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The current investigation aims to underline the impact of salicylic acid or calcium chloride seed pre-treatments on mineral status and oxidative stress markers, namely levels of electrolyte leakage (EL) and lipid peroxidation levels, measured as thiobarbituric reactive substances (TBARS), and the activity of some antioxidant enzymes in roots and leaves of plants in two barley species grown under various salt treatments. Overall, our results revealed that salinity inhibits essential nutrient absorption such as iron, calcium, magnesium and potassium and stimulates the absorption of sodium. Also, this environmental constraint induced oxidative stress in plants in comparison with the control conditions. This state of oxidative stress is reflected by an increase in TBARS content as well as the stimulation of EL values. In addition, salinity induced disturbances in the activity of antioxidant enzymes, which were mainly dependent on the applied salt concentration and the species. In addition, Hordeum marinum maintained high antioxidant enzyme activity and low levels of oxidative stress parameters, which reinforces its salt-tolerant character. Importantly, salicylic acid or calcium chloride seed priming alleviated the mineral imbalance and the oxidative damage induced by salinity. Moreover, seed priming improves iron, calcium magnesium and potassium content and limitsthe accumulation of sodium. Also, both treatments not only decrease TBARS levels and limit EL, but they also stimulate the antioxidant enzyme activities in the leaves and roots of the stressed plants as compared with stressed plants grown from non-primed seeds. Interestingly, the beneficial effects of the mentioned treatments were more notable on Hordeum vulgare species.

Iron (Fe) is a vital nutrient for the development of many plants. Therefore, enhancing plant performance and production in relation to Fe deficiency is becoming a serious challenge. In this work, we intended to survey the effect of seed pretreatment with salicylic acid (SA) on oxidative status, phenolic composition, and related antioxidant activities in two varieties of Sulla carnosa (Sidi Khlif: SK and Kalbia: KA) treated with different Fe concentrations. In unprimed plants, the levels of phenolic compounds were very distinguishable among the two varieties, being superior in KA compared to SK. Interestingly, priming KA seeds with SA under control conditions or deficient conditions (D+SA treatment) caused a decreasing tendency in the contents of total phenolic compounds (TPC) and total flavonoids (TFC), whereas an opposite behavior was observed in SK. Moreover, an improvement of hydroxycinnamic and flavonoid groups, in addition to antioxidant activities (TAC, DPPH●, β-carotene and FRAP), was markedly found in SK primed with SA. According to these findings, SA seed pretreatment had a beneficial effect on the metabolic performance of this species under different Fe supply, regardless of whether the intensity of improvement was related to Fe concentration applied, variety, as well as plant organ. The results suggest that SA can account for the effective modulation of the secondary metabolites metabolism in S. carnosa plants to deal with the detrimental impacts of Fe deficiency.

The current work aimed to investigate the effect of seed priming with different agents (CaCl2, KCl, and KNO3) on germination and seedling establishment in seeds of the barley species of both Hordeum vulgare (L. Manel) and Hordeum maritimum germinated with three salt concentrations (0, 100, and 200 mM NaCl). The results showed that under unprimed conditions, salt stress significantly reduced the final germination rate, the mean daily germination, and the seedling length and dry weight. It led to a decrease in the essential nutrient content (iron, calcium, magnesium, and potassium) against an increase in sodium level in both of the barley species. Moreover, this environmental constraint provoked a membrane injury caused by a considerable increase in electrolyte leakage and the malondialdehyde content (MDA). Data analysis proved that seed priming with CaCl2, KCl, and KNO3 was an effective method for alleviating barley seed germination caused by salt stress to varying degrees. Different priming treatments clearly stimulated germination parameters and the essential nutrient concentration, in addition to increasing the seedling growth rate. The application of seed priming reduced the accumulation of sodium ions and mitigated the oxidative stress of seeds caused by salt. This mitigation was traduced by the maintenance of low levels of MDA and electrolyte leakage. We conclude that the priming agents can be classed into three ranges based on their efficacy on the different parameters analyzed; CaCl2 was placed in the first range, followed closely by KNO3, while the least effective was KCl, which placed in the third range.