Mitigating cold stress in damask rose through zearalenone, melatonin, and bio bloom

This study investigated mitigating cold stress in damask rose (Rosa damascene Mill.) using zearalenone (ZEN: 10 µL L⁻¹), melatonin (MT: 50 mM), bio bloom (BB: 1 and 2 ppm), and a combination treatment (ZEN-MT-BB: 0.5 µL L⁻¹, 10 mM, 20 ppm). Results showed that cold stress significantly increased electrolyte leakage and malondialdehyde (MDA) levels, indicating membrane damage. The ZEN-MT-BB treatment was most effective, reducing leaf and stem electrolyte leakage by 86.8% and 78.6%, and MDA Content by over 91%, compared to the control. Treatments also significantly boosted osmoprotectants: ZEN increased leaf proline by 80.7%, MT raised stem proline by 37.1%, and ZEN-MT-BB elevated soluble Carbohydrates in leaves and stems by over 173%. Antioxidant compounds (anthocyanins, phenolics, flavonoids) were also enhanced. The ZEN-MT-BB treatment resulted in the largest flower diameter and petal fresh weight. In conclusion, the ZEN-MT-BB combination effectively alleviates cold stress by stabilizing membranes, enhancing osmolyte accumulation, and boosting antioxidant activity, showcasing strong potential to improve damask rose resilience in cold climates.