Blackhead disease is a major disease affecting Korla fragrant pear during storage; it severely compromises the quality of stored pears and hampers the development of the pear industry. In this study, Pichia caribbica at a concentration of 1 × 108 cells mL−1 significantly inhibited the spread of blackhead disease throughout the entire storage period. A combined study of histone acetylation and transcriptional levels in pears at 120 d, the peak period of disease onset, revealed that the number of H3K27ac differential acetylation peaks was significantly higher in P. caribbica-treated fruits than in the control. The transcription factors PybZIP and Pyzf-HD, along with three key defence genes—PyHHT1, PySMAX1-LIKE 7-like (PySMXL 7-like) and PyCORYNE were all significantly enriched and highly expressed in the treated pear fruits. Transcriptomic analysis and validation revealed that the acetylases PyKAT6A and PyMYST were significantly upregulated in treated fruits. Furthermore, P. caribbica promoted the expression of PyPLCδ, PyPIP5K, and PyDGK, increased the levels of PIP2, IP3, DAG, PA, and Ca²⁺, and activated the phosphoinositide signaling pathway, thereby enhancing the disease resistance of fragrant pear fruits. This study represents the first epigenetic analysis of P. caribbica's role in combating postharvest blackhead disease in Korla fragrant pear. It explores the potential regulatory functions of the phosphatidylinositol signaling pathway, providing a scientific basis for deepening theoretical understanding of postharvest fruit immunity and for developing targeted epigenetic control strategies against postharvest diseases in Korla fragrant pear.
The combined treatment of 1-MCP and sucrose has been shown to delay postharvest senescence in leafy vegetables, but the underlying mechanisms remain unclear. In this study, pakchoi was treated with 1‑MCP, sucrose, or their combination and stored at 20 °C for 7 days. The combined treatment (MST) exhibited the strongest effect in comprehensively delaying leaf yellowing, reducing ROS accumulation, and suppressing the expression of chlorophyll degradation genes. MST also inhibited protease activity and downregulated the autophagy‑related gene BrATG7, while all treatments preserved RuBisCO activity relative to the control, with ST showing the strongest protective effect. Furthermore, MST effectively protected chloroplast ultrastructure. Correlation analysis revealed that BrATG7 expression was significantly associated with quality parameters and chlorophyll degradation. Overexpression of BrATG7 in pakchoi significantly reduced RuBisCO activity. Furthermore, the transcription factor BrNAC29 was shown to bind the BrATG7 promoter. These results suggest that the combined treatment delays senescence by simultaneously alleviating carbon starvation, suppressing ROS accumulation, and inhibiting the transcription factor BrNAC29. This, in turn, downregulates BrATG7, thereby limiting BrATG7-mediated autophagic degradation of chloroplast proteins. This study provides a novel mechanism for postharvest preservation and identifies BrATG7 as a potential molecular target.
Fresh-cut lavender rapidly loses its ornamental quality during cold-chain handling and subsequent vase life because of severe water imbalance, accelerated ethylene production, and oxidative damage. This study investigated whether nitric oxide (NO) fumigation could improve postharvest performance and elucidated the physiological and molecular mechanisms underlying its protective effects. Freshly harvested lavender stems were fumigated with different concentrations of NO before cold storage for 1–3 d, followed by transfer to ambient vase conditions. NO treatment markedly improved fresh-weight retention, water balance, flowering rate, and vase life, with 40 μL L−1 providing the greatest overall benefit. The protective effect remained evident after prolonged cold storage, indicating enhanced resilience during the transition from refrigerated storage to ambient conditions. NO suppressed ethylene biosynthesis by reducing 1-aminocyclopropane-1-carboxylic acid accumulation and inhibiting the activities of the two key ethylene-biosynthetic enzymes. Simultaneously, oxidative stress was alleviated through reduced reactive oxygen species accumulation, lower membrane lipid peroxidation, enhanced antioxidant capacity, and maintenance of cellular redox homeostasis via the ascorbate–glutathione cycle. Transcriptome analysis further revealed stage-dependent transcriptional reprogramming, characterized by the early repression of ethylene biosynthesis and signaling pathways and the subsequent activation of genes associated with antioxidant metabolism and peroxisomal function. Integration of physiological, biochemical, and transcriptomic evidence demonstrated that NO delayed postharvest senescence by coordinating water relations, ethylene metabolism, antioxidant defense, and redox homeostasis. These findings provide mechanistic insight into NO-mediated regulation of postharvest senescence and support NO fumigation as a promising strategy for preserving the commercial quality of fresh-cut lavender during cold-chain distribution.
