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Acidic electrolyzed oxidizing water (AEOW) was applied to suppress disease development and maintain good quality of fresh fruit. However, the involvement of AEOW in improving disease resistance of fresh longan remains unknown. Here, transcriptomic and metabolic analyses were performed to compare non-treated and AEOW-treated longan during storage. The transcriptome analysis showed AEOW-induced genes associated with phenylpropanoid and flavonoid biosynthesis. The metabolome analysis found the contents of coumarin, phenolic acid, and tannin maintained higher levels in AEOW-treated longan than non-treated longan. Moreover, the weighted correlation network analysis (WGCNA) was performed to identify hub genes, and a gene-metabolite correlation network associated with AEOW-improved disease resistance in longan was constructed by the co-analysis of transcriptomics and metabolomics. These findings identified a series of important genes and metabolites involving in AEOW-induced disease resistance of longan fruit, expanding our knowledges on fruit disease resistance and quality maintenance at the transcript and metabolic levels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Postharvest harmful pathogenic infestation leads to rapid decay in longan fruit. Compared with P. longanae-infected longans, AEOW alleviated fruit disease severity and diminished the O 2 production rate and MDA content. It also increased APX, CAT, and SOD activities, delayed the decrease in the levels of GSH and AsA, as well as the reducing power and DPPH radical scavenging ability, which resulted in a decline in membrane lipid peroxidation in P. longanae-infected longans. Additionally, AEOW reduced LOX, lipase, PI-PLC, PC-PLC, and PLD activities, maintained higher levels of PC, PI, IUFA, USFAs, and U/S, while reducing levels of PA, DAG, SFAs, and CMP. These effects alleviated membrane lipid degradation and peroxidation in P. longanae-infected longans. Consequently, AEOW effectively maintained membrane integrity via improving antioxidant capacity and suppressing membrane lipid peroxidation. This comprehensive coordination of ROS and membrane lipid metabolisms improved fruit resistance and delayed disease development in longans.-. production rate and MDA content. It also increased APX, CAT, and SOD activities, delayed the decrease in the levels of GSH and AsA, as well as the reducing power and DPPH radical scavenging ability, which resulted in a decline in membrane lipid peroxidation in P. longanae-infected longans. Additionally, AEOW reduced LOX, lipase, PI-PLC, PC-PLC, and PLD activities, maintained higher levels of PC, PI, IUFA, USFAs, and U/S, while reducing levels of PA, DAG, SFAs, and CMP. These effects alleviated membrane lipid degradation and peroxidation in P. longanae-infected longans. Consequently, AEOW effectively maintained membrane integrity via improving antioxidant capacity and suppressing membrane lipid peroxidation. This comprehensive coordination of ROS and membrane lipid metabolisms improved fruit resistance and delayed disease development in longans., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Postharvest longan fruits are subjected to Phomopsis longanae Chi (P. longanae) infection that lead to fruit quality deterioration. We hypothesized that ε-poly-l-lysine (ε-PL) could enhance fruit disease resistance in longans. Through physiological and transcriptomic analyses, the results showed that, compared to P. longanae-infected longan fruit, ε-PL + P. longanae treatment reduced the disease development of longan fruits. Additionally, ε-PL + P. longanae treatment increased the contents of disease-resistant substances (lignin and H 2 O 2 ) and the activities of disease-resistance enzymes (CHI, PAL, PPO, C4H, CAD, GLU, 4CL, and POD). Furthermore, the expressions of genes relevant to the phenylpropanoid biosynthesis pathway and plant-pathogen interaction pathway (Rboh, FLS2, WRKY29, FRK1, and PR1) were up-regulated by ε-PL + P. longanae treatment. These findings demonstrated that ε-PL treatment inhibited the disease development of postharvest longan fruits were associated with the increased accumulation of disease-resistant related substances, as well as the raised