Abstract:Previous researches showed that phytoene synthase (PSY) is the first regulatory point in carotenogenesis in Dunaliella bardawil. In this study, two sets of adjacent gene specific primers (pSP1, pSP2 and pSP3; tSP1, tSP2 and tSP3) were designed and LA PCR-based genomic walking approach was performed for isolation of psy promoter and terminator in D.bardawil, respectively; and subsequent analysis of conserved regulatory sequences were conducted by online promoter analysis softwares. Finally, using bioinformatics methods, the protein structure of DbPSY was also predicted. The calculated results found two conserved regulatory sequences in PSY promoter: BOXLCOREDCPAL and GT1GMSCAM4. BOXLCOREDCPAL was induced by UV to up-regulate expression of downstream gene; and GT1GMSCAM4 up-regulates expression of downstream gene induced by NaCl. Protein structure analysis demonstrated low homology of N-terminus between D. bardawil and other algae. Therefore we speculated the regulation mechanisms may partly involve in the conserved sequences of psy promoter and the diversity of N-terminus of DbPSY compared to other species.
