Utilization of Proline to Enhance Cell Viability of Transgenic Rice Cells during Cryopreservation

초록

Transgenic rice cell lines (Oryza sativa L.) producing recombinant human cytotoxic T-lymphocyte antigen 4- immunoglobulin (hCTLA4Ig) were traditionally maintained by repeated subcultures. For industrial purpose of using transgenic plant cells, long-term preservation and continuous supply of cells have been required. To prevent cells from freezing damage during cryopreservation, cryoprotectants were used. Transgenic rice cells have been cryopreserved with cryoprotectants consisting of sucrose, glycerol, and dimethylsulfoxide (DMSO). Toxicity of cryoprotectants and generation of reactive oxygen species (ROS) are fundamental limiting factors for successful cryopreservation. The aim of this study was to identity the influences of proline as a non-toxic alternative cryoprotectant. Proline protected cells against osmotic stress by increasing their antioxidant enzyme capacity. Cryopreservation with proline led to enhance post-thaw cell viability and improved the stabilization of cells. These results indicate that proline is suitable for the cryopreservation of transgenic rice cells and has the potential to replace DMSO as a cryoprotectant.