activities and genes expressions of disease-resistance related enzymes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The impacts of chilling injury (CI) temperature (2 °C) and non-CI temperature (8 °C) on the CI development, browning occurrence, and its underlying mechanism in Chinese olives were investigated. The results showed that, 2 °C induced higher levels of CI index, browning degree, chromaticity a* and b* values, but lower values of h°, chlorophyll and carotenoid contents in Chinese olives as compared to 8 °C. Furthermore, 2 °C raised cell membrane permeability, increased the activities of phospholipase D, lipase and lipoxygenase, accelerated the hydrolyses of phosphatidylcholine and phosphatidylinositol to phosphatidic acid, and promoted the conversions of unsaturated fatty acids to saturated fatty acids in Chinese olives. Moreover, 2 °C-stored Chinese olives showed higher activities of peroxidase and polyphenol oxidase, but lower contents of tanin, flavonoid and phenolics. These findings demonstrated that the CI and browning developments in Chinese olives were closely associated with the metabolisms of membrane lipid and phenolics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

This work studied the difference in pulp breakdown between two cultivars of longan cv. 'Dongbi' and 'Fuyan' from the aspect of metabolisms of lipid and energy. The results reflected that, compared to 'Fuyan' longan, 'Dongbi' longan had higher levels of energy charge, U/S and IUFA, and higher amounts of USFA, PC, PI, ATP and ADP. Moreover, 'Dongbi' longan exhibited lower levels of SFA, PA, AMP and cell membrane permeability. Also, lower PLD, LOX and lipase activities, but higher ATPase activity, lower pulp breakdown index, and better pulp appearance were exhibited in 'Dongbi' longan. These data revealed that the mitigated pulp breakdown in 'Dongbi' longan was due to the comprehensive coordination of metabolisms in lipid and energy through maintaining a higher level of energy, a higher unsaturation degree of fatty acids, delaying the degradation of phospholipids, and better retaining the membrane structural integrity of microsome and entire cell., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Compared with P. longanae-infected longan, 2, 4-dinitrophenol (DNP) treatment for P. longanae-infected longan displayed the lower levels of pulp firmness, cell wall materials, ionic-soluble pectin, covalent-soluble pectin, hemicellulose, or cellulose, but the higher amount of water-soluble pectin, the higher activities of cell wall-degrading enzymes (CWDEs) (PG, β-Gal, PME, Cx, and XET), and the higher transcript levels of CWDEs-related genes (DlPG1, DlPG2, Dlβ-Gal1, DlPME1, DlPME2, DlPME3, DlCx1, and DlXET30). On the contrary, ATP treatment for P. longanae-infected longan exhibited opposite effects. The above results imply that DNP accelerated P. longanae-induced pulp softening and breakdown of fresh longan, which was because DNP up-regulated the transcript levels of CWDEs-related genes, enhanced the CWDEs activities, and accelerated the degradation of cell wall polysaccharides (CWP). However, ATP suppressed longan pulp softening and breakdown caused by P. longanae, because ATP down-regulated the transcript levels of CWDEs-related genes, lowered the CWDEs activities, and reduced the CWP degradation., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The influences of Kadozan, a novel chitosan formulation, on the pulp breakdown and ROS metabolism in postharvest 'Fuyan' longans were studied. Compared with control longans, the longans treated with 1:500 Kadozan dilution (V Kadozan : V Kadozan + Water ) exhibited the suppressed development of pulp breakdown, higher AsA and GSH amounts, higher activities of ROS-scavenging enzymes like SOD, CAT, APX and POD, higher reducing power, and higher scavenging ability for DPPH radical, but a lower MDA amount, lower levels of ROS including O 2 - and H 2 O 2 . These findings indicated that the application of 1:500 Kadozan dilution (V Kadozan : V Kadozan + Water ) for harvested longans could enhance the ROS-scavenging capacity to decrease the generation and accumulation of ROS, and a lower level of ROS could slow down the peroxidation progress of membrane lipids, alleviate