Under non-cold-chain ambient shelf conditions, flat peach (Prunus persica var. compressa) softens rapidly while developing its characteristic lactone aroma, making it difficult to preserve texture while maintaining flavor formation. Although fatty-acid-derived metabolism is central to lactone biosynthesis, how postharvest lipid remodeling is associated with lactone aroma formation remains unclear. Using 1-MCP to probe ethylene-associated ripening, we conducted concurrent lipidomics and transcriptomics on 1-MCP-treated and control ‘Yulu’ flat peach across a 10-day ambient storage period and integrated these data with previously published flavoromics from the same biological replicates. The lipidome, comprising 280 molecular species, underwent extensive remodeling, including a 2.5-fold increase in total glycerophospholipids, accumulation of lysophospholipids, phosphatidic acid, and ceramides, and a decline in plastidial galactolipids. Within structural phospholipids, low-unsaturation species declined whereas polyunsaturated species accumulated, increasing the membrane lipid unsaturation index by approximately 30%. This remodeling was tightly associated with γ-lactone accumulation: membrane lipid unsaturation index correlated strongly with five major γ-lactones (r = 0.85–0.99), and these correlations remained significant in complementary analyses accounting for ethylene-related covariation, storage day, and treatment. Chain-resolved acyl-pool analysis showed that the PC-bound 18:2 pool declined by 78%, consistent with possible consumption during lactone accumulation, whereas 18:3 accumulated continuously. A co-expression gene module corresponding to a “desaturation–phospholipase–β-oxidation” pathway corroborated this link and was suppressed by 1-MCP. These multi-omics association results suggest that membrane phospholipids may constitute a candidate precursor pool for flat peach lactone aroma and identify candidate targets for preserving flavor formation while managing texture loss during postharvest handling.
Colletotrichum musae, isolated from diseased banana fruits showing typical anthracnose symptoms, is a major pathogen responsible for postharvest rot and related losses in bananas. This study investigated the antifungal effectiveness and potential mechanisms of cinnamon essential oil (CEO) against C. musae. The minimum inhibitory concentration (MIC) was 0.342 μL/mL. CEO disrupted membrane integrity, increased the release of cellular materials, and reduced ergosterol content. CEO treatment was also associated with increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels, reduced mitochondrial enzyme activities, and ATP depletion. In vivo, CEO reduced anthracnose lesion expansion on inoculated banana fruit. These findings indicate that CEO may affect multiple fungal cellular processes and has potential as a green postharvest control strategy for banana anthracnose.
Gibberellic acid (GA₃) and forchlorfenuron (CPPU) are widely used to promote fruit development and expansion. In this study, physiological and transcriptomic analyses were performed to investigate how preharvest GA₃ and CPPU treatments affect postharvest quality in mango fruit. GA₃ and CPPU treatments significantly increased fruit size and single-fruit weight and delayed several aspects of postharvest quality deterioration. During storage, treated fruit maintained higher firmness, showed reduced membrane lipid peroxidation, and exhibited enhanced antioxidant enzyme activities compared with the control. However, different quality parameters responded differently to the treatments, indicating that the effects of GA₃ and CPPU were trait-dependent. GA₃ and CPPU treatments also delayed the decline in endogenous GA₃ and indole-3-acetic acid levels and delayed the peaks in abscisic acid and ethylene accumulation, suggesting delayed activation of ripening-related hormonal signals. Transcriptome analysis revealed stage-dependent transcriptional reprogramming in mango fruit pulp under GA₃ and CPPU treatment. KEGG enrichment analysis indicated that pathways associated with hormone signaling, oxidative stress response, glutathione metabolism, peroxisome, and cell wall- or carbohydrate-related metabolism were involved in the storage response. Further candidate gene analysis, WGCNA, and qRT-PCR validation identified several genes related to oxidative stress response, cell wall remodeling, ABA signaling and metabolism, and transcriptional regulation, including MiCAT1, MiCSD, MiPER73, MiPGs, MiMYB73, MiERF016, MiERF109, MiPYL4, and MiPP2C37. These results suggest that improved mango storability under preharvest GA₃ and CPPU treatments was associated with coordinated changes in antioxidant defense, ABA- and ethylene-related hormonal responses, transcription factor-mediated responses, and cell wall remodeling.
