Melatonin delays leaf senescence of postharvest Chinese flowering cabbage through ROS homeostasis

Xiao-Li Tan; Ya-Ting Zhao; Wei Shan; Jian-Fei Kuang; Wang-Jin Lu; Xin-Guo Su; Neng-Guo Tao; Prakash Lakshmanan; Jian-Ye Chen

doi:10.1016/j.foodres.2020.109790

Melatonin delays leaf senescence of postharvest Chinese flowering cabbage through ROS homeostasis

Food Res Int. 2020 Dec;138(Pt B):109790. doi: 10.1016/j.foodres.2020.109790. Epub 2020 Oct 15.

Authors

Xiao-Li Tan¹, Ya-Ting Zhao², Wei Shan², Jian-Fei Kuang², Wang-Jin Lu², Xin-Guo Su³, Neng-Guo Tao⁴, Prakash Lakshmanan⁵, Jian-Ye Chen⁶

Affiliations

¹ State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center of Southern Horticultural Products Preservation, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou 510642, China; School of Chemical Engineering, Xiangtan University, Xiangtan 411105, China.
² State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center of Southern Horticultural Products Preservation, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou 510642, China.
³ Guangdong AIB Polytechnic, Guangzhou, 510507, China. Electronic address: suxg@gdyzy.edu.cn.
⁴ School of Chemical Engineering, Xiangtan University, Xiangtan 411105, China.
⁵ Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin (CAGD), College of Resources and Environment, Southwest University, Chongqing 400715, China; Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, QLD, St Lucia 4072, Australia.
⁶ State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables/Engineering Research Center of Southern Horticultural Products Preservation, Ministry of Education, College of Horticulture, South China Agricultural University, Guangzhou 510642, China; Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou 510642, China. Electronic address: chenjianye@scau.edu.cn.

PMID: 33288176
DOI: 10.1016/j.foodres.2020.109790

Abstract

Reactive oxygen species (ROS) trigger and accelerate leaf senescence. Melatonin, a low molecular compound with several biological functions in plants, is known to delay leaf senescence in different species, including Chinese flowering cabbage. However, the mechanism(s) underpinning melatonin-delayed leaf senescence remains unclear. Here, we found that melatonin lowered the expression of chlorophyll catabolic genes (BrPAO and BrSGR1) and senescence-associated genes (BrSAG12 and BrSEN4), decreased chlorophyll loss, minimized the alteration in Fv/Fm ratio and remarkably delayed senescence of Chinese flowering cabbage after harvest. Moreover, the over-accumulation of O₂^•-, hydrogen peroxide (H₂O₂) and malondialdehyde contents and the expression of respiratory burst oxidase homologues (RBOH) genes (BrRbohB, BrRbohC, BrRbohD, BrRbohD2 and BrRbohE) were significantly inhibited by melatonin treatment. Melatonin-treated cabbages also showed higher O₂^•-, OH^• and DPPH radical scavenging capacity and enhanced activities of peroxidase (POD), superoxide dismutase (SOD) and their gene expressions. Up-regulation of key components of ascorbate-glutathione (AsA-GSH) cycle, the metabolic pathway that detoxify H₂O₂, was also observed in melatonin-treated cabbages. These findings suggest that melatonin-delayed postharvest leaf senescence of postharvest Chinese flowering cabbage may be mediated, at least in part, by maintaining ROS homeostasis through restraining RBOHs-catalyzed ROS production and enhancing the activity of ROS-scavenging system including major antioxidant enzymes and AsA-GSH cycle.

Keywords: Chinese flowering cabbage; Leaf senescence; Melatonin; ROS homeostasis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Brassica* / genetics
Brassica* / metabolism
China
Gene Expression Regulation, Plant
Homeostasis
Hydrogen Peroxide
Melatonin*
Plant Leaves / metabolism
Plant Proteins / genetics
Plant Proteins / metabolism
Reactive Oxygen Species / metabolism

Substances

Plant Proteins
Reactive Oxygen Species
Hydrogen Peroxide
Melatonin