the damage of longan pulp cellular membrane structure, and ultimately suppress pulp breakdown occurrence of harvested longans., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Longan (Dimocarpus longan Lour.) is prone to pulp softening and pulp breakdown, leading to a loss of its nutrients including polysaccharides. ROS is one main factor affecting fruit quality. This work intended to explicate the influences of hydrogen peroxide, acting as a ROS, on pulp softening, pulp breakdown, and cell wall polysaccharides metabolism in longan fruit during storage. Contrasted to the control group, hydrogen peroxide-treated samples exhibited lower firmness, lower amounts of CWM, ISP, CSP, hemicellulose and cellulose, but higher breakdown index, WSP amount, expression levels of DlPG, DlPE, Dlβ-Gal, DlCx and DlXET and activities of their corresponding enzymes (PG, PE, β-Gal, Cx, XET). These results suggested that hydrogen peroxide reduced longan pulp firmness due to the increased gene expression levels and enzymes activities related to cell wall polysaccharide degradation to boost their decomposition, thereby led to the accelerated pulp softening and the expedited pulp breakdown of harvested longans., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Anxi persimmon is a popular fruit because of its appealing flavor and rich nutrients such as polysaccharides. However, the harvested persimmon fruit softens and deteriorates quickly. This study explored the influences of the treatment of papers containing 1-methylcyclopropene (1-MCP) on the contents of cell wall polysaccharides and activities of cell wall-degrading enzymes in harvested Anxi persimmons, as well as its effect on fruit softening. The results demonstrated that, in comparison to the control Anxi persimmons, the Anxi persimmons treated with 1.35 μL/L 1-MCP manifested higher fruit firmness, higher contents of protopectin, cellulose, and hemicellulose, but a lower level of water-soluble pectin, lower activities of pectin methylesterase, polygalacturonase, cellulase, and β-galactosidase in Anxi persimmons during postharvest storage. These findings suggested that the treatment of papers containing 1.35 μL/L 1-MCP could retard softening of harvested Anxi persimmon fruit via inhibiting the degradation of cell wall polysaccharides., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This study aimed to investigate the effect of hydrogen peroxide (H 2 O 2 ) on membrane lipids metabolism and its relation to pulp breakdown development of longan fruit during postharvest storage. Compared to the control longans, H 2 O 2 -treated longans showed higher pulp breakdown index, cell membrane permeability, and activities of phospholipase D (PLD), lipase and lipoxygenase (LOX). Moreover, H 2 O 2 -treated longans maintained higher levels of pulp phosphatidic acid (PA) and saturated fatty acids (SFA). However, H 2 O 2 -treated longans exhibited lower levels of pulp phosphatidylcholine (PC), phosphatidylinositol (PI) and unsaturated fatty acids (USFA), lower index of unsaturated fatty acids (IUFA), and lower ratio of USFA to SFA (U/S). These findings demonstrated that H 2 O 2 caused the increased activities of enzymes involving in membrane lipids degradation and the accelerated decompositions of membrane USFA and phospholipids in longan pulp, which eventually triggered the destruction of the pulp cell membrane structure and the development of pulp breakdown in longans during storage., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Longan pulp is an excellent source of polysaccharides and other nutrients that have many health benefits. However, longans is susceptible to pulp breakdown after harvest and loses its nutrition values. To solve this problem, this study aimed to study the effects of a novel chitosan, Kadozan, on pulp breakdown index, contents of pectin, cellulose and hemicelluloses, and activities of enzymes in longan pulp relating to disassembly of polysaccharides (XET, PE, PG, β-Gal, and cellulase). The data illustrated that, compared to the control longans, chitosan-treated longans contained higher amounts of CWM, CSP, ISP, cellulose and hemicelluloses, but exhibited lower pulp breakdown index, lower activities of cell wall-disassembling enzymes, and