Alternaria alternata is a common contaminant of crops, fruit, and cereals, presenting serious risks to food safety, human health, and resulting in considerable economic losses. Therefore, green, safe, and environmentally friendly antifungal agents are urgently needed to control this pathogen. In this study, the antifungal effects of carvone and a lipopeptide crude extract from Bacillus velezensis JZ against A. alternata were evaluated. Inhibitory activities on mycelial growth and pathogenicity in postharvest strawberries were investigated, along with the underlying mechanisms. In vitro assays revealed that both carvone and the lipopeptide crude extract markedly inhibited mycelial growth. The minimum inhibitory concentration (MIC) of carvone was 0.30 μL/mL, while that of the lipopeptide crude extract was 2%. In vivo experiments showed that both treatments effectively suppressed A. alternata mycelium growth on postharvest strawberry. To elucidate their distinct antifungal mechanisms, transcriptomic analysis was performed, revealing divergent transcriptional patterns. Combined physiological-biochemical and transcriptomic analyses revealed that carvone and lipopeptide crude extract suppressed A. alternata growth by jointly disrupting ergosterol synthesis, cell wall remodeling, DNA repair, ROS homeostasis and mitochondrial metabolism. Carvone triggered more severe damage to cell membranes, DNA and energy metabolism, with differential regulation of ergosterol content, energy metabolism, ion transport and DNA replication-related genes; while the lipopeptide crude extract mainly induced marked cell wall destruction and excessive ROS accumulation, and inhibited cell wall synthesis, CoQ2 and ion transport genes without affecting DNA replication. Both treatments down-regulated Cyp51, DNA repair and CatB genes but up-regulated autophagy-related genes. These findings delineate both divergent and common transcriptional regulatory patterns induced by carvone and the lipopeptide crude extract in A. alternata, providing a theoretical basis for understanding their antifungal mechanisms and supporting the development of novel antifungal agents against this pathogen.
To mitigate the storage intolerance problem of Actinidia arguta, clarify the sources of suitable male pollen. This study investigates the effects of different male pollens on the storage quality of late-maturing A. arguta and establishes a storage evaluation system. The study uses four late-maturing resources and four types of pollen for pollination experiments, through sensory and flavor analysis, the compatible male plants for each resource are selected as SNWS1 ×XZ1, SNWS2 ×XZ1, SNWS3 ×XZ2, and SNWS4 ×XZ1. The fruit from the compatible combinations are stored at 25 °C and 2 °C, and their quality changes are systematically analyzed. Based on correlation analysis, principal component analysis, the CRITIC method, and grey relational analysis, a comprehensive evaluation model for storage quality was established. The results shows that a weighted grey relational model is constructed based on six core indicators: rot rate, relative conductivity, vitamin C, catalase enzyme, chromatic aberration, and flavone. The evaluation indicates that SNWS4 has the best quality in the early storage period, SNWS2 and SNWS3 perform better in the middle and late stages, while SNWS1 is least suitable. This study provides a theoretical basis for the selection of pollination combinations and postharvest storage management of late-maturing A. arguta.
After harvesting, fruits and vegetables (F&Vs) suffer over 30% losses during transportation and distribution due to vigorous internal metabolism and external microbial invasion. Traditional packaging and preservation technologies are limited by high energy consumption, heavy pollution, and single functionality. Metal-organic frameworks (MOFs), with ultra-high specific surface area, adjustable structure, and diverse functions, have become a core direction for novel collaborative preservation and show great potential as carriers for next-generation preservation technologies for F&Vs. This review first analyzed the research overview of MOF-based collaborative preservation via bibliometric analysis, then briefly outlined MOF classification, design principles, synthesis methods, and parameter control. It elaborates on preservation mechanisms in terms of gas environment regulation, antibacterial activity, environmental stress protection, active substance loading and stabilization, intelligent quality detection and response, and synergy with other technologies. Furthermore, it highlighted the application progress in gas regulation, microbial control, preservation packaging optimization, and multifunctional packaging integrating quality monitoring and preservation. Despite advantages of multi-mechanism collaboration, green sustainability, and artificial intelligence adaptability, MOF-based preservation faces challenges including toxicity verification, scaling costs, and lack of standards. In this regard, this review innovatively proposes strategic pathways toward green synthesis, AI-driven material design, and industrial translation. This work offers a foundational reference for advancing MOF-integrated postharvest F&V preservation from laboratory innovation to commercial deployment, contributing to global food security and sustainability objectives.
