Cloning and expression profile of betaine aldehyde dehydrogenase gene of Ipomoea batatas in response to salt stress

Betaine aldehyde dehydrogenase (BADH) is a key enzyme for glycine betaine synthesis, which plays an important role in improving plant tolerance to salinity. Until now, little is known about the molecular biology of BADH gene in sweet potato (Ipomoea batatas (L.) Lam.). Here, we report the cloning, sequencing, and expression of IbBADH gene of sweet potato. The sequencing results showed that IbBADH contains a 1509 bp open reading frame coding for a protein of 502 amino acid residues. It is also found that there are three highly homologous isoforms (identity > 99%) of IbBADH in sweet potato. The results from both digital gene expression profiling and semi-quantitative reverse transcription-polymerase chain reaction demonstrated that the expression levels of IbBADH were different among various tissues and development stages under natural condition and salt stress.