Carvacrol delays Phomopsis stem-end rot development in pummelo fruit in relation to maintaining energy status and antioxidant system

Antofine Triggers the Resistance Against Penicillium italicum in Ponkan Fruit by Driving AsA-GSH Cycle and ROS-Scavenging System

“…The results from our preliminary experiment showed the minimum fungicidal concentration (MFC) value of ATF against P. italicum was 6.25 mg/L ( Chen et al, 2019b ). The in vivo inhibitory effects of ATF at different concentrations [0 × (control), 1.25 ×, 2.5 ×, 5 ×, 10 × MFC] for controlling postharvest BM development on Ponkan fruit was disposed by adopting our previous method described by Chen et al (2022) . For each Ponkan fruit, one wound (diameter of 3 mm and depth of 3 mm) was made using a sterilized punch.…”

“…The diameter of water-soaked lesion on the P. italicum -infected Ponkan fruit was used as one of the direct indexes of blue mold development and recorded in millimeter (mm) in the initial stage of infection progress ( Chen et al, 2022 ).…”

“…Peel firmness (N) of 10 fruits from two P. italicum -infected groups was determined by using a TAXT Plus texture tester (SMS, Godalming, United Kingdom) fitted with a 2 mm diameter probe, with the results expressed as Newton (N). For the assessment of membrane stability, electrolyte leakage in Ponkan peel was assayed by the method elaborated by Chen et al (2022) with the aid of a portable conductivity meter (DDS-307A, Leici Inc., Shanghai, China). The hydroxylamine method elaborated by Sadeghi et al (2020) was applied to determine superoxide anion (O 2 •– ) production rate, and the value was expressed as μmol –1 min g –1 .…”

“…When invaded by latent fungi, the defense barrier of plant cells was weakened by a disordered reactive oxygen species (ROS) homeostasis due to fungal virulence ( Segal and Wilson, 2018 ; Xu et al, 2019a ; Zhang et al, 2020 ). Nevertheless, over-produced ROS at infection sites can induce oxidative stress, leading to a range of physiological disorders, such as cell permeability breakdown, membrane lipid peroxidation, energy depletion, protein denaturation, and DNA oxidization, thereby resulting in cell death ( Zhang et al, 2020 ; Chen et al, 2022 ). Postharvest disorder of cellular ROS homeostasis, accompanied by excessive superoxide anion (O 2 •– ) production and malondialdehyde (MDA) accumulation, will rapidly cause the oxidative damage of cellular membrane as well as cell wall and aggravate the fruit quality deterioration of harvested fruits like Ponkan mandarin ( Huang et al, 2021a ), orange ( Elsherbiny et al, 2021 ), pummelo ( Chen et al, 2022 ), grape ( Wang et al, 2020 ), pear ( Liu et al, 2021 ), and muskmelon ( Xue et al, 2020 ).…”

“…Nevertheless, over-produced ROS at infection sites can induce oxidative stress, leading to a range of physiological disorders, such as cell permeability breakdown, membrane lipid peroxidation, energy depletion, protein denaturation, and DNA oxidization, thereby resulting in cell death ( Zhang et al, 2020 ; Chen et al, 2022 ). Postharvest disorder of cellular ROS homeostasis, accompanied by excessive superoxide anion (O 2 •– ) production and malondialdehyde (MDA) accumulation, will rapidly cause the oxidative damage of cellular membrane as well as cell wall and aggravate the fruit quality deterioration of harvested fruits like Ponkan mandarin ( Huang et al, 2021a ), orange ( Elsherbiny et al, 2021 ), pummelo ( Chen et al, 2022 ), grape ( Wang et al, 2020 ), pear ( Liu et al, 2021 ), and muskmelon ( Xue et al, 2020 ). To minimize the toxic effects of excessive ROS and reduced oxidative stress, plant cells have evolved an efficient ROS-scavenging system that includes non-enzymatic antioxidants, such as phenolics, flavonoids, ascorbic acid (AsA, also known as vitamin C), glutathione (GSH), and anthocyanins, and enzymatic antioxidants, such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and six key enzymes in AsA-GSH cycle, namely, ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), mono-DHAR (MDHAR), GSH reductase (GR), GSH peroxidase (GPX), and GSH S-transferase (GST; Hasanuzzaman et al, 2019 ; Sadeghi et al, 2020 ; Xue et al, 2020 ).…”