Fresh-cut lettuce is one of the most commercially important and perishable products in the fresh-cut vegetable industry. Tissue deterioration following processing is driven by a complex interplay of genetic, physiological, and preharvest factors determining both respiration rate and membrane stability. Fifteen accessions of Lactuca sativa were evaluated across 15 independent experiments spanning production environments, leaf developmental stages, storage temperatures, and processing conditions. Nine respirometric parameters were assessed for their capacity to predict electrolyte leakage (electrical conductivity, EC), a measure of membrane deterioration. Across three analytical approaches (Pearson correlation, partial least squares, and random forest), Time Under Hypoxia (TUH) was the strongest predictor of EC, while CO₂ area was the most robust continuous metabolic predictor. A universal critical oxygen threshold of approximately 0.50% O₂ was identified as the anaerobic compensation point, below which both the Gas Stability Index (GSI) and EC diverged sharply from their baselines, independent of cultivar, leaf age, and production environment. Temperature sensitivity (Q10) was similar for O₂ consumption (3.0) and EC (2.9), but EC was disproportionately sensitive to the 2–13 °C shift (Q10 = 4.3 vs. 1.9), underscoring the importance of cold-chain maintenance. A meta-analysis revealed a borderline non-significant correlation between CO₂ area and EC across cultivars (r = 0.489, p = 0.062), with perfect concordance between the favorable qSL4 allele and low deterioration regardless of respiration rate. A 10-day jar assay predicted 37-day MAP performance with high accuracy (r = 0.764, p = 0.0004), validating it as a rapid platform for postharvest screening and breeding.
Wax apple is a typical cold sensitive fruit and prone to chilling injury (CI) during cold storage. This study investigated the effects and mechanisms of cold shock treatment (CST) combined with salicylic acid (SA) treatment in wax apple. Wax apple was treated with CST combined with SA and stored at 5 ℃ for 16 days, followed by a 2-d shelf life simulation at 25 ℃ to assess CI-related performance. By response surface methodology optimization, 20 min CST + 1 mM SA was determined as the best combined treatment, which significantly reduced CI, browning, and maintained nutritional quality. The combined treatment inhibited the decrease in antioxidant enzyme activities and enhanced free radical scavenging capacity, reducing reactive oxygen species (ROS) accumulation and oxidative damage of wax apple. Meanwhile, combined treatment reduced the activities of phospholipase D (PLD), phospholipase C (PLC), and lipase, delayed the decrease in unsaturated fat content, inhibited membrane lipid peroxidation, and maintained the integrity and fluidity of the cell membrane. Moreover, combined treatment inhibited the activities of cell wall-degrading enzymes such as polygalacturonase (PG) and pectin methylesterase (PME), maintained high soluble pectin content, and inhibited the accumulation of hemicellulose and cellulose, thus maintaining the stability of cell wall structure, enhancing cold tolerance and delaying fruit softening. Collectively, CST combined with SA treatment maintained the integrity of the cell membrane and cell wall by regulating related metabolic processes, thereby reducing the postharvest CI of wax apple.
