Targeted expression of hepatitis B surface antigen (HBsAg) in potato tubers using transient expression system

In order to study the efficiency of the tuber specific promoter (Patatin1), the expression of the HBsAg antigen of the hepatitis B vaccine was evaluated using a transient expression method (AgroInfiltration) in the tubers and leaves of potato plants. Material and Methods: A tuber specific promoter (Pat1) was isolated from the potato plant using a specific primer pairs by Polymerase Chain Reaction (PCR). It was cloned in the upstream of a synthetic optimized codon of the HBsAg gene in the binary plant vector pBI121. In order to compare the tissue specificity of Pat1, the HBsAg gene also was used under the control of a consultative CaMV35S promoter. The genetic constructs were transferred to the tubers and leaves of potato plants using the Agroinfiltration method. An HBsAg antigen content was measured using ELISA method. The level of HBsAg antigens in the leaves and tubers of potato plants indicated that Pat1 promoter specifically induced HBsAg high expression in the tuber tissues. Very low expression by the Pat1 promoter in the leaf tissues has been also reported and can be partly dependent on the presence of inducing factors in the inoculation media. However, the expression of HBsAg antigen occurs in both leaf and tuber tissues under the consultative promoter CaMV35S. The results showed that the codon optimized HBsAg gene for potato plant was expressed properly in plant tissues. findings indicate that potato tuber specific promoter Pat1 can be used effectively to express the synthetic optimized HBsAg antigen in the transgenic potato plants.