Regulation of gene expression during cellular adaptation to water stress

Gradual adaptation to water stress was accomplished by a set of metabolic adjustments, including proline accumulation, synthesis ofde novo proteins, and changes in gene expression. The ability of the adapted cells to maintain the cellular and subcellular membrane integrity under conditions of severe water stress was found to be associated with a reduced level of unsaturation of fatty acids of membrane lipids. By cloning two different desaturase genes (?9-stearoyl-ACP-desaturase and a ?12-oleoyl-desaturase gene, respectively) it was possible to establish that the reduced level of unsaturation observed in the adapted cells was related to the down-regulation of this class of gene