Tripterygium wilfordii suspension cell cultures (MeJA-induction 12-24-48h)
Total RNA of the MeJA-induction 12-24-48h suspension cells was isolated using the cetyltrimethylammonium bromide (CTAB) method (Del Sal et al., 1989). The total RNA was treated with RNase-free DNase I (NEB, USA) and purified by RNA Purification Kit (Tiangen Biotech, Beijing, China). A total of 3 μg purified RNA was used as input material for the RNA sample preparations. Sequencing libraries were generated using NEBNext® Ultra™ RNA Library Prep Kit for Illumina® (NEB, USA) following the manufacturer’s recommendations. Index codes were added to correlate sequences to each sample. The clustering of the index-coded samples was performed on a cBot Cluster Generation System using TruSeq PE Cluster Kit v3-cBot-HS (Illumina) according to the manufacturer’s instructions. After cluster generation, the library preparations were sequenced on an Illumina Hiseq 2000 platform and paired-end reads were generated. Transcriptome assembly was accomplished using Trinity (Grabherr et al., 2011).