Similar Responses of Relatively Salt-Tolerant Plants to Na and K during Chloride Salinity: Comparison of Growth, Water Content and Ion Accumulation.

The aim of the present study was to compare changes in growth, ion accumulation and tissue water content in relatively salt-tolerant plant taxa- subsp. , subsp. var. , , and -as a result of NaCl and KCl salinity in controlled conditions. Similar growth responses to Na and K salinity in a form of chloride salts were found for all model plants, including growth stimulation at low concentrations, an increase in water content in leaves, and growth inhibition at high salinity for less salt-resistant taxa. All plant taxa were cultivated in soil except , which was cultivated in hydroponics. While the morphological responses of subsp. var. , subsp. and plants to NaCl and KCl were rather similar, plants tended to perform worse when treated with KCl, but the opposite was evident for . Plants treated with KCl accumulated higher concentrations of K in comparison to the accumulation of Na in plants treated with equimolar concentrations of NaCl. KCl-treated plants also had higher tissue levels of electrical conductivity than NaCl-treated plants. Based on the results of the present study, it seems that both positive and negative effects of Na and K on plant growth were due to unspecific ionic effects of monovalent cations or/and the specific effect of Cl.