Cloning and Expression of Calcium-Dependent Protein Kinase (CDPK) Gene Family in Common Tobacco (Nicotiana tabacum)

To further study the function of calcium-dependent protein kinase (CDPK) gene family in common tobacco (Nicotiana tabacum), it is necessary to isolate more CDPKs from common tobacco and describe the sequence characteristics, evolutionary relationship and gene expression. Reverse transcription-PCR (RT-PCR), rapid amplification of cDNA (RACE) and bioinformatics methods were used to isolate CDPKs from common tobacco. A phylogenetic tree was created using the MEGA4.0 program and expression patterns of the three full-length CDPK genes were studied by RT-PCR. After all aforementioned efforts, we obtained eight additional common tobacco CDPK genes, of which three possessed complete open reading frames (ORFs). Phylogenetic analysis divided 11 full-length Nicotiana CDPK genes into four subfamilies, and two putative common tobacco and Arabidopsis orthologous CDPK genes might correspond to well-conserved functions. Three full-length CDPK genes in common tobacco were detected in all tobacco organs tested, but their expression patterns were significantly different. Eight non-redundant common tobacco CDPK genes were isolated in this study. Along with the previously characterized CDPK genes, at least 15 members of the CDPK family exist in common tobacco. This work establishes a foundation for a genome-wide study of this important gene family in common tobacco.