Expression analysis of SiSOD gene family during Sesamum indicum L. seed germination under various abiotic stresses

Sesame (Sesamum indicum L.) seed is a rich source of oil and protein, which could be used for cooking or primary source for some industrial applications. Seed germination is the most fundamental stage of a plant’s life cycle, which is significantly influenced by various abiotic stresses. As a first report, the study attempted to evaluate the effect of environmental factors (i.e., low, optimum and high temperatures (T), water potential (ψ) and salinity) on eight superoxide dismutase (SOD) gene expressions (two Mn-SOD, two Cu/Zn-SOD and four Fe-SOD) during sesame germination. Results showed that all studied treatments remarkably influenced germination characteristics of sesame (P ≤ 0.05). In general, the negative impact of each stress on sesame germination could be ranked as ψ > salt stress > high T > low T, indicating that the germination was more influenced by ψ than salt stress and T. There was a strong association between the decrease in germination parameters (relative to the optimal T) and the decrease in SiSOD expression under various stresses. Our results discovered that the SiSODs expression patterns were stress-specific. However, when subjected to the same stress, the majority of SiSOD genes displayed similar expression patterns. The findings of this study could lead to a better understanding of SOD's role in other plants and the mechanisms involved in plants' stress responses, especially during their early stages of development.