Effects of Calcium Nitrate on Nitrate Reductase Activity, Amino Acids, Nitrate and Ion Accumulation of Pistacia Vera L., Badami Zarand, Under Sodium Chloride Stress

Nitrogen is considered as an essential nutrient for plants and could be taken up in large amounts by plants. Nitrogen fertilizers are known to have beneficial effects when added to pistachio and other fruit trees. But the nitrogen assimilation of Pistacia species in response to salinity, including uptake and NO-3 reduction, has not been well understood. In this study, nitrate reductase activity, total amino acids, nitrate, calcium and sodium accumulation were evaluated in seedlings of Pistacia vera L. Badami Zarand̕ in response to sodium chloride (0, 75, 150 mm) and calcium nitrate (0, 10, 15 mm). Results showed that by increasing the level of salinity, nitrate reductase activity in leaves and the concentration of nitrate, total amino acids and calcium (Ca2) were reduced in the leaves and roots of P. Vera seedlings. Calcium nitrate induced a significant increase in both the root and leaf nitrate and total amino acids or nitrate reductase activity in leaf under NaCl stress. Calcium nitrate, also, significantly increased root/ leaf total amino acids ratio and decreased Naﰦ, ratio in the roots. Results showed that salinity affects the nitrate assimilation in P. Vera plants. Also, results suggest an efficient salt protective mechanism in P. Vera seedlings mediated by free total amino acids and calcium ions