Abstract: One important homologous flowering-regulating transcription factor gene SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1（SOC1）was obtained from tree peony（Paeonia rockii）by RT-PCR. It was designated as PrSOC1 and GenBank accession number was KJ427808. The open reading frame（ORF）of PrSOC1 was 678 bp，with 421 bp in the 3′ UTR，and could encode 225 amino acids.Sequence alignment and motif analysis showed that the deduced amino acids contained typical MADS-box and K-box domain，and a highly conserved motif named SOC1 MOTIF near the carboxy terminus. The phylogenetic analysis showed that it has close relationship with Vitis vinifera，and belongs to SOC1/TM3 subfamily of MADS-box superfamily. The results of semi-quantitative RT-PCR revealed that the highest expression levels were appeared in the flower-bud of Paeonia rockii，followed by root，shoot and leaves，and the lowest in the seed. The expression patterns of PrSOC1 and PsCOL4 from flower-buds was not significant differences in different varieties. It was deduced that PrSOC1 was much conserved in tree peony and it may play important role in flowering of tree peony. PrSOC1 was successfully expressed in the E.coli cell and the plant expression vector was constructed. The results will afford useful information for study PrSOC1 gene function.

Key words: tree peony, PrSOC1, semi-quantitative RT-PCR, prokaryotic expression