Expression Analysis Of SIBADH In The Halophyte Suaeda Liaotungensis K. And PB-BADH Transgenic Tobacco Under Abiotic Stress

Abiotic stresses have adverse effects on plant growth and crop yield worldwide. Glycinebetaine (GB) is a compatible quaternary amine that is particularly effective in conferringprotection against abiotic stresses. Because betaine aldehyde dehydrogenase (BADH) is a keyenzyme in GB synthesis, BADH expression in plants is a topic of much current interest.Several studies have shown variable BADH expression under abiotic stress in different plants.As a typical halophyte living in saline environments along seashores, Suaedaliaotungensis K. may have evolved a unique salt-tolerance mechanism.In this study, SlBADHgene expression patterns in response to NaCl, PEG, chilling, and abscisic acid (ABA) in roots,stems, and leaves of S. liaotungensis and pB-BADH transgenic tobacco were investigatedusing semi-quantitative RT-PCR and real-time quantitative RT-PCR.The main results are as follows:1.Under normal non-stressed conditions,SlBADH gene expression was detected in roots,stems, and leaves of S. Liaotungensis K.,the expression level in leaves is much higher thanthat in stems and roots; SlBADH was highly induced by salt and chilling stress in roots, stems,and leaves of S. Liaotungensis K., and only induced by drought stress in roots; under ABAtreatment conditions,SlBADH was decreased in roots, stems, and leaves of S. LiaotungensisK., SlBADH is ABA-independent in S. Liaotungensis K..2.Under normal non-stressed conditions,SlBADH gene expression was detected in roots,stems, and leaves of pB-BADH transgenic tobacco,the expression level in leaves is muchhigher than that in stems and roots; SlBADH was highly induced by salt stress in roots, stems,and leaves of pB-BADH transgenic tobacco, but only induced by drought and ABA stress instems;3.The expression pattern of SlBADH in S. Liaotungensis K.is similar to that inpB-BADH transgenic tobacco under salt stress.The pB promoter may only contain saltstress-induced component,with no stress-induced component of chilling,drought andABA.The pB promoter can act as a salt-induced promoter and may be useful in plantsalt-resistance genetic engineering.