Document Type : Research paper
Authors
1
Crop and Horticultural Science Research Department, East Azerbaijan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran
2
Department of Horticultural Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
3
Department of Horticulture, University of Tabriz, Tabriz, Iran
Abstract
Nitric oxide (NO) is recognized as a crucial signaling molecule involved in plant defense mechanisms, including salinity stress. The present study investigated the effects of sodium nitroprusside (SNP) application, as a donor of NO, on some morphophysiological and biochemical characteristics of stress tolerance in Pyrodwarf pear rootstocks (Pyrus communis) under salinity stress. The experiment was conducted as a factorial design tested 4 SNP (0, 0.1, 0.5, and 1 mM) × 4 NaCl (0, 50, 100, and 150 mM) levels. Salinity stress reduced leaf number, shoot length, and protein content. However, it increased electrolyte leakage, H2O2, ascorbate content, and leaf concentrations of Na+ and Cl–. SNP application significantly increased leaf number, protein content, leaf chlorophyll and carotenoids. Moreover, it effectively reduced electrolyte leakage (EL), H2O2, and leaf concentrations of Na+ and Cl–. The activity of ascorbate peroxidase (APX), an important antioxidant enzyme, increased in response to NaCl stress, and notably, the application of SNP further enhanced the activity of this enzyme. The results indicated that SNP application reduced NaCl stress to some extent. Although no significant interaction was detected for growth indices, SNP mitigated the adverse effects of salinity primarily through its main effects on growth and its interactive effects on biochemical and antioxidant traits. Overall, the findings highlight the pivotal role of SNP in enhancing salinity tolerance under short-term stress conditions by modulating physiological and biochemical responses.
Keywords
)