Proline, sodium and potassium concentration changes in gamma rays and NaCl

In this study, the effects of gamma rays on changes of proline, sodium and potassium in potato calli (Solanum tuberosoum L.) cultivar "White Desiree" were investigated. After irradiation of calli by 60 and 80 Gy of gamma radiation, irradiated and non irradiated calli were transferred to a callus production medium containing 0, 30, 60, 90, 120 and 150 mM NaCl. After 26 days post treatment amounts of proline, Na+ and K+ were measured. The results showed that generally in each of gamma ray treatment, amounts of proline at 120 and 150 mM NaCl were significantly more than 0, 30, 60 and 90 mM salt. A significant difference observed only at 150 mM NaCl between irradiated and non irradiated calli. This result could be related to the proline role in osmotic adjustment at high concentration of salt. The amounts of sodium increased by increasing salt the concentration but the amount of potassium decreased. These results showed that the sodium influx inhibited the potassium uptake, and may be because of strong inhibitory effect of sodium on the potassium uptake system or efflux potassium from the cells. The Na+/K+ ratio decreased at 150 mM by 60 and 80 Gy of gamma radiation.