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Postharvest fungal diseases are the main cause of economic losses in lemon production. The continued use of synthetic fungicides to control the diseases favors the emergence of resistant strains, which encourages the search for alternatives. The aim of this study was to assess the efficacy of metallic nanoparticles (NPs) as antifungal agents against local isolates of Penicillium digitatum and Penicillium italicum, each of them in a fungicide-sensitive and -resistant version, and a Geotrichum citri-aurantii isolate. NPs of ZnO, CuO, and Ag were synthesized and characterized by spectroscopy and microscopy, presenting average sizes < 25 nm and spherical shapes. ZnO-NPs did not present antifungal activity at the assayed conditions, while the minimum fungicidal concentrations (MFCs) were 1000 and 10 µg mL−1 for CuO-NPs and Ag-NPs, respectively. The NPs' antimicrobial action included conidial membrane permeability and strong intracellular disorganization. Moreover, the Ag-NPs reduced green mold incidence on inoculated lemons when applied to the fruit. Taken together, Ag-NPs were effective in inhibiting both fungicide-sensitive and -resistant isolates of the main lemon postharvest pathogens, suggesting their potential use as an alternative approach. [ABSTRACT FROM AUTHOR]

Background: Penicillium saprophytic species, which primarily consume organic biodegradable materials, is a common example of a fungal species. The preparation filtrates of Penicillium italicum, a saprophyte on citrus fruits frequently linked to post-harvest diseases in this crop, were included in the current investigation. Objective: This investigation aimed determine the most efficient culture medium for the production of antibacterial secondary metabolites. Patients and Methods: included identifying the growth medium for P. italicum and produce its metabolites through the use of gas chromatographymass spectrometry (GC MS) for both solid-state fermentation filtrate (SSFF) and liquid fermentation filtrate (LFF). Additionally, the antimicrobial activity of the mold filtrate against certain pathogenic bacteria was assessed using the agar well diffusion method. Results: indicated that the biomass used for mold growth was heavier in SSFF than LFF, and according to the findings, the selective active isolate's crude filtrate from two duplicates of the P. italicum Yeast Extract Sucrose YES culture medium was 0.063 mg, while the crude extract from rotten orange (as a solid medium) containing P. italicum was 0.11 mg. Tetracosane and other substances with a track record of therapeutic activity were found in the two mold extracts, according to GC MS data. Overall, both SSFF and LFF demonstrated antibacterial activity against Klebsiella pneumonia, Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus, with the inhibition zones± standard deviation (IZ ± SD) being 24.7 ± 0.57, 18.2 ± 0.28, 26.3 ± 0.59, 21.6 ± 0.51, and 32.8 ± 0.21 (for SSFF) mm and 0.0, 12.3±0.57, 28.16±0.20, 19.3±1.15, and 28±0.2 (for LFF) mm, respectively. Conclusion: the filtrate of P. italicum from a natural medium (rotted orange) as a solid state fermentation was more weighted and gave many effective metabolites compared to what was produced by liquid fermentation on a synthetic medium, and both liquid and solid fermentation filtrates demonstrated efficacy against harmful bacteria. [ABSTRACT FROM AUTHOR]

Blue mold, caused by Penicillium italicum, is one of the main postharvest diseases of citrus fruits during storage and marketing. The pathogenic mechanism remains largely unclear. To explore the potential pathogenesis-related genes of this pathogen, a T-DNA insertion library of P. italicum PI5 was established via Agrobacterium tumefaciens-mediated transformation (ATMT). The system yielded 200–250 transformants per million conidia, and the transformants were genetically stable after five generations of successive subcultures on hygromycin-free media. 2700 transformants were obtained to generate a T-DNA insertion library of P. italicum. Only a few of the 200 randomly selected mutants exhibited significantly weakened virulence on citrus fruits, with two mutants displaying attenuated sporulation. The T-DNA in the two mutants existed as a single copy. Moreover, the mutant genes PiBla (PITC_048370) and PiFTF1 (PITC_077280) identified may be involved in conidia production by regulating expressions of the key regulatory components for conidiogenesis. These results demonstrated that the ATMT system is useful to obtain mutants of P. italicum for further investigation of the molecular mechanisms of pathogenicity and the obtained two pathogenesis-related genes might be novel loci associated with pathogenesis and conidia production. Highlights: •The ATMT approach has been optimised to construct mutant library of P. italcum. •Two mutants deficient in conidia production with reduced pathogenicity on citrus. •The corresponding mutant genes were identified as PiBla and PiFTF1, respectively. •The expression of three key regulators of conidiogenesis was altered in the mutants. [ABSTRACT FROM AUTHOR]

In this study, yeasts isolated from citrus groves, trees and leaves were identified, phylogenetic analyzes were performed and their antifungal effects were determined. Wickerhamomyces anamolus (M72), Meyerozyma guilliermondii (M77), and Pichia kudriavzevii (M74) species were identified and were found to have antifungal effects against P. digitatum and P. italicum. Pichia kudriavzevii (M74), which has the highest antifungal effect, showed 67% and 62% inhibition rates against P. digitatum and P. italicum, respectively. An encapsulation study was carried out using a microencapsulation process to ensure that the M74 strain, which has the most antifungal effect, is long-lived enough to be a biopesticide. The optimum spray drying process parameters as well as the optimum concentration values of wall materials were investigated in the spray drying process for the microencapsulation of Pichia kudriavzevii (M74) through the Taguchi methodology. The formulation containing 0.1% sodium alginate (SA) and 10% corn starch (CS) showed a good performance in the inhibition of P. digitatum, a mold that causes losses in orange, thanks to its high percentage of viability (73%). The inhibition percentages may indicate that this formulation may be a candidate to be considered as a potential alternative application to synthetic fungicides on orange fruits for the effective control of P. digitatum mold. [ABSTRACT FROM AUTHOR]

Citrus fruits, particularly mandarins, are highly valued globally for their nutritional benefits and versatile culinary uses. However, the challenge of post-harvest decay, primarily due to blue mold (Penicillium italicum) infections, results in significant food losses and necessitates effective preservation strategies. Traditional methods often rely on fungicides, raising concerns about chemical residues and environmental impact. This study investigates the efficacy of ozone as an alternative approach to controlling blue mold in mandarins. Various gaseous ozone treatments were tested, including single, double, and triple treatments, with durations ranging from 10 to 60 min and concentrations from 3.3 to 20 ppm. Additionally, ozonated water treatments were evaluated with concentrations of 2, 4, and 6 ppm. To simulate a realistic infestation scenario, mandarins were artificially infected with P. italicum spores before undergoing both gaseous ozone and ozonated water treatments. The storage conditions for the mandarins were meticulously controlled, maintaining a humidity level of 50–60% and a temperature range of 10–12 °C. Each fruit was analyzed, and the presence of P. italicum infection was determined two and three weeks after the ozonation. Results indicated that ozone treatments significantly reduced mold growth, with gaseous ozone demonstrating efficacy rates up to 97.5% and ozonated water treatments achieving preservation rates between 95% and 97%. These results underscore ozone's potential as a safe, efficient, and sustainable alternative to conventional fungicides, offering promising solutions for extending the shelf life of mandarins. Further research is recommended to optimize ozone treatment parameters, assess long-term effects on fruit quality and nutritional content, and refine application techniques to harness ozone's potential in citrus fruit preservation fully. This approach not only addresses food security challenges but also aligns with global efforts to reduce chemical inputs in agriculture and promote environmentally sustainable practices. [ABSTRACT FROM AUTHOR]