Citrus green mold caused by Penicillium digitatum (P. digitatum) severely limits the postharvest quality and storage life of citrus fruit worldwide. Lignification is a key defense response restricting pathogen invasion, yet miRNA-mediated regulation of this process in citrus remains poorly understood. In this study, Csi-miR20, a novel miRNA identified by small RNA sequencing, was found to enhance postharvest resistance to P. digitatum. CsMT760 was identified as a direct target of Csi-miR20 based on psRNATarget prediction, degradome sequencing, dual-luciferase assays in Nicotiana benthamiana (N. benthamiana), and expression analysis in citrus fruit, which revealed a negative correlation between their expression levels. CsMT760 encoded a previously uncharacterized protein with conserved domains and showed a distant evolutionary relationship to homologs in model plants. Functional assays indicated that CsMT760 acted as a negative regulator of postharvest resistance and partially attenuated the Csi-miR20-mediated reduction in disease incidence and lesion development. Integrated transcriptomic and biochemical analyses indicated that CsMT760 overexpression modulated lignin biosynthesis by regulating lignin-associated pathway genes, related enzyme activities, and lignin accumulation in citrus peel. In conclusion, Csi-miR20 enhanced postharvest resistance to P. digitatum by repressing CsMT760-mediated lignification. This study identified a previously uncharacterized miRNA-CsMT760 regulatory module governing lignification-associated defense in postharvest citrus fruit.
Ozone treatment is widely regarded as an effective postharvest preservation strategy; however, its underlying metabolic regulatory mechanisms in Hami melon (Cucumis melo L.) remain unclear. In this study, integrative metabolomics combined with weighted gene co-expression network analysis (WGCNA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment was employed to investigate ozone-induced metabolic reprogramming during postharvest storage. Differential metabolites were identified using combined multivariate and univariate statistical analyses, including partial least squares discriminant analysis (PLS-DA) and volcano plot analysis, and then integrated with WGCNA-derived hub metabolites to obtain key intersection metabolites. The results showed that ozone treatment significantly reshaped metabolic profiles, with key metabolites mainly associated with carbohydrate metabolism, amino acid metabolism, and transport-related processes, and broadly distributed across multiple co-expression modules, indicating strong network-level metabolic coordination. KEGG pathway enrichment analysis of the intersection metabolites revealed enrichment in carbohydrate metabolism, amino acid metabolism, and ABC transporter-related processes, suggesting coordinated regulation of primary metabolism and transport systems under ozone treatment. Integration of metabolite profiling and network analysis demonstrated that ozone induces a network-coupled metabolic system that integrates carbon and nitrogen metabolism into a unified regulatory architecture rather than acting through isolated pathway responses. Overall, this study reveals a systems-level metabolic response to ozone treatment in Hami melon. Coordinated metabolic reprogramming was associated with enhanced antioxidant capacity and physiological stability, leading to delayed senescence and prolonged postharvest shelf life.
During the withering process of white tea, the degradation of astringent flavonol glycosides (FGs) plays a vital role in enhancing quality. However, the molecular mechanism underlying this process remains unclear. This study aimed to clarify the molecular mechanism and physiological significance of the degradation of nine key astringent FGs during white tea withering. Two key genes, CsGH3B (β-glucosidase) and CsPPO1 (polyphenol oxidase), were identified using FGs quantification, transcriptomics, and weighted gene co-expression network analysis (WGCNA). Prokaryotic expression, protein purification, and in vitro enzyme activity assays confirmed that recombinant CsGH3B hydrolyzed all nine FGs, whereas recombinant CsPPO1 did not. Transient inhibition of CsGH3B expression in tea leaves significantly increased the contents of the nine FGs (P < 0.05). Overexpression of CsGH3B in Nicotiana benthamiana promoted the hydrolysis of FGs, further confirming its in vivo function. Molecular docking revealed that CsGH3B binds to FGs through hydrogen bonds and hydrophobic interactions. Our results indicate that dehydration stress during white tea withering induces the accumulation of reactive oxygen species, which may be associated with the upregulation of CsGH3B, catalyzing the hydrolysis of FGs to generate potent antioxidant flavonol aglycones (quercetin and kaempferol) that potentially contribute to oxidative stress alleviation. This process also reduces the bitterness and astringency of white tea products by lowering FG content, thereby improving taste quality. Together, these findings provide a molecular-level insight into the concept that "adversity yields fine tea" and offer a potential theoretical basis for postharvest flavor regulation and quality improvement of white tea.
