Wild type and high free proline suspension-cultured carrot cell lines were used to determine whether proline influences cold tolerance. In addition, various stressful environments were imposed on the suspensions by varying media ingredients, such as the addition of mannitol and absicisic acid (ABA), in an effort to induce proline production. Results showed that an optimum concentration of proline hardened the control lines and acted as a growth stimulant under normal growth conditions. When both lines were grown at 3 C the high proline mutant line C-63, proved to be the hardiest. When grown at room temperature, C-63 was actually the weaker of the two lines. This relationship indicates that proline directly or indirectly influences cold hardiness in carrot cells. Mannitol, which induces osmotic pressure on plant cells, did not significantly increase proline accumulation. Abscisic acid had a lethal effect on the cells even at 10-4 M. concentrations. Smaller concentration may still induce proline production, but this possibility was not explored.
University of Illinois
proline, osmoregulation, carrot, tissue cultures, suspension, temperature stress
Shane, Jackie. "Proline's Function in Cold Stress and Osmoregulation in Carrot Tissue Culture Suspensions." (1986). https://digitalrepository.unm.edu/ulls_fsp/22