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[Display omitted] Penicillium expansum is a harmful plant fungal pathogen that causes blue mold disease and produces mycotoxin patulin, leading to huge economic losses and food safety hazard. Set1 associated complex Set1/COMPASS deposits the methylation at lysine 4 of histone H3, which is associated with gene expression in diverse biological processes of fungi. However, the function and underlying mechanisms of Set1/COMPASS are poorly defined in P. expansum. The study aimed to identify Set1/COMPASS and investigate its regulation mechanisms on growth, pathogenicity, and patulin biosynthesis of P. expansum. Analyses of phylogenetic relationship, conserved structural domain, and gene deletion were used to identify components of Set1/COMPASS. Phenotype analysis and stress tolerance test of gene deletion mutants were conducted to analyze the function of these components. Yeast two-hybrid, Co-Immunoprecipitation (Co-IP), and point mutation were performed to verify the protein interaction. Western blot was conducted for detection of H3K4 methylation levels. P. expansum owns six components of Set1/COMPASS besides PeSet1. Absence of each component resulted in reduction of H3K4 methylation levels and impaired growth, pathogenicity, and patulin biosynthesis, as well as altered stress responses of P. expansum. One component PeBre2p was found to interact with the conserved global regulator PeVelB (Ve lvet L ike protein B) at Asp294 of PeBre2p. This interaction affected fungal growth and utilization of fructose, lactose, glycine, and proline in P. expansum. This study revealed the important roles of Set1/COMPASS in P. expansum and clarified for the first time the combined regulation of PeBre2p and PeVelB in fungal growth and nutrition utilization. These results will provide potential targets for the control of blue mold disease. [ABSTRACT FROM AUTHOR]

Patulin is a mycotoxin produced by several species of Penicillium sp., Aspergillus sp., and Byssochlamys sp. on apples and pears. Most studies have been focused on Penicillium expansum , a common postharvest pathogen, but little is known about the characteristics of Penicillium paneum. In the present study, we evaluated the effects of temperature, pH, and relative humidity (RH) on the growth of P. paneum OM1, which was isolated from pears, and its patulin production. The fungal strain showed the highest growth rate at 25 °C and pH 4.5 on pear puree agar medium (PPAM) under 97 % RH, while it produced the highest amount of patulin at 20 °C and pH 4.5 on PPAM under 97 % RH. Moreover, RT-qPCR analysis of relative expression levels of 5 patulin biosynthetic genes (patA , patE , patK , patL, and patN) in P. paneum OM1 exhibited that the expression of the 4 patulin biosynthetic genes except patL was up-regulated in YES medium (patulin conducive), while it was not in PDB medium (patulin non-conducive). Our data demonstrated that the 3 major environmental parameters had significant impact on the growth of P. paneum OM1 and its patulin production. These results could be exploited to prevent patulin contamination by P. paneum OM1 during pear storage • The highest growth of P. paneum OM1 at 25 °C and pH 4.5 under 97 % relative humidity. • The highest patulin production by the fungus at 20 °C and pH 4.5 under 97 % relative humidity. • The expression of patA , patE , patK , and patN was up-regulated in YES medium. • The expression of patA , patE , patK , and patN was not up-regulated in PDB medium. • The expression of patL remained constantly in both YES and PDB media. [ABSTRACT FROM AUTHOR]

Blue mold decay caused by Penicillium expansum is one of the most important postharvest diseases of grapes, leading to considerable economic losses. Regarding the increasing demand for pesticide-free foods, this study aimed to find potential yeast strains for biological control of blue mold on table grapes. A total of 50 yeast strains were screened for antagonistic activity against P. expansum using the dual culture method and six strains significantly inhibited the fungal growth. All six yeast strains (Coniochaeta euphorbiae , Auerobasidium mangrovei , Tranzscheliella sp., Geotrichum candidum , Basidioascus persicus , and Cryptococcus podzolicus) reduced the fungal growth (29.6–85.0%) and the decay degree of wounded grape berries inoculated with P. expansum while G. candidum was found to be the most efficient biocontrol agent. On the basis of antagonistic activity, the strains were further characterized by in vitro assays involving inhibition of conidial germination, production of volatile compounds, iron competition, production of hydrolytic enzymes, biofilm-forming capacity, and exhibited three or more putative mechanisms. To our knowledge, the yeasts are reported for the first time as potential biocontrol agents against the blue mold of grapes but more study is required to evaluate their efficiency related to field application. [Display omitted] • Fifty yeast strains were screened for antagonistic activity against P. expansum in vitro. • Six novel yeast strains with biocontrol activity against P. expansum on grapes were introduced. • Treatment of grapes with G. candidum resulted in an 85% reduction in P. expansum growth. • G. candidum showed higher biofilm-forming capacity in vitro than the other strains. [ABSTRACT FROM AUTHOR]

Penicillium expansum (P. expansum), a widespread fungal pathogen, causes serious economic loss and public health concerns. The aim of this research is to investigate the antifungal effect of Kluyveromyces marxianus YG-4 (K. marxianus YG-4) against P. expansum and possible mechanism. The results showed that competition for nutrients and space, as well as the release of volatile organic compounds (VOCs), are the antifungal mechanisms. Citronellol may be the antifungal component of K. marxianus YG-4 VOCs based on GC–MS analysis. Further experiments had shown that citronellol inhibited the growth of P. expansum LPH9 by damaging the cell structure, disrupting the redox system, reducing antioxidant enzyme activity, and causing oxidative damage. K. marxianus YG-4, K. marxianus YG-4 VOCs and citronellol can effectively inhibit the spore germination of P. expansum on apples. The above results indicated that K. marxianus YG-4 had strong biocontrol activity and can be used as an excellent candidate strain for fruit preservation. • K. marxianus YG-4 have biocontrol efficacy against P. expansum. • Antibacterial mechanism includes competition in nutrient space and release of VOGs. • Citronellol may be the antibacterial component of K. marxianus YG-4 VOCs. • K. marxianus YG-4 can inhibit P. expansum on apples after 15 days. [ABSTRACT FROM AUTHOR]

• GRAS salts were evaluated in Kinnow mandarin against post-harvest losses caused by penicillium digitatum sacc. • Seven yeast isolates, nine local botanicals and six GRAS salts were tested. • GRAS salts exerted a substantial enhanced nutrient composition and fruit quality. • The study demonstrated multifaceted approach as a viable alternative to synthetic fungicides. Green mold caused by Penicillium digitatum Sacc. is a serious disease of Kinnow mandarin fruits, causing up to 90 per cent fruit rot. The use of chemical fungicides has raised concerns about residual toxicity in edible fruits. To find effective alternatives to chemical fungicides, yeasts, plant leaf extracts, and GRAS salts were investigated to determine post-harvest losses. Seven yeast isolates from different sources, nine locally available plant leaf extracts, and six GRAS salts were tested for resistance against P. digitatum under in vitro conditions. S accharomyces cerevisiae (yeast) isolates, namely, R, BK 6, and BK 4, inhibited the pathogen hyphal growth by 66.66, 53.5 and 48.14 per cent, respectively. Aqueous plant extracts of Roylea cinerea (D. Don) Baill (Ash Roylea, 84.81 %), Murraya koenigii (L.) Sprengel (Curry Leaves, 78.70 %) and Mentha piperita L. (Mint, 76.47 %) were found to be effective in inhibiting the mycelial growth of the pathogen. Among the GRAS salts, salicylic acid (0.25 %), sodium bicarbonate (0.50 %) and potassium sorbate (0.75 %) completely inhibited the mycelial growth of the pathogen. The yeast, plant leaf extract (10 %) and GRAS salt (0.25 %) found to be effective under in vitro conditions were further investigated under in vivo conditions as fruit protectants to determine their effectiveness against Dactylopius digitatus to examine the target damaged areas on the fruit surface and also as fruit pastes. In fruits treated with S. cerevisiae isolate BK 6, Ashy Roylea, and salicylic acid at the affected lesion sites, the incidence was reduced by 50, 33.3, and 66.7 per cent, respectively. Similarly, fruit dip containing broth of S. cerevisiae isolate BK 6, Ashy Roylea aqueous extract, and salicylic acid reduced disease severity by 63.3, 33.3 and 78 per cent, respectively. The study found that yeast isolates and GRAS salts had a significant impact on the nutritional composition of the fruit, thereby improving the quality of Kinnow fruits. The results obtained in this study using various biological and chemical agents demonstrate the potential of a multifaceted approach as a viable alternative to synthetic fungicides. It is concluded that application of GRAS salts, botanicals and yeasts can be a promising integrated approach to manage postharvest diseases in the Citrus industry, ensuring better fruit quality and promoting environmentally friendly practices through synergistic effects, increasing the overall effectiveness of controlling postharvest diseases. [ABSTRACT FROM AUTHOR]

Blue mold disease, caused by Penicillium expansum , is the most devastating post-harvest fungal disease affecting apples. During the fungal infection, there is a significant interaction between the pathogen and the apple, leading to the production of important metabolites and the activation of related metabolic processes. As one of the metabolites, pectin lyase is an important pectin-modifying enzyme that regulates the elasticity and permeability of cell wall and plays a key role in plant disease resistance and fruit softening. In this study, a pectin lyase protein MdPL was identified, which has the function of regulating cell wall permeability. It is up-regulated in the process of apple defense against P. expansum infection, and may have a key defense function. Protein bioinformatics analysis showed that MdPL belonged to the PL1 family, and subcellular localization was predicted to be located in the nucleus. The protein expression of P. expansum at different stages of infection was analyzed by RT-qPCR. The results of subcellular localization of Agrobacterium transformation showed that MdPL was localized in the nucleus, which was consistent with the results of bioinformatics analysis. The Y2H system explored the proteins interacting with apple proteins during P. expansum infection. The results showed that apple bait protein had no self-activation and no toxic effect on Y2H cells. The interacting protein MdPL-PeXR was screened from 10 pairs of candidates interacting protein pairs. HDOCK was used to analyze the interaction protein of MdPL, the results showed that the docking score was −225.61 and the confidence score was 0.8194, which verified the results of the Y2H test. This study provides ideas and references for further exploring the interaction mechanism between apple and P. expansum , and is of great significance for the study of plant-pathogen interaction. • The physicochemical properties and structure of MdPL were analyzed by bioinformatics. • Y2H was used to screen the proteins interacting with MdPL in P. expansum infection. • Bioinformatics and confidence analysis of P. expansum and MdPL interacting proteins. [ABSTRACT FROM AUTHOR]

