A Cloned Gene HuBADH from Hylocereus undatus Enhanced Salt Stress Tolerance in Transgenic Arabidopsis thaliana Plants

Betaine aldehyde dehydrogenase (BADH) catalyzes the synthesis of glycine betaine and is considered to be a type of osmoregulator, so it can play a role in plants' responses to abiotic stresses. In this study, a novel gene from (pitaya) was cloned, identified, and sequenced. The full-length cDNA included a 1512 bp open reading frame that encoded a 54.17 kDa protein consisting of 503 amino acids. Four oxidation-related stress-responsive marker genes ( , , , and ) were analyzed by Quantitative real-time reverse transcription (qRT-PCR) in wild type (WT) and transgenic overexpression lines under NaCl stress. HuBADH showed high homology (79-92%) with BADH of several plants. The gene was genetically transformed into and overexpressed in transgenic lines, which accumulated less reactive oxygen species than WT plants, and had higher activities of antioxidant enzymes under NaCl stress (i.e., 300 mM). All four marker genes were significantly upregulated in WT and -overexpressing transgenic plants under salt stress. Glycine betaine (GB) content was 32-36% higher in transgenic lines than in WT in the control (70-80% in NaCl stress). Our research indicates that in pitaya plays a positive modulatory role when plants are under salt stress.