ABSTRACT
The growth of even the most salt-tolerant halophytic flowering plants is inhibited by some maximum level of soil salinity. The decrease in dry mass production induced by increasing salinities may be the result of a change in the balance of growth regulator substances when plants are exposed to salinity, because of either an osmotic stress or a specific ion toxicity. Cytokinins are produced in the roots of plants and are then transported to shoots. Plants exposed to salt stress and cytokinins have been reported to have a lower water content than untreated plants. Cytokinins influence stomatal movement, and exogenous applications of this growth regulator may cause an increase in the transpiration rate which would put plants under water stress, causing a reduction in plant water content and a decrease in growth. Increases in ethylene production appear to be caused by an osmotic effect rather than a specific ion toxicity.