Phlorotannins (PTs) are compounds with notable bioactive characteristics obtained from brown algae. In the present study, PTs from the Sargassum ilicifolium seaweed were extracted, characterized, and evaluated for their anti-polyphenol oxidase (PPO) enzyme activity and in vitro antifungal activity against spoilage molds (Aspergillus flavus and Penicillium expansum) of button mushrooms. Then, PTs were used as a coating in combination with alginate (AL) to improve the shelf life of Agaricus bisporus mushrooms under storage conditions. HPLC analysis identified phloroglucinol as the predominant component in the PT extract (18.1 %), which demonstrated an 86 ± 1.02 % radical scavenging activity in the DPPH test. The PPO enzyme activity significantly decreased from 320.34 ± 2.1 units to 34.4 ± 1.4 units in the presence of 1.5 mL of PT extract. The PT extract's antifungal properties were observed through well diffusion assays, mycelial growth inhibition, and scanning electron microscopy on treated spoilage mold colonies. Better preservation of the physicochemical properties of mushrooms coated with AL + PT was confirmed through various tests, including assessments of weight loss, browning, malondialdehyde levels, total phenol content, and vitamin C content. Additionally, sensorial tests and evaluations of visual and microstructure changes during storage at 4 °C confirmed the enhanced preservation after treatment. Findings indicated that in addition to the antifungal properties of S. ilicifolium -derived PT, which can act as a natural antifungal, this substance, when used in combination with AL coating, can increase the shelf life of A. bisporus mushrooms 12 d of storage at 4 °C. [Display omitted] • PTs from Sargassum ilicifolium inhibit polyphenol oxidase enzyme of mushroom. • PTs completely inhibited the mycelial growth of spoilage fungi. • Mushrooms coated with AL + PT had the best visual and microstructural preservation. • AL + PT coating maintained mushroom properties during storage at 4 °C. [ABSTRACT FROM AUTHOR]

Penicillium expansum causes postharvest disease, fruit loss and patulin (PAT) accumulation in a broad host range and is responsible for considerable health risks and economic losses. In this study, the dynamic volatile organic compounds (VOCs), fungal growth, and PAT accumulation were investigated in apple, pear, citrus and tomato. These indicators revealed the response specificity of fruit to P. expansum attack. PAT content ranged from 2.54 mg/kg to 4.48 mg/kg, while the highest accumulation was detected in citrus. A total of 247 VOCs were identified using GC-IMS and HS-SPME-GC/MS, esters were the most abundant components, followed by alcohols, aldehydes, and ketones. OPLS-DA analysis revealed that the different infection stages were classified successfully. Furthermore, 21, 23, 19, 34 VOCs from each fruit showed significant correlations with PAT accumulation, respectively. Isovaleric acid and 1-hexanol were identified as potential biomarkers in all the fruit. Taken together, P. expansum inoculation caused decay and PAT accumulation in fruit under suitable conditions, leading to a change in VOCs during storage and release of specific volatiles. The present work lays the foundations for studying the interaction mechanism between P. expansum and host, as well as early detection of P. expansum infection and PAT accumulation in postharvest fruit. • P. expansum caused distinct infections and produced patulin in different fruit. • The VOCs profiles were investigated dynamically by GC-IMS and HS-SPME-GC/MS. • OPLS-DA and VIP values were used to classify the infection stages and key VOCs. • Isovaleric acid and 1-hexanol were significantly correlated with PAT in fruit. [ABSTRACT FROM AUTHOR]

The synergistic biocontrol effects of Cryptococcus laurentii cultured with carboxymethyl cellulose (CMC) were studied to control Penicillium italicum in postharvest grapefruit. The results showed that C. laurentii was cultured in 0.5 % (w/v) CMC (CMC- C. laurentii) significantly inhibited elongation of germ tubes, decreased germination of conidia in P. italicum , and reduced disease in grapefruit. Besides, CMC significantly increased ATP synthase and population proliferation of C. laurentii. Moreover, metabolomics analysis revealed 24 significantly differentially metabolites in CMC -C. laurentii including the citrate cycle, metabolism of glyoxylic acid, dicarboxylic acid, phenylalanine, tyrosine, and tryptophan and amino acid biosynthesis. These results demonstrate that CMC could significantly enhance the ATP synthase by promoting the citrate cycle, providing energy for strain growth, and thereby increasing the biocontrol effectiveness of C. laurentii. Furthermore, adding CMC enhanced the activities of strain extracellular hydrolases and antioxidases, which increased the resistance to stress, thus improving the antagonistic effect of C. laurentii. • 0.5 % CMC-induced promote the cells growth and ATP synthase activity of C. laurentii. • The synergistic antibacterial effect in blue mould by CMC-C. laurentii in vivo and in vitro. • CMC regulated 8 metabolic pathways and promoted accumulation of TCA cycle intermediates of yeast. • CMC increased the activities of GLU, CHI, GR, CAT, and decreased MDA content of C. laurentii. [ABSTRACT FROM AUTHOR]

Green mould (caused by Penicillium digitatum) is the largest contributor to loss due to postharvest decay of citrus fruit. Imazalil (IMZ) in the IMZ sulphate formulation is the most important fungicide in green mould management in citrus packhouses. Studies have highlighted the importance of pH and temperature of IMZ sulphate solutions, as well as the exposure time of fruit to the solution, but were focussed on dip application as this was the most common IMZ application method. The heated flooder (in-line drench or cascade) has widely replaced the use of a dip or bath for IMZ application in citrus packhouses globally; however, studies on its optimal use and efficacy were needed. Variables that were studied included the effects of pH (3, 4, 5 and 6), the temperature of the solution (45, 55 and 65 °C at pH 6), and concentration (250 or 500 mg L−1) in a time of 8 s. Imazalil residue loading models were developed for the effects of pH and temperature. Imazalil residue levels loaded on Satsuma mandarin, lemon, navel and Valencia orange fruit increased as pH, temperature range and concentration were increased, and were generally in the range between 0.4 and 3.0 mg kg−1. The South African Maximum Residue Limit (MRL) of 5.0 mg kg−1 was often exceeded at a pH of 6 at temperatures of 55 and 65 °C. At residue levels below the MRL, IMZ application using the heated flooder offered excellent curative action on 24-hour-old infections, excellent protective control, as well as sporulation inhibition. Sporulation inhibition of P. digitatum from green mould lesions was modelled on residue levels, and 90 % inhibition was obtained at residue levels of 1.84–2.47 mg kg−1. • Flooder applying imazalil sulphate offers excellent green mould control. • Imazalil residue increased with increasing pH at 45°C. • Imazalil residue increased with increasing temperature at pH 6. • 90 % P. digitatum sporulation inhibition with ∼ 2 mg.kg−1 imazalil residue. [ABSTRACT FROM AUTHOR]

The aim of this work is the application of pectin coatings containing Cryptococcus laurentii as a method of biocontrol of Penicillium expansum for postharvest protection of apples. For this purpose, the yeast was incorporated into a pectin matrix, and its viability and biocontrol activity in vitro and in vivo against P. expansum was evaluated over time. In addition, the influence of the sterilization process on coating thickness was studied. Results showed that pectin coating with C. laurentii enhanced mycelial growth inhibition in vitro studies, while no significant differences were observed in disease incidence and severity reduction in vivo studies. The sterilization process reduced the viscosity of the pectin solution, resulting in coating thicknesses ranging from 0.5 to 1 μm. As a general evaluation, in vitro and in vivo , biocontrol assays were useful in demonstrating better postharvest protection of the yeast at 7 °C concerning 25 °C. [Display omitted] • Pectin coatings maintain Cryptococcus laurentii viability over 8 weeks. • Penicillium expansum is one of the most damaging postharvest fungi for apples. • In vitro assays revealed mycelial growth inhibition of up to 80 %. • In vivo assays showed 45 % of severity reduction and 27 % disease incidence at 7 °C. • Temperature is a determinant in the efficacy of yeast against blue mold. [ABSTRACT FROM AUTHOR]

A critical transcription factor, PacC, modulates the expression of fungal pH signaling. Although PacC-mediated environmental pH has been reported to regulate the growth and pathogenicity of postharvest pathogens, the involvement of PacC in sucrose metabolism, sugar transport, and the pentose phosphate pathway (PPP) in different zones of decayed fruit remains unclear. Our work showed that the inoculation with a PePacC deletion strain of Penicillium expansum (Δ PePacC) accelerated sucrose catabolism and glucose and fructose accumulation in different zones of apple fruit. This was attributed to an increase in sucrose metabolism enzyme activities and up-regulation of the sugar transporter protein-related gene expression. Moreover, Δ PePacC inoculation increased the PPP-related enzyme activities and the levels of nicotinamide adenine dinucleotide phosphate (NADPH) and NADP+. In conclusion, PacC modulates sucrose metabolism, sugar transport, and the PPP in apple fruit by mediating dynamic changes in environmental pH, thereby enhancing fruit disease resistance. • PePacC modulated the sucrose catabolism in fruit colonized by P. expansum. • PePacC regulated the sugar transport in fruit colonized by P. expansum. • PePacC mediated PPP-induced resistance response in fruit colonized by P. expansum. [ABSTRACT FROM AUTHOR]