Penicillium italicum, a major postharvest pathogen, causes blue mold rot in citrus fruits through the deployment of various virulence factors. Recent studies highlight the role of the epigenetic reader, SntB, in modulating the pathogenicity of phytopathogenic fungi. Our research revealed that the deletion of the SntB gene in P. italicum led to significant phenotypic alterations, including delayed mycelial growth, reduced spore production, and decreased utilization of sucrose. Additionally, the mutant strain exhibited increased sensitivity to pH fluctuations and elevated iron and calcium ion stress, culminating in reduced virulence on Gannan Novel oranges. Ultrastructural analyses disclosed notable disruptions in cell membrane integrity, disorganization within the cellular matrix, and signs of autophagy. Transcriptomic data further indicated a pronounced upregulation of hydrolytic enzymes, oxidoreductases, and transport proteins, suggesting a heightened energy demand. The observed phenomena were consistent with a carbon starvation response potentially triggering apoptotic pathways, including iron-dependent cell death. These findings collectively underscored the pivotal role of SntB in maintaining the pathogenic traits of P. italicum, proposing that targeting PiSntB could offer a new avenue for controlling citrus fungal infections and subsequent fruit decay. [ABSTRACT FROM AUTHOR]

Penicillium digitatum and Penicillium italicum are responsible for citrus green and blue moulds (GM and BM), respectively, which are major citrus postharvest diseases. The aim of this study was to develop an optimal dipping mixture of an aqueous solution of different food additives: sodium bicarbonate (SB), sodium benzoate (SBen), and potassium sorbate (PS), in combination with heat, to control GM and BM using response surface methodology. The ranges of SB (0.0%, 3.0%, 6.0%), SBen (0.0%, 0.5%, 1.0%), PS (0.0%, 0.5%, 1.0%) and temperature (20 °C, 35 °C, 50 °C) with a dipping time of 60s were tested for their impact on GM and BM on artificially inoculated oranges. Within these tested ranges, SB reduced GM severity and incidences of both GM and BM. PS affected BM severity and incidence, but not GM. SBen and temperature did not have impact on GM and BM. The most suitable food additive concentrations were identified to be 4.7% SB, 1.0% SBen and 0.7% PS, with a dipping solution temperature of 50 °C. This treatment was shown to reduce GM and BM incidence from 85 and 86% on control fruit dipped in tap water at 20 °C to 3 and 10%, respectively. Additionally, the severity of GM and BM was reduced from 64 and 26 mm on control fruit to <1 and 2.8 mm, respectively. [ABSTRACT FROM AUTHOR]

Background: Penicillium saprophytic species, which primarily consume organic biodegradable materials, is a common example of a fungal species. The preparation filtrates of Penicillium italicum, a saprophyte on citrus fruits frequently linked to post-harvest diseases in this crop, were included in the current investigation. Objective: This investigation aimed determine the most efficient culture medium for the production of antibacterial secondary metabolites. Patients and Methods: included identifying the growth medium for P. italicum and produce its metabolites through the use of gas chromatography-mass spectrometry (GC MS) for both solid-state fermentation filtrate (SSFF) and liquid fermentation filtrate (LFF). Additionally, the antimicrobial activity of the mold filtrate against certain pathogenic bacteria was assessed using the agar well diffusion method. Results: indicated that the biomass used for mold growth was heavier in SSFF than LFF, and according to the findings, the selective active isolate's crude filtrate from two duplicates of the P. italicum Yeast Extract Sucrose YES culture medium was 0.063 mg, while the crude extract from rotten orange (as a solid medium) containing P. italicum was 0.11 mg. Tetracosane and other substances with a track record of therapeutic activity were found in the two mold extracts, according to GC MS data. Overall, both SSFF and LFF demonstrated antibacterial activity against Klebsiella pneumonia, Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus, with the inhibition zones± standard deviation (IZ± SD) being 24.7± 0.57, 18.2± 0.28, 26.3± 0.59, 21.6± 0.51, and 32.8± 0.21 (for SSFF) mm and 0.0, 12.3±0.57, 28.16±0.20, 19.3±1.15, and 28±0.2 (for LFF) mm, respectively. Conclusion: the filtrate of P. italicum from a natural medium (rotted orange) as a solid state fermentation was more weighted and gave many effective metabolites compared to what was produced by liquid fermentation on a synthetic medium, and both liquid and solid fermentation filtrates demonstrated efficacy against harmful bacteria.

Citrus fruits stand as pivotal and extensively cultivated fruit crops on a global scale, boasting substantial economic and nutritional significance. Despite their paramount importance, citrus growers and the industry face a formidable obstacle in the form of post-harvest losses caused by plant pathogens. Effectively addressing this challenge has become imperative. The predominant approach to tackle these pathogens has traditionally involved the use of chemical fungicides. However, the escalating environmental concerns associated with chemical interventions, coupled with a growing consumer preference for pesticide-free produce, have catalyzed an earnest quest for alternative methods of disease control in the citrus industry. The antagonistic yeasts hold great promise as biocontrol agents for mitigating post-harvest fungal diseases in citrus. In this regard, this review summarizes the current state of knowledge regarding the study of yeast strains with biocontrol potential. Thus, the various modes of action employed by these yeasts and their effectiveness against prominent citrus pathogens such as Penicillium digitatum, Penicillium italicum and Geotrichum citri were discussed. Additionally, the review delved into the challenges associated with the practical implementation of yeast-based biocontrol strategies in citrus post-harvest management and investigated the potential of yeast-based approaches to enhance the safety and quality of citrus produce, while reducing the reliance on chemical fungicides and contributing to the sustainable and environmentally responsible future of the citrus industry. [ABSTRACT FROM AUTHOR]

The aim of the study was to develop an effective bio-formulation for preventing post-harvest fungal rots in fresh citrus fruit through a multi-step process that includes isolation and characterization of lactic acid bacteria (LABs) from citrus fruit peel, selection of LAB strains with high antifungal activity, chemical characterization of cell free supernatants (CFS), formulation of a lemon peel powdery-based medium (LM) activated with LAB fermentates, chemical characterization of fermented LM, and evaluation of the efficacy of the new bio-formulation against blue mold. Thirteen LABs were recovered from the rind of citrus fruit and identified by the peptide mass fingerprinting method. The antifungal activity of LABs, isolated from citrus fruit, as well as cell free supernatants (CFSs), obtained from their liquid cultures, was tested against diverse plant pathogenic fungi and oomycetes, using the dual-culture overlay and the diffusion agar assays, respectively. Two isolates designated as N3B2 and M2B2, both identified as Lactiplantibacillus plantarum, were selected among the others for their relevant antifungal activity. Both isolates showed a broad spectrum antagonistic activity comprising also major postharvest pathogens of citrus fruit, such as Penicillium digitatum and P. italicum, the causal agents of green and blue moulds, respectively, Alternaria alternata, Colletotrichum gloeosporioides, C. karsti, Phytophthora citrophthora and Ph. nicotianae. The N3B2 and M2B2 isolates were used as starter cultures to ferment a lemon peel powder medium enriched with a nutrient water solution (LM). The two formulations obtained by fermenting LM with the N3B2 and M2B2 isolates showed a strong in vitro inhibitory activity on the same broad range of pathogens used in the preliminary screening of LABs. Moreover, the two LM-based formulations reduced the severity of blue mold infection and inhibited the sporulation of P. italicum on artificially inoculated lemon fruit. The chemical analysis of LM-based bioformulations revealed their antifungal activity was very probably due to the LAB-derived acidic components, including lactic, acetic, DL-3-phenyllactic, 3-4-dihydroxyhydrocinnamic, salicylic acid vanillic acids. These innovative LM-based bioformulations activated with LAB-derived antifungal compounds will be exploited as edible and biodegradable fruit coatings to prolong the shelf-life and prevent post-harvest rots of fresh citrus fruit.

