Abstract: Vernalization is required for floral transition in Dendrobium nobile. From the axillaries of vernalized D. nobile，a full-length cDNA that predictably encode a peptide in length of 227AA was identified in this study. BlastX searching indicates it is similar to AtSEP3 and the following phylogenetic analysis indicates both of them belong to the SEP3 clade in SEP subfamily. Thus，this protein was named DnSEP3-like. DnSEP3-like protein lacks a certain motif in C-region，which is similar to some other SEP3 proteins in Dendrobium species. Expression of DnSEP3-like gene is up-regulated with the extending of vernalizaiton，suggesting that it would function in vernalization-induced floral transition.

Key words: Dendrobium nobile, SEP3, vernalization