University of Isfahan Journal of Plant Biological Sciences 3041-9603 13 3 2021 11 22 Pretreatment of psyllium (Plantago ovata) seeds with salicylic acid and physiological and biochemical responses of seedlings to salinity stress Pretreatment of psyllium (Plantago ovata) seeds with salicylic acid and physiological and biochemical responses of seedlings to salinity stress 21 42 26807 10.22108/ijpb.2021.128482.1252 FA Ehsan Hatami Department of Biology, faculty of science, University of Sistan and Baluchestan, Zahedan, Iran Alireza Einali Department of Biology, faculty of science, University of Sistan and Baluchestan, Zahedan, Iran Abdulshakoor Raissi Department of Horticulture, Faculty of Agriculture, Velayat University, Iranshahr, Iran Hossain Piri Department of Horticulture, Faculty of Agriculture, Velayat University, Iranshahr, Iran Journal Article 2021 05 15 Salicylic acid (SA) is known as an influential signal molecule in plant responses to environmental stresses. In this study, the effects of SA as a pre-treatment of psyllium (<em>Plantago ovata</em>) seeds on seedling growth, photosynthetic pigments, proteins and amino acids, and accumulation of soluble sugars and starch in response to salinity stress were investigated. Psyllium seeds were soaked with 0 and 500 μM SA for 24 h and sown in the research greenhouse of Iranshahr University in 2019, and the seedlings were exposed as a factorial design to 0, 25, 50, 100, 150 and 300 mM NaCl at 3-day intervals for 20 days. The results showed the seedling growth rate, photosynthetic pigments including chlorophylls and carotenoids, protein concentration as well as accumulation of soluble sugars and starch were severely reduced due to salinity stress. However, the accumulation of free amino acids and proline increased in response to salt stress. SA treatment improved the length of the shoot, increased the amount of pigments, decreased the amount of amino acids, and caused the accumulation of proteins and proline. In addition, an increase in the amount of non-reducing sugars and starch, which was associated with no change or decrease in the concentration of reducing sugars at high salinity levels, occurred in response to SA. These results show that priming the seeds with SA before sowing can increase the plant tolerance to salinity stress through the accumulation of non-reducing sugars and proline and thus maintain the turgor pressure of cells. Salicylic acid (SA) is known as an influential signal molecule in plant responses to environmental stresses. In this study, the effects of SA as a pre-treatment of psyllium (<em>Plantago ovata</em>) seeds on seedling growth, photosynthetic pigments, proteins and amino acids, and accumulation of soluble sugars and starch in response to salinity stress were investigated. Psyllium seeds were soaked with 0 and 500 μM SA for 24 h and sown in the research greenhouse of Iranshahr University in 2019, and the seedlings were exposed as a factorial design to 0, 25, 50, 100, 150 and 300 mM NaCl at 3-day intervals for 20 days. The results showed the seedling growth rate, photosynthetic pigments including chlorophylls and carotenoids, protein concentration as well as accumulation of soluble sugars and starch were severely reduced due to salinity stress. However, the accumulation of free amino acids and proline increased in response to salt stress. SA treatment improved the length of the shoot, increased the amount of pigments, decreased the amount of amino acids, and caused the accumulation of proteins and proline. In addition, an increase in the amount of non-reducing sugars and starch, which was associated with no change or decrease in the concentration of reducing sugars at high salinity levels, occurred in response to SA. These results show that priming the seeds with SA before sowing can increase the plant tolerance to salinity stress through the accumulation of non-reducing sugars and proline and thus maintain the turgor pressure of cells. https://ijpb.ui.ac.ir/article_26807_727c58d9d9a5fb860c2b18001b31cea3.pdf