Citrus is an economically important fruit crop in Pakistan; however, its productivity is affected by various insect pests and pathogens. Spores of Penicillium italicum Warmer are airborne and cause citrus blue mold disease in citrus plants. The main objective of this study was to assess the in-vitro efficacy of different concentrations of selected fungicides against P. italicum applied at different times. Before pouring, potato dextrose agar was made and modified with fungicides. For each concentration, three plates were poured. After the plates had solidified, a 5 mm mycelial plug of the fungus P. italicum was inserted in the center Five fungicides i.e., Nativo, Topsin-M, Metalaxyl+Mancozeb, Copper Oxychloride, Success were tested at three concentrations i.e., 100 ppm, 200 ppm, and 300 ppm. The findings of the study showed that Nativo was the best fungicide as the inhibition rate of P. italicum was 81.0-87.0%, after 7 days of application. The second most effective fungicide was Success, which showed 77.5-81.0% inhibition of P. italicum after 3 days and 78.0-80.0% after 7 days of application. Similarly, Topsin M showed 68.3-77.0% inhibition of P. italicum on 3 days and 77.0-81.0% on 7 days of application. Metalaxyl+Mancozeb and copper did not prove effective against P. italicum, even at higher concentrations. The higher concentration of each fungicide resulted in maximum inhibition of P. italicum. Thus, the current study suggests that Nativo, Success, and Topsin M could manage the citrus blue mold disease at the standardized concentration. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the antifungal effect of Iranian oak Jaft extract on Penicillium italicum and Penicillium digitatum, as an indicator of mold spoilage after citrus fruits harvest. Different extraction methods were used to obtain tannins and flavonoids from the Oak Jaft. The study investigated the Minimum Inhibitory Concentration (MIC), Minimum Fungicidal Concentration (MFC), and non-growth diameter of the molds using three different methods: tube dilution, surface culture, and diffusion in agar well. The results showed that different concentrations of aqueous extract had varying effects on the non-growth diameter of the molds. The antifungal effect was significantly increased with a concentration of 40 and 80 mg/ml of aqueous extract. In comparison, the control group, which used Fludioxonil 25% poison, showed a significant difference in mold growth. Therefore, the extract of Iranian oak Jaft can be used as an alternative to control fungal spoilage of citrus fruits. [ABSTRACT FROM AUTHOR]

Litsea cubeba essential oil (LCEO) has attracted wide attention as a natural antibacterial material due to its advantages of high safety, no drug resistance and broad-spectrum antibacterial activity. The purpose of this study was to investigate the antibacterial activity of LCEO against Penicillium italicum in citrus fruits and its mechanism. The minimum inhibitory concentration (MIC) of LCEO, and its influence on the mycelial growth, spore germination, release of cell components, extracellular pH and electrical conductivity of Penicillium italicum were determined after LCEO treatment. The changes of the surface morphology of Penicillium italiana mycelia caused by LCEO were observed by scanning electron microscopy (SEM), and the integrity of the spore membrane was detected by propidium iodide (PI) staining. The disease incidence and lesion diameter in citrus fruits infected with Penicillium italicum were determined. The MIC of LCEO against Penicillium italicum was 1.17 mg/mL. LCEO could significantly inhibit the mycelial growth and spore germination of Penicillium italicum, and the inhibition rates of mycelial growth and spore germination were (88.17 ± 0.30)% and (97.78 ± 0.30)% after 1 000 mg/L LCEO treatment, respectively. With an increase in LCEO concentration, the extracellular conductivity and extracellular pH of Penicillium italicum increased gradually, and the leakage of nucleic acid became more serious. SEM observation showed the mycelial linearity was lost, and irreversible morphological changes such as distortion, shrinkage and shriveling appeared on the mycelial surface after LCEO treatment. The higher the concentration of LCEO, the more serious the damage to the integrity and permeability of Penicillium italicum mycelia. The results of PI staining showed that the integrity of the cell membrane of the spores was damaged. In addition, the in vivo experiments showed that the disease incidence and lesion diameter of LCEO-treated citrus fruits decreased significantly compared to the untreated control group (P < 0.05), and the best effect was observed at 4 800 mg/L concentration. LCEO could effectively inhibit the spread of Penicillium italicum in citrus fruits, and it had a good control effect on citrus blue mold.

Citrus fruits, particularly mandarins, are highly valued globally for their nutritional benefits and versatile culinary uses. However, the challenge of post-harvest decay, primarily due to blue mold (Penicillium italicum) infections, results in significant food losses and necessitates effective preservation strategies. Traditional methods often rely on fungicides, raising concerns about chemical residues and environmental impact. This study investigates the efficacy of ozone as an alternative approach to controlling blue mold in mandarins. Various gaseous ozone treatments were tested, including single, double, and triple treatments, with durations ranging from 10 to 60 min and concentrations from 3.3 to 20 ppm. Additionally, ozonated water treatments were evaluated with concentrations of 2, 4, and 6 ppm. To simulate a realistic infestation scenario, mandarins were artificially infected with P. italicum spores before undergoing both gaseous ozone and ozonated water treatments. The storage conditions for the mandarins were meticulously controlled, maintaining a humidity level of 50–60% and a temperature range of 10–12 °C. Each fruit was analyzed, and the presence of P. italicum infection was determined two and three weeks after the ozonation. Results indicated that ozone treatments significantly reduced mold growth, with gaseous ozone demonstrating efficacy rates up to 97.5% and ozonated water treatments achieving preservation rates between 95% and 97%. These results underscore ozone’s potential as a safe, efficient, and sustainable alternative to conventional fungicides, offering promising solutions for extending the shelf life of mandarins. Further research is recommended to optimize ozone treatment parameters, assess long-term effects on fruit quality and nutritional content, and refine application techniques to harness ozone’s potential in citrus fruit preservation fully. This approach not only addresses food security challenges but also aligns with global efforts to reduce chemical inputs in agriculture and promote environmentally sustainable practices.