contained lower WSP amount. These results suggested that Kadozan with a dilution of 1:500 (V Kadozan : V Kadozan + Water ) could significantly decrease activities of disassembling-enzymes and depolymerization of polysaccharides in cell wall, and subsequently alleviate pulp breakdown and prolong storage-life of postharvest longans., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The effects of Kadozan (a novel chitosan formulation) treatment on physiological attribute, nutritional quality and storage behavior of harvested "Wuye" litchi fruit were studied. Compared with control litchis, Kadozan treatment significantly decreased fruit respiration rate, retarded the increase of pericarp cell membrane permeability, maintained higher contents of anthocyanins and flavonoids and higher values of L ∗ , a ∗ and b ∗ in litchi pericarp, and reduced the decreases of titratable acidity, total soluble solids, total soluble sugars, and vitamin C contents in litchi pulp, maintaining better quality of litchis. Furthermore, Kadozan treatment decreased browning index and disease index of litchis, kept higher rate of commercially acceptable fruit, and reduced fruit weight loss, showing better storage behavior of litchis under ambient temperature. The optimal Kadozan treatment for litchis was the 1:100 (V Kadozan : V Kadozan + Water ) dilution, which might be a promising method for keeping quality and prolonging shelf-life of harvested "Wuye" litchi fruit., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Effects of Lasiodiplodia theobromae inoculation on disease development, pericarp browning and membrane lipids metabolism of harvested "Fuyan" longan fruit were studied. Compared with control fruit, L. theobromae-inoculated longans showed higher fruit disease index, pericarp browning index and cell membrane permeability, as well as higher activities of phospholipase D, lipase and lipoxygenase. Additionally, there were lower contents of membrane phospholipids but higher content of phosphatidic acid, and lower level of unsaturated fatty acids but higher level of saturated ones with lower ratio of unsaturated fatty acid to saturated fatty acid and lower index of unsaturated fatty acids in pericarp of L. theobromae-inoculated longans. These results suggested that L. theobromae-induced disease development and pericarp browning of harvested longans might be attributed to the damaged cellular membrane structural integrity, induced by the activated membrane lipids-degrading enzymes increasing the degradation of membrane phospholipids and unsaturated fatty acids in pericarp of harvested longan fruit., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Lasiodiplodia theobromae (Pat.) Griff. & Maubl. is a major pathogen causing decay of harvested longan fruit. The roles of energy status regulated by 2,4-dinitrophenol (DNP) and adenosine triphosphate (ATP) in disease development regarding respiratory metabolism of L. theobromae-inoculated "Fuyan" longan fruit were studied. Compared with L. theobromae-inoculated longans, DNP treatment could promote the index of fruit disease, accelerate the decrease in energy charge, increase respiration rate and the activities of respiratory terminal oxidases like CCO, AAO and PPO, elevate contents of NAD and NADH, but decrease NAD kinase activity, as well as contents of NADP and NADPH; however, exogenous ATP supply acted contrarily. Above results suggested the different energy status caused by DNP and ATP treatments accelerated or delayed the disease development of L. theobromae-inoculated longans via regulating Embden-Meyerhof pathway (EMP) and tricarboxylic acid (TCA) cycle, pentose phosphate pathway (PPP) and activities of respiratory terminal oxidases., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