Scoparone is a stress-induced phytoalexin that accumulates in citrus fruit; however, the mechanism underlying its biosynthesis remains unclear. In this study, a coumarin synthase gene, CsCOSY, was identified and investigated for its putative role in scoparone biosynthesis and resistance against P. italicum through expression analysis, molecular docking, and transient expression assays. The results showed that the expression of CsCOSY was markedly induced by wounding or inoculation with the virulence-attenuated ΔPiCreA mutant of P. italicum, and this induction was positively correlated with scoparone accumulation. Furthermore, molecular docking predicted a structurally favorable binding of CsCOSY to both 6-hydroxyferuloyl-CoA and 2,4-dihydroxycinnamoyl-CoA. Moreover, transient overexpression or silencing of CsCOSY altered scoparone accumulation and was associated with corresponding changes in the expression of upstream phenylpropanoid pathway genes in citrus fruit. Accordingly, transient overexpression of CsCOSY significantly reduced lesion diameter caused by blue mold, whereas silencing CsCOSY enhanced lesion development. Together, these findings indicate that CsCOSY contributes to stress-induced scoparone biosynthesis and postharvest resistance against P. italicum in citrus fruit, offering new insights into the metabolic regulation of phytoalexin-mediated defense in citrus.
Pear fruit hard-end disorder is a physiological disorder characterized by excessive lignin accumulation at the calyx end, which seriously affects postharvest texture quality and marketability due to excessive lignin accumulation at the calyx end. Although lignification has been recognized as the major cause of hard-end formation, the upstream hormonal signaling mechanisms remain largely unclear. This study demonstrates that the endogenous abscisic acid (ABA) levels were elevated in the calyx-end flesh of hard-end fruits. Further analysis reveals that ABA treatment notably raised the incidence of hard-end disorder, while using an ABA biosynthesis inhibitor reduced its occurrence. In this study, we identified an ABA-responsive regulatory cascade in which PpMYB1R1 directly activates PpNAC187, thereby promoting expression of the lignin biosynthetic gene PpCCR. Functional analysis showed silencing either PpNAC187 or PpMYB1R1 reduced ABA-induced lignin accumulation in pear fruit. Stable transgenic analyses further confirmed the positive regulatory role of PpMYB1R1 in pear lignification. Notably, PpMYB1R1 represents a non-canonical 1R-type MYB transcription factor lacking the conserved EAR repression motif, revealing a previously unrecognized mechanism underlying ABA-mediated lignification during fruit physiological disorder. Collectively, our findings uncover a novel ABA-dependent transcriptional module regulating lignin accumulation during pear hard-end disorder and provide new insights into the molecular basis of fruit physiological disorder in pear.
Rapid fruit softening, weight loss and pathogen infection induced by mechanical wound are major factors causing postharvest losses in muskmelon. As a secondary messenger, calcium can enhance plant resistance to various stresses. However, it remains unknown whether exogenous calcium affects wound healing and softening in wounded muskmelon fruit. In this study, calcium chloride (CaCl2) and ethylene glycol tetraacetic acid (EGTA) were applied to wounded muskmelon fruit, respectively. After that, all fruit were stored in darkness at 20 ± 1 °C and 85% relative humidity. The results showed that CaCl2 treatment activated phenylpropanoid metabolism related enzymes at the wound sites and promoted the accumulation of phenolic acid monomers and lignin precursors, thereby accelerating the deposition of suberin polyphenolic periderm (SPP) and lignin during wound healing. Meanwhile, CaCl2 treatment suppressed respiration rate and ethylene production, and reduced the content of total soluble solids during storage. By inhibiting the activities of cell wall-degrading enzymes, it further inhibited the degradation of cell wall components such as pectin, cellulose and hemicellulose, consequently delaying fruit softening. In contrast, EGTA treatment inhibited the deposition of SPP and lignin at the wound sites, and promoted wound ethylene production and respiration rate, and accelerated the degradation of cell wall components, thus accelerating fruit softening. In conclusion, exogenous CaCl2 treatment can effectively reduce quality deterioration during storage by accelerating the formation of wound healing structures and delaying softening in wounded muskmelon fruit. These findings offer potential application value for reducing postharvest losses of muskmelon caused by mechanical wound.