Biopolymeric films offer an ecological alternative to obtain containers or coatings for food. These offer a barrier against moisture and are biocompatible. Mixtures of different polymers make it possible to obtain materials with unique physicochemical properties. The objective of this study was to assess the effect of different soluble fraction of organosolv lignin on the antifungal and physicochemical properties of starch films. The lignin was extracted using a mixture of organic solvents, fractionated in alcohol, and the alcohol-soluble lignin fraction was incorporated into starch films at concentrations of 1, 3, 5, and 10 %. The resulting films underwent analysis through Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electronic Microscopy (SEM). Additionally, thickness, color, the mechanical properties, and the inhibition capacity against P. italicum fungus of the films were also evaluated. The FTIR and SEM results revealed significant chemical interactions between starch and alcohol-soluble lignin fraction confirming a correct integration of both polymers. Moreover, the incorporation of alcohol-soluble lignin fraction had a plasticizing effect on the films, substantially enhancing their flexibility. Regarding antifungal activity, the films with 5 % alcohol-soluble lignin fraction exhibited the highest percentage of inhibition of the P. italicum fungus (91.7 ± 0.56 %), while the lowest inhibition was obtained in the films containing 10 % (64.0 ± 0.32 %). The starch/ alcoholsoluble lignin fraction films demonstrated effective antifungal in vitro properties, providing a viable alternative to control the development microorganism that affect the shelf life of foods. [ABSTRACT FROM AUTHOR]

While Mexican lime is an economic tree species, its fruits are prone to postharvest diseases caused by fungal species of the genus Penicillium, which can inflict severe economic loss. To alleviate these adverse effects, there has been a rise in interest for environmentally-friendly treatments in the fruit industry due to consumers' concern for food safety. Here, thyme (Thymus vulgaris) essential oil (TEO) (0.2%) and carboxy methyl cellulose (CMC) coating (1.5%) were evaluated for in vitro and in vivo activities against green and blue molds on Mexican lime. Using a combination of TEO and CMC led to the highest antifungal activity in vitro. Moreover, a decrease in disease incidence and severity was observed in vivo when Mexican lime fruits were treated with either TEO (0.2%) or CMC (1.5%). The results of scanning electron microscopy (SEM) showed that CMC + TEO caused changes in the morphology of both P. digitatum and P. italicum hyphae, resulting in non-linear and wrinkled surfaces. Therefore, a combination of TEO and CMC can be used as an effective treatment for green and blue mold on Mexican lime. [ABSTRACT FROM AUTHOR]

Citrus fruits are vulnerable to green mold (caused by Penicillium digitatum) and blue mold (caused by Penicillium italicum) during storage, posing significant challenges to the industry. Therefore, biological control utilizing antagonistic bacteria has emerged as a dependable strategy for managing postharvest diseases. In this study, halophilic bacterial isolates were carefully selected from diverse saline ecosystems, including the Dead Sea, the Agadir Sea, the Rabat Sea, saline soil, and water of the Amassine Oued in Taounate, based on rigorous in vitro and in vivo antagonism bioassays. Out of 21 bacteria from different saline environments, 10 were chosen for further characterization based on the 16S rDNA gene. Notably, the EAM1 isolate demonstrated exceptional inhibitory effects, reaching a 90% inhibition rate against P. digitatum, while the ER2 isolate closely followed with an 89% inhibition rate against P. italicum. Furthermore, in bacterial supernatant experiments, six bacterial isolates effectively curbed the growth of P. digitatum, and three demonstrated efficacy against P. italicum development. In an in vivo trial spanning ten days of incubation, three highly effective isolates against P. digitatum displayed zero severity, and two of these isolates also demonstrated zero severity against P. italicum. Interestingly, a comparison of bacterial filtrates revealed that all isolates exhibited a severity level of over 50% against the pathogen causing green rot (P. digitatum), while the severity was lower than 50% for the supernatants of the two isolates used against P. italicum. In conclusion, this study highlights the promising role of halophilic bacteria, specifically Bacillus amyloliquefaciens EAM1 and B. amyloliquefaciens ER2, in controlling postharvest fruit pathogens. The findings shed light on the potential of utilizing these bioprotective agents to address the challenges posed by green and blue citrus molds, providing valuable insights for the citrus industry. [ABSTRACT FROM AUTHOR]

Abstract Postharvest pathogens can affect a wide range of fresh fruit and vegetables, including grapes, resulting in significant profit loss. Isoquinoline alkaloids of Mahonia fortunei, a Chinese herbal medicine, have been used to treat infectious microbes, which might be effective against postharvest pathogens. The phytochemical and bioactive investigation of this plant led to the isolation of 18 alkaloids, of which 9 compounds inhibited the growth of Botrytis cinerea and 4 compounds against Penicillium italicum. The antifungal alkaloids could change the mycelium morphology, the total lipid content, and leak the cell contents of B. cinerea. Furthermore, the two most potent antifungal alkaloids, berberine (13) completely inhibited effect on gray mold of table grape at 512 mg L−1, while jatrorrhizine (18) exhibited an inhibition rate > 90% on grape rot at the same concentration, with lower cytotoxicity and residue than chlorothalonil, which suggested that ingredients of M. fortunei might be a low-toxicity, low-residue, eco-friendly botanical fungicide against postharvest pathogens. Graphical Abstract

Lemons (Citrus limon L.) are one of the most economically important and consumed fruit worldwide. The species is vulnerable to several postharvest decay pathogens, of which Penicillium italicum associated with blue mold disease is the most damaging. This study investigates the use of integrated management for blue mold of lemon using lipopeptides (LPs) extracted from endophytic Bacillus strains and resistance inducers. Two resistance inducers; salicylic acid (SA) and benzoic acid (BA) were tested at 2, 3, 4, and 5mM concentrations against the development of blue mold on lemon fruit. The 5mM SA treatment produced the lowest disease incidence (60%) and lesion diameter (1.4cm) of blue mold on lemon fruit relative to the control. In an in vitro antagonism assay eighteen Bacillus strains were evaluated for their direct antifungal effect against P. italicum; CHGP13 and CHGP17 had the greatest inhibition zones of 2.30 and 2.14cm. Lipopeptides (LPs) extracted from CHGP13 and CHGP17 also inhibited the colony growth of P. italicum. LPs extracted from CHGP13 and 5mM SA were tested as single and combined treatments against disease incidence and lesion diameter of blue mold on lemon fruit. SA+ CHGP13+ PI had the lowest disease incidence (30%) and lesion diameter (0.4cm) of P. italicum on lemon fruit relative to the other treatments. Furthermore, the lemon fruit treated with SA+ CHGP13+ PI had the highest PPO, POD, and PAL activities. The postharvest quality analysis of the lemon fruit including fruit firmness, total soluble solids, weight loss, titratable acidity, and ascorbic acid content revealed that the treatment SA+ CHGP13+ PI had little effect on fruit quality compared to the healthy control. These findings indicate that Bacillus strains and resistance inducers can be used as components of integrated disease management for the blue mold of lemon. [ABSTRACT FROM AUTHOR]

