Fatty Acid Profiling of Polyethylene Glycol Adapted and Un-Adapted Cell Lines of Oryza sativa L.cv. Swat-1 under Temperature Stress

Higher plants can adapt to abiotic stress to a certain degree. In this study, the impact of temperature stress on osmotic stress adapted and un-adapted cell lines of rice (Oryza sativa L.cv Swat-1) was observed. For the change in proline content, relative growth rate, saturated and unsaturated fatty acid were evaluated. The cell lines were incrementally adapted to 20% polyethylene glycol. The adapted lines showed significantly higher growth rate and proline content as compared to the un-adapted cell lines on temperature stress. Among saturated fatty acids palmitic acid (C16:0), stearic acid (C18:0) and myristic acid (C14:0) were the prominent fatty acids detected while among unsaturated fatty acid Oleic acid (C18:1c) and Linoleic acid (C18:2c) were the major fatty acids found. Under low temperature stress the percentage of saturated fatty acids was found to be lower (53%) in adapted cell line as compared to the un-adapted cell line (63%) while the percentage of saturation increased (83%) in adapted line under high temperature stress as compared to un-adapted line (70%). On the other hand at low temperature stress the percent level of unsaturated fatty acids in the adapted line was higher (48%) than the un-adapted cell line (37%). In conclusion, adaptation to one abiotic stress confers co-tolerance to the other abiotic stresses. Fatty acids saturation level could be a crucial factor in the plant ability to tolerate heat and cold stress.