pepper seeds were extracted using a Hipure tissue DNA kit (Magen,
Guangdong, China) according to the manufacturer’s protocol.
Briefly, 50 mg Sichuan pepper seeds were ground in liquid nitrogen
and digested overnight with Buffer ATL, which is a component of the
Hipure tissue DNA kit, before 250 μL of absolute alcohol was
added to the sample and loaded onto a HiPure gDNA Mini column. The
genomic DNA was eluted with 100 μL of Buffer AE (Magen, Guangdong,
China). Forward primer CDS1-F (GAAGCTGGCGTCACAGAGTTCTG) and reverse
primer CDS4-R (GTTCTGGATAACGTCCAACGGCAGC) were designed based on master
protein accession (Uniprot: V4S993) were obtained by mass spectrometry.
Blunt-end PCR products were ligated into a pUCm-T vector (Sangon Biotech)
after A-Tailing. Positive clones were screened on X-gal (Sango, B541006,
Shanghai, China) plates and sequenced in both directions.