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Blue mold caused by Penicillium italicum imposes a serious problem in economically important citrus fruit during the storage period. Traditionally, synthetic chemicals have been widely used to control blue molds; however, this use of chemicals has caused critical environmental problems. This has encouraged scientists to look for safer and readily available alternatives from natural eco-friendly sources such as botanical extracts. In line with that, the present study aims to investigate the antifungal efficiency of twelve methanolic extracts from eight plant species against P. italicum in vitro and to further select the most promising extracts to study their efficacy in vivo on reduction of disease severity and some physiological aspects of 'Washington Navel©' orange fruit under storage conditions. Being the most effective treatment, Sansevieria cylindrica leaf extract was subjected to GC-MS analysis to identify phytochemical components. The results obtained signified the potential efficacy of the tested plant extract to reduce the mycelial growth of P. italicum under in vitro conditions. The most effective extracts were Balanites aegyptiaca fruit, Polianthes tuberosa bulbs, Acacia nilotica fruit and Sansevieria cylindrica leaves at 1000 µg/mL inhibition % of mycelial of 54.3, 42.4, 41.3 and 31.5%, respectively. When compared under storage conditions of orange fruit, the lowest disease incidence and, thus, the highest reduction of disease severity (86.7%) were caused by S. cylindrica leaf extract. These effects were supported by high values of total phenols content (TPC) and total flavonoids content (TFC) in treated fruit, along with elevated activities of antioxidant enzymes: peroxidase (PO) and polyphenol oxidase (PPO). The identified phytochemicals in S. cylindrica leaf extract were dominated by fatty acids and their esters, which, together with the other compounds, have evidence of microbial activity. To sum up, using methanolic extracts of S. cylindrica as a substitute for chemical fungicides may help control P. italicum in 'Washington Navel©' oranges. [ABSTRACT FROM AUTHOR]

Penicillium digitatum and Penicillium italicum are responsible for citrus green and blue moulds (GM and BM), respectively, which are major citrus postharvest diseases. The aim of this study was to develop an optimal dipping mixture of an aqueous solution of different food additives: sodium bicarbonate (SB), sodium benzoate (SBen), and potassium sorbate (PS), in combination with heat, to control GM and BM using response surface methodology. The ranges of SB (0.0%, 3.0%, 6.0%), SBen (0.0%, 0.5%, 1.0%), PS (0.0%, 0.5%, 1.0%) and temperature (20 °C, 35 °C, 50 °C) with a dipping time of 60s were tested for their impact on GM and BM on artificially inoculated oranges. Within these tested ranges, SB reduced GM severity and incidences of both GM and BM. PS affected BM severity and incidence, but not GM. SBen and temperature did not have impact on GM and BM. The most suitable food additive concentrations were identified to be 4.7% SB, 1.0% SBen and 0.7% PS, with a dipping solution temperature of 50 °C. This treatment was shown to reduce GM and BM incidence from 85 and 86% on control fruit dipped in tap water at 20 °C to 3 and 10%, respectively. Additionally, the severity of GM and BM was reduced from 64 and 26 mm on control fruit to

Lemons (Citrus limon L.) are one of the most economically important and consumed fruit worldwide. The species is vulnerable to several postharvest decay pathogens, of which Penicillium italicum associated with blue mold disease is the most damaging. This study investigates the use of integrated management for blue mold of lemon using lipopeptides (LPs) extracted from endophytic Bacillus strains and resistance inducers. Two resistance inducers; salicylic acid (SA) and benzoic acid (BA) were tested at 2, 3, 4, and 5 mM concentrations against the development of blue mold on lemon fruit. The 5 mM SA treatment produced the lowest disease incidence (60%) and lesion diameter (1.4 cm) of blue mold on lemon fruit relative to the control. In an in vitro antagonism assay eighteen Bacillus strains were evaluated for their direct antifungal effect against P. italicum; CHGP13 and CHGP17 had the greatest inhibition zones of 2.30 and 2.14 cm. Lipopeptides (LPs) extracted from CHGP13 and CHGP17 also inhibited the colony growth of P. italicum. LPs extracted from CHGP13 and 5 mM SA were tested as single and combined treatments against disease incidence and lesion diameter of blue mold on lemon fruit. SA + CHGP13 + PI had the lowest disease incidence (30%) and lesion diameter (0.4 cm) of P. italicum on lemon fruit relative to the other treatments. Furthermore, the lemon fruit treated with SA + CHGP13 + PI had the highest PPO, POD, and PAL activities. The postharvest quality analysis of the lemon fruit including fruit firmness, total soluble solids, weight loss, titratable acidity, and ascorbic acid content revealed that the treatment SA + CHGP13 + PI had little effect on fruit quality compared to the healthy control. These findings indicate that Bacillus strains and resistance inducers can be used as components of integrated disease management for the blue mold of lemon.

The aim of this study was to investigate the phytochemical analysis and antifungal activities of ethanolic extract of Ficus benghalensis on the growth of fungal strains causing rot in orange fruit during storage (Penicillium digitatum and Penicillium italicum). Total phenol content was evaluated according to Folin-Ciocalteu method, total flavonoid content was evaluated according to aluminum chloride colorimetric method, and antioxidant activity was evaluated based on DPPH and ABTS free radical scavenging methods. Various methods (disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum fungicidal concentration) were used to evaluate the antifungal activity of ethanolic extract of F. benghalensis. The amount of phenol and flavonoids in the whole extract was 110.49 mg GAE/g and 62.60 mg QE/g, respectively. Antioxidant activity of ethanolic extract of F. benghalensis based on DPPH and ABTS radical inhibition methods was 48.56 and 57.20 μg/ml, respectively. The results of disk diffusion agar and well diffusion agar tests showed that the antifungal activity of the extract was concentration dependent and the fungal strains of Penicillium digitatum and Penicillium italicum with the lowest and highest diameter of growth inhibition zone, were the most resistant and sensitive species to the extract, respectively. The minimum inhibitory concentrations for the above strains were 16 and 8 mg/ml, respectively, and the minimum fungicidal concentrations were 512 and 128 mg/ml, respectively. According to the results, ethanolic extract of F. benghalensis is an important source of antioxidant and antifungal compounds and can be used to increase the shelf life of horticulturalproducts. [ABSTRACT FROM AUTHOR]

[Objective] The study intends to isolate the Penicillium strains from postharvest mold citrus, and identify the parasitic mycovirus in Penicillium pathogen. [Method] Using decaying fruits in citrus orchard as materials, conidia were selected and separated by streaking on PDA medium.Virus strains with additional nucleic acid fragments of the genome were screened according to total genome electrophoresis map, and the corresponding viruses were identified by RT-PCR amplification of additional fragments. [Result] According to the colony morphology, two types of Penicillium（25 strains in total） with distinct colony characteristics were isolated, including 16 strains of Penicillium with grey-green colonies and 9 strains of Penicillium with dark yellow-green colonies.Two representative strains of P.italicum and P.digitatum（DY10 and DY18） were amplified by ITS and the PCR product was sequenced.The identification results showed that they were P.italicum and P.digitatum, respectively.The total genome of Penicillium strains possessed an additional element with a size of about 6000 bp.It was speculated that it might be homologous to the reported PdV1 virus genome.Using PdV1 genome as a reference sequence, a primer pair was designed to amplify cDNA from the dsRNA by RT-PCR.The PCR product was a specific fragment with a size of about 500 bp spanned CP to RdRp encoding genes partial sequences, which was sequenced to obtain a sequence of 444 bp by Sanger sequencing.The BLASTx alignment showed that the cDNA sequence derived from the viral dsRNA was 99.7% identity with the homology region of the P.digitatum virus 1（KU257669.1, KU933932.1）. [Conclusion] Four strains of P.digitatum virus were identified as different virus strains of the same species as PdV1 belonging to the genus Victorivirus.The research provides more biocontrol virus resources for the study of the interaction mechanism between mycovirus and the host fungi, and the green prevention and control of the citrus green mold. [ABSTRACT FROM AUTHOR]

