Enhancement of Growth and Antioxidant Enzyme Activities on Kimchi Cabbage by Melatonin Foliar Application under High Temperature and Drought Stress Conditions

Melatonin, an indoleamine molecule, regulates a wide range of physiological functions during the growth, morphogenesis, and response plants to abiotic stresses. We examined effect exogenous melatonin application (5, 10, 20 mg·L-1) on growth antioxidant enzyme activity Kimchi cabbage under high temperature (air 32/26°C) drought stress (soil moisture 20–24%) conditions. Application 10 mg·L-1 alleviated stress-induced inhibition increased shoot fresh weight leaf surface area seedlings by 22.7% 13.9%, respectively, compared control condition. Indeed, foliar at caused increase net photosynthetic rate transpiration The lowest level H2O2 content was also observed concentration treatment, while no significant alterations in lipid peroxidation or concentrations malondialdehyde were detected treatment with different melatonin. In addition, significantly elevated levels ascorbate peroxidase (APX) superoxide dismutase (SOD) measured without changes ascorbic acid (AsA) proline contents These results suggest that ameliorates damages combination water deficit heat enhances enzymes such as APX SOD, thereby improving tolerance against cabbage.