Fatemeh Fath Fathabadi, Marzieh Etehadpour, Mohadeseh Shamsaddin Saied,
Volume 12, Issue 2 (3-2026)
Abstract
Objective: This study was conducted to evaluate the effects of seed priming with abiotic stimulants, including salicylic acid, proline, γ-aminobutyric acid (GABA), and melatonin, on improving salt stress tolerance in Calendula officinalis L.
Methods: The experiment was carried out under controlled laboratory conditions using a factorial arrangement in a completely randomized design with three replications. Treatments consisted of four salinity levels (0, 3, 6, and 9 dS m-1) and six seed priming treatments: non-primed control, hydropriming (distilled water), salicylic acid (1.5 mM), proline (100 mg L-1), GABA (10 mM), and melatonin (100 µM). Seeds were primed for 24 h in darkness at 20°C prior to exposure to salinity stress. Parameters evaluated included germination percentage and rate, seedling vigor index, root and shoot length, and dry weight of roots and shoot.
Results: Increasing salinity levels significantly reduced all measured germination and growth traits. Germination percentage decreased by 6.7%, 18.9%, and 24.5% at 3, 6, and 9 dS m-1, respectively, compared with the control. Seed priming significantly mitigated the adverse effects of salinity stress. Among the tested stimulants, hydropriming consistently improved germination percentage, germination rate, seedling vigor index, and biomass accumulation across all salinity levels, and maintained its positive effect even under severe salinity stress (9 dS m-1). GABA and salicylic acid produced the greatest increases in shoot dry weight, while proline, melatonin, and GABA also enhanced early seedling growth. Under severe salinity, primed plants showed lower performance reduction with increasing salt level, indicating improved stress tolerance.
Conclusions: Overall, seed priming with appropriate abiotic stimulants represents an effective, economical, and environmentally friendly strategy for reducing salinity-induced damage and improving the establishment and productivity of medicinal plants in salt-affected environments. The positive effects of priming treatments were dependent on both the type of stimulant and the severity of salinity stress.
Highlights:
- Proline and GABA mitigated salinity effects on marigold germination.
- Hydropriming consistently enhanced biomass under all salinity levels.
- Elicitor effectiveness depended on salinity severity and trait type.
