Fenling-Liu1, Min-Zhang, Shushen-Yang, Xiping-Deng and Lun-Shan
College of Life Sciences, Northwest A&F University, China
In recent years, the cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC) have been emerged as a multifunctional gene with defined functions in numerous subcellular processes, especially in abiotic stress tolerance. But several of them also had been considered as a constitutive housekeeping gene. We have previously identified six GAPC genes from wheat (Triticum aestivum L.) and the result of qRT-PCR showed that four of the TaGAPC genes could be a reference gene. In this study, to elucidate the regulatory mechanisms of similar reference gene in different wheats, two corresponding promoters of TaGAPC genes were isolated, which were 87.54% identical. Different cis-acting elements were harbored in two promoters, such as series dehydration and hormone responsive elements (MYBCORE?WREY and ASF1MOTIFCAMV) in P1683 and cold induced response elements (MYC and LTRCORE) in P1693. To further verification, the promoters were fused to GUS reporter gene and Agrobacterium-mediated transient expression assay were conducted. The GUS staining showed that both the two promoters could drive GUS gene and tissues transiently transformed by TaGAPC promoter-β-glucuronidase (GUS) gene fusion were differentially activated by NaCl, abscisic acid and low temperature. The results suggested that promoters from different reference gene contributed different to abiotic stresses.
Keywords: Triticum aestivum L.; GAPDH ; Promoter; Stress response; Abiotic stress.