Identification of novel Trichoderma hamatum genes expressed during mycoparasitism using subtractive hybridisation

Abstract

Subtractive hybridisation was used to target novel genes involved in the mycoparasitic interaction of the biocontrol agent Trichoderma hamatum with the phytopathogen Sclerotinia sclerotiorum. Nineteen novel T. hamatum genes were identified that showed increased expression during mycoparasitism compared to a T. hamatum control. Sequence analysis revealed some cDNA fragments had similarity to known fungal or bacterial genes whereas others had no similarity to any genes previously described. Only one of the novel genes has been characterised in another Trichoderma species, the Trichoderma reesei hex1gene. The proteins encoded by the novel genes included three monooxygenases, a metalloendopeptidase, a gluconate dehydrogenase, an endonuclease and a proton ATPase.