Melatonin Treatment Alleviates Chilling Injury of Loquat Fruit via Modulating ROS Metabolism.
Study Goal
The researchers aimed to investigate the effects of melatonin on alleviating chilling injury (CI) in loquat fruit during cold storage and explore the role of reactive oxygen species (ROS) metabolism.
Results Summary
Melatonin at 50 μM effectively reduced chilling injury symptoms, lowered ROS accumulation, maintained higher antioxidant levels, and enhanced antioxidant enzyme activities in loquat fruit during cold storage.
Population
Loquat fruits (not human subjects).
Effective Dosage
50 μM melatonin.
Duration
16 days.
Interactions
None mentioned.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
50 μM melatonin | decrease | CI index and cell membrane permeability | loquat fruit | - | was the optimal concentration to inhibit the increase in | #1 |
50 μM melatonin | decrease | malonaldehyde (MDA) content | loquat fruit | 17.8% | inhibited | #2 |
50 μM melatonin | decrease | O2-. production rate | loquat fruit | 7.2% | inhibited | #3 |
50 μM melatonin | decrease | H2O2 content (ROS accumulation) | loquat fruit | 11.8% | inhibited | #4 |
50 μM melatonin | increase | 1-diphenyl-2-picrylhydrazyl radical-scavenging ability | loquat fruit | - | maintained higher levels of | #5 |
50 μM melatonin | increase | reducing power | loquat fruit | - | maintained higher levels of | #6 |
50 μM melatonin | increase | contents of ascorbic acid (AsA) | loquat fruit | - | maintained higher levels of | #7 |
50 μM melatonin | increase | contents of glutathione (GSH) | loquat fruit | - | maintained higher levels of | #8 |
50 μM melatonin | increase | antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) | loquat fruit | - | enhanced the activities of | #9 |
50 μM melatonin | increase | activities of SOD | loquat fruit | 1.1-times | increased | #10 |
50 μM melatonin | increase | activities of CAT | loquat fruit | 1.1-times | increased | #11 |
50 μM melatonin | increase | activities of APX | loquat fruit | 1.1-times | increased | #12 |
Cold storage is one of the most effective methods to maintain postharvest fruit quality. However, loquat fruits are prone to chilling injury (CI) during cold storage, appearing as symptoms such as browning and pitting, which leads to quality deterioration and economic losses. In this study, the effects of melatonin on CI alleviation and the potential role of reactive oxygen species (ROS) metabolism in loquat fruit were investigated. The results showed that 50 μM melatonin was the optimal concentration to inhibit the increase in CI index and cell membrane permeability. Moreover, compared to control fruits, 50 μM melatonin inhibited the malonaldehyde (MDA) content, O2-. production rate and H2O2 content (ROS accumulation) by 17.8%, 7.2% and 11.8%, respectively, during cold storage. Compared to non-treated loquats, 50 μM melatonin maintained higher levels of 1-diphenyl-2-picrylhydrazyl radical-scavenging ability and reducing power, as well as the contents of ascorbic acid (AsA) and glutathione (GSH). Additionally, 50 μM melatonin enhanced the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) by increasing relevant gene expressions. The activities of SOD, CAT and APX were increased by up to 1.1-, 1.1- and 1.1-times (16 d) by melatonin, as compared with the control fruits. These findings indicate that melatonin mitigation of CI is involved in maintaining cellular redox apphomeostasis in loquat fruit during cold storage.