Isolation and characterization of the betaine aldehyde dehydrogenase gene in Ophiopogon japonicus

Betaine aldehyde dehydrogenase (BADH) catalyzes the last step in the synthesis of the glycine betaine from choline. The BADH gene from turfgrass Ophiopogon japonicus has not been reported. In this study, we first isolated the full length cDNA of betaine aldehyde dehydrogenase gene (OjBADH) from O. japonicus using Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and Rapid Amplification of cDNA Ends (RACE) techniques. The OjBADH gene (GenBank accession number: DQ645888) has 1785 nucleotides with the 5' untranscribed region (UTR) of 63 nucleotides, 3' UTR of 219 nucleotides, and an open reading frame of 1503 nucleotides. This gene encodes a polypeptide of 500 amino acids. It shares a high homology with BADH genes of other Chenopodiaceae species. The putative protein includes a conservative region of phosphofructokinase, aldehyde dehydrogenase, and glutamy phosphoric acid reductase. Overexpression of OjBADH in transgenic tobacco plants demonstrated 2-2.5 folds increase of glycine betaine content and 60-85% increase of survival rate under salt tolerance. These results suggested that the O. japonicus BADH gene may be used to engineer plants for salt stress tolerance. © Liu et al.; Licensee Bentham Open.