Effects of exogenous salicylic acid and nitric oxide on growth, photosynthesis, and ion distribution in tomato seedlings under NaCl stress

Salicylic acid (SA) and nitric oxide (NO) are two biologically active signaling molecules in plants. Both of these molecules play important roles in various aspects of plant growth and development, including seed germination, root growth, leaf elongation, stomatal movement, and respiration. Scientists inspired by the "cross-talk" and synergistic interactions have produced research on the synergistic induction of signaling pathways to improve plant resistance using exogenous SA and sodium nitroprusside (SNP), a NO donor. Few studies have focused on synergistic induction of defense pathways using both SA and NO to improve plant resistance to salt stress. In our experiments, we evaluated the synergistic effects of SA and NO on the resistance of tomato (Lycopersicon esculentum Mill. cultivar "Qin Feng Bao Guan") seedlings to salt stress. The results of our research show that a combined application of exogenous SA and SNP has a synergistic effect on improving the salt tolerance of tomato seedlings.