The application of essential oils has been shown to be an effective and sustainable alternative against the multiplication of spoilage and pathogenic microorganisms in food. The aim of this work was to study the antimicrobial activity effect of Cerrado Rosemary (Baccharis dracunculifolia DC.), Pepper Rosemary (Lippia sidoides Cham.), Mandarin (Citrus nobilis Lour.), Mexican Lime (Citrus aurantifolia Swingle) essential oils, and the thymol and R-limonene compounds against strains of Penicillium expansum , Pichia kudriavzevii , Salmonella Thypimurium and Staphylococcus aureus. The essential oils were characterized in terms of their chemical composition, the Minimum Inhibitory Concentration, and Minimum Bactericidal and Fungicidal Concentration; using the microdilution method in 96-well plates. In addition, effects from mixtures of the essential oils, and the isolated compounds in sub-inhibitory concentrations were performed. The Pepper Rosemary essential oil and thymol, separately, showed the lowest Minimum Inhibitory Concentration values against all the microorganisms evaluated, with the lowest ranging from 0.03 to 1.25 mg. mL−1 for P. expansum and 0.31–1.25 mg. mL−1 for S. Thypimurium. Mandarin and Mexican lime, have an enhanced antimicrobial effect when used in mixture. The R-limonene compound showed a synergistic additive effect when combined with the essential oils, against S. aureus strains only. The application of thymol and Lippia was able to reduce growth by 3 log10 for S. aureus and S. Typhimurium in 24 h. Therefore, the Pepper Rosemary essential oil, applied freely or in combination with the thymol compound, has greater potential for use as an antifungal and bactericidal agent, against the microorganisms evaluated. [Display omitted] • Lippia sidoides showed the greatest antimicrobial activity among the essential oils. • Thymol showed the greatest antimicrobial activity among the compounds evaluated. • S. aureus strains showed greater sensitivity to R-limonene. • Lippia sidoid es oil and thymol showed great potential for mycelial growth for P. expansum and P. kudriavzevii. [ABSTRACT FROM AUTHOR]

Yeast-derived cell wall polysaccharides possess numerous biological activities, but their application in postharvest preservation is rarely reported. The aim of this research was to investigate the effects of Kluyveromyces marxianus soluble cell wall polysaccharide (SCWP) on preventing the infection of Penicillium expansum in pear fruit. The results showed that K. marxianus SCWP treatment could significantly improve the resistance of pear fruit to P. expansum , with respect to Saccharomyces cerevisiae -derived SCWP. Composition of both SCWPs was mannan with the main chains consisting of a → 6)-α-D-Manp-(1 → unit and the branch structure formed by → 2)-α-D-Manp-(1 except that K. marxianus SCWP took on a shorter side chain and a rougher surface than S. cerevisiae SCWP. In addition, mechanisms of K. marxianus SCWP on stimulating resistance response were associated with the apparent oxidative burst, increased gene expression and enzyme activity of antioxidant and defense systems in pear fruit. Our findings suggest that K. marxianus SCWP can be used as an innovative and promising candidate for preventing postharvest fungal decay and extending fruit shelf life. • Component of yeast-derived soluble cell wall polysaccharide (SCWP) was mannan. • K. marxianus SCWP showed a better effect on postharvest control than S. cerevisiae SCWP. • Structure and surface morphology of SCWP affect fruit resistance response. • Defense-related enzyme activities were enhanced in pear treated with K. marxianus SCWP. • K. marxianus SCWP stimulates a positive response in oxidative stress system of pear. [ABSTRACT FROM AUTHOR]

Penicillium expansum causes blue mold in fruit, leading to the accumulation of patulin, a harmful toxin. Current detection methods for patulin are costly and complex, highlighting the need for a simplified approach. This study investigates the impact of P. expansum on 'Golden Delicious' and 'Fuji' apples, focusing on significant changes in lesion characteristics and fruit properties. Correlation analysis revealed strong positive associations between patulin content and lesion diameter, lesion depth, and fruit weight loss, while negative correlations were observed with apple firmness and flesh firmness. Of the four machine learning models used - Back Propagation Neural Network (BPNN), Random Forest (RF), Extreme Gradient Boosting (XGBoost) and Gradient Boosting Regression Tree (GBRT) - all showed good predictive performance without overfitting the data. BPNN outperformed the others in accurately predicting patulin accumulation (Golden Delicious: RMSE=0.72, MAE=0.217, R²=0.982; Fuji: RMSE=0.289, MAE=0.08, R²=0.994). Key features influencing patulin accumulation, identified using SHapley Additive exPlanation (SHAP) measures, included lesion diameter, lesion depth, and fruit weight loss. This research highlights the potential of machine learning to predict patulin accumulation based on these critical factors, providing a simplified detection method for postharvest fruit quality management. • The BPNN model excels at accurately predicting patulin levels in apples. • SHAP measures identify key characteristics that influence patulin accumulation. • Simplified patulin detection using lesion characteristics and fruit characteristics. [ABSTRACT FROM AUTHOR]

Antifungal proteins (AFPs) are promising antimicrobial compounds that represent a feasible alternative to fungicides. Penicillium expansum encodes three phylogenetically distinct AFPs (PeAfpA, PeAfpB and PeAfpC) which show different antifungal profiles and fruit protection effects. To gain knowledge about the structural determinants governing their activity, we solved the crystal structure of PeAfpB and rationally designed five PeAfpA::PeAfpB chimeras (chPeAFPV1-V5). Chimeras showed significant differences in their antifungal activity. chPeAFPV1 and chPeAFPV2 improved the parental PeAfpB potency, and it was very similar to that of PeAfpA. chPeAFPV4 and chPeAFPV5 showed an intermediate profile of activity compared to the parental proteins while chPeAFPV3 was inactive towards most of the fungi tested. Structural analysis of the chimeras evidenced an identical scaffold to PeAfpB, suggesting that the differences in activity are due to the contributions of specific residues and not to induced conformational changes or structural rearrangements. Results suggest that mannoproteins determine protein interaction with the cell wall and its antifungal activity while there is not a direct correlation between binding to membrane phospholipids and activity. This work provides new insights about the relevance of sequence motifs and the feasibility of modifying protein specificity, opening the door to the rational design of chimeras with biotechnological applicability. • The three P. expansum antifungal proteins (PeAFPs) have potential as biofungicides. • PeAfpB high-resolution crystal structure has been solved by X-ray crystallography. • PeAFP chimeras (chPeAFPs) show significant differences in their antifungal profile. • Differences in chPeAFP potency are due to the contributions of specific residues. • Mannoproteins but not phospholipids determine chPeAFP antifungal activity. [ABSTRACT FROM AUTHOR]

Citrus is susceptible to Penicillium digitatum (P. digitatum) infection in post-harvest storage, resulting in enormous economic losses. This study aimed to investigate the antifungal activity and potential mechanism of the combination of Polymethoxylated flavones (PMFs) and citral (two natural antifungal components derived from citrus) against P. digitatum in vitro and citrus fruit. The results show that PMFs can enhance the antifungal activity of citral nanoemulsion, and PMFs-loaded citral nanoemulsion (PCT) has significant antifungal activity in a concentration-dependent manner. PCT can evidently inhibit spore germination and mycelial growth in vitro , and effectively control the growth of green mold on postharvest citrus fruit. Furthermore, PCT treatment resulted in the alteration of mycelia morphology, accumulation of reactive oxygen species, and membrane lipid peroxidation. These changes can disrupt the normal structure and function of the cell membrane, as evidenced by the reduction of total lipid and ergosterol content in the mycelia and the stronger red fluorescence of the cells emitted after PI staining. Based on the above results, we infer that PCT has a strong inhibitory effect on P. digitatum , and its potential mechanism is related to the destruction of the cell membrane. Therefore, PCT can be considered as a botanical fungicide for citrus preservation. [Display omitted] • Addition of PMFs enhances the antifungal activity against P. digitatum of citral nanoemulsions. • PCT exhibits antifungal effects against P. digitatum in vitro and in vivo. • PCT damages the cell membrane of P. digitatum. • PCT stimulates the accumulation of ROS in the mycelia of P. digitatum. [ABSTRACT FROM AUTHOR]

Apples (Malus domestica) are one of the most consumed fruits globally. It is a relevant crop in Argentina and Spain, and one of the main fruits for export and industrialization in these countries. Quality control of apples, fundamentally in the postharvest stage, is critical to prevent fungal diseases. The blue mould, caused by Penicillium expansum , is responsible for great economic losses due to the deterioration of the fruit and mycotoxin production. Many studies have characterized this pathogen; however, little is known about the differences between populations from distant geographical origins. The objective of the present study was to characterize two P. expansum populations, from Argentina and Spain, through morphological, metabolomic and molecular approaches, and to evaluate the existence of differences related to their geographical source. A total of 103 isolates, 53 from Argentina and 50 from Spain were studied. Their morphological features were consistent with the species description. The secondary metabolite profiles revealed low chemical diversity. All 103 isolates shared the production of 13 compounds, namely andrastins, aurantioclavine, chaetoglobosins, communesins, expansolides, roquefortine C and patulin. Penostatins and citrinin were produced by 102 and 101 isolates, respectively. A region of the β-tubulin gene was selected to analyse the diversity of the P. expansum isolates. No substantial differences were observed between isolates of different geographical origins through morphology, patulin accumulation, secondary metabolite profiles and phylogenetic analysis. However, the analysis of polymorphisms revealed 29 haplotypes with a relative separation between isolates of both populations; 13 haplotypes contained Argentinean isolates, while Spanish isolates were separated into 16 haplotypes. The diversity indices of Shannon (H'= 2.075; H'= 2.402) and Simpson (Si D = 0.850; Si D = 0.895) for isolates from Argentina and Spain, respectively, indicated that the diversity of P. expansum is greater in Spain than in Argentina. This distribution could be explained both by the existence of haplotype exchange between both countries, with the ancestral haplotypes originating in Spain, and the subsequent adaptation to the environmental conditions or apples varieties grown in each region. • Penicillium expansum populations from Argentinean and Spanish apples were compared. • P. expansum populations showed low secondary metabolite diversity. • Phylogenetic analyses did not allow establishing evolutionary relationships. • Relative separation was revealed by analysis of polymorphisms in the β-tub fragment. • A significant geographical genetic structure was found in the populations. [ABSTRACT FROM AUTHOR]

