Genes associated with the release of dormant buds in tree peonies (Paeonia suffruticosa)

A subtractive cDNA library was developed to study genes associated with the release of dormant buds in tree peony. To identify genes that are highly expressed in buds released from dormancy, 588 clones were examined by differential screening and then 185 clones were selected to be sequenced. A total of 31 unique genes were obtained, of which only 25 sequences had matches in the NCBI database or Arabidopsis thaliana protein database while 6 sequences with no matches. Many of the different genes were identified as having unknown or hypothetical functions while others were speculated to have different molecular functions. The expression profiles of the selected “candidate” genes which may be associated with dormancy release according to their putative function and previous reports were assessed by northern blot and semi-quantitative RT-PCR. The results indicated that the transcriptional expressions of the isolated genes are related to growth regulation and stress response. Our results provide interesting information for further understanding the molecular mechanism of bud dormancy release in tree peony.