An exploration of the rapid transformation method for Dunaliella salina system

As a new expression system, Dunaliella salina (D. salina) has bright prospects and applications in various fields. However, its application is currently restricted because of the low expression and instability of foreign gene in D. salina cells. During genetic operation, transformation is a crucial step for genes expression in D. salina system. Although several transformation methods are existing currently, many inherent deficiencies and limitations still can be found in actual practice. Thus, we attempted to set up a rapid transformation method using the change of salt concentrations for D. salina. Based on osmotic pressure difference, exogenous genes can be spontaneously transferred into D. salina cells. After that, transformed D. salina cells were subjected to histochemical and molecular analysis. The results showed that the reporter gene, beta-glucuronidase genes were successfully expressed in the positive transformants, and detected in all of transformed cells by PCR analysis. Moreover, different transformation parameters, containing the salt gradient, time, dye dosage and Triton X-100 concentration, were optimized to obtain an optimal transformation result. Taken together, we preliminarily established a rapid transformation method with the features of fast, simple, economic, and high-efficient. This method will provide a strong genetic manipulation tool for the future transformation of D. salina system.