Comprehensive Morphological and Proteomic Insights into Salinity Stress in Soybean (Glycine max): Elucidating Tolerance Mechanisms and Biomarker Discovery

This study aimed to investigate the effects of salinity stress on growth parameters and proteomic responses in soybean. The experiment was conducted as a completely randomized design with three replications and four salinity levels (۰, ۳, ۶, and ۹ dS·m-۱) under controlled greenhouse conditions at the Faculty of Agriculture, Mohaghegh Ardabili University, in ۲۰۱۹. The results indicated that salinity stress significantly and negatively affected morphological traits. The intensity of these effects varied by genotype, with the DPX cultivar exhibiting the least reduction and the highest tolerance. The traits were stem length, root length, leaf number, and total seedling dry weight. DPX showed the highest tolerance. According to the results of the three-way ANOVA (sampling time × salinity level × genotype), salinity stress significantly affected all evaluated traits, with differences being significant at the ۱% and ۵% probability thresholds. In the proteomic analysis, two-dimensional electrophoresis (۲-DE) of soybean leaves revealed that salinity stress induced significant changes in the expression of several key cellular proteins. Proteins such as Glutathione S-transferase, Ferritin, ATPase, and Glutamine synthetase were upregulated in the DPX genotype, while the expression of Rubisco and Phosphoribulokinase was reduced in the sensitive cultivar, Arian. These results indicate the activation of defense mechanisms, antioxidant responses, ion regulation, and metabolic balance maintenance in the salt-tolerant DPX genotype. Accordingly, the DPX cultivar can be considered a salt-tolerant genotype for use in breeding programs and cultivation in saline soils. Moreover, the identified proteins may serve as potential biomarkers for screening salt-tolerant genotypes and developing molecular-level breeding strategies. These findings contribute to the understanding of soybean salinity tolerance mechanisms and support the integration of proteomic markers into molecular breeding strategies. Ultimately, this approach may accelerate the development of salt-tolerant soybean cultivars to ensure food security under climate change and soil degradation.

کلیدواژه ها:

Morphological traits ، Proteomic analysis ، Salinity stress ، Salt tolerance ، Soybean