Identification of differentially expressed genes associated with bud dormancy release in tree peony(Paeonia suffruticosa) by suppression subtractive hybridization

A subtractive cDNA library was developed to study genes associated with bud dormancy release in tree peonies.In order to identify genes that are highly expressed in buds released from dormancy,588 clones were examined by differential screening.Of these,185 clones were selected to be sequenced.A total of 37 unique sequences were obtained of which only 31 sequences have matches in the NCBI database or the Arabidopsis thaliana protein database.Semi-quantitative RT-PCR was used to confirm further the expression profiles for 12 transcripts identified within the subtractive cDNA library.Gene ontology analyses indicated that many of the different genes identified have unknown or hypothetical functions while it is speculated that other genes play different molecular roles.In our study,genes involved in bud dormancy release were growth-related or stress-responsive,while low-temperature-induced ribosomal proteins may also play a role in bud dormancy release.Our results provide interesting information for further understanding of the molecular mechanism of bud dormancy release in tree peonies.