Postharvest diseases account for major economic losses worldwide, while also contributing to food waste and loss. Blue mold, caused by Penicillium expansum , is one of the most prevalent postharvest diseases of pome fruit. This necrotrophic fungal pathogen is mycotoxigenic and presents a danger to food safety via the production of patulin. In addition, fungicide resistance threatens blue mold management strategies, creating a need for the development of novel control strategies. The apple storage/processing industry uses wood and plastic harvest bins to harvest and store apples for weeks, months, and even up to 1 year. Although it has been hypothesized that apple harvest bins can serve as a viable inoculum source to incite decay, there is no experimental evidence that has conclusively demonstrated this concept. In this study, we report the presence of Penicillium spp. in apple storage bins (plastic) in the mid-Atlantic USA and developed small scale methods to test 1) if harvest bins can serve as a source of inoculum for blue mold decay and 2) evaluate novel bin sanitation methods as preventative and curative applications. We demonstrated that apple harvest bin materials can serve as a source of inoculum when in direct contact with wounded apples. Additionally, it was shown that UV-C irradiation, sodium hypochlorite, and 2-phenylethanol effectively reduce inoculum viability on plastic materials in a curative fashion. It is envisioned that these findings can aid in the development of large-scale bin sanitation strategies and their applications have great potential to impact a broader range of postharvest pathogens and stored commodities. • Plastic or wooden harvest bin materials can hold viable P. expansum conidia. • New treatments to sanitize both wooden and plastic materials have been tested. • These treatments include UV-C irradiation, sodium hypochlorite, and 2-phenylethanol. • Application of these cause a reduction in P. expansum spore viability in plastic. • The treatments are effective in fungicide sensitive and resistant P. expansum strains. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of tea tree essential oil (TTO) on blue mold severity, volatile compound profiles, and postharvest quality of 'Fuji' apples during cold storage. Two experiments were conducted using laboratory-extracted TTO from Brazil and commercial TTO from Australia, applied by vaporization at various concentrations. Both types of TTO affected major volatile compounds, including terpinen-4-ol, γ-terpinene, and α-terpinene. The laboratory-extracted TTO had higher of 1,8-cineole, while commercial TTO had more p-cymene. TTO reduced blue mold severity up to 115 μL L−1 (laboratory) and 99 μL L−1 (commercial). Ethylene production decreased with laboratory-extracted TTO up to 64 μL L−1, while commercial TTO decreased ethylene production. Laboratory TTO increased the respiratory up to 41 μL L−1 before declining, whereas commercial TTO continuously decreased the respiratory. Higher concentrations of laboratory TTO decreased flesh firmness and lightness.TTO types altered the apples' volatile profiles, reducing 'Fuji' apple aromas. • Postharvest application of Melaleuca a lternifolia essential oil (TTO) reduces blue mold. • The application of TTO reduces the production of ethylene during the storage of apples. • Application of TTO causes unwanted changes in the quality and aromas of stored apples. [ABSTRACT FROM AUTHOR]

The ability of an electronic nose system to differentiate alterations in the volatile organic compound (VOCs) profile caused by early spoilage of 'Golden Delicious' apples due to Penicillium expansum was thoroughly evaluated. Three strains of this mould species (M639, pe2280 and pe2278) were individually used to inoculate 'Golden Delicious' apples, resulting in four different batches: (i) M639, (ii) pe2280, (iii) pe2278 and (iv) a control group (inoculated with sterile water). Volatile compounds were identified and quantified by gas chromatography/mass spectrometry (GC/MS), and signals from an electronic nose system (E-nose) were recorded for each batch with three different growth diameters: early stage (10 mm), middle stage (20 mm) and late stage (40 mm). A strong correlation was observed between the responses from multiple E-nose biosensors and the aromatic profile associated with fungal alterations in apples. Using linear discriminant analysis (LDA) models based on E-nose sensor data from the specified batches, we successfully differentiated healthy and infected samples, specifically three distinct groups: control, M639+pe2280 and pe2278. Remarkably, the recognition rates for total external samples exceeded 87% and reached 97% for samples in the early stage of fungal infection. These results validate the online capability of E-nose technology for the non-destructive evaluation of apple storage processes. • 81 VOCs found in infected with Penicillium expansum strains and sound apples. • 6 esters, 1 aldehyde, 1 eter and 1 alcohol were identified as main markers of infection. • e-nose sensors RBME680, H2SGP30 and CO2CCS811showed a good response to markers of infection. • RBME680, CO2SGP30, TVOCSGP30 and H2SGP30 were the most discriminating for early infection and global samples. [ABSTRACT FROM AUTHOR]

Green mold is a common postharvest disease infected by Penicillium digitatum that causes citrus fruit decay, and severely affects fruit storage quality. This work aimed to investigate the antifungal activity of Sanxiapeptin against P. digitatum , and elucidate the possible mechanisms involved. Sanxiapeptin was capable of inhibiting spore germination, germ tube length and mycelial growth. The SYTOX green staining assay revealed that Sanxiapeptin targeted the fungal membrane, and changed the membrane permeability, leading to the leakage of cell constituents. Meanwhile, Sanxiapeptin could influence the cell wall permeability and integrity by increasing the activities of chitinase and glucanase, resulting in abnormal chitin consumption and the decrease of glucan. Intriguingly, Sanxiapeptin could effectively control postharvest decay in citrus fruits, and activate the host resistance responses by regulating the phenylpropanoid pathway. In conclusion, Sanxiapeptin exhibits multiphasic antifungal mechanisms of action to control green mold in citrus fruits, shows great potential as novel food preservatives. [Display omitted] • Antimicrobial peptide Sanxiapeptin inhibited the growth of P. digitatum in vitro. • Sanxiapeptin treatment disrupted the cell membrane and wall integrity of P. digitatum. • Sanxiapeptin reduced the green mold incidence of citrus fruit in vivo. • Sanxiapeptin could induce resistance against green mold in citrus fruit. [ABSTRACT FROM AUTHOR]

Induced resistance is considered as a sustainable strategy to control postharvest decay of fruits, while light emitting diodes (LEDs) as a green physical technology are of more and more interest in postharvest fruit preservation field. In this study, we evaluated for the first time the resistance inducing ability of LED irradiation with different light wavelengths and photoperiods for cherry tomatoes (Solanum lycopersicum L. 'Qianxi'). Results indicated the exposure to 40 W m-2 of four light wavelengths for 3 d decreased B. cinerea lesion diameter on harvested cherry tomatoes, notably the best effect in blue light (470 nm). Meanwhile, the mechanism of blue light-induced disease resistance is the enhancement of defense-enzyme activity and the expression of defense-related genes. Moreover, results revealed that blue light enhanced vitamin C content and the firmness of the fruit exocarp, suggesting the potential usage of blue light in the postharvest preservation of cherry tomatoes. • LEDs of different wavelengths in inducing disease resistance of fruits were studied. • The best results were obtained by blue light continuously at 40 W m-2 for 3 d. • Blue light enhanced the activities of defense enzymes and antioxidant enzymes. • Blue light maintained soluble solids, vitamin C content and peel hardness. [ABSTRACT FROM AUTHOR]

The study prepared and used eugenol nanoemulsion loaded with nobiletin as fungistat to study its antifungal activity and potential mechanism of Penicillium italicum (P. italicum). The results showed that the minimum inhibitory concentration (MIC) of eugenol nanoemulsion loaded with nobiletin (EGN) was lower than that of pure eugenol nanoemulsion (EG), which were 160 μg/mL and 320 μg/mL, respectively. At the same time, the mycelial growth inhibition rate of EGN nanoemulsion (54.68 %) was also higher than that of EG nanoemulsion (9.92 %). This indicates that EGN nanoemulsion is more effective than EG nanoemulsion. Compared with EG nanoemulsion, the treatment of EGN nanoemulsion caused more serious damage to the cell structure of P. italicum. At the same time, in vitro inoculation experiments found that EGN nanoemulsion has better control and delay the growth and reproduction of P. italicum in citrus fruits. And the results reflected that EGN nanoemulsion may be considered as potential resouces of natural antiseptic to inhibit blue mold disease of citrus fruits, because it has good antifungal activity. • Nobiletin-loaded eugenol nanoemulsion was designed against the citrus pathogen Penicillium italicum. • Nobiletin significantly increased the antifungal effect of eugenol nanoemulsion in vitro and in vivo. • Nobiletin-loaded eugenol nanoemulsion damages the integrity of the cell membrane of Penicillium italicum. • Nobiletin-loaded eugenol nanoemulsion might be a natural antifungal agent. [ABSTRACT FROM AUTHOR]

The apple tree, belonging to the Rosaceae family producing pome fruit, holds global economic significance. Despite this, apples face considerable postharvest disease challenges, particularly blue mold caused by Penicillium expansum and gray mold Botrytis cinerea. Synthetic fungicides are traditionally used for control, but their drawbacks necessitate exploring environmentally friendly alternatives. The current research investigates the antifungal activity of Agave americana and Agave sisalana aqueous extracts against these post-harvest diseases. In vitro tests demonstrated a concentration-dependent antifungal effect, with A. americana completely inhibiting mycelial growth and spore germination at 50 g L−1. A. sisalana exhibited a 75% reduction at the same concentration. A. americana at 6 g L−1 inhibited 50% of spore germination, while A. sisalana at 8 and 9 g L−1 achieved the same for B. cinerea and P. expansum. Regarding In vivo tests, both extracts reduced infection severity, particularly A. americana, which lowered gray mold and blue mold incidences to 23 and 26%. High polyphenol and flavonoid content in Agave extracts likely contributed to their efficacy. Phytochemical analyses identified 35 metabolites, including citric acid and piscidic acid, which are potential inhibitors of the fungal cell enzyme sterol 14 α-demethylase (CYP51), according to the results of molecular Docking analyses. Similarly, FTIR results indicated compounds with significant antimicrobial activity. Importantly, these biological treatments preserved apple quality during storage, suggesting their potential as effective and sustainable alternatives to synthetic fungicides. • A.americana and A.sisalana aqueous extracts effectively controlled apple decays. • Both extracts, rich in polyphenols and flavonoids, exhibited potent antifungal effects. • Agave extracts could be a promising alternative to synthetic fungicides. [ABSTRACT FROM AUTHOR]

