ISSN: 0894-0282 [Print] United States |
PMID | 18785828
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
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Topics |
- Colletotrichum
(genetics, metabolism)
- Fungal Proteins
(genetics, metabolism)
- Gene Library
- Reverse Transcriptase Polymerase Chain Reaction
- Zea mays
(microbiology)
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