The Efficiency of Different Priming Agents for Improving Germination and Early Seedling Growth of Local Tunisian Barley under Salinity Stress

Abstract

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.

Priming-mediated triggering of antioxidative response to induce drought tolerance in Maize (Zea mays L.)

“…6). The above results are as per the findings of (33), who reported that the maximum stability in the membrane and the synthesis of the least amount of MDA along with the accumulation of osmolytes (proline content) and catalase activity in priming treatments reform the damage of morphological as well as biochemical to overcome from drought conditions (34,35). Furthermore, analysis of the correlation coefficient of studied parameters also provides a glimpse of the positive and negative relationships with priming treatments for drought tolerance (Table 2).…”

Seed priming mitigates high salinity impact on germination of bread wheat (Triticum aestivum L.) by improving carbohydrate and protein mobilization

“…A threshold level of hydration is actually required for the synthesis of hydrolytic enzymes, which are responsible for the hydrolysis of the stored compounds in mature seeds (Rosental et al, 2014 ). Confirming previous studies (Ben Youssef et al, 2021 ; Debez et al, 2020 ; Uçarlı, 2020 ), our findings indicated that salt exposure not only impaired seed imbibition (Figure 2a ) but also led to high sodium accumulation in plant tissues.…”

“…Interestingly, calcium chloride priming was found to act on ionic balance decreasing significantly Na + accumulation in coleoptile, radicle and endosperm with respect to NPS group. Ben Youssef et al ( 2021 ) reported similar observations in barley upon use of CaCl 2 and KNO 3 seed priming, which limited the absorption and accumulation of sodium ions, maintained potassium content and decreased the sodium/potassium ratio in seedling tissues. Tian et al ( 2015 ) reported equivalent finding in wheat seedlings exposed to 100 mM NaCl after calcium application.…”

“…As the addition of 17.5 mM Ca (NO 3 ) 2 mitigated the salt effect and maintained ion homeostasis increasing concentrations of potassium (K + ), calcium (Ca 2+ ), magnesium (Mg 2+ ), zinc (Zn 2+ ), iron (Fe 2+ ), and copper (Cu 2+ ). High Na + resulted in the deficiency of mineral nutrients (Ben Youssef et al, 2021 ; Tian et al, 2015 ). The major cause of salt sensitivity in wheat may be attributed to a mineral deficiency, in particular calcium depletion.…”

SES1 is vital for seedling establishment and post-germination growth under high-potassium stress conditions in Arabidopsis thaliana

“…We found that SES1 can maintain the seedling K + /Na + balance, and the expression of K + transporter genes and ER stress-related genes were altered between WT and ses1 mutants under high potassium conditions during seedling establishment and post-germination growth. Seed priming with KCl was an effective method for alleviating seed germination caused by salt stress ( Ben Youssef et al, 2021 ) and improve emergence and seedling establishment under stress ( Ella, Dionisio-Sese & Ismail, 2011 ; Haider & Rehman, 2022 ) through a changed K + /Na + ratio. While high K + concentrations could also induce salt stress and inhibit seedling establishment and post-germination growth of plants ( Bakshi et al, 2018 ; Hassini et al, 2017 ), perhaps through plant hormone signal transduction and the mitogen-activated protein kinase signaling pathway ( Bakshi et al, 2018 ; Li et al, 2021b ).…”