Penicillium expansum , a causal agent of blue mold rot, leads to substantial postharvest losses in the fruit industry. Due to environmental pollution and the emergence of fungicide-resistant strains, the use of synthetic chemical fungicides faces severe challenges. Natural antifungal compounds derived from plants are considered promising alternatives. In this study, the antifungal activities of coumarin and five hydroxylated derivatives against P. expansum and involved mechanisms were investigated. Among the six coumarins, 3-hydroxycoumarin (3-HC) demonstrated strong inhibitory effects on mycelial growth, germ tube elongation, conidiation, patulin production, and the best control effect on blue mold in apple and jujube fruit. Moreover, 3-HC increased the sensitivity of P. expansum to the cell wall, oxidative, and osmotic stresses. In silico analyses, including target fishing, molecular docking, and molecular dynamics simulations, revealed that the mitogen-activated protein kinase (MAPK) family in P. expansum (Pempks), were the potential targets of 3-HC. Bio-layer interferometry and ATP competition assays found that 3-HC could directly bind to PempkB and PempkC , and inhibit the MAPK activity. Our results suggested that 3-HC may act as an ATP-competitive MAPK inhibitor to affect the MAPK signaling pathway and inhibit the development and pathogenicity of P. expansum. • Coumarins have antifungal activity against Penicillium expansum. • 3-hydroxycoumarin shows the best inhibitory effects on P. expansum. • Pempks, the mitogen-activated protein kinases, are the targets of 3-hydroxycoumarin. [ABSTRACT FROM AUTHOR]

Penicillium expansum is one of the primary pathogens causing postharvest blue mold of pears, which leads to the spoiling of pulp and produces patulin, endangering food security. Mitogen-activated protein kinase (MAPK) signaling pathway regulates the growth and development, cell wall integrity, and pathogenicity of fungi. Mitogen-activated protein kinase kinase (MKK) in the MAPK signaling pathway has been reflected to be associated with fungal cell wall integrity. Nevertheless, the pivotal function of MKK in the process of P. expansum infection remained unexplored. In this study, MKK was knocked out and repaired by the Agrobacterium -mediated homologous recombination technology to explore the function of MKK in P. expansum infection process. It has been found that the deletion of MKK induces morphological changes in the mutant strain and delayed mycelium and spore growth. Further studies showed that the mutant strain was susceptible to cell wall interference compounds and showed a significant decrease in decay diameters and virulence during the infection of the pears. RT-qPCR analysis showed that the deletion of MKK affected the relative expression levels of its upstream and downstream genes. Our results suggest that MKK is essential in the growth and development, cell wall integrity, pathogenicity, and toxigenic capacity of P. expansum. • MAP kinase MKK negatively affects the growth of Penicillium expansum. • The knockout of MKK reduces the ability of P. expansum to infect the pears. • The knockout of MKK diminishes the toxigenic capacity of P. expansum infecting pears. [ABSTRACT FROM AUTHOR]

Blue mold caused by Penicillium italicum is a severe postharvest disease in citrus fruits. In this study, the fermentation product (FP-E) of Aspergillus aculeatu s GC-09, an endophytic fungus isolated from a citrus plant, was found to exhibit antifungal activity against P. italicum with a MIC of 0.3125 mg/mL. The fungus A. aculeatu s GC-09 was identified based on the studies of morphology and ITS nucleotide sequence. FP-E significantly inhibited the spore germination and mycelial growth of P. italicum. Scanning electron microscopy (SEM) results of P. italicum treated with FP-E showed shrunken, distorted and collapsed hyphae and conidiospores, indicative of the cell membrane damage, which was further confirmed by the propidium iodide (PI) fluorescent staining analysis. Consistent with the microscopy observation, FP-E led to the leakage of cellular constituents from P. italicum , which is evident from the increase in electrical conductivity and nucleic acid contents in the mycelial solution incubated with FP-E. In addition, FP-E treatment considerably increased the intracellular reactive oxygen species (ROS) content, and reduced the enzyme activities of both catalase (CAT) and peroxidase (POD) in P. italicum cells. Furthermore, orange fruits treated with FP-E showed fewer disease symptoms compared to the untreated fruits. These results suggested that the antifungal activity of FP-E might be associated with the disruption of cell membrane integrity, the accumulation of ROS level, and the reduction of the antioxidant enzymes activity of P. italicum. Therefore, A. aculeatu s GC-09 might be a potential microbial resource for the biocontrol of citrus postharvest blue mold. • Fermentation product (FP-E) of A. aculeatu s GC-09 strongly inhibited P. italicum. • FP-E disrupted the cell membrane integrity of P. italicum. • FP-E induced the accumulation of ROS level in P. italicum. • FP-E reduced both the CAT and POD activities in P. italicum. • FP-E delayed the symptom development of citrus blue mold. [ABSTRACT FROM AUTHOR]

Penicillium expansum is the causal agent of blue mold in harvested fruits and vegetables during storage and distribution, causing serious economic loss. In this study we seek the action modes of bifonazole against this pathogen. Bifonazole exhibited strong antifungal activity against P. expansum by inhibiting ergosterol synthesis. The ergosterol depletion caused damage to the cell structure and especially cell membrane integrity as observed by SEM and TEM. With increased unsaturated fatty acids contents, the cell membrane viscosity decreases and can no longer effectively maintain the cytoplasm, which ultimately decreases extracellular conductivity, changes intracellular pH and ion homeostasis. Exposure of hyphal cells to bifonazole shows that mitochondrial respiration is inhibited and reactive oxygen species (ROS) levels–including H 2 O 2 and malondialdehyde (MDA) – are significantly increased. The functional impairment of mitochondria and cell membrane eventually cause cell death through intrinsic apoptosis and necroptosis. [Display omitted] • Bifonazole exhibited significant antifungal activity against Penicillium expansum by inhibiting ergosterol synthesis. • The ergosterol depletion caused by bifonazole greatly changed the lipid component of cell membrane and its function. • Mitochondrial activity was inhibited and ROS was accumulation by bifonazole treatment. • Bifonazole induced cell death of P. expansum through intrinsic apoptosis and necroptosis mechanism. [ABSTRACT FROM AUTHOR]

• Methylparaben (MP) efficiently inhibits the growth of P. digitatum in vitro. • MP undermines the cell wall and plasma membrane of P. digitatum. • MP destroys the mitochondria and vacuolates cytoplasmic matrix of P. digitatum. • MP disturbs the redox level and induces the antioxidant system of P. digitatum. Parabens are one of the "generally regarded as safe" salts since its lower toxicity for the environment and human health. The curative activities of methylparaben (MP) had been detected previously by applying them into coating films in some fruits. In this study, we investigated the antifungal activities and putative mechanisms of MP against Penicillium digitatum , which causes the destructive citrus green mold disease during postharvest period. The results indicated that MP inhibited the P. digitatum hyphal growth in vitro at a minimum inhibitory/fungicidal concentration of 0.40 and 0.60 g L−1, respectively. The conidial germination rates were also distinctly restrained. Under scanning and transmission electron microscopies, the treated hyphae were slender and shrunken, had defects in developing conidiophores, and exhibited apoptotic mitochondria and vacuolated cytoplasmic matrix. Meanwhile, MP damaged the plasma membrane to accelerate the intracellular substances leaking out, and induced the activity of chitinase to degrade cell wall. The MP-treated hyphae showed activated the antioxidant enzymes, superoxide dismutase and peroxidase, and stimulated the content of antioxidant glutathione. MP alleviated the disease prevalence of inoculated citrus in the fruit decay test, but did not display good preservative effect in storage experiment. Collectively, our findings basically elucidate the underlying physiological antifungal mechanism of MP against P. digitatum. [ABSTRACT FROM AUTHOR]

Inducing disease resistance in fruit is one of the mechanisms of antagonistic yeast. Antagonistic yeast induces disease resistance in postharvest fruit and delays fruit decay. In our study, tryptophan enhanced the ability to induce disease resistance in citrus fruit by Metschnikowia citriensis against blue mold, sour rot, and green mold. The disease incidence of blue mold on the 5th d decreased by 16.6% compared with the M. citriensis treatment group. Conversely, the disease incidence of sour rot on the 9th d decreased by 10.0% relative to the M. citriensis group, and the disease incidence of green mold on the 4th d decreased by 20.0% compared with the M. citriensis group. Further validation revealed that M. citriensis and tryptophan-treated M. citriensis significantly induced the upregulation of genes related to the biosynthesis of salicylic acid and its transduction pathways, sugar metabolism, the shikimic acid pathway, MYB transcription factors, the phenylpropane biosynthesis pathway, pathogenesis-related proteins, and activated defense pathways in citrus fruit. Moreover, the genes induced by the tryptophan-treated M. citriensis group showed significantly higher expression than those in the M. citriensis –treated group alone. These genes are linked to the biosynthesis of disease-resistant compounds in citrus. The upregulation of genes showed an enhancement in the defense mechanisms of citrus fruit against biotic stress, enabling them to allocate more resources to withstand unfavorable conditions. Further verification was conducted to establish the connection between the stimulation of disease resistance in citrus fruit by M. citriensis and the synthesis of pulcherriminic acid (PA). Results obtained from inoculation in citrus fruit by the PA-deficient mutant strain Δ M. citriensis showed a significant increase in disease incidence compared with M. citriensis ; the disease incidence of blue mold was 16.6% higher than the M. citriensis –treated group alone on the 4th d; the disease incidence of sour rot was 19.4% higher on the 5th d; and the disease incidence of green mold was 16.7% higher on the 5th d. This suggests that PA impacts the effectiveness of M. citriensis in stimulating disease resistance in citrus fruits. Furthermore, the pulcherrimin secreted by M. citriensis was extracted, and it was discovered that PA extract significantly boosted the disease resistance of the fruit to blue and green molds. This suggests that PA produced by M. citriensis may play a role in yeast-induced disease resistance in citrus fruit. • Tryptophan enhanced the disease resistance of citrus fruit induced by M. citriensis. • Tryptophan-treated M. citriensis significantly activated defense pathways. • PA affects the efficacy of M. citriensis in inducing disease resistance. • PA extracts significantly induced disease resistance in citrus fruit. [ABSTRACT FROM AUTHOR]

