Resistance to abiotic stresses

Unfavourable soil and water conditions are important constraints and lower crop yields. The adaptive response of plants to water and salt stress involves the activation of a large number of genes. The individual function of these genes is not well understood in as much as most of the genes are not specific to these types of stresses.³⁶ The number of plants that have been engineered for salt or drought resistance is therefore very limited. However, a yeast salt-tolerance gene encoding a water-soluble protein HAL1 has been transferred to two cultivars of Cucumis melo via A. tumefaciens. Some halotolerance has been observed in primary transformants³⁷ that could be transmitted to self-pollinated progeny.³⁸