The transcript levels of hemicelluloses induced by L-arabinose and L-arabitol in N. crassa wild-type stain (A) and xr deletion (B) strain. The wild-type strain and xr mutant strain were precultured in Vogels’ minimal medium with 2% D-glucose for 16 h, washed and transferred to minimal medium supplemented with 2% L-arabinose or 2% L-arabitol for an additional 4 h. The expression levels of hemicellulase genes were monitored by quantiative real time-PCR, after growth on L-arabinose (light grey bars), or L-arabitol (light black bars). Transcript levels were assessed relative to gene expression in minimal medium with 2% D-glucose within each experiment. The experiment used actin as the internal standard. The values shown are the means of three independent experiments.