G proteins are signaling proteins in eukaryotes that transduce extracellular signals into the intracellular space. There are three classes of Gα proteins in fungi, among which class III Gα proteins play crucial roles for fungal growth, secondary metabolism, and pathogenicity. In this study, we found that the Gα3 protein from Penicillium expansum belongs to the P-loop NTPase superfamily and contains a G-alpha conserved domain and an adenylate cyclase binding site that can bind to guanine nucleotides. Deletion of Gα3 downregulated the expression of the cAMP/PKA signaling pathway genes AC , PkaC , and PkaR , and the PKC signaling related genes PKC1 , PKC2 , and PLC of P. expansum. The Gα3 -deleted strain showed slow colony growth, irregular depression at the colony edge, and increased branching at the mycelial tip. Gα3 deletion decreased spore production, inhibited spore germination, and reduced the expression levels of genes that regulate conidiospore formation, including abaA , wetA , vosA and brlA. In addition, the Gα3 -deleted strain grew faster in carbon and NO 3 - medium, and was more sensitive to salt and oxidative stress, but less sensitive to cell wall stress. Gα3 deletion significantly downregulated the expression of patulin biosynthesis-related genes except for PatF and PatM , and reduced the patulin levels in vivo and in vitro. In addition, loss of Gα3 reduced the pathogenicity of the strain on fruit, with down-regulated expression of the extracellular enzyme genes PG , PL , and PLA. In conclusion, Gα3 can regulate growth and development, carbon and nitrogen response, stress response, patulin biosynthesis and pathogenicity by mediating cAMP/PKA and PKC signaling pathways of P. expansum. • Gα3 deletion downregulated cAMP and PKC signaling pathways in P. expansum. • Gα3 deletion decreased colony growth, and inhibited sporulation and germination. • Gα3 deletion reduced the patulin content by inhibiting the expression of related genes. • Gα3 deletion reduced the virulence of P. expansum on apple and pear fruit. [ABSTRACT FROM AUTHOR]

Postharvest pear fruit is highly susceptible to infection by pathogens, particularly by Penicillium expansum. The cytochrome P450 family plays a crucial role in the plant's defense response against pathogen invasion. However, the mechanism underlying CYP714C2 defense in pear fruit remains unclear. In this study, we investigated the molecular and physiological changes in pears after overexpressing CYP714C2 using transient expression technology and transcriptomics analysis. Our findings demonstrate that the up-regulation of CYP714C2 significantly enhances the expression of genes related to pear resistance, including CDPK , CNGC , FLS2 , WRKY22 , WRKY29 , PYL1 , E TR , ERS , EIL3 , ERF1 , NPR , GST , BGLU and others. Moreover, CYP714C2 overexpression altered starch and sucrose metabolism, pentose and glucuronate interconversions, glutathione metabolism, plant hormone signal transduction, MAPK signaling pathway - Plant, plant-pathogen interaction and other resistance-related pathways. Meanwhile, SOD, POD and GST activities of pear were increased. The transient expression of CYP714C2 also resulted in reduced incidence and severity of pathogen infection in pears. It was also found that CYP714C2 protein can interact with GA2ox1 which is a key protein in gibberellin metabolic pathway. As a result, the research showed that CYP714C2 played a role in enhancing resistance in pear fruit and detailed its molecular mechanism for enhancing fruit resistance. This provides a theoretical foundation for future exploration of fruit disease resistance. • The up-regulation of CYP714C2 enhances the expression of genes related to resistance. • CYP714C2 overexpression activated resistance-related pathways. • The transient expression of CYP714C2 reduced severity of pathogen infection in pears. • Elaborated on CYP714C2's molecular mechanism for improving fruit resistance. [ABSTRACT FROM AUTHOR]

Cold storage conditions do not inhibit the development of Penicillium expansum , a wound pathogen that causes significant losses in terms of quantity and quality in table grape´s production. The adoption of integrated strategies is recommended to enhance postharvest disease control and diminish reliance on synthetic fungicides and their adverse effects. Biocontrol is compatible with these purposes but to date there are no studies that have assessed the combination of different antifungal strategies by using statistical Mixture Design Models (MDM) and optimizing through the Response Surface Methodology (RSM). The aim of this work was optimizing a compatible combination of antimicrobials agents (antimicrobial substances and UV-C light exposure) with native biocontrol yeasts looking for an integrated strategy to reduce the disease severity (DS) caused by P. expansum on table grapes at 2 ±1°C. Three psychrotrophic yeast isolates belonging to the species Metschnikowia pulcherrima (Mp22, Mp36, Mp43) and four P. expansum (PSS4, PSS6, PRG3, PRG2) pathogen isolates were used. Isolates sensitivity was evaluated under in vitro assays with chemical and physical antimicrobial agents. An augmented simplex-centroid mixture design was selected and RSM was used to optimize the compatible combination of biocontrol yeasts and sodium bicarbonate (NaHCO 3) to control P. expansum DS on Superior Seedless grape clusters under cold storage conditions. A Special Cubic model best fitted the data from the response variable (p < 0.0001; R2=0.9334). The combination of yeasts (Mp22, Mp36) and NaHCO3, after optimization, reduced 90% the DS in grape bunches stored for 30 days at 2±1 °C (validation assays). Results obtained in the present work suggest biocontrol integrating M. pulcherrima yeasts and NaHCO 3 effectively reduces the growth of P. expansum in table grapes. The use of MDM and RSM is a methodological novelty in biocontrol studies that leads to more precise integrating strategies against fungal diseases on table grapes under cold storage conditions. • Optimized mixture of M. pulcherrima yeasts and NaHCO 3 inhibited P. expansum in vivo. • Blue mold severity decreased by 90% in grape bunches stored for 30 d at 2±1 °C. • The use of mixture design is methodologically novel for optimizing mold biocontrol. • The best fit was obtained with a special cubic model (p < 0.0001; R2=0.9334). [ABSTRACT FROM AUTHOR]

This research aimed to develop, optimize, and evaluate a new antifungal nanoemulsion system based on the crude reuterin-synergistic essential oils (EOs) hybrid to overcome the EOs application limits. At first, the antifungal effects of the Lactobacillus plantarum and Lactobacillus reuteri cell-free extracts (CFE) were tested against the Botrytis cinerea , Penicillium expansum , and Alternaria alternata as indicator fungus using broth microdilution method. The L. reuteri CFE with the MIC of 125 μL/mL for B. cinerea and 250 μL/mL for P. expansum and A. alternata showed more inhibitory effects than L. plantarum. Next, reuterin as a significant antibacterial compound in the L. reuteri CFE was induced in glycerol-containing culture media. To reach a nanoemulsion with maximum antifungal activity and stability, the reuterin concentration, Tween 80 %, and ultrasound time were optimized using response surface methodology (RSM) with a volumetric constant ratio of 5 % v /v oil phase including triple synergistic EOs (thyme, cinnamon, and rosemary) at MIC concentrations. Based on the Box-Behnken Design, the maximum antifungal effect was observed in the treatment with 40 mM reuterin, 1 % Tween 80, and 3 min of ultrasound. The growth inhibitory diameter zones of B. cinerea , P. expansum , and A. alternata were estimated 6.15, 4.25, and 4.35 cm in optimum nanoemulsion, respectively. Also, the minimum average particle size diameter (16.3 nm) was observed in nanoemulsion with reuterin 40 mM, Tween 80 5 %, and 3 min of ultrasound treatment. Zeta potential was relatively high within −30 mV range in all designed nanoemulsions which indicates the nanoemulsion's stability. Also, the prepared nanoemulsions, despite initial particle size showed good stability in a 90-d storage period at 25 °C. In vivo assay, showed a significant improvement in the protection of apple fruit treated with reuterin-EOs nanoemulsions against fungal spoilage compared to free reuterin nanoemulsion. Treatment of apples with nanoemulsion containing 40 mM reuterin showed a maximum inhibitory effect on B. cinerea (5.1 mm lesion diameter compared to 29.2 mm for control fruit) within 7 d at 25 °C. In summary, the present study demonstrated that reuterin-synergistic EOs hybrid with boosted antifungal activities can be considered as a biopreservative for food applications. • Antifungal effect of L. routeri and L. plantarium cell free extracts was tested. • Reuterin-synergistic Essential oils nanoemulsion was successfully developed. • The nanoemulsion antifungal activity & stability were optimized using RSM approach. • Reuterin-EOs nanoemulsion boosted antifungal activities in vitro as well as in vivo. [ABSTRACT FROM AUTHOR]

Botrytis cinerea and Penicillium expansum are phytopathogenic fungi that produce the deterioration of fruits. Thus, essential oil (EO) has emerged as a sustainable strategy to minimize the use of synthetic fungicides, but their volatility and scarce solubility restrict their application. This study proposes the EO of Oreganum vulgare and Thymus vulgaris -loaded solid lipid nanoparticles (SLN) based chitosan/PVA hydrogels to reduce the infestation of fungi phytopathogen. EO of O. vulgare and T. vulgaris -loaded SLN had a good homogeneity (0.21–0.35) and stability (−28.8 to −33.0 mV) with a mean size of 180.4–188.4 nm. The optimization of EO-loaded SLN showed that the encapsulation of 800 and 1200 μL L−1 of EO of O vulgare and T. vulgaris had the best particle size. EO-loaded SLN significantly reduced the mycelial growth and spore germination of both fungi pathogen. EO-loaded SLN into hydrogels showed appropriate physicochemical characteristics to apply under environmental conditions. Furthermore, rheological analyses evidenced that hydrogels had solid-like characteristics and elastic behavior. EO-loaded SLN-based hydrogels inhibited the spore germination in B. cinerea (80.9 %) and P. expansum (55.7 %). These results show that SLN and hydrogels are eco-friendly strategies for applying EO with antifungal activity. • Solid lipid nanoparticles (SLN) were suitable nanocarriers for essential oil (EO) • EO-loaded SLN reduced mycelial growth and spore germination of fungi. • Hydrogel based on chitosan/PVA showed a good property to contain SLN. • EO-loaded SLN based hydrogel reduce spore germination of fungi. [ABSTRACT FROM AUTHOR]