As compared with P. longanae-inoculated longans, DNP treatment for P. longanae-inoculated longans exhibited higher fruit disease index and pericarp browning index, lower ATP amount and energy charge level, lower activities of SOD, CAT and APX, lower amounts of AsA and GSH, lower levels of DPPH radical scavenging activity and reducing power, higher O 2 - generating rate and MDA amount. However, supply of ATP for P. longanae-inoculated longans showed the contrary effects. These results gave convincing evidence that DNP treatment for accelerating pericarp browning and disease development of harvested longans caused by P. longanae was due to decreases of energy production and ROS scavenging capacity, and increases of O 2 - accumulation and membrane lipid peroxidation. Whereas, supply of ATP for retarding pericarp browning and disease development of harvested longans caused by P. longanae was due to increases of energy production and ROS scavenging capacity, and reductions of O 2 - accumulation and membrane lipid peroxidation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Energy metabolism of "Fuyan" longan fruit treated with hydrogen peroxide (H 2 O 2 ), the most stable of the reactive oxygen, and its relationship to pericarp browning were investigated in this work. The results displayed that H 2 O 2 significantly decreased contents of adenosine triphosphate (ATP) and adenosine diphosphate (ADP). It also inhibited activities of H + -ATPase, Ca 2+ -ATPase and Mg 2+ -ATPase in membranes of plasma, vacuole and mitochondria during the early-storage and mid-storage (except for mitochondrial membrane Mg 2+ -ATPase). These results gave convincing evidence that the treatment of H 2 O 2 accelerating pericarp browning in harvested longans was due to a decrease of ATPase activity and available ATP content. This might break the ion homeostasis and the integrity of mitochondria, which might reduce energy charge and destroy the function and compartmentalization of cell membrane. These together aggravated browning incidence in pericarp of harvested longan fruit., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Effects of propyl gallate on membrane lipids metabolism and its relation to storability of harvested longan fruits were studied. The results showed that the propyl gallate-treated longans maintained lower activities of pericarp phospholipase D (PLD), lipase and lipoxygenase (LOX) than those in control fruits. Such treatments could maintain higher levels of pericarp unsaturated fatty acids (USFAs), higher pericarp indices of unsaturated fatty acids (IUFA), and higher pericarp ratio of unsaturated fatty acids to saturated fatty acids (U/S) than those in control fruits. Furthermore, propyl gallate also delayed color changes of pericarp in the harvested longans. Therefore, the postharvest treatments of longan fruits with propyl gallate for increasing storability of longan fruits might be explained by a decrease in activities of PLD, lipase and LOX, and an the increased unsaturation of fatty acids, which could delay membrane lipids metabolism and maintain cell membrane characteristics., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Disassembly of cell wall polysaccharides accompanied with softening is very common in harvested fruits. To develop a facile postharvest approach, which can be used at ambient temperature, for suppressing softening and maintaining higher nutritive cell wall polysaccharides of Younai plums, influences of paper containing 1-methylcyclopropene (1-MCP) on firmness, activities of cell wall-degrading enzymes, and contents of cell wall polysaccharide in Younai plums during storage at 25 ± 1 °C were investigated. As compared to the control plums, 1.2 μL·L −1 1-MCP-treated plums exhibited higher firmness, lower activities of cell wall-degrading enzymes (pectinesterase, polygalacturonase, cellulase and β-galactosidase), higher contents of cell wall polysaccharides (sodium carbonate-soluble pectin, chelate-soluble pectin, cellulose, and hemicelluloses), and lower content of water-soluble pectin. The results suggested that paper containing 1-MCP, which was convenient to apply under ambient temperature, could significantly inhibit activities of cell wall degrading-enzymes and decrease disassembly of cell wall polysaccharides, and subsequently retard softening in Younai plums. [ABSTRACT FROM AUTHOR]

