en Study of gene expression in a mutant rice cultivar under salt stress تنش شوري Salt Stress پژوهشي Research <div style="text-align: left;"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><b><span style="font-size:10.0pt">Salinity stress dramatically impacts growth and production in rice. Expanding the genetic diversity of rice varieties through artificial mutation should &quot;lead to discovering&quot; new salt tolerant varieties. In this study, a potential salt-tolerant advanced mutant was compared to its high-quality background, Hashemi, to identify its improved salinity response mechanism. Therefore, various effective biochemical criteria related to salinity tolerance and the expression of two genes encoding superoxide dismutase (<i>SOD</i>) and glutathione (<i>GR</i>) were evaluated under 100 mM and 150 mM salinity, in comparison to no stress condition at 3 and 5 days after the application of stress. A significant difference was identified in proline, glycine betaine, soluble sugars, and soluble protein content between the wild-type and the mutant. Proline content was significantly higher in the mutant under both salinity levels and time points in comparison to the wild-type background. The mutant Hashemi rice showed greater tolerance to salt stress compared to wild-type Hashemi, making it a more dynamic cultivar. This greater resistance to salt stress in the mutant in comparison to its wild-type background was at least partially attributed to its increased ability to produce proline and glycine betaine, as well as heightened expression of antioxidant genes (<i>SOD</i> and <i>GR</i>) in two sampling stages. These traits help the mutant variety to survive and grow better under salt stress conditions. Selection of this variety in breeding programs could lead to the development of varieties with high tolerance and better performance in saline areas and help create effective strategies for rice cultivation in these areas, especially under the impact of climate change. The results of these findings indicate a significant survival and growth advantage for the mutant variety in saline environmental conditions. Therefore, selecting this variety in breeding programs can result in the creation of more tolerant and better-performing rice varieties in areas with salt stress. This is especially important for enhancing the sustainability of rice cultivation in saline and critical areas by combining mutant traits with local genotypes to improve yield and efficiency of saline water use. Additionally, combining metabolic traits (such as proline and glycine betaine) and the expression of antioxidant genes like <i>SOD</i> and <i>GR</i> in optimized lines can further improve salt tolerance.</span></b></span></span></div> <span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><b><span style="font-size:10.0pt">Salinity stress dramatically impacts growth and production in rice. Expanding the genetic diversity of rice varieties through artificial mutation should &quot;lead to discovering&quot; new salt tolerant varieties. In this study, a potential salt-tolerant advanced mutant was compared to its high-quality background, Hashemi, to identify its improved salinity response mechanism. Therefore, various effective biochemical criteria related to salinity tolerance and the expression of two genes encoding superoxide dismutase (<i>SOD</i>) and glutathione (<i>GR</i>) were evaluated under 100 mM and 150 mM salinity, in comparison to no stress condition at 3 and 5 days after the application of stress. A significant difference was identified in proline, glycine betaine, soluble sugars, and soluble protein content between the wild-type and the mutant. Proline content was significantly higher in the mutant under both salinity levels and time points in comparison to the wild-type background. The mutant Hashemi rice showed greater tolerance to salt stress compared to wild-type Hashemi, making it a more dynamic cultivar. This greater resistance to salt stress in the mutant in comparison to its wild-type background was at least partially attributed to its increased ability to produce proline and glycine betaine, as well as heightened expression of antioxidant genes (<i>SOD</i> and <i>GR</i>) in two sampling stages. These traits help the mutant variety to survive and grow better under salt stress conditions. Selection of this variety in breeding programs could lead to the development of varieties with high tolerance and better performance in saline areas and help create effective strategies for rice cultivation in these areas, especially under the impact of climate change. The results of these findings indicate a significant survival and growth advantage for the mutant variety in saline environmental conditions. Therefore, selecting this variety in breeding programs can result in the creation of more tolerant and better-performing rice varieties in areas with salt stress. This is especially important for enhancing the sustainability of rice cultivation in saline and critical areas by combining mutant traits with local genotypes to improve yield and efficiency of saline water use. Additionally, combining metabolic traits (such as proline and glycine betaine) and the expression of antioxidant genes like <i>SOD</i> and <i>GR</i> in optimized lines can further improve salt tolerance.</span></b></span></span> Rice, Abiotic stress, Salinity, Gene expression Rice, Abiotic stress, Salinity, Gene expression 45 56 http://jispp.iut.ac.ir/browse.php?a_code=A-10-1223-5&slc_lang=en&sid=1 Hourieh Najafi ‎ Hourieh Najafi ‎ horeyeh.1372@gmail.com No Department of Plant Breeding and Biotechnology at Gorgan University of Natural Resources and ‎Agricultural Sciences, Gorgan, Iran Department of Plant Breeding and Biotechnology at Gorgan University of Natural Resources and ‎Agricultural Sciences, Gorgan, Iran Elahe ‎ Tavakol ‎ Elahe ‎ Tavakol ‎ elahetavakol@gmail.com Yes Department of Plant Breeding and Biotechnology at Shiraz University, Shiraz, Iran Department of Plant Breeding and Biotechnology at Shiraz University, Shiraz, Iran Saeid Navabpour‎ Saeid Navabpour‎ s.navabpour@yahoo.com No Department of Plant Breeding and Biotechnology at Gorgan University of Natural Resources and ‎Agricultural Sciences, Gorgan, Iran Department of Plant Breeding and Biotechnology at Gorgan University of Natural Resources and ‎Agricultural Sciences, Gorgan, Iran