Disruption of the Cyanide Hydratase Gene in Gloeocercospora sorghi Increases Its Sensitivity to the Phytoanticipin Cyanide but Does Not Affect Its Pathogenicity on the Cyanogenic Plant Sorghum
| Autor: | Ping Wang, Hans D. VanEtten, Robert W. Sandrock |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Cyanide
Blotting Western Mutant Hydrogen cyanide Virulence Plant disease resistance Poaceae Microbiology chemistry.chemical_compound Transformation Genetic Ascomycota Hydrogen Cyanide Genetics Potassium Cyanide Hydro-Lyases Plant Diseases chemistry.chemical_classification Gloeocercospora sorghi biology food and beverages biology.organism_classification Cyanide hydratase Enzyme chemistry Biochemistry Plasmids |
| Zdroj: | Fungal Genetics and Biology. 28:126-134 |
| ISSN: | 1087-1845 |
| Popis: | The release of hydrogen cyanide (HCN) from preformed cyanogenic compounds in plants such as sorghum is thought to provide a protective barrier against infection by microorganisms. Gloeocercospora sorghi, a fungal pathogen of sorghum, produces the enzyme cyanide hydratase (CHT) which converts HCN to the less toxic compound formamide. There is considerable prior evidence indicating that this mechanism for detoxifying HCN plays an important role in the pathogenicity of G. sorghi on sorghum. In the present study, the CHT gene was made nonfunctional in G. sorghi through transformation-mediated gene disruption. The transformant lacked CHT activity and no reacting polypeptides were detected with CHT-specific antibodies. This CHT mutant was highly sensitive to HCN, confirming that CHT is an HCN detoxifying mechanism, but it retained virulence on sorghum, causing lesions indistinguishable from those caused by the wild-type strain. This result indicates that G. sorghi does not require CHT for pathogenicity on cyanogenic lines of sorghum and suggests that cyanogenic compounds in plants may serve functions other than providing a mechanism of disease resistance. |
| Databáze: | OpenAIRE |
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