Isolation And Salt-inducible Characterization Of The SlPEAMT Promoter From Suaeda Liaotungensis K.

phosphoethanolamine N-methyltransferase (PEAMT) is the key enzyme in the synthesis of choline. Choline is the substrate in the synthesis of glycine betaine(GB). Glycine betaine is a non-toxi osmopretectant and plays an important role in osmotic stress. PEAMT gene has been cloned from many plants and the expression of PEAMT is induced by salt, This study is about SlPEAMT promoter from Suaeda liaotungensis K... Specific work and results are as follows:In this study, the5’flanking region of SIPEAMT was isolated by TAIL-PCR from Suaeda liaotungensis and a1450bp sequence was obtained. The transcription start site was identified as T and localized at-340bp upstream of the start ATG codon with the TSSP-TCM program. Functional elements were analyzed by the PLACE and PlantCARE programs. Aside from the basal transcriptional element TATA-box, a number of stress-responsive elements such as MYBCORE, MBS, LTR (CCGAAA), W-box, MYC recognition site, GT-1elements, WRKY710S and LTRECOREATCOR15had been found.In order to further examine the function of promoter, we made a series of5’deletion promoter, the three5’deletion promoter named as pP1(-897～+343bp), pP2(-817～+343bp) and pP3(-364～+343bp), respectively. Three different5’deletion fragments were inserted into pCAMBIA1301instead of the CaMV35S promoter. The constructs were named pCAMBIA1301-pPl, pCAMBIA1301-pP2and pCAMBIA1301-pP3, respectively.We obtained transgenic plants of tobacco (Nicotiana tabacum) by Agrobacterium-mediated leaf-disc transformation. The transgenic plants had been obtained by PCR detection and Histochemical GUS assays.The salt-induced function properties of each promoter fragment were examined by β-glucuronidase (GUS) histochemical staining and fluorescence quantitative analysis in transgenic tobacco leaves. Non-stressed transgenic plants showed decreased GUS activity in the leave. GUS enzyme activity was enhanced18.6-fold in pP1transgenic tobacco leaves with the presence of250mmol L-1NaCl compared to the non-inductive leaves.This study showed that, the longest promoter fragment pP1(-897to+343bp) possesses all of the essential and salt-induced cis-acting elements, the pP1promoter can also drive downstream gene expression and is sufficient for NaCl induction.