بررسي اثر پوترسين بر برخي شاخص هاي فيزيولوژيكي و رشد گياه Withania coagulans (Stocks) Dunal تحت تنش شوري در شرايط كشت در شيشه

The effect of putrescine on the growth an‎d physiological indicators of Withania coagulans (Stocks) Dunal under in vitro salt stress

زيست شناسي گياهي و جانوري

The medicinal plant Withania coagulans (Stocks) Dunal is a member of the Solanaceae family an‎d is native to arid an‎d semi-arid regions of South Asia, including Iran. This valuable medicinal plant possesses numerous pharmacological properties due to its diverse phytochemical compounds, particularly withanolides. This study aimed to investigate the effect of different concentrations of putrescine on the physiological, biochemical, an‎d enzymatic an‎d non-enzymatic antioxidant system responses of W. coagulans under salinity stress in in vitro culture conditions. For this purpose, different putrescine treatments (0, 0.5, 1, an‎d 2 mM) an‎d two salinity levels (100 an‎d 200 mM NaCl) were applied individually an‎d in combination to the plantlets. The results showed that salinity stress alone significantly reduced growth indices, including fresh an‎d dry weight, total chlorophyll content, carotenoids, an‎d total protein, while increasing levels of reactive oxygen species, lipid peroxidation (MDA), hydrogen peroxide (H2O2), an‎d sodium ion accumulation in plant tissues. The application of putrescine, especially at a concentration of 1 mM, led to significant improvements in growth indices, reduction of H₂O₂ an‎d MDA, maintenance of ionic balance through increased K⁺/Na⁺ ratio, an‎d strengthening of the antioxidant defense system. The activity of antioxidant enzymes, including superoxide dismutase, catalase, an‎d ascorbate peroxidase, showed a significant increase in putrescine-treated plants under salinity stress compared to plants under salinity stress alone. Furthermore, the levels of total phenolic compounds, flavonoids, flavonols, anthocyanins, proline, glycine betaine, an‎d total antioxidant capacity increased with different concentrations of putrescine under salinity stress conditions. Overall, the results demonstrate that putrescine plays an important role in enhancing the salinity tolerance of W. coagulans through regulating ionic balance, strengthening enzymatic an‎d non-enzymatic defense systems, reducing oxidative stress, an‎d increasing the biosynthesis of osmolytes an‎d phenolic compounds. The findings of this research indicate that applying putrescine as a growth regulator at an appropriate concentration can be an effective strategy for improving growth an‎d increasing resistance of this valuable medicinal plant under salinity stress.

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