Induction of defense response against Alternaria rot in Zaosu pear fruit by exogenous L-lysine through regulating ROS metabolism and activating defense-related proteins

Lignin Biosynthesis Pathway and Redox Balance Act Synergistically in Conferring Resistance against Penicillium italicum Infection in 7-Demethoxytylophorine-Treated Navel Orange

“…italicum (Figure F,G). The results are consistent with the observation of Liu et al, where exogenous 0.1 mM l -lysine reduces A. alternata-induced oxidative damage by suppressing O 2 •– production and MDA accumulation, thus inducing Alternaria rot resistance in “Zaosu” pear fruit.…”

“…Reduction of firmness loss and electrolyte leakage following exogenous treatment of Botrytis cinerea-infected “Akihime” strawberry with linalool, Botryosphaeria dothidea-infected “Fuji” apple with benzothiadiazole, and A. alternata-infected “Zaosu” pear with l -lysine was reported, indicating that these PAAs support the maintenance of the cell wall structure and cell membrane integrity and in turn mediate antifungal resistance in harvested fruit.…”

“…20−23 Recently, some PAAs such as the poplar bud extract and its main component pinocembrin, 24 2-methoxy-1,4-naphthoquinone, 25 limonin, 26 SA, and plant essential oil 8 suppressed P. italicum growth and improved resistance to postharvest CBM. In addition, Liu et al 27 reported that 0.1 mmol L −1 L-lysine could reduce Alternaria rot incidence in "Zaosu" pear by activating the host-defense responses to Alternaria alternata infection. 7-Demethoxytylophorine (DEM) or antofine, a natural water-soluble phenanthroindolizidine alkaloid, has been mainly isolated from Asclepiadaceae plants and exhibits antiangiogenic activity, 28 cholinesterase inhibitory activity, 29 antiproliferative and antitumor activity, 30 and antifungal activity against phytopathogen Fusarium graminearum.…”

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

“…Our current result showed that ATF treatment suppressed the increases of peel firmness loss, electrolyte leakage, O 2 •– production rate, and MDA content in P. italicum -infected Ponkan fruit, indicating that ATF treatment controlled blue mold development in Ponkan fruit by reducing P. italicum -induced oxidative damage. Many similar studies indicated lower firmness loss, electrolyte leakage, and MDA accumulation following the exogenous treatment of linalool in Botrytis cinerea- infected “Akihime” strawberry ( Xu et al, 2019b ), benzothiadiazole (BTH) in Botryosphaeria dothidea -infected “Fuji” apple ( Huang et al, 2021b ), and L -lysine in Alternaria alternata -infected “Zaosu” pear ( Liu et al, 2021 ), demonstrating that these PAAs treatments enhanced the maintenance of cell wall structure and cell membrane stability and triggered the resistance against fungal infection in fruits.…”

“…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 ).…”