The fresh roots of 15-year Shizhu ginseng and 6-year Yuan ginseng purchased from Fusong (Jilin Province, China) were treated in accordance with the following procedures. Clean P. ginseng washed with ultra-pure water was sterilized in 70% ethanol and then rinsed using sterile water. After air-drying, it was cut into pieces, followed by quick-freezing with liquid nitrogen for total RNA extraction using Trizol reagent (Qiagen, Dusseldorf, Germany) according to the manufacturer’s protocols for P. ginseng root RNA extraction. Following the purification procedure with DNase I, the extracted total RNA was determined for quality and integrity by agarose gel electrophoresis (Liuyi, Beijing, China), TGem micro spectrophotometer (Tiangen, Beijing, China) and Agilent 2100 Bioanalyzer (Agilent, Santa Clara, USA).
Roots of three plants of Yuan ginseng with the same growth environment and the same growth period were taken to repeat the above operation. After passing the quality test (RNA integrity number (RIN) >7.0, 28S/18S ≥ 0.7), the three tubes were mixed and used for sequencing. The operation of roots of Shizhu ginseng was the same as above.
Roots of three plants of Yuan ginseng with the same growth environment and the same growth period were taken to repeat the above operation. After passing the quality test (RNA integrity number (RIN) >7.0, 28S/18S ≥ 0.7), the three tubes were mixed and used for sequencing. The operation of roots of Shizhu ginseng was the same as above.