Methyl Jasmonate's Role in Alleviating Salt Stress-Induced Challenges in Narcissus Growth

High soil salinity, a result of salt stress, poses a significant obstacle to crop cultivation, particularly for ornamental plants like narcissus. Plant growth regulators, such as methyl jasmonate (MeJA), have the potential to mitigate the impact of stressful conditions. This study involved different MeJA concentrations (0, 50, 100, and 200 mu M) and varying levels of salt stress (4 and 8 dS m(-1)), along with a control level, in a pot experiment conducted using a complete randomized block design with three replicates at the Research Greenhouse, Islamic Azad University, Isfahan (Khorasgan) Branch. The research revealed that salt stress led to a substantial increase in leaf proline and flavonoid levels, as well as electrolyte leakage (EL), hydrogen peroxide (H2O2), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) enzymatic activities. These increases were more pronounced when MeJA was applied concurrently with a decrease in EL, H2O2, and MDA. Conversely, salt stress was observed to reduce chlorophyll and carotenoid levels, relative water content (RWC), flower fresh weight, flower longevity on the plant, and flowering duration. This underscores MeJA's potential as a growth regulator that safeguards narcissus against salinity toxicity. The findings indicate that 100 mu M MeJA activates an effective mechanism to mitigate the adverse effects of salinity.