Preparation of a Seed Specific Construct Containing Sequences OMEGA and SAR in Order to Increasing Gene Expression in Plant Seed

Low level expression of transgene is one of the most important factors limiting production of recombinant proteins in plants. Some ways that help to increasing gene expression are selecting of appropriate tissue and improving transgen expression. For this، purpose، in this study we endeavorto obtain specifically gene expressionin plant seeds as well as improving desired gene expression by design and preparation of seed specific construct containing effective sequences in expression (OMEGA and SAR). Omega sequence acts as translation regulator and enhances the translation efficiency. It is believed that SAR fragment inhibits the silence of transgene by different mechanisms. In the first step، omega sequence joined to upstream of GUS gene by specific primers and PCR reaction. The SAR sequence (pS206-1)، isolated from tobacco genome and then spliced to downstream of GUS gene by SOEingPCR reaction. The resulting fusion fragment with the expected size cloned in TA cloning vector. Cloning in TA vector was confirmed by colony-PCR، restriction enzyme digestion and sequencing. To obtain seed specific cassette we subcloned fusion fragment in plant expression vector pBI121 in which CaMV35s promoter has been replaced with seed specific promoter. Cloning was confirmed by colony-PCR and digestion.