Wampee (Clausena lansium) is a relative of cultivated citrus in the Rutaceae family. Its cracked fruit in orchard is not susceptible to Penicillium italicum infection, but the mechanism remains unknown. In this study, it was found that the volatiles from wampee leaf (WL) and wampee pericarp (WP) can repress the infection and development of P. italicum in vitro. Additionally, WL exhibited strong antifungal effects in in vivo experiments as well. Antifungal activity analysis of WL volatile organic compounds (VOCs) demonstrated that (E)-2-hexenal is the key antifungal compound against P. italicum by disrupting the integrity of cell membrane. Moreover, exogenous (E)-2-hexenal treatment significantly reduced the area covered by mycelia on citrus fruits and increased the expression of genes and accumulation of various metabolites related to disease resistance. These results indicate that WL can be used as a promising natural preservative in citrus postharvest handling mainly due to the antifungal activity of (E)-2-hexenal. • Volatiles from wampee leaves have antifungal activities. • (E)-2-hexenal is an important antifungal component in wampee leaves. • Exogenous (E)-2-hexenal treatment enhances the resistance of citrus fruit to blue mold. [ABSTRACT FROM AUTHOR]

In order to analyze the function of PacC, a pH-signaling transcription factor of Penicillium italicum, which was a postharvest pathogen of citrus fruits. The gene had 1921 bp cDNA and an intron, which encoded 636 amino acids and contains three typical zinc finger domains of transcription factors. Phylogenetic tree analysis showed that the PacC was clustered with Penicillium digitatum and Penicillium chrysogenum. In vitro test, the PacC gene was stably expressed during the growth of P.italicum. The pH of the medium affected the growth of P.italicum and the expression level of PacC, and the expression level was significantly down-regulated under acidic conditions(P

Penicillium italicum is the causal agent of citrus blue mold, which is a major threat to the global citrus fruit industry. Antofine, a natural phenanthroindolizidine alkaloid, is water-soluble and exhibits a broad range of biological activities. However, whether it can inhibit P. italicum growth and the potential inhibitory mechanism remains to be elucidated. This study aimed to investigate the antifungal mechanism of antofine against P. italicum using scanning electron microscopy, transmission electron microscopy (TEM), propidium iodide staining, and tandem mass tag-labeled quantitative proteomic analysis. Antofine was found to exhibit its preeminent antifungal activity against P. italicum with a minimum inhibitory concentration of 1.56 mg/L and a minimum fungicidal concentration of 6.25 mg/L. The challenge test revealed that antofine inhibited the development of citrus blue mold during a 6-d P. italicum -infected period. Antofine acted on its potential multitargets to inhibit P. italicum growth by synergistically activating oxidative stress through accumulating excess reactive oxygen species, impairing membrane integrity, inducing membrane lipid peroxidation, and disrupting mitochondrial function, thereby disrupting the membrane system and reducing cell viability. Moreover, antofine treatment downregulated most differentially expressed proteins involved in carbon metabolism, pyruvate metabolism, and the tricarboxylic acid cycle (TCA) in P. italicum mycelia, which may explain the mitochondrial decomposition observed by TEM and the declines in ATP levels as well as the activities of TCA-related enzymes. These results indicate that antofine treatment inhibited P. italicum growth by targeting the cell membrane and mitochondria. [ABSTRACT FROM AUTHOR]

In this study, we present the development of a novel CaMn4O8–G–SiO2 (CaMnGS) sensor to detect the presence of Penicillium italicum mold. CaMnGS as ternary type nanocomposite was synthesized using a self-assembly technique. CaMnGS sample demonstrated outstanding stability, high selectivity, and notable characteristics for Penicillium italicum fungus detection. For Penicillium italicum fungus sensing, the CaMnGS displayed a large linear range of (50–100) μL, and a low detection limit of 0.50 μL. Significantly, the CaMnGS sensor was capable of swiftly detecting the Penicillium italicum fungus in wastewater. The CaMnGS has been proven to improve the selectivity for Penicillium italicum and had tremendous potential for Penicillium italicum fungal sensing. The mesoporous CaMnGS sensor may also detect the presence or absence of the fungus Penicillium italicum. This method might be used to identify the fungus Penicillium italicum. This is also the first attempt to discuss the fabrication of an electrochemical sensor employing a mesoporous CaMnGS nanoparticle composite as a platform for the selective detection of Penicillium italicum. Penicillium italicum sensing [ABSTRACT FROM AUTHOR]

During the postharvest period, citrus fruits are exposed to Penicillium italicum, Penicillium digitatum, and Geotrichum candidum. Pesticides such as imazalil (IMZ), thiabendazole (TBZ), orthophenylphenol (OPP), and guazatine (GUA) are commonly used as antifungals. Glyphosate (GP) is also used in citrus fields to eliminate weed growth. The sensitivity of fungal pathogens of citrus fruit to these pesticides and 1,8-cineole was evaluated, and the effect of GP on the development of cross-resistance to other chemicals was monitored over a period of 3 weeks. IMZ most effectively inhibited the mycelial growth and spore germination of P. digitatum and P. italicum, with minimum inhibitory concentrations (MICs) of 0.01 and 0.05 mg/mL, respectively, followed by 1,8-cineole, GP, and TBZ. 1,8-Cineole and GP more effectively inhibited the mycelial growth and spore germination of G. candidum, with minimum inhibitory concentrations (MICs) of 0.2 and 1.0 mg/mL, respectively, than OPP or GUA. For the spore germination assay, all substances tested showed a total inhibitory effect. Subculturing the fungal strains in culture media containing increasing concentrations of GP induced fungal tolerance to GP as well as to the fungicides. In soil, experiments confirmed that GP induced the tolerance of P. digitatum to TBZ and GP and the tolerance of P. italicum to IMZ, TBZ, and GP. However, no tolerance was recorded against 1,8-cineole. In conclusion, it can be said that 1,8-cineole may be recommended as an alternative to conventional fungicides. In addition, these results indicate that caution should be taken when using GP in citrus fields. [ABSTRACT FROM AUTHOR]

Citrus fruits are vulnerable to green mold (caused by Penicillium digitatum) and blue mold (caused by Penicillium italicum) during storage, posing significant challenges to the industry. Therefore, biological control utilizing antagonistic bacteria has emerged as a dependable strategy for managing postharvest diseases. In this study, halophilic bacterial isolates were carefully selected from diverse saline ecosystems, including the Dead Sea, the Agadir Sea, the Rabat Sea, saline soil, and water of the Amassine Oued in Taounate, based on rigorous in vitro and in vivo antagonism bioassays. Out of 21 bacteria from different saline environments, 10 were chosen for further characterization based on the 16S rDNA gene. Notably, the EAM1 isolate demonstrated exceptional inhibitory effects, reaching a 90% inhibition rate against P. digitatum, while the ER2 isolate closely followed with an 89% inhibition rate against P. italicum. Furthermore, in bacterial supernatant experiments, six bacterial isolates effectively curbed the growth of P. digitatum, and three demonstrated efficacy against P. italicum development. In an in vivo trial spanning ten days of incubation, three highly effective isolates against P. digitatum displayed zero severity, and two of these isolates also demonstrated zero severity against P. italicum. Interestingly, a comparison of bacterial filtrates revealed that all isolates exhibited a severity level of over 50% against the pathogen causing green rot (P. digitatum), while the severity was lower than 50% for the supernatants of the two isolates used against P. italicum. In conclusion, this study highlights the promising role of halophilic bacteria, specifically Bacillus amyloliquefaciens EAM1 and B. amyloliquefaciens ER2, in controlling postharvest fruit pathogens. The findings shed light on the potential of utilizing these bioprotective agents to address the challenges posed by green and blue citrus molds, providing valuable insights for the citrus industry.

