Effects of Nitrogen Sources for Growth Enhancement in Transgenic Rice Cells in Suspension Cultures

초록

High density cultivation was applied to enhance cell growth for effective production of plant-made recombinant protein. In transgenic rice cell cultures, amino acid (AA) media has been commonly used.1) However, AA media has low concentration of nitrogen source. Therefore, additional nitrogen source is necessary to improve the growth of transgenic rice cells. For the application of nitrogen source, both inorganic and organic nitrogen sources were supplemented in AA media during the growth period of transgenic rice cells in two-stage culture. As an inorganic nitrogen source, 120 mM potassium nitrate and 60 mM ammonium nitrate were used. In addition, as an organic nitrogen source, 1, 2, 3% (w/v) peptide mixtures were used in 100-mL Erlenmeyer flask cultures during the growth period.2,3) Cell masses of rice culture suspensions, in both fresh weight and dry weight, were measured during growth period to confirm the enhancement of growth. To analyze the growth characteristics of transgenic rice cells, cell viability, osmolarity, conductivity and pH were also measured. In conclusion, supplementing peptide mixtures showed better cell growth compared with that in control culture without peptide mixtures and inorganic nitrogen supplementation. The application of peptide mixtures could promote the growth rate, increase cell density in transgenic rice suspension cell cultures, and enhance the cell growth. In combination, this enhance growth could increase the production of target protein.