Cloning And Function Analysis Of Fructan Biosynthesis Enzyme Gene Promoter In Wheat

Fructan is one of the most important carbohydrate in wheat, and also is the main content of water soluble carbohydrate (WSC). As an osmosis regulatory factor, fructan not only plays a significant role in resistance to drought and cold stress, but also contributes to grain-filling for wheat. Drought is the extremely important abiotic stress element for wheat yield. The research on fructan biosynthesis enzyme (FBE) genes will be benefit to select excellent wheat varieties with high fructan content and resistant to drought, and provide the theoretical basis for wheat genetic breeding. The promoters of FBE genes, with vital function for transcription of FBE genes, still have not been deeply understood. The functional assay of FBE genes’promoters will shed light on the research focusing on yield increase and drought resistance for wheat in molecular perspective.In this study, the gDNA of common wheat Hanxuan10was used as the template to amplify the promoters of1-FFT and6-SFT in wheat by PCR. Sequences analysis and cis-acting elements prediction of the promoter regions were conducted with bio-information database. The promoter of1-FFT in wheat was deleted form5’end into different fragments in length, and recombined with pCAMBIA1391z vector. The promoter fragments was transformed into Arabidopsis thaliana to express the GusA gene. Detected the transformation plants with Gus staining and Gus activity assay to clarify the effects of1-FFT promoter different regions have on the transcription and expression of downstream gene.The cloned promoters of1-FFT and6-SFT are respectively1895bp and1866bp in length upstream form the first translate code ATG. The transcription start site located on the-68bp A residue for1-FFT and-94bp C residue for6-SFT. Multiply cis-acting elements were found in the promoter region which are related to adversity stress resistance. There were4tandem repeat sequence units in the site between-1034bp and-227bp.8different promoter fragments in length of1-FFT were obtained by5’end deletion and transformed in Arabidopsis thaliana. Results of Gus staining and Gus activity assay indicate the1-FFT promoter relate to tissue-specific expression and different fragments lead to different expression. The region P1-P3contains cis-acting elements inducing transcription while the repressor cis-regulating element located in the region P3-P7.