Exogenous melatonin activates the antioxidant system and maintains postharvest organoleptic quality in Hami melon (Cucumis. melo var. inodorus Jacq.)

Yue Wang; Minrui Guo; Weida Zhang; Yujie Gao; Xiaoqin Ma; Shaobo Cheng; Guogang Chen

doi:10.3389/fpls.2023.1274939

Exogenous melatonin activates the antioxidant system and maintains postharvest organoleptic quality in Hami melon (Cucumis. melo var. inodorus Jacq.)

Front Plant Sci. 2023 Oct 30:14:1274939. doi: 10.3389/fpls.2023.1274939. eCollection 2023.

Authors

Yue Wang^{1

2}, Minrui Guo^{1

2}, Weida Zhang^{1

2}, Yujie Gao^{1

2}, Xiaoqin Ma^{1

2}, Shaobo Cheng^{1

2}, Guogang Chen^{1

2}

Affiliations

¹ College of Food Science and Technology, Shihezi University, Shihezi, Xinjiang, China.
² Research Center of Xinjiang Characteristic Fruit and Vegetable Storage and Processing Engineering, Ministry of Education, Shihezi, Xinjiang, China.

Abstract

Hami melon is prone to postharvest perishing. Melatonin is a signaling molecule involved in a variety of physiological processes in fruit, and it improves fruit quality. We hypothesized that melatonin treatment would improve the storage quality of Hami melon by altering its respiration and reactive oxygen species (Graphical abstract). Our results indicated that optimal melatonin treatment (0.5 mmol L^-1) effectively slowed the softening, weight loss, and respiratory rate of the Hami melon fruit. Furthermore, melatonin markedly improved the antioxidant capacity of the fruit and protected it from oxidative damage by decreasing its contents of superoxide anions, hydrogen peroxide, and malondialdehyde. Melatonin significantly enhanced the activities of superoxide dismutase, catalase, ascorbate peroxidase, and peroxidase. The total phenol, total flavonoids, and ascorbic acid contents were maintained by melatonin treatment. This treatment also repressed the activities of lipase, lipoxygenase, and phospholipase D, which are related to lipid metabolism. Thus, exogenous melatonin can maintain postharvest organoleptic quality of Hami melon fruit by increasing its antioxidant activity and inhibiting reactive oxygen species production.

Keywords: Hami melon; antioxidant capacity; fruit quality; melatonin; postharvest storage; reactive oxygen species.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was financially supported by the Scientific research project of Shihezi University (grant numbers CXBJ202206, CXPY202015), the Eighth Division Science and Technology Program (grant number 2023TD02), and Key research and Development of Xinjiang Uygur Autonomous Region (2022395491).