• GABA reduced O 2 −. generation rate and MDA content in cold-stored Chinese olives. • GABA retained higher activities of APX, CAT and SOD in cold-stored Chinese olives. • GABA retained higher amounts of GSH and AsA in cold-stored Chinese olives. • GABA retained higher ability of scavenging DPPH radical and higher reducing power. • GABA reduced chilling injury of Chinese olives via raising ROS scavenging capacity. Chinese olives are susceptible to chilling injury (CI) during refrigeration. Exploring economical and convenient approaches to suppress CI development is important for preserving fruit quality and prolonging postharvest shelf-life of Chinese olives. In this study, the effects of 1.0 mM γ-aminobutyric acid (GABA) treatment on CI development and ROS metabolism in cold-stored Chinese olives at 2 °C for 100 d were evaluated. The results demonstrated that, compared to control Chinese olives, GABA treatment observably alleviated CI development, remarkably suppressed the increased CI index, O 2 −. production rate, and MDA amount, but retained higher SOD, CAT and APX activities, higher values of GSH and AsA, higher abilities of scavenging DPPH radical, and higher reducing power. On the last day of storage (day 100), CI index, O 2 −. production rate, and MDA content in control Chinese olives were 2.06-, 1.28, 1.48-fold higher compared with those of GABA-treated fruits. In contract, SOD, CAT and APX activities in GABA-treated fruits were 1.54-, 3.24, 1.57-fold higher than in that of control Chinese olives. The GSH and AsA contents, DPPH scavenging ability and reducing power were 64.7%, 128.4%, 51.8% and 35.0% higher in GABA-treated olives, as compared to control fruits. Together, these findings indicate that 1.0 mM GABA shows a potential application in improving antioxidant capacity and alleviating CI development of Chinese olives during cold storage. [ABSTRACT FROM AUTHOR]

Cold storage is widely applied in postharvest fruit for quality maintenance. However, Chinese olive fruit suffers severe chilling injury (CI) during improper cold storage. In present work, the metabolisms of energy and proline in Chinese olive fruit during CI occurrence were investigated. Compared with the cold storage at 8 °C, the cold storage at 2 °C raised CI index, reduced the activities of Mg2+-ATPase, Ca2+-ATPase and H+-ATPase in the membranes of mitochondria, plasma and vacuole, decreased the levels of energy charge, ATP, and ADP, but elevated the content of AMP in Chinese olive fruit. Furthermore, 2 °C cold-stored fruit presented lower proline amount, lower P5CS and OAT activities, but higher PDH activity. These data demonstrated that the reduced levels of energy and proline were associated with the CI occurrence of cold-stored Chinese olives. [Display omitted] • 2 °C induced chilling injury in Chinese olive fruit during storage. • 2 °C decreased the ATP and ADP contents and energy status in Chinese olive fruit. • 2 °C reduced Ca2+-ATPase, Mg2+-ATPase and H+-ATPase activities in Chinese olive fruit. • 2 °C reduced the proline content in Chinese olive fruit • 2 °C lowered P5CS and OAT activities, but raised PDH activity in Chinese olive fruit. [ABSTRACT FROM AUTHOR]

Energy transport system plays a pivotal role in maintaining cellular energy status. The adenine nucleotide translocator (ANT) family includes ATP/ADP carrier (AAC) and ATP/AMP translocator (ADNT). This research aims to illuminate the role of energy transport in pericarp browning process of postharvest longans. The results elucidated that the ATP content decreased with longan pericarp browning, and was positively correlated with expression levels of DlAAC1 and DlAAC5. Besides, the bongkrekic acid (BKA) treatment, which has a strong energy transport inhibitory property, could down-regulate the expressions of DlANTs , maintain lower energy level and activities of Ca2+-ATPase, Mg2+-ATPase and H+-ATPase in membranes of plasmas, mitochondria and vacuoles, and hasten the browning development of postharvest longan. While the ATP treatment kept higher expression levels of DlANTs , higher energy level and ATPase activities, and reduced the occurrence of longan pericarp browning. These findings suggested that the expression of DlANTs was regulated by energy status, and the inhibition of energy transport could lead to the reduction of energy level, the decreased ATPase activities, the down-regulated expressions of DlANTs , which might cause energy deficiency and thus accelerated pericarp browning of harvested longan fruit. [Display omitted] • The inhibition of energy transport accelerated the browning of longan. • The inhibition of energy transport induced the energy deficiency of longan. • The inhibition of energy transport accelerated the reduction of ATPase activities. • Energy status affected the expression characteristics of DlANTs. • The DlAAC1 and DlAAC5 might play key roles in energy transport of longan. [ABSTRACT FROM AUTHOR]

