Cloning and sequence analysis of CONSTANS homologous gene from Dendrocalamus xishuangbannaensis.

CONSTANS (CO) is one of the key genes controlling flowering time of the flowering plants in Photoperiod Pathways.In current study,two primers,COS1 and COA1,based on the conserved region of Hd1 sequences from CO-like gene of rice(Oryza sativa),were employed to amplify a 1 520 bp fragment by polymerase chain reaction(PCR) with genomic DNA of Dendrocalamus xishuangbannaensis D.Z.Li H.Q.Yang.The fragment was cloned into a pGEM-T vector and then sequenced.Result of the 1 520 bp fragment cloned into a pGEM-T vector produced a fragment of gene,i.e.DxCO1,with accession number GQ358925 in GenBank.The DNA sequence analysis indicated that DxCO1 included one intron of 590 bp and two exons encoding putative 310 amino acids.Using homology analyses of DNA sequence,DxCO1 was homologous to the other six CO-like genes from Gramineae plants with 81%-91% supports,respectively.Phylogenetic analysis,based on protein sequences of DxCO1 and the known CO-like genes of seed plant in GenBank,showed that DxCO1 and other five CO-like genes from Gramineae plants clustered into a monophyly with bootstrap value of 92%.Meanwhile,there was a zinc-finger B-box(Cx2Cx8Cx7Cx2Cx4Hx8H) domain near amino terminus and a CCT(CO,CO-like,TOC1) domain near carboxy terminus in putative amino acid sequence of DxCO1.These results suggested that DxCO1 belonged to CO-like gene family,and it might have the same function of controlling flowering time like other CO homologous genes.