Ste12 transcription factor homologue CpST12 is down-regulated by hypovirus infection and required for virulence and female fertility of the chestnut blight fungus Cryphonectria parasitica.

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TitleSte12 transcription factor homologue CpST12 is down-regulated by hypovirus infection and required for virulence and female fertility of the chestnut blight fungus Cryphonectria parasitica.
Publication TypeJournal Article
Year of Publication2007
AuthorsDeng, F, Allen, TD, Nuss, DL
JournalEukaryot Cell
Volume6
Issue2
Pagination235-44
Date Published2007 Feb
ISSN1535-9778
KeywordsAscomycota, Cloning, Molecular, Down-Regulation, Fertility, Fungal Proteins, Gene Expression Profiling, Gene Expression Regulation, Fungal, Oligonucleotide Array Sequence Analysis, Phenotype, Reverse Transcriptase Polymerase Chain Reaction, RNA Viruses, Transcription Factors, Transcription, Genetic, Virulence
Abstract

A putative homologue of the Saccharomyces cerevisiae Ste12 transcription factor was identified in a series of expressed sequence tag-based microarray analyses as being down-regulated in strains of the chestnut blight fungus, Cryphonectria parasitica, infected by virulence-attenuating hypoviruses. Cloning of the corresponding gene, cpst12, confirmed a high level of similarity to Ste12 homologues of other filamentous fungi. Disruption of cpst12 resulted in no alterations in in vitro growth characteristics or colony morphology and an increase in the production of asexual spores, indicating that CpST12 is dispensable for vegetative growth and conidiation on artificial medium. However, the disruption mutants showed a very substantial reduction in virulence on chestnut tissue and a complete loss of female fertility, two symptoms normally conferred by hypovirus infection. Both virulence and female fertility were restored by complementation with the wild-type cpst12 gene. Analysis of transcriptional changes caused by cpst12 gene disruption with a custom C. parastica cDNA microaray chip identified 152 responsive genes. A significant number of these putative CpST12-regulated genes were also responsive to hypovirus infection. Thus, cpst12 encodes a cellular transcription factor, CpST12, that is down-regulated by hypovirus infection and required for female fertility, virulence and regulated expression of a subset of hypovirus responsive host genes.

DOI10.1128/EC.00302-06
Alternate JournalEukaryotic Cell
PubMed ID17114597
PubMed Central IDPMC1797951
Grant ListGM55981 / GM / NIGMS NIH HHS / United States