Transcriptional profiling of cellulase and expansin-related genes in a hypercellulolytic Trichoderma reesei

Expression kinetics of six cellulase and four expansin-related genes were studied in the hypercellulolytic Trichoderma reesei CL847 mutant in response to Solka Floc cellulose and soluble inducers. Real-time PCR showed a parallel increase of transcript levels for the cellulase genes cbh1/cel7a, egl1/cel7b, egl4/cel61a, the β-glucosidase genes bgl1/cel3a, bgl2/cel1a , and the swo1 gene, encoding the cell-wall loosening protein swollenin. To evaluate a putative implication of three newly identified e xpansin/family 45 e ndoglucanase- l ike (EEL) proteins in lignocellulose degradation, their expression was also analysed. Only eel2 was found to be transcribed under the present conditions, and showed constitutive expression similar to the endoglucanase encoding cel5b gene.