The Solute Accumulation: The Mechanism for Drought Tolerance in RD23 Rice (Oryza sativa L) Lines

Abstract

Four drought tolerant RD23 rice lines were selected from somaclonal variants arising in vitro. They had been selected under the drought condition for 5 generations before the progenies were used for the experiments. After five weeks in the nutrient solution containing 150 g/L PEG6000, the six-week old drought-tolerant seedlings had approximately 4-fold increase in total soluble sugar content, while the original drought sensitive line had only 2.5-fold, when compared with the non-stressed plants. Proline content was also determined in these rice lines. After five weeks of drought treatment, nine-to fifteen-fold increase in proline content was detected in the drought tolerant lines, while the original line had approximately five-fold increase in proline content. These data suggested that the ability to accumulate the solute contributes to better performance in drought-tolerance.