Today, recombinant human proteins make up a considerable part of FDA-approved biotechnological drugs. The selection of proper expression platform for manufacturing recombinant protein is a vital factor in achieving the optimal yield and quality of a biopharmaceutical in a timely fashion. This experiment was aimed to compare the transient expression level of human serum albumin gene in different tobacco genotype. For this, the Agrobacterium tumefaciens strains LB4404 and GV3101 harboring pBI121-HSA binary vector were infiltered in leaves of three tobacco genotypes, including Nicotiana benthamiana and N. tabacum cv Xanthi and Samsun. The qRT-PCR, SDS-PAGE, western blotting and ELISA analysis were performed to evaluate the expression of HSA gene in transgenic plantlets. Our results illustrated that the expression level of rHSA in tobacco leaves was highly dependent on Agrobacterium strains, plant genotypes and harvesting time. The highest production of recombinant HSA protein was obtained in Samsun leaves infected with A. tumefaciens strain GV3101 after 3 days of infiltration.

Keywords: Agroinfiltration; Biopharmaceutical; Expression system; Tobacco; Transgenic plants.