Evaluation of biochemical traits and gene expression in wild and mutant rice cultivars under salt stress

Salinity stress is one of the most significant abiotic challenges affecting crop production worldwide, posing a serious threat to agricultural yields globally. rice, which ranks second in global production after wheat, is particularly sensitive to salt stress. developing salinity-tolerant rice varieties is crucial for mitigating yield reductions in saline environments. therefore, investigating and identifying the expression patterns of effective genes in response to salinity stress is essential for introducing tolerant genotypes. in this study, we examined an advanced mutant line of hashemi rice (tolerant to salinity stress) resulting from gamma-ray irradiation, alongside its wild counterpart (hashmi line - sensitive to salt stress). both lines were subjected to salt stress in randomized complete block design with three replications using a hydroponic solution. the main factors in the factorial design included salinity treatment (0, 100, and 150 mm sodium chloride) and sampling time, with genotypes as the sub-factor. we evaluated biochemical traits and gene expression post-salt stress through qrt-pcr analysis. the results indicate significant effects of salinity stress on biochemical traits and gene expression in both wild and mutant rice cultivars. the mutants showed lower sensitivity to salinity compared to the wild cultivar, as evidenced by changes in biochemical traits, including chlorophyll content, antioxidant capacity, and sodium and potassium ion concentrations. additionally, gene expression analysis revealed that several salinity tolerance-associated genes, such as superoxide dismutase and catalase, were expressed at higher levels in the mutants than in the wild cultivar. these findings suggest that different mechanisms are involved in the response to salinity stress between the wild and mutant cultivars, which could inform breeding strategies aimed at enhancing salt tolerance in rice. consequently, this study lays the groundwork for future research into identifying and analyzing salt tolerance genes in rice and other agricultural crops, ultimately aiming to develop effective strategies to mitigate environmental stresses.