Fig. 4
The growth profiles and phenotypic differences in wild type, S. pogona-Δsp1418 and S. pogona-Sp1418. a Cold field emission scanning electron micrographs of mycelium. The mycelium of S. pogona-Sp1418 grew longer and was more branched than that of S. pogona. Little mycelium was found in S. pogona-Δsp1418, exhibiting a specific spore-germination phenotype. b The phenotypic comparison of the wild-type and engineered strains on CSM medium. Spores were produced on the second day of culture on the medium. S. pogona-Δsp1418 exhibited a typically white phenotype, which grew more abundantly and faster than the wild-type strain. The spores of S. pogona-Sp1418 were hardly observed on the medium. c Expression levels of bldD, sigF, ssgA, whiA and whiB in S. pogona and S. pogona-Sp1418. mRNA samples were isolated from wild-type and engineered strain cells after 48 h of incubation. The transcriptional levels (log10) of the bldD gene were 0.49-fold higher in S. pogona-Sp1418 and 0.28-fold lower in S. pogona-Δsp1418 than in S. pogona. The transcriptional levels (log10) of sigF, ssgA, whiA and whiB were 0.31-, 0.33-, 0.81- and 0.34-fold lower in S. pogona-Sp1418 than in S. pogona, respectively, and were 2.30-, 0.85-, 1.33-, 1.20-fold higher in S. pogona-Δsp1418 than in S. pogona, respectively. The 16S rRNA gene was used as an internal control to quantify the relative expression of the target genes. Gene expression differences are shown by the bar height. Error bars represent the standard deviation of the mean. *, **and *** indicated P < 0.05, P < 0.01 and P < 0.005, respectively, compared to S. pogona under the same conditions. Error bars indicated standard errors of results from n = 3 replicates