• Dongbi longan had a lower aril breakdown index and respiration rate than Fuyan longan. • Dongbi longan had lower aril PGI, SDH, CCO, AAO, PPO activities and NAD(H) content. • Dongbi longan had higher aril NADK and G-6-PDH+6-PGDH activities and NADP(H) content. • Lower aril breakdown of Dongbi via reducing EMP, TCA, CCP and raising PPP respiratory. • Higher aril breakdown of Fuyan by raising EMP, TCA, CCP, and reducing PPP respiratory. This study aimed to investigate the difference between 'Fuyan' longan (Dimocarpus longan Lour. cv. Fuyan) fruit and 'Dongbi' longan (Dimocarpus longan Lour. cv. Dongbi) fruit in term of their aril breakdown and respiratory metabolism. As compared to 'Fuyan' longans, the 'Dongbi' longans exhibited lower fruit respiration rate, lower aril breakdown index, higher NADK activity, higher total activities of G-6-PDH and 6-PGDH, higher contents of NADP and NADPH, lower activities of AAO, CCO, PPO, PGI, and SDH, and lower contents of NAD and NADH in aril. These findings suggest that better storability and lower aril breakdown index in 'Dongbi' longans than 'Fuyan' longans might be due to lower activities of respiratory terminal oxidases, and lower respiratory metabolic pathways of EMP-TCA cycle related-enzymes in 'Dongbi' longan aril, which decreased respiratory rate and reduced the consumption of substrates, and subsequently maintained the integrity of the aril of 'Dongbi' longans during storage. [ABSTRACT FROM AUTHOR]

Chilling injury (CI) and browning occurrence are pivotal issues during the cold storage of postharvest Chinese olive fruit. This study evaluates the effects of non-chilling temperature (8 °C) and chilling temperature (2 °C) on CI development, browning occurrence, and respiratory metabolism in postharvest Chinese olives. Compared to storage at 8 °C, storage at 2 °C significantly induced CI, accompanied by higher indices of CI and browning, as well as a higher fruit respiratory rate. Storage at 2 °C increased the activities of phosphohexose isomerase (PGI), succinate dehydrogenase (SDH), ascorbic acid oxidase (AAO), and cytochrome C oxidase (CCO) by 55.1%, 11.1%, 26.4%, and 98.8%, respectively, on day 120. On the other hand, storage at 2 °C reduced the activities of NAD kinase (NADK), 6-phosphogluconate dehydrogenase (6-PGDH) + glucose-6-phosphate dehydrogenase (G-6-PDH) by 95.6% and 6.6%, respectively, on day 120. The contents of nicotinamide adenine dinucleotide (NAD) and its reduced form of NAD (NADH) increased by 10.0% and 22.8%, respectively, in fruit stored at 2 °C on day 120. Conversely, the contents of nicotinamide adenine dinucleotide phosphate (NADP) and its reduced form (NADPH) decreased by 58.3% and 64.4%, respectively, in fruit stored 2 °C on day 120. These findings indicate that CI development and browning occurrence in Chinese olives induced by storage at 2 °C were associated with a higher respiratory rate, increased activities of PGI, SDH, AAO, and CCO, higher contents of NAD(H), reduced activities of 6-PGDH + G-6-PDH, and lower contents of NADP(H). • Chilling injury was found in chilling temperature (2 °C)-stored Chinese olive fruit. • 2 °C-stored fruit showed higher respiration rate than non-chilling temperature (8 °C). • 2 °C-stored fruit displayed higher activities of PGI, SDH, AAO, and CCO than 8 °C. • 2 °C-stored fruit manifested higher contents of NAD and NADH than 8 °C. • 2 °C reduced activities of NADK, 6-PGDH + G-6-PDH, and NADP(H) content than 8 °C. [ABSTRACT FROM AUTHOR]

