Percentage of transcripts belonging to (A) CAZy families and (B) particular enzyme activities. Expression levels were measured following 24 h of culturing A. niger in media containing ball-milled willow as the only carbon source. CAZy families representing more than 2% of total CAZy expression are indicated. The percentage values are the RPKM values for (A) particular CAZy families expressed as a proportion of the total RPKM value of all the families in the GH, CE, PL and AA classes or (B) particular enzyme activities expressed as a proportion of the total RPKM value of all the activities analysed. Classifications for CAZy are according to CAZy.org. Genes were assigned to particular enzyme activities as described in the Methods section and Additional file 7.