Summary of 454 data generated for cork oak root transcriptome and quality filtering.

aTotal number of base pairs sequenced for each tissue sample. bTotal number of reads for each tissue sample. cNumber of low-quality reads removed. dNumber of trimmed reads containing primer/adaptor sequence. eNumber of short reads (less than 100 bp) removed. fNumber of reads identified as chloroplast reads. gNumber of reads identified as mitochondrial reads. hNumber of reads identified as P. tinctorius reads. iNumber of reads identified as fungi, bacteria and virus reads. jNumber of high-quality reads used for further analysis. kAverage length of high quality reads in bp.