Figure 2

Qualitative and quantitative evaluation of promoter strength via the expression level of egfp reporter gene. Fluorescence microscopy of EGFP in Trichoderma hyphae (A - F). Transformant M0 (A and B) was under control of the wild type cbh1 promoter, and M1 (C and D) and M2 (E and F) corresponded to the mutated promoters pcbh1m1 and pcbh1m2, respectively. The GFP channel is shown in the top part of each figure, while the lower part shows the bright field image. T. reesei hyphae under the repressing condition (2% glucose as repressor) were shown in A, C and E, while those under the inducing condition (3% cellulose and 2% wheat bran as inducer) were in B, D and F. Scale bar = 5 μm. Relative expression levels of egfp (G) were calculated in comparison with the expression of act encoding for actin. Error bars are representing the standard deviation between three independent measurements.