Overall, 180 yeasts and bacteria isolated from the peel of citrus fruits were screened for their in vitro antagonistic activity against Penicillium digitatum and P. italicum, causative agents of green and blue mold of citrus fruits, respectively. Two yeast and three bacterial isolates were selected for their inhibitory activity on mycelium growth. Based on the phylogenetic analysis of 16S rDNA and ITS rDNA sequences, the yeast isolates were identified as Candida oleophila and Debaryomyces hansenii while the bacterial isolates were identified as Bacillus amyloliquefaciens, B. pumilus and B. subtilis. All five selected isolates significantly reduced the incidence of decay incited by P. digitatum and P. italicum on 'Valencia' orange and 'Eureka' lemon fruits. Moreover, they were effective in preventing natural infections of green and blue mold of fruits stored at 4 °C. Treatments with antagonistic yeasts and bacteria did not negatively affect the quality and shelf life of fruits. The antagonistic efficacy of the five isolates depended on multiple modes of action, including the ability to form biofilms and produce antifungal lipopeptides, lytic enzymes and volatile compounds. The selected isolates are promising as biocontrol agents of postharvest green and blue molds of citrus fruits. [ABSTRACT FROM AUTHOR]

[Display omitted] • Optical absorption and scattering were compared in diseased citrus flavedo. • Light propagation in diseased flavedo was investigated by Monte Carlo simulation. • The μ a increased at 482 nm and decreased at 675 nm in diseased citrus fruits. • The photon packets weight and penetration depth reduced at 482 nm during storage. This original work investigated the optical properties and Monte-Carlo (MC) based simulation of light propagation in the flavedo of Nanfeng tangerine (NF) and Gannan navel orange (GN) infected by Penicillium italicum. The increase of absorption coefficient (μ a) at around 482 nm and the decrease at around 675 nm were both observed in infected NF and GN during storage, indicating the accumulation of carotenoids and loss of chlorophyll. Particularly, the μ a in NF varied more intensively than GN, but the limited differences of reduced scattering coefficient (μ s ') were detected while postharvest infection. Besides, MC simulation of light propagation indicated that the photon packets weight and penetration depth at 482 nm in NF were reduced more than in GN flavedo, while there were almost no changes at the relatively low absorption wavelength of 926 nm. The simulated absorption energy at 482 nm in NF and GN presented more changes than those at 675 nm during infection, thus could provide better detection of citrus diseases. Furthermore, PLS-DA models can discriminate healthy and infected citrus, with the accuracy of 95.24 % for NF and 98.67 % for GN, respectively. Consequently, these results can provide theoretical fundamentals to improve modelling prediction robustness and accuracy. [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]

A new method was proposed to produce alginate bio-films containing Pichia membranifaciens and Wickerhamomyces anomalus killer yeast to control the post-harvest fungal decay in organic apples caused by Botrytis cinerea and Penicillium italicum. Coatings with W. anomalus killer yeast effectively controlled the growth of P. italicum during storage at 22 °C. W. anomalus killer yeast incorporated in alginate reduced the P. italicum incidence from 90% (control) to 35% after 14 days of storage at 22 °C. Alginate biofilms with W. anomalus or P. membranifaciens also limited the incidence of the fungal decay of apples inoculated with B. cinerea compared with the control fruits, although the antagonistic capability against B. cinerea was lower than against P. italicum. The survival of W. anomalus cells in alginate coating was higher than P. membranifaciens. The incorporation of killer yeasts into alginate had no significant effect on the mechanical properties (tensile strength, percent elongation at break) of alginate coating, however, they increased the thickness of the biofilm. The bioactive coating reduced the fruit weight loss and had no significant effects on the fruit firmness during storage at 2 °C. As organic apples, produced without any synthetic fungicides, are especially prone to fungal decay during storage, the proposed alginate biofilms containing killer yeast seem to be a very promising solution by offering non-chemical, biological control of post-harvest pathogens. [ABSTRACT FROM AUTHOR]

Blue mold caused by Penicillium italicum is one of the two major postharvest diseases of citrus fruits. The interactions of pathogens with their hosts are complicated, and virulence factors that mediate pathogenicity have not yet been identified. In present study, a prediction pipeline approach based on bioinformatics and transcriptomic data is designed to determine the effector proteins of P. italicum. Three hundred and seventy-five secreted proteins of P. italicum were identified, many of which (29.07%) were enzymes for carbohydrate utilization. Twenty-nine candidates were further analyzed and the expression patterns of 12 randomly selected candidate effector genes were monitored during the early stages of growth on PDA and infection of Navel oranges for validation. Functional analysis of a cell wall integrity-related gene Piwsc1, a core candidate, was performed by gene knockout. The deletion of Piwsc1 resulted in reduced virulence on citrus fruits, as presented by an approximate 57% reduction in the diameter of lesions. In addition, the mycelial growth rate, spore germination rate, and sporulation of ΔPiwsc1 decreased. The findings provide us with new insights to understand the pathogenesis of P. italicum and develop an effective and sustainable control method for blue mold. [ABSTRACT FROM AUTHOR]

Penicillium italicum (P. italicum), a citrus blue mold, is a pathogenic fungus that greatly affects the postharvest quality of citrus fruits with significant economic loss. Our previous research showed that 2-methoxy-1, 4-naphthoquinone (MNQ) inhibited the growth of Penicillium italicum. However, the water dispersibility of MNQ will limit its further application. Herein, we synthesized MNQ-based carbon dots (2−CDs) with better water dispersibility, which showed a potential inhibitory effect on P. italicum (MIC = 2.8 μg/mL) better than that of MNQ (MIC = 5.0 μg/mL). Transcriptomics integrated with metabolomics reveals a total of 601 differentially enriched genes and 270 differentially accumulated metabolites that are co-mapped as disruptive activity on the cell cytoskeleton, glycolysis, and histone methylation. Furthermore, transmission electron microscopy analysis showed normal appearances and intracellular septum of P. italicum after treatment. These findings contribute tofurther understanding of the possible molecular action of 2−CDs. [ABSTRACT FROM AUTHOR]

