Total RNA from the DP and DW samples was extracted using the RNAiso kit for polysaccharide-rich plant tissue (Takara Biotechnology (Dalian) Co., Ltd.) and purified using RNeasy plant mini kit (Qiagen, Valencia, CA) to avoid DNA contamination. The RNA quality was analysed by measuring the absorbance at 260 nm/280 nm (A260/A280) using a ND-1000 spectrophotometer (Nano-Drop Technologies, Wilmington, DE, USA). Further, RNA Integrity Number (RIN) values were determined using a Bioanalyzer 2100 (Aligent Technologies, Santa Clara, CA) to make sure all samples had a RIN greater than 8.5. Two separate RNA pools for the DP and DW cultivars were prepared for cDNA library construction, each comprising 15 RNA samples from 15 tubers of five plants per cultivar.
Two sequencing libraries were constructed using a cDNA Synthesis kit (Illumina Inc., San Digo, CA, USA) following the manufacturer’s instructions. Paired-end (2 × 150 bp) sequencing of the cDNA libraries was performed on the Illumina HiSeq 2000 (Illumina Inc., San Diego, CA, USA). Libraries from both the cultivars yielded more than 4 GB of clean data. Sequencing was completed by the Hangzhou Woosen Bio-technology Co. Ltd. (Hangzhou, China).
Two sequencing libraries were constructed using a cDNA Synthesis kit (Illumina Inc., San Digo, CA, USA) following the manufacturer’s instructions. Paired-end (2 × 150 bp) sequencing of the cDNA libraries was performed on the Illumina HiSeq 2000 (Illumina Inc., San Diego, CA, USA). Libraries from both the cultivars yielded more than 4 GB of clean data. Sequencing was completed by the Hangzhou Woosen Bio-technology Co. Ltd. (Hangzhou, China).