Genes for tolerance to water and osmotic stress in glycophyte plants

Most of the crops are extremely susceptible to environmental stresses, because they have been selected for a high yield performance under optimal growth conditions. Not tolerant plants (glycophytes) respond to changes in the environment with complex mechanisms, involving a network of genes, which are either up- or down-regulated. Some of the genes induced are common between glycophytes and typically tolerant plants, e.g. xerophytes and halophytes, supporting the contention that stress tolerance mechanisms are ubiquitous. In this paper the changes in gene expression observed in potato cells upon abrupt imposition of water stress compared to the changes induced during a gradual acclimation to the same conditions are reported. Data on the involvement or not of the phytohormone abscisic acid in controlling such changes are also reported. The regulation of specific genes (osmotin, Em) during the stress have been studied in glycophyte plants, such as tomato and wheat.