BTH Treatment Delays the Senescence of Postharvest Pitaya Fruit in Relation to Enhancing Antioxidant System and Phenylpropanoid Pathway.

Xiaochun Ding,Xiaoyang Zhu,Xuewu Duan,Fengjun Li,Wang Zheng,Shuangling Xiao

doi:10.3390/foods10040846

Abstract

The plant resistance elicitor Benzo (1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) can enhance disease resistance of harvested fruit. Nonetheless, it is still unknown whether BTH plays a role in regulating fruit senescence. In this study, exogenous BTH treatment efficiently delayed the senescence of postharvest pitaya fruit with lower lipid peroxidation level. Furthermore, BTH-treated fruit exhibited lower hydrogen peroxide (H2O2) content, higher contents of reduced ascorbic acid (AsA) and reduced glutathione (GSH) levels and higher ratios of reduced to oxidized glutathione (GSH/GSSG) and ascorbic acid (AsA/DHA), as well as higher activities of ROS scavenging enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and glutathione reductase (GR) in comparison with control fruit. Moreover, BTH treatment enhanced the activities of phenylpropanoid pathway-related enzymes, including cinnamate-4-hydroxylase (C4H), phenylalanine ammonia-lyase (PAL) and 4-coumarate/coenzyme A ligase (4CL) and the levels of phenolics, flavonoids and lignin. In addition, BTH treatment upregulated the expression of HuSOD1/3/4, HuCAT2, HuAPX1/2 and HuPOD1/2/4 genes. These results suggested that application of BTH delayed the senescence of harvested pitaya fruit in relation to enhanced antioxidant system and phenylpropanoid pathway.

Highlights

Pitaya (Hylocereus undatus) is a tropical and subtropical non-climactic fruit, rich in vitamins, amino acids, total phenols and betaine
It has been shown that BTH enhances plant disease resistance and improves the quality of horticultural products such as muskmelon [7,8], strawberry [9], apple [10] and mango [11]
Pitaya fruit were immersed in distilled water for 15 min as the control group

Summary

Introduction

Pitaya (Hylocereus undatus) is a tropical and subtropical non-climactic fruit, rich in vitamins, amino acids, total phenols and betaine. Techniques are developed to maintain the quality of harvested pitaya, including chemical treatments (BABA, methyl jasmonate, nitric oxide) [1,2], heat shock [3] and low temperature and bagging [4]. It has been shown that BTH enhances plant disease resistance and improves the quality of horticultural products such as muskmelon [7,8], strawberry [9], apple [10] and mango [11]. BTH delays fruit ripening in climacteric muskmelon and banana [12,13]. It is still unknown whether BTH regulate the senescence of non-climacteric fruit

Methods

Results

Conclusion