Construction and Characterization of cDNA Library from Water-Stressed Plantlets Regenerated in vitro of Populus hopeiensis

In order to isolate and clone water-stress-responsive genes, total RNA was extracted from water-stressed plantlets regenerated in vitro of Populus hopeiensis using a QIAGEN RNeasy Plant Mini Kit. CDNA, synthesized by LD-PCR with the SMART cDNA Library Construction Kit, was in vitro packaged into a phage λTriplEx2 vector. The resulting primary library and amplified library have a titer of 1.68×10⁶ and 1.69×10⁹ pfu·mL^-1 respectively. The combination ratio reached 98.8% and the average size of inserts was about 800 bp. In addition, the percentage of inserted fragments (>400 bp) was approximately 90%. The results indicate that a cDNA library has been successfully constructed.