Exogenous Melatonin Enhances Rice Blast Disease Resistance by Promoting Seedling Growth and Antioxidant Defense in Rice

作者：Hongliang Yuan, Jingya Qian, Chunwei Wang, Weixi Shi, Huiling Chang, Haojie Yin, Yi Xiao, Yue Wang, Qiang Li · 发表于：International Journal of Molecular Sciences · 年份：2025 · DOI：10.3390/ijms26031171 · 被引用次数：14 · 研究领域：Circadian rhythm and melatonin、Light effects on plants、Photosynthetic Processes and Mechanisms

In order to analyze the physiological regulation mechanisms associated with exogenous melatonin on rice blast, this study treated rice seedlings with different concentrations of melatonin (0, 20, 100, and 500 µmol/L) in order to investigate the growth characteristics, root morphology, superoxide dismutase (SOD) activity, peroxidase (POD) activity, catalase (CAT) activity, malondialdehyde (MDA) content, hydrogen peroxide (H2O2) content, and soluble protein content of rice seedlings. The results indicated that 100 µmol/L of melatonin exhibited a significant effect, improving the growth and antioxidant capacity of rice seedlings under rice blast fungus infection. The disease resistance level of rice seedlings against rice blast significantly decreased by 31.58% when compared to the 0 µmol/L melatonin treatment, while the plant height, stem base width, plant leaf area, total root length, aboveground dry weight, aboveground fresh weight, and underground fresh weight significantly increased by 8.72% to 91.38%. Treatment with 100 µmol/L of melatonin significantly increased catalase activities and soluble protein content, with respective increases of 94.99% and 31.14%. Simultaneously, the contents of malondialdehyde and hydrogen peroxide significantly decreased, reaching 18.65% and 38.87%, respectively. The gray relational grade analysis indicated that hydrogen peroxide content and resistance level exhibit the highest gray relational grades with melatonin concentration and, so, can b...