Cloning and molecular characterization of a polygalacturonase gene of the white-rot fungus Chondrostereum purpureum
Date
1997
Authors
Tang, Yijian
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Abstract
The basidiomycete Chondrostereum purpureum is a white-rot fungus which is pathogenic to many hardwood species. We are interested in determining what factors make this fungus an effective pathogen.
Certain steps are crucial to the establishment of fungal pathogenicity. For the pathogen C. purpureum, penetration of the host and colonization of the host tissue seem to be especially important to the disease establishment. The plant cell wall is central to plant pathogens as both a barrier to infection and a source of metabolizable substrates. Cell wall degrading enzymes (CWDEs) have been implicated in the pathogenicity of certain phytopathogenic fungi. Endopolygalacturonase (endoPG) is a key CWDE in that it breaks down peptic polymers, a major wall component of plant cell. The endoPG produced by C. purpureum is able to cause the silver-leaf symptom of infected fruit trees and endoPG purified from culture filtrates of C. purpureum has been shown to cause necrois of leaf disc. A positive correlation between endoPG secretion level and the virulence of the fungus among different strains of C. purpureum has also been reported.