Abstract: Using RACE (rapid amplification of cDNA ends) method, the full-length cDNA of dehydration-responsive protein RD22 was cloned from Polygonum sibricum treated with 3%NaHCO₃ solution for 48. The sequence analysis shows that the rd22 gene is 1 302 bp in length, including 59 bp of 5′untranslated region, 25 bp of 3′untranslated region and 1 218 bp of open reading frame (ORF).The rd22 gene encodes a protein of 405 amino acids. The C-terminal of the RD22 protein contains a conserved BURP domain, and the N-terminal contains 5 copies of a repetitive sequence of THV-VGKGGV-V. Signal peptide prediction shows the RD22 protein is a secretory protein, and has a signal peptide structure at the first 21 amino acids region. The amino acid sequence of RD22 prutein from Polygonum sibricum has a high homology with grape of 60%. This rd22 gene has been accepted by GenBank, and the accession number of gene sequence is DQ836050.

Key words: Polygonum sibricum, rd22 gene, cloning, sequence analysis