This study evaluated the efficacy of various bioactive extracts (BEs) as sustainable alternatives to synthetic fungicides for controlling postharvest peduncular rot caused by Fusarium falciforme and F. sulawesiense in ‘Yellow’ melon (Cucumis melo L.). Under in vitro conditions, all tested extracts - eucalyptus extract (EUE), brown propolis extract (BPE), red propolis extract (RPE), green propolis extract (GPE), and pyroligneous extract (PYE) - demonstrated concentration-dependent inhibition of fungal growth, with the highest efficacy observed at 8% (v/v) concentration. Notably, PYE and RPE emerged as the most potent inhibitors, exhibiting statistically significant differences compared to the other treatments. This superior activity was likely due attributed to the high concentrations of acetic acid, phenols, and isoflavonoids, which are known to disrupt fungal membrane integrity and mitochondrial function. In in vivo assays, BEs application significantly reduced postharvest peduncular rot severity did not compromising the physicochemical quality of the fruits. Critical parameters, such as total soluble solids (TSS) and pH, remained stable across treatments, indicating that these bio-based solutions can successfully replace conventional fungicides (e.g., fludioxonil) without impacting the marketability of melon fruits. Biochemical analysis revealed that the extracts significantly increased the activities of oxidative defense enzymes, including catalase (CAT) and peroxidase (POX), alongside key phenylpropanoid pathway enzymes, namely phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). This induction of the host’s defense system, coupled with a concomitant reduction in hydrogen peroxide (H2O2) levels, suggests that BEs mitigate disease by promoting reactive oxygen species (ROS) detoxification and tissue lignification in postharvest melon fruit. Based on in vitro and in vivo data, bioactive extracts, particularly RPE and GPE, are highly effective at suppressing Fusarium species while preserving essential postharvest fruit quality. These findings offer a promising, eco-friendly strategy for managing postharvest decay in melon production systems destined for premium international markets.
Red banana (Musa spp. Red subgroup AAA) is a distinctive cultivar valued for its red peel pigmentation and high nutritional quality. However, the mechanisms by which storage temperature regulates postharvest ripening of red banana peel remain poorly understood. This study investigated the effects of three storage temperatures (13 °C, 22 °C, and 30 °C) on peel ripening using integrated phenotypic, physiological, transcriptomic, and metabolomic analyses. 30 °C accelerated peel ripening by stimulating ethylene biosynthesis, promoting starch degradation and cell wall disassembly, and enhancing chlorophyll breakdown. In contrast, 13 °C delayed ripening through selective activation of flavonoid, lignin, and carotenoid biosynthetic pathways while suppressing ethylene-related softening processes. Transcriptome analysis identified temperature-responsive regulatory genes and transcription factors, including those associated with ethylene signaling, starch metabolism, cell wall modification, and secondary metabolism. These findings elucidate the molecular mechanisms underlying temperature-mediated ripening regulation in red banana peel and provide a theoretical basis for optimizing postharvest storage strategies.
Green mold, caused by Penicillium digitatum, remains one of the most destructive postharvest citrus diseases. In this study, indigenous endophytic strain, Bacillus subtilis L1–21 was applied to citrus fruits and associated culturable epiphytic and endophytic microorganism were subsequently isolated and screened for antagonistic activity against P. digitatum. A total of 21 bacterial and 7 fungal isolates were recovered, among which 6 bacterial strains showed in vitro antagonism. Three highly effective isolates (strains 2, 14, and 16) were selected and combined with endophyte L1–21 to construct three Bacillus-based synergistic consortia (SynCom-1, 2, 3). In dual-culture assays, single strains inhibited P. digitatum by 53–66%, whereas SynCom treatments achieved up to 90% inhibition. In vivo assays further showed that SynCom-3 provided > 95% disease suppression compared with untreated controls. Defense-related activities (peroxidase; POD, chitinase, lipase, phenylalanine ammonia-lyase; PAL and protease) and fruit acids (organic acids and sugars) were quantified, indicating that endophyte treatments were associated with treatment-dependent modulation of host physiological and defense responses during pathogen challenge. In addition, microbiome profiling showed that endophyte L1–21 application caused shifts in citrus-associated beneficial microbiome composition and differential enrichment of multiple bacterial taxa (Bacillus, Levilactobacillus, Leuconostoc) and suppressed opportunistic genera such as Kozakia and Shimwellia. Overall, these results support the development of indigenous Bacillus-based SynCom as a promising biocontrol candidate against citrus green mold and provide an ecological context for endophyte L1–21-associated microbiome changes.
