Isolation and Characterization of a Salt Inducible Promoter from PKVL7422.

is a eukaryotic organism that can be used as an industrial host to produce recombinant proteins. In this study, a salt-inducible promoter (SIP) was isolated from the freshwater species PKVL7422 from the screening of genes that were upregulated after salt treatment. Several -acting elements, including stress response elements, were identified in the isolated SIP. Moreover, the Gaussia luciferase gene was cloned after the SIP and transformed into to test the inducibility of this promoter. Reexamination of transcriptome of revealed that genes involved in the synthesis of methyl jasmonic acid (MeJA), gibberellin (GA), and abscisic acid (ABA) were upregulated when was treated with salt. Furthermore, the expression level of recombinant luciferase increased when the transformed was treated with salt and MeJA, GA, and ABA. This study represents the first report of the SIP and highlights how transformed microalgae could be used for robust expression of recombinant proteins.