Evaluating Seedling Vigor of Soybean Genotypes of Various Maturity Groups Following Short and Prolonged Seed Exposure to Abiotic Stress

This study investigated the vigor and molecular responses of soybean (Glycine max) seedlings belonging to cultivars from various maturity groups under simulated abiotic stress. Seeds and seedlings were subjected to varying concentrations of NaCl (150–300 mM) and PEG-6000 (20–30%), during long-term (12 days) and short-term (72 h) treatments, to evaluate the impact of salinity and drought on seedling viability and gene expression. Molecular analysis via qRT-PCR focused on the transcriptional profiles of the auxin transmembrane influx carrier LAX6, the vacuolar pyrophosphatase H+-PP-ase, and the stress protein kinase StrK2. The data indicated a dose-dependent correlation between stress intensity and developmental inhibition; increased concentrations of stress agents generally resulted in delayed germination and reduced survival rates. Certain soybean genotypes exhibited a robust transcriptional response, characterized by a several-fold increase in the expression of all studied genes following stress induction. These findings suggest that soybean abiotic stress responses may be influenced by a complex interaction between stress severity, exposure duration, genotype specificity and the maturity group.