Abstract
Four mutants of
Trichoderma reesei defective in cellulose utilization were characterized at the molecular level. Genomic analysis of the cellulase-encoding genes
(cel) and transcript induction using two well-established inducers of the
cel system the insoluble polymer, cellulose and the soluble inducer, sophorose, - revealed that these mutants are defective in the transcription of
cel genes. The results also indicate that the
cel genes are coordinately expressed and most probably are regulated by the same mechanism. Using a heterologous gene construct, in which the hygromycin-B-resistance-encoding gene was placed under the control of the promoter of the major cel gene,
cbhl, we showed that the mutants synthesize basic levels of cellulase, but are defective in the
cel induction.