[Display omitted] • P. expansum isolated from contaminated land exhibited bioleaching capabilities. • Initial pH and phosphate concentration were fundamental to optimize REE bioleaching. • A gluconic acid-rich biolixiviant was produced by P. expansum. • Bioleaching of ∼ 70 % Pr, Nd, Gd, 50 % Tb, and 40 % La was achieved in only 24 h. • Direct use of crude cell-free biolixiviant could simplify large scale applications. The recovery of rare earth elements (REE) from electronic waste is crucial for ensuring future demand security, as there is a high supply risk for this group of elements, and mitigating the environmental impacts of conventional mining. This research focuses on extracting REE from waste printed circuit boards through bioleaching, addressing the limited attention given to this source. A strain of Penicillium expansum demonstrated efficient bioleaching under optimal conditions of 7.5 initial pH, 0.1 mM phosphate concentration, and excluding a buffering agent. The study achieved significant improvements in La and Tb extraction and enhancements in Pr, Nd, and Gd recovery, approaching 70 % within 24 h. Fungal mechanisms involved in REE extraction included fungal pH control, organic acid biosynthesis, phosphate bioavailability, and potential fungal proton pump involvement. This approach offers a promising solution for sustainable REE recovery from e-waste, contributing to resource security and circular economy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Penicillium expansum has the smallest mitogenome among other Penicillium mitogenomes reported. • Mitochondrial genomes of all Penicillium species retained the core protein-coding genes and had fewer intronic regions compared to other ascomycetes. • Among Penicillium species, cob exhibited the highest genetic distance while atp 8 exhibited the lowest genetic distance. Penicillium expansum is an important phytopathogenic fungus that causes blue mold disease. In this study, the novel mitochondrial genome of P. expansum was sequenced, assembled, annotated, and compared with the previously published Penicillium mitogenomes. P. expansum mitogenome is composed of circular DNA molecules with a genome size of 25,496 bp. It encodes 16 protein-encoding genes (PCGs), two rRNA genes, and 25 tRNA genes. Comparative analysis with six other Penicillium species revealed that gene length, GC content, AT skew, and GC skew were variable among the core protein-coding genes. The Penicillium species' gene synteny analysis identified several gene rearrangements. Among the core 15 PCGs, atp8 had the lowest K2P genetic distance, which shows that this gene is highly conserved. The Ka/Ks value of most PCGs was less than 1, which shows that these genes have undergone purifying selection. Phylogenetic analysis based on 14 concatenated core mitochondrial genes revealed that P. expansum shares a close relationship with P. solitum. This study served as a first report on the complete mitochondrial genome of P. expansum and its comparative analysis that will contribute to population genetics and rapid evolutionary studies among Penicillium species. [ABSTRACT FROM AUTHOR]

Postharvest loss caused by a range of pathogens necessitates exploring novel antifungal compounds that are safe and efficient in managing the pathogens. This study evaluated the antifungal activity of ethyl ferulate (EF) and explored its mechanisms of action against Alternaria alternata , Aspergillus niger , Botrytis cinerea , Penicillium expansum , Penicillium digitatum , Geotrichum candidum and evaluated its potential to inhibit postharvest decay. The results demonstrated that EF exerts potent antifungal activity against a wide board of postharvest pathogens. Results also revealed that its antifungal mechanism is multifaceted: EF may be involved in binding to and disturbing the integrity of the fungal plasma membrane, causing leakage of intracellular content and losing normal morphology and ultrastructure. EF also induced oxidative stress in the pathogen, causing membrane lipid peroxidation and malondialdehyde accumulation. EF inhibited the critical gene expression of the pathogen, affecting its metabolic regulation, antioxidant metabolism, and cell wall degrading enzymes. EF exhibited antifungal inhibitory activity when applied directly into peel wounds or after incorporation with chitosan coating. Due to its wide board and efficient antifungal activity, EF has the potential to provide a promising alternative to manage postharvest decay. • Ethyl ferulate (EF) exerts a prominent antifungal effect. • EF exerts multifaceted antifungal mechanisms of action. • EF causes morphological damage, membrane integrity loss, and oxidative stress of the pathogen. • EF can directly act in the fruit wound or be incorporated with edible coating to control postharvest decay. [ABSTRACT FROM AUTHOR]

Penicillium digitatum is the main fungi causing postharvest decay of citrus fruits. In this study, the strain h217 was identified as Bacillus altitudins and it showed strong biocontrol activity against P. digitatum in citrus. In vitro tests, B. altitudins h217 can effectively inhibit the growth of P. digitatum and form an inhibitory region with a diameter of 52.79 mm in PDA plate. It can also effectively delay the occurrence of P. digitatum , and reduce the incidence rate and the severity of P. digitatum in vivo. In addition, B. altitudins h217 could produce volatile organic compound (VOCs), and its VOCs have an inhibitory rate of 76.83% against P. digitatum. Three possible antifungal substances (5-methyl-2-hexanone, methoxy-phenyl oxime and 2-pentylfuran) were identified through gas chromatography-mass spectrometry (GC-MS). Acetophenone oxime (alternative compounds of methoxy-phenyl oxime) was selected for antifungal tests in vitro and in vivo, which confirmed its antifungal activity. Fluorescence staining experiments showed that B. altitudins h217 can severely damage the cell membrane of P. digitatum and cause an explosion of intracellular reactive oxygen species (ROS). In addition, B. altitudins h217 can significantly reduce the activity of peroxidase (POD) in P. digitatum. These results indicated that B. altitudins h217 has great potential in controlling postharvest diseases of citrus, and its VOCs can also provide new ideas for the development of postharvest fumigants for citrus. This study may provide a new biocontrol agent for controlling P. digitatum in citrus and deepen understanding of the biocontrol mechanism of B. altitudins h217. • Bacillus altitudins h217 exhibited broad-spectrum antifungal activity. • B. altitudins h217 produced volatile organic compounds with antifungal activity. • B. altitudins h217 destroy the cell membrane of Penicillium digitatum and induce intracellular ROS explosions. • B. altitudins h217 effectively alleviate the damage of P. digitatum in citrus fruit [ABSTRACT FROM AUTHOR]

Fruit decay and toxin contamination caused by pathogenic fungi have attracted public attention. As the causal agent of blue mold, Penicillium expansum has caused serious losses to various fruit. Additionally, P. expansum produces patulin, a carcinogenic toxin that can contaminate fruit and fruit products. Wuyiencin has been widely used to control fungal diseases. However, the inhibitory effects of wuyiencin on P. expansum and its mechanisms of action are still unclear. In this study, the effects of wuyiencin on the growth, spore germination, virulence and patulin production of P. expansum were investigated. Possible mechanisms were examined and verified by transcriptomic analysis, RT-qPCR, FDA/PI staining and cell leakage detection. Wuyiencin inhibited the growth, spore germination, virulence and patulin production of P. expansum. A large number of genes encoding membrane proteins were up-regulated and expressed. However, genes encoding membrane-bound organelles were down-regulated under wuyiencin treatment. The integrity of the cell membrane was destroyed. In addition, the expression of some genes related to patulin synthesis and translation/protein processing was altered. These results suggested that wuyiencin effectively controlled the growth, spore germination, virulence, and patulin production of P. expansum by destroying cell membrane integrity and altering the expression of patulin synthesis-related genes and translation/protein processing related genes. • Wuyiencin inhibited the growth, virulence and patulin production of P. expansum. • Wuyiencin could disrupt the cell membrane integrity of P. expansum. • Patulin synthesis-related genes expression in P. expansum were altered by wuyiencin. • Wuyiencin altered the expression of translation/protein processing-related genes. [ABSTRACT FROM AUTHOR]

Plants resist the invasion and establishment of pathogens through the existence of structural barriers and biochemical response mechanisms. In this regard, long non-coding RNAs (lncRNAs) have been found to play a role in various plant growth and developmental processes, as well as plant disease resistance. This study used high-throughput sequencing and bioinformatics to identify lncRNAs in kiwifruit and predict their function based on their inferred target genes. A total of 591 differentially expressed lncRNAs and 1819 mRNAs were identified in kiwifruit samples infected with P. expansum for 24 h. GO enrichment analysis indicated that the highest number of differentially expressed genes (DEGs) fell into the biological processes category of the three major ontology categories. KEGG pathway analysis indicated that most DEGs were annotated in the Plant-pathogen interaction and Plant hormone signal transduction pathways. LncRNAs in kiwifruit may be involved in the response to pathogen infections through salicylic acid (SA), gibberellin (GA), and abscisic acid (ABA) pathways. In this regard, genes, such as PP2C , GA20ox , and A-ARR , exhibited varying degrees of differential expression in kiwifruit in response to P. expansum infection. Our results provide insight into the molecular response of kiwifruit to invasion by P. expansum and provide a theoretical foundation for understanding and improving disease resistance. [Display omitted] • Identification of lncRNAs in tissues of kiwifruit. • Differential expression analysis of lncRNAs and mRNAs. • Studying the integrated relationship of lncRNAs and mRNAs. • Confirming the reliability of the differential expression genes by RT-qPCR. [ABSTRACT FROM AUTHOR]

Pathogenic fungi are a major cause of postharvest loss of fresh produce. While chemical fungicides effectively control postharvest diseases their use raises concerns and alternatives are required. Natural compounds with antifungal properties and natural defense response elicitors are explored. Among those compounds, phytocannabinoids are secondary metabolites generated from Cannabis sativa that are of particular interest. Among the non-psychotropic cannabinoids are cannabidiol (CBD) and cannabigerol (CBG). The current study investigates the effect of CBD and CBG's effect on postharvest fungal pathogens and the fruit defense response. CBD and CBG inhibit the growth of major postharvest pathogens such as Botrytis cinerea, Penicillium expansum , and Colletotrichum gloeosporioides. Moreover, CBD and CBG significantly decreased gray mold development caused by B. cinerea on grapes. Studying their mode of action indicated that both CBD and CBG affected B. cinerea fungal cell wall composition and cell-wall-related remodeling genes, as well as cell membrane fluidity and permeability. CBD treatment causes hyperpolarization of the fungal mitochondria membrane, which results in increased intracellular ROS levels. Evaluation of the effect of CBD and CBG on the fruit defense response displayed a priming effect by up-regulating pathogenic related proteins and induced salicylic acid and flavonols production resulting in inhibition of decay development. Overall, the results of the current study reveal the direct and indirect ability of natural phytocannabinoids to control fungal decay development and reduce food loss. This novel eco-friendly postharvest treatment has the potential to replace chemically hazardous fungicides. ● Non-psychotropic cannabinoids inhibit fungal growth and fruit colonization. ● Cannabinoids change fungal cell wall composition and membrane integrity. ● Cannabinoids prime the fruit defense response. ● Non-psychotropic cannabinoids could be a novel eco-friendly postharvest treatment. [ABSTRACT FROM AUTHOR]

