Summary: | 碩士 === 國立臺灣大學 === 植物科學研究所 === 102 === Basic region/leucine zipper (bZIP) and WRKY transcription factors (TFs) belong to a large gene family in plants. Previous researches showed that WRKYs and bZIPs participate in many abiotic stress responses. WRKYs and bZIPs can regulate many downstream genes, which are responsive to stresses. However, the transcriptional network and the molecular mechanism in plants are still not very clear. 14-3-3 protein is a scaffold protein, which can interact with other target proteins to change the subcellular localization, stability or activity. 14-3-3 protein was reported to interact with TFs. In this study, by using protoplast transactivation assay, the potential target genes of ABF3 and WRKYs, including DREB1A, MYB2, ABI5 and RD22 gene expression. In addition, to investigate the relationship between WRKYs, ABF3 and 14-3-3 protein in the transcriptional regulation in Arabidopsis thaliana, confocal microscope was used to observe the subcellular localization of these TFs are localized to the nucleus. The bimolecular fluorescence complementation (BiFC) assay demonstrated that WRKY25, -33, 40 and ABF3 proteins physicaly interacted with 14-3-3in protoplast cells. Moreover, the transactivation assay, showed that ABF3 up-regulated a reporter gene driven by the DREB1A promoter, possibly via the direct binding to the ABRE cis-elements, co-expression of 14-3-3 enhanced the transcriptional activity of ABF3. Taken together this study demonstrated that DREB1A is a target gene of ABF3, and 14-3-3 has a role in participating with ABF3 to regulate the downstream genes expression.
|