Cloning and characterization of the 14-3-3 protein gene from Ipomoea batatas (L.) Lam

The 14-3-3 proteins are a group of highly conserved and widely distributed eukaryotic proteins with diverse functions. In plants, it regulates basal metabolism, ion transport, cell passage, enzyme activity and gene expression, and it is also important in disease resistance, anti-oxidation and drought resistance. Based on assembled sequences of sweet potato (Ipomoea batatas L. Lam) transcriptome, 14-3-3 protein cDNAs were cloned for the first time, and the sequencing analysis revealed the presence of three highly homologous isoforms of 14-3-3 protein cDNAs, designated as Ib14-3-3a, Ib14-3-3b and Ib14-3-3c. Three cDNA isoforms are all 1176 bp in length with 7 mutation sites and have a 789 bp of open reading frame encoding a polypeptide of 262 amino acids. The results from digital gene expression (DGE) profiling showed that the expression levels of 14-3-3 genes are different among tissues, predominantly in harvested tuberous roots (223.08 TPM) and very low in mature leaves (85.07 TPM), which were also confirmed by semi-quantitative Reverse transcription polymerase chain reaction (RT-PCR) analysis.