In our previous studies we determined that, chitosan can significantly increase the biological control efficiency of the antagonistic yeast Wickerhamomyces anomalus against Penicillium expansum in table grapes. However, the molecular mechanism of chitosan enhancing the yeast's disease resistance has not been explored. In this study, we investigated the role of chitosan in stress tolerances and molecular changes of W. anomalus using TMT proteomics techniques. The results showed that after 1% (w v-1) chitosan culture, the oxidative stress tolerance of W. anomalus was increased. In addition, the expression of proteins related to growth, energy metabolism, membrane function, cell regulation and stress response of W. anomalus was up-regulated. Generally, incubation of the yeast with chitosan can significantly up-regulate proteins and metabolic pathways which are important for the yeast survival, adaptation, and reproduction. The results of this study can provide a theoretical basis for the combination of chitosan as an exciter and to improve the antagonistic efficacy of W. anomalus. • Chitosan increased oxidative stress tolerance of W. anomalus. • Proteins related to growth and stress response of W. anomalus were up-regulated. • Pathways of the yeast survival and reproduction were enhanced. • The yeast membrane function and cellular regulation were promoted. [ABSTRACT FROM AUTHOR]

Antifungal proteins (AFPs) from filamentous fungi have enormous potential as novel biomolecules for the control of fungal diseases. However, little is known about the biological roles of AFPs beyond their antifungal action. Penicillium expansum encodes three phylogenetically different AFPs (PeAfpA, PeAfpB and PeAfpC) with diverse profiles of antifungal activity. PeAfpA stands out as a highly active AFP that is naturally produced at high yields. Here, we provide new data about the function of PeAfpA in P. expansum through phenotypical characterization and transcriptomic studies of null mutants of the corresponding afpA gene. Mutation of afpA did not affect axenic growth, conidiation, virulence, stress responses or sensitivity towards P. expansum AFPs. However, RNA sequencing evidenced a massive transcriptomic change linked to the onset of PeAfpA production. We identified two large gene expression clusters putatively involved in PeAfpA function, which correspond to genes induced or repressed with the production of PeAfpA. Functional enrichment analysis unveiled significant changes in genes related to fungal cell wall remodeling, mobilization of carbohydrates and plasma membrane transporters. This study also shows a putative co-regulation between the three afp genes. Overall, our transcriptomic analyses provide valuable insights for further understanding the biological functions of AFPs. [ABSTRACT FROM AUTHOR]

Generally in plants, cell wall polysaccharides are the main determinants of tissue properties and contents of an essential part of dietary fiber, prebiotics, or cosmetic ingredients. Therefore, evaluation of the content and structure of polysaccharides is crucial to understanding and controlling their functionality. Vibrational spectroscopy has already proven to be very useful in studying wall-based compounds. Here, it was proposed to use the FT-IR and FT-Raman spectra combined with PCA analysis to discriminate and distinguish pectic and hemicellulosic fractions isolated from apple parenchyma as an example. Reference measurements have been done on commercially available polysaccharides in order to identify relevant fingerprint bands. The similarities of different polysaccharide fractions from apple: water, imidazole, dilute alkali-soluble polysaccharides (WSP, ISP, DASP, respectively), and polysaccharides soluble in three potassium hydroxide concentration (KOHs) to the reference polysaccharides were found. In the case of both types of spectroscopy, the region below 1800 cm−1 was used to differentiate the samples. The results showed that the WSP, ISP, and DASP fractions have band patterns similar to the pectic polysaccharides, but also contain bands characteristic of polysaccharides containing arabinan and galactan. While the KOH fractions showed the greatest similarities to the hemicellulose polysaccharides, especially the glucomannan and xyloglucan. The results showed that FT-IR and FT-Raman spectra supported by PCA can be useful for studying the structure of polysaccharide fractions directly isolated from plant cell wall material. [Display omitted] • Various commercially available pectins and hemicelluloses were used as reference samples. • The WSP, ISP, DASP, and KOH fractions were isolated from apple cell wall. • PCA analysis on the basis of FT-IR and FT-Raman spectra was performed. • WSP, ISP and DASP fractions showed the greatest similarities to pectin polysaccharides. • 1KOH and 4KOH fractions likely were composed of glucomannan and xyloglucan. [ABSTRACT FROM AUTHOR]

Sporidiobolus pararoseus Y16, a species of significant ecological importance, has distinctive physiological and biological regulatory systems that aid in its survival and environmental adaptation. The goal of this investigation was to understand the complex interactions between physiological and molecular mechanisms in pear fruits as induced by S. pararoseus Y16. The study investigated the use of S. pararoseus Y16 and ascorbic acid (VC) in combination in controlling blue mold decay in pears via physiological and transcriptomic approach. The study results showed that treatment of S. pararoseus Y16 with 150 μg/mL VC reduced pears blue mold disease incidence from 43% to 11%. Furthermore, the combination of S. pararoseus Y16 and VC significantly inhibited mycelia growth and spore germination of Penicillium expansum in the pear's wounds. The pre-treatment did not impair post-harvest qualities of pear fruit but increased antioxidant enzyme activity specifically polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT) activities as well as phenylalanine ammonia-lyase (PAL) enzyme activity. The transcriptome analysis further uncovered 395 differentially expressed genes (DEGs) and pathways involved in defense mechanisms and disease resistance. Notable pathways of the DEGs include plant-pathogen interaction, tyrosine metabolism, and hormone signal transduction pathways. The integrative approach with both physiological and transcriptomic tools to investigate postharvest pathology in pear fruits with clarification on how S. pararoseus Y16 enhanced with VC, improved gene expression for disease defense, and create alternative controls strategies for managing postharvest diseases. • Ascorbic acid and yeast combination increased PPO, POD, PAL, and CAT enzyme activities. • Ascorbic acid improved S. pararoseus Y16's altered 395 DEGs in pear fruits. • Ascorbic acid improved S. pararoseus Y16's biocontrol efficacy against P. expansum. [ABSTRACT FROM AUTHOR]

The mycotoxin patulin is primarily produced as a secondary metabolite by numerous fungal species and predominantly by Aspergillus , Byssochlamys , and Penicillium species. It is generally associated with fungal infected food materials. Penicillium expansum is considered the only fungal species liable for patulin contamination in pome fruits, especially in apples and apple-based products. This toxin in food poses serious health concerns and economic threat, which has aroused the need to adopt effective detection and mitigation strategies. Understanding its origin sources and biosynthetic mechanism stands essential for efficiently designing a management strategy against this fungal contamination. This review aims to present an updated outline of the sources of patulin occurrence in different foods and their biosynthetic mechanisms. It further provides information regarding the detrimental effects of patulin on human and agriculture as well as its effective detection, management, and control strategies. [Display omitted] • Patulin is mainly produced by Aspergillus , Byssochlamys , and Penicillium species. • Patulin contaminates pome fruits, especially apples and apple-based products. • Patulin contaminated products have serious human health impacts. • Management strategies are required for the safety and security of food. [ABSTRACT FROM AUTHOR]

Patulin, one of the most common mycotoxins produced primarily by the Penicillium , Aspergillus and Byssochlamys species, is often associated with fruits and fruit-based products. Biodegradation by microbes is an effective method to remove or detoxify mycotoxins. In this study, a bacterial strain with patulin degradation capability was selectively isolated using oxindole, an analogue to patulin, as the sole carbon source, and identified as Pseudomonas poae JSU-Y1 by phylogenetic analysis on the basis of 16S rRNA sequence. This isolated bacterium could inhibit the growth of Penicillium expansum both on plate medium and apple fruit with inhibition ratio of 30.3% and 44.9%, respectively. Up to 87.7% of the initial patulin (2.5 μg/mL) was removed after incubation with Pseudomonas poae JSU-Y1 in liquid medium at 30 °C for 72 h. When challenged with apple juice, 79% of patulin could be degraded by this isolated strain. Additionally, ascladiol was tentatively identified as the patulin degradation intermediate by LC-MS analysis. Taken together, the experiment results indicated that the isolated Pseudomonas poae JSU-Y1 would be a promising bacterial resource to control patulin contamination and toxigenic fungal growth in agricultural products. [Display omitted] • Pseudomonas poae JSU-Y1 can degrade patulin. • P. poae JSU-Y1 exhibits growth inhibition on Penicillium expansum. • P. poae JSU-Y1 reduces blue mold rot of apple fruits. • Ascladiol is tentatively to be the patulin degradation intermediate. [ABSTRACT FROM AUTHOR]

Olives and their derivatives, in particular olive oil, represent one of the most significant agricultural products in the Mediterranean basin. Storage under inadequate conditions poses serious problems concerning fungal contamination, with consequent defects and potential mycotoxin production in olives and olive oils. Penicillium expansum represents one of the most significant postharvest pathogens in several fruits, including olives. Not only it causes blue mold but also is one of the most relevant patulin producing species of the genus Penicillium. The aim of this research was to evaluate the ecophysiological conditions governing growth and PAT production by P. expansum strains previously isolated from Tunisian olives. For this purpose, four P. expansum isolates were tested in a synthetic medium (Czapek Yeast Autolysate, CYA) and in olive-based medium (OM) for their ability to grow and produce PAT under different temperatures (4 °C, 15 °C and 25 °C) for 10 and 20 d. The mycotoxin was analysed by HPLC-UV. Results showed that all isolates were able to grow on tested media at different temperatures. Different PAT production profiles were found, showing that at 25 °C P. expansum isolates were able to produce PAT on CYA and OM medium. At 15 °C the production of PAT was only detected on CYA medium, while no PAT production was detected at 4 °C for the two media. • Penicillium expansum produced patulin on olive-based medium at 15 °C but not at 4 °C. • Olive matrix permits patulin accumulation under abusive storage temperatures. • Contamination of olives with patulin must be considered a potential safety risk. [ABSTRACT FROM AUTHOR]