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dc.contributor.authorSjaarda, Calvin
dc.date.accessioned2013-09-12T13:06:15Z
dc.date.available2014-01-11T10:00:05Z
dc.date.issued2013-09-12
dc.identifier.urihttp://hdl.handle.net/10464/4986
dc.description.abstractTrichoderma spp are effective competitors against other fungi because they are mycoparasitic and produce hydrolytic enzymes and secondary metabolites that inhibit the growth of their competitors. Inhibitory compounds produced by Trichoderma aggressivum, the causative agent of green mold disease, are more toxic to the hybrid off-white strains of Agaricus bisporus than the commercial brown strains, consistent with the commercial brown strain’s increased resistance to the disease. This project looked at the response of hybrid off-white and commercial brown strains of A. bisporus to the presence of T. aggressivum metabolites with regard to three A. bisporus genes: laccase 1, laccase 2, and manganese peroxidase. The addition of T. aggressivum toxic metabolites had no significant effect on MnP or lcc1 transcript abundance. Alternatively, laccase 2 appears to be involved in resistance to T. aggressivum because the presence of T. aggressivum metabolites results in higher lcc2 transcript abundance and laccase activity, especially in the commercial brown strain. The difference in laccase expression and activity between A. bisporus strains was not a result of regulatory or coding sequence differences. Alteration of laccase transcription by RNAi resulted in transformants with variable levels of laccase transcript abundance. Transformants with a low number of lcc transcripts were very sensitive to T. aggressivum toxins, while those with a high number of lcc transcripts had increased resistance. These results indicated that laccase activity, in particular that encoded by lcc2, serves as a defense response of A. bisporus to T. aggressivum toxins and contributes to green mold disease resistance in commercial brown strains.en_US
dc.language.isoengen_US
dc.publisherBrock Universityen_US
dc.subjectGreen molden_US
dc.subjectlaccaseen_US
dc.subjectmolecular biologyen_US
dc.subjectgene expressionen_US
dc.subjectRNA silencingen_US
dc.titleDefence of Agaricus bisporus against toxic secondary metabolites from Trichoderma aggressivum.en_US
dc.typeElectronic Thesis or Dissertationen_US
dc.degree.namePh.D. Biological Sciencesen_US
dc.degree.levelDoctoralen_US
dc.contributor.departmentDepartment of Biological Sciencesen_US
dc.degree.disciplineFaculty of Mathematics and Scienceen_US
dc.embargo.terms4 Monthsen_US


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