• Lasiodiplodia theobromae induced disease development of harvested longan fruit. • L. theobromae stimulated fruit softening and displayed lower fruit firmness of longan. • L. theobromae promoted degradation of cell wall polysaccharides in longan pericarp. • L. theobromae enhanced cell wall-disassembling enzymes activities in longan pericarp. • L. theobromae boosted disease development via disassembling cell wall polysaccharides. Cell wall polysaccharides in fruits act a pivotal role in their resistance to fungal invasion. Lasiodiplodia theobromae (Pat.) Griff. & Maubl. is a primary pathogenic fungus causing the spoilage of fresh longan fruit. In this study, the influences of L. theobromae inoculation on the disassembly of cell wall polysaccharides in pericarp of fresh longans and its association with L. theobromae -induced disease and softening development were investigated. In contrast to the control, samples with L. theobromae infection showed more severe disease development, lower firmness, lower amounts of cell wall materials, covalent-soluble pectin, ionic-soluble pectin, cellulose and hemicellulose, whereas higher value of water-soluble pectin, higher activities of cell wall polysaccharide-disassembling enzymes (cellulase, β -galactosidase, polygalacturonase and pectinesterase). These findings revealed that cell wall polysaccharides disassembly induced by enzymatic manipulation was an essential pathway for L. theobromae to infect harvested longans, and thus led to the disease occurrence and fruit softening. [ABSTRACT FROM AUTHOR]

• Exogenous ATP treatment retarded the senescent process of harvested longan fruit. • Exogenous ATP treatment delayed browning development in pericarp of harvested longans. • Exogenous ATP treatment maintained higher levels of energy in harvested longan fruit. • ATP treatment reduced the induced expression of DlAOX1 , DlAOX2 , DlPUMP3 and DlPUMP5. • ATP delayed longan senescence and pericarp browning by reducing energy dissipation. The harvested longan fruit are prone to senescence, leading to a decline in fruit quality like pericarp browning. There are two energy dissipative proteins involving in fruit senescence: alternative oxidase (AOX) and plant uncoupling mitochondrial protein (PUMP). The purpose of this work was to elucidate the influence of adenosine triphosphate (ATP) treatment on energy dissipation system in postharvest longan fruit during senescence. The results showed that the ATP content in postharvest longan fruit exhibited negative correlations with the expressions of DlAOX1 , DlAOX2 , DlPUMP3, and DlPUMP5. Moreover, compared to the control longan fruit, the treatment of exogenous ATP prevented the increases in the expressions of DlAOX1 , DlAOX2 , DlPUMP3, and DlPUMP5 , helped maintain higher contents of ATP, ADP and higher level of energy charge, but lower respiration rate, lower cell membrane permeability, and lower pericarp browning index in postharvest longan fruit. These data indicated that the supply of exogenous ATP could reduce the induction of the expressions of DlAOX1, DlAOX2 , DlPUMP3 and DlPUMP5 , and consequently reduce the energy dissipation and retard the decline of energy level, which lead to the delayed senescence in postharvest longan fruit. [ABSTRACT FROM AUTHOR]

• SA retarded the disease development of harvested longans caused by P. longanae. • SA raised longan disease resistance via regulating energy and respiratory metabolism. • SA maintained a higher level of energy charge in P. longanae- inoculated longans. • SA reduced respiration rate but raised PPP pathway in P. longanae -inoculated longans. • SA raised EMP, TCA cycle and CCP pathways in P. longanae -inoculated longans. This study investigated the effects of salicylic acid (SA) on the disease development, respiration rate, energy status, and respiratory metabolism in Phomopsis longanae Chi-inoculated longans. SA treatment reduced the fruit disease index and respiration rate of P. longanae -inoculated longans as compared to the fruit with mere inoculation. SA treatment suppressed the decline of energy charge, decreased the activities of PGI, SDH and CCO, but boosted the G-6-PDH+6-PGDH and NADK activities. Meanwhile, the NAD and NADH contents were decreased, but NADP and NADPH contents were increased. These findings demonstrated that SA could be used to the inhibit disease development in harvested longans because SA treatment helped maintain a high energy charge level, decreased respiration rate and respiratory pathways like EMP-TCA cycle and CCP, but increased PPP respiratory pathway. This study indicated that the SA treatment was a facile and effective way to retard the disease development of postharvest longans. [ABSTRACT FROM AUTHOR]