Chitosan-based film with and without antagonistic yeast was prepared and its effect against Penicillium italicum was evaluated. The biocompatibility of yeast cells in the developed films was assessed in terms of population dynamics. Furthermore, the impact on physicochemical properties of the prepared films with and without yeast cells incorporated were evaluated in terms of thickness, mechanical properties, color and opacity. Chitosan films with the antagonistic yeast entrapped exhibited strong antifungal activity by inhibiting the mycelial development (55%), germination (45%) and reducing the sporulation process (87%). Chitosan matrix at 0.5% and 1.0% was maintained over 9 days of cell viability. However, at 1.5% of chitosan the population dynamics was strongly affected. The addition of yeast cells only impacted color values such as a*, b*, chroma and hue angle when 1.0% of chitosan concentration was used. Conversely, luminosity was not affected in the presence of yeast cells as well as the opacity. Besides, the addition of antagonistic yeast improved the mechanical resistance of the films. The addition of D. hansenii in chitosan films improve their efficacy for controlling P. italicum, and besides showed desirable characteristics for future use as packaging for citrus products. [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]

Abstract Background Penicillium italicum (blue mold) is one of citrus pathogens causing undesirable citrus fruit decay even at strictly-controlled low temperatures (

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The present work reports the bioassay-guided isolation of four bioactive fatty acid derivatives involving a new butenolide, namely sinulolide I (1) together with three known metabolites (2–4) from the deep-sea sediment derived fungus Aspergillus terreus SCSIO 41202. The chemical structure of compound 1 was elucidated based on extensive spectroscopic methods (1D/2D NMR and HR-ESI-MS), optical rotation and circular dichroism analyses, while the structures of the known compounds (2–4) were established by comparison of NMR spectral data with those reported in literature. All of these four compounds (1–4) exhibited significant antifungal activity against citrus postharvest pathogen Penicillium italicum (MICs around 0.031–0.125 mg/mL). [ABSTRACT FROM AUTHOR]

Summary: The present study evaluated the effects of 15 μL L‐1 nitric oxide (NO) on the fruit defence response of 'Newhall' navel orange. The decay rate of NO‐treated navel orange fruits was significantly lower than that of control fruits during storage at 20 °C storage (P < 0.05). Treatment with NO suppressed the increase in disease incidence and lesion area in orange fruits inoculated with Penicillium italicum (P. italicum); significantly increased the activities of phenolic metabolism‐associated enzymes and pathogenesis‐related (PR) proteins, including polyphenoloxidase (PPO), phenylalanine ammonia‐lyase (PAL), β‐1,3‐glucanase (GLU) and chitinase (CHT); and enhanced the activities of key enzymes, including 4‐coumarate: CoA ligase (4CL), cinnamate‐4‐hydroxylase (C4H) and chalcone isomerase (CHI) in the phenylpropanoid pathway. The contents of total phenolics, flavonoids and lignin were also higher in NO‐treated fruits than in control fruits. The findings suggest that exogenous NO could induce disease resistance against P. italicum in navel orange fruits. [ABSTRACT FROM AUTHOR]

Citrus is susceptible to infection by a variety of fungi during storage and transportation, leading to severe economic loss. Penicillium italicum is one of two major postharvest diseases of citrus fruits, causing blue mold. It is crucial to seek a safe and effective way to replace or reduce the use of synthetic fungicides for health and environmental concerns. Since the ammonium carbonate can be expected to inhibit P. italicum activity in recent years, it still remains unknown on the specific mechanism and the effect on the fruit quality of different citrus species. Taking the "Navel" orange, "Tribute" citrus, and "Fertile" orange as the research objects, this study aims to investigate the antifungal activity of ammonium carbonate against Penicillium italicum causing blue mold in fruits via interfering reactive oxygen metabolism. A possible mechanism of ammonium carbonate was also clarified to evaluate the storage qualities under the safe and limited growth of P. italicum after treatment. Scanning and transmission electron microscope (SEM/TEM) were utilized to characterize the mycelial morphology and mitochondrial structure. The mitochondrial ATPase activities and H2O2 content were also measured to determine the inhibition of substances against the pathogens. Furthermore, the activity of antioxidant enzymes and the content of reduced glutathione were measured to further clarify the effect of ammonium carbonate on the accumulation of reactive oxygen species (ROS). In addition, an in-vivo experiment was carried out to explore the effects of ammonium carbonate on the storage quality, such as soluble solids, vitamin C, titratable acid, reducing sugar, and color of citrus. The results showed that ammonium carbonate greatly inhibited the spore germination and mycelial growth of P. italicum in a dose-dependent manner. Specifically, ammonium carbonate at 0.4 and 0.8 g/L completely inhibited the spore germination and mycelial growth, respectively. The morphology observation showed that ammonium carbonate caused the growth of mycelia with sparse nodes and fewer branches. Ultrastructural observation showed that the hypha was seriously shrunk to the abnormal structure of mitochondria. Physiological and biochemical analysis indicated that ammonium carbonate treatment caused the decrease of Na+ /K+ -ATPase, Ca2+-ATPase, and Mg2+ -ATPase activities in the mitochondria of hypha, further resulted in the loss of reduced glutathione content and glutathione reductase activity, concurrently interrupted the balance of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities in the scavenging system of ROS, and finally to promote the H2O2 accumulation in hypha of P. italicum. Nevertheless, the addition of Cysteine (Cys), a scavenger of ROS, partially restored the spore germination that inhibited by ammonium carbonate. In-vivo test, 16 g/L ammonium carbonate treatment significantly reduced the lesion diameter of citrus fruits inoculated with P. italicum (P<0.05), and then alleviated the disease severity in Novel orange, Tribute citrus, and Fertile orange. Correspondingly, the ammonium carbonate treatment can be expected to reduce the natural disease incidence without adverse effects on fruit weight loss, color, and quality parameters, including soluble solids, titratable acid, vitamin C, and reducing sugar contents. These results demonstrated that ammonium carbonate can be used to damage the mitochondrial structure and function of P. italicum, thereby promoting the accumulation of ROS for the antifungal activity. The powerful antifungal activity of ammonium carbonate against P. italicum can offer great potential application in control of postharvest decay of citrus fruits. [ABSTRACT FROM AUTHOR]

Penicilliumphytopathogenic species provoke severe postharvest disease and economiclosses.Penicillium expansumis the main pome fruit phytopathogen whilePenicillium digitatumandPenicillium italicumcause citrus green and blue mold, respectively. Control strategies rely on theuse of synthetic fungicides, but the appearance of resistant strains and safety concerns have ledto the search for new antifungals. Here, the potential application of different antifungal proteins(AFPs) including the threePenicillium chrysogenumproteins (PAF, PAFB and PAFC), as well as theNeosartorya fischeriNFAP2 protein to controlPenicilliumdecay, has been evaluated. PAFB wasthe most potent AFP againstP. digitatum,P. italicumandP. expansum, PAFC and NFAP2 showedmoderate antifungal activity, whereas PAF was the least active protein. In fruit protection assays,PAFB provoked a reduction of the incidence of infections caused byP. digitatumandP. italicuminoranges and byP. expansumin apples. A combination of AFPs did not result in an increase in theefficacy of disease control. In conclusion, this study expands the antifungal inhibition spectrum of theAFPs evaluated, and demonstrates that AFPs act in a species-specific manner. PAFB is a promisingalternative compound to controlPenicilliumpostharvest fruit decay. [ABSTRACT FROM AUTHOR]