Isolation, optimization, and functional analysis of the cDNA encoding transcription factor OsDREB1B in Oryza Sativa L.
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- Qin, Q., Liu, J., Zhang, Z. et al. Mol Breeding (2007) 19: 329. doi:10.1007/s11032-006-9065-7
A previous study had indicated that the transcription factors DREB/CBF (DRE-binding protein/C-repeat binding factor) play important roles in the expression of many stress inducible genes under cold-temperature, dehydration and high-salt conditions. In this study, we have isolated a cDNA clone that encoded a DRE-binding protein from rice cDNA library using the yeast one-hybrid system with DRE cis-acting element in the promoter region of rd29A gene as bait. Sequence analysis of the deduced amino acid sequence showed this protein was a putative AP2/EREBP transcription factor with a conserved AP2/EREBP domain and a potential nuclear localization signal (NLS). Expression pattern studies of this DRE-binding protein revealed that this gene was not only strongly induced by cold-temperature as reported by previous study but also induced by high-temperature as well. For the purpose of analyzing this gene conveniently, we attempted to apply the codon optimization method to reconstruct the gene of transcription factor in plants. A new sequence having decreasing GC contents, secondary structures, optimized codons and identical amino acid sequence with native gene was synthesized, which named OsDREB1BI, and then this optimized gene was transformed into Arabidopsis thaliana cv. Columbia by floral dip method. Results indicated that the OsDREB1BI gene was over-expressed in transgenic plants under cold and high-temperature, meanwhile, those transgenic plants also revealed freezing and heat tolerance. These might lay a strong foundation for exploiting the freezing and heat tolerance of rice and other species.