Fig. 4

Expression of PoxCxrA, PoxClrB and major cellulase genes in P. oxalicum, and their regulation. a Expression of PoxCxrA and PoxClrB in the mutant strain ∆PoxClrB and ∆PoxCxrA subjected to Avicel as the sole carbon source, respectively. b Transcriptional levels of genes PoxCxrA and PoxClrB in ∆PoxKu70 in the presence of different carbon sources. Gene expression levels were investigated in P. oxalicum strains cultivated on Avicel at four different time points (4, 12, 24 and 48 h) after a shift from glucose by real-time quantitative reverse-transcription PCR. Relative expression on the y-axis indicates differences in values for transcription between tested and reference genes, or between tested genes in deletion mutants and the parental strain ΔPoxKu70. *p ≤ 0.05 and **p ≤ 0.01 indicate differences among samples assessed by Student’s t-tests. All experiments were carried out with at least three independent replicates