biologia plantarum

Biologia plantarum 53:625-630, 2009 | DOI: 10.1007/s10535-009-0114-z

cDNA cloning and expression analysis of a Poncirus trifoliata CBF gene

H. L. Wang¹, J. J. Tao¹, L. G. He¹, Y. J. Zhao¹, M. Xu¹, D. C. Liu¹, Z. H. Sun^1,*

¹ Key Laboratory of Horticultural Plant Biology, Ministry of Education, Citrus Research Institute, Huazhong Agricultural University, Wuhan, P.R. China

The transcription factors CBF/DREB play an important role during low temperature, drought and high-salt stress in higher plants. A new CBF (CRT/DRE binding factor) gene was cloned from trifoliate orange [Poncirus trifoliata (L.) Raf.] by RT-PCR with degenerate primers and rapid amplification of cDNA ends (RACE) techniques. The full-length cDNA of CBF gene from trifoliate orange (designated as Ptcbfb) was 847 bp containing a 732 bp open reading frame (ORF), encoding a 243 amino acid protein. The predicted protein (designated as PtCBFb) had over 60 % identity to CBFs from some other plant species. Bioinformatical analysis showed that PtCBFb contained N-terminal bipartite nuclear targeting sequence, potential C-terminal acid domain and high conserved AP2 domain. Some other loci such as phosphorylation sites of several protein kinases, N-myristoylation site, tyrosine sulfation site and amidation site were also conserved in PtCBFb. Predicted three-dimentional structure of PtCBFb was similar to CBF from Arabidopsis thaliana. Expression pattern analysis revealed Ptcbfb expression in every tested organ, and Ptcbfb was cold induced.

Keywords: full-length cDNA; PtCBFb; RACE; trifoliate orange

Subjects: open reading frame; polymerase chain reaction (PCR); Poncirus trifoliata; rapid amplification of cDNA ends (RACE); temperature, low; transcription factors

Received: November 12, 2007; Accepted: April 27, 2008; Published: December 1, 2009  Show citation