Penicillium Expansum Infection Research Articles

Influence of Polyphenols on the Resistance of Traditional and Conventional Apple Varieties to Infection by Penicillium expansum during Cold Storage

This study investigates the impact of polyphenols on the susceptibility of traditional and conventional apple varieties to Penicillium expansum infection and subsequent patulin biosynthesis during cold storage. Traditional varieties, notably ‘Bobovec’, exhibit significantly higher levels of total polyphenols (650.56 ± 9.85 mg/L) and flavonoids (184.11 ± 1.48 g/kg dw) compared to conventional ones after six months of storage, accompanied by the identification of key polyphenols such as chlorogenic acid, epicatechin, phloridzin, quercetin and procyanidins B1 and B2. These traditional varieties demonstrate enhanced resistance to P. expansum infection, as evidenced by prolonged periods for colony formation, particularly ‘Bobovec’ with an average of 384 h. Furthermore, the traditional variety ‘Winter Banane’ and conventional varieties ‘Idared’ and ‘Fuji’ showed increased patulin biosynthesis postinoculation, indicating higher susceptibility to fungal infection. The findings underscore the potential of polyphenols from traditional apple varieties as natural defences against fungal infections, suggesting the importance of selecting or breeding varieties with higher polyphenol content to improve resistance to postharvest pathogens, thereby enhancing the quality and safety of stored apples.

Metabonomic Investigation of Penicillium expansum Infection of Apples and Salicylic Acid-Mediated Disease Resistance

Metabonomic Investigation of Penicillium expansum Infection of Apples and Salicylic Acid-Mediated Disease Resistance

Assay for transposase accessible-chromatin with high throughput sequencing (ATAC-seq) analysis the molecular responses of postharvest pear during Penicillium expansum infection

Blue mold decay caused by Penicillium expansum is a global destructive postharvest disease, which has brought huge economic losses to the pear industry. Transcription factors play an important role in pear anti-infection defense, and it has been observed that they have multiple functions. However, the roles of numerous TFs in the defense of pear against P. expansum have not been adequately explored. In this study, ATAC-seq was used to screen the TFs of pear against P. expansum, thereby understanding the chromatin-mediated gene regulation in the defense of pear against infection. The peak of differential expression enriched 9 transcription factors (AGL27, AT5G02460, AT2G28810, AT5G66940, AT3G46070 and OBP1, TCP3, BPC1 and TCP17). The up-regulated genes in our study were implicated in the MAPK signaling pathway-plant, plant hormone signal transduction pathway, plant-pathogen interaction pathway, glutathione metabolism pathway, phenylpropanoid biosynthesis, flavonoid biosynthesis pathway and carotenoid biosynthesis pathway were identified. Especially the transcription factors TGA, gene SAUR and CYCD3 in plant hormone signal transduction pathway and NCED, CYP707A in carotenoid biosynthesis pathway were differentially regulated. RT-qPCR analysis of twelve randomly selected differentially expressed peak-related genes confirmed the accuracy of ATAC-seq analysis of P. expansum infected pear.

Genome-wide investigation and analysis of C2H2 Zinc Finger Protein gene family in apple: Expression profiles during Penicillium expansum infection process

The gene family known as C2H2 zinc finger genes is widely recognized for its significant role in facilitating plant growth, development and reproduction. Many C2H2 zinc finger proteins (C2H2-ZFPs) have been identified and intensively studied in other plants, but little is known about their function in apples. In this study, the C2H2-ZFPs genes of apples were identified and analyzed by whole genome sequence analysis. In our study, 70 members of the C2H2-ZFPs gene family were identified in apples. Phylogenetic analyses divided the apple C2H2-ZFPs gene family into 6 subgroups, with the same subgroups having similar gene structures and motif patterns and speculating on their possible functions. After analysis based on numerous cis-elements on gene promoters, the apple C2H2-ZFPs family contained many light-responsive elements, phytohormone-responsive elements, plant growth and development-related elements, and stress-responsive elements, which indicated the diversity of their functions. The RNA-seq results of apples under P. expansum treatment revealed that fifteen C2H2-ZFPs genes were differentially expressed. The RT-qPCR further validated the same trend as transcriptome data. C2H2-ZFPs genes were significantly expressed in the process of P. expansum infestation. Our analysis evidenced that the apple C2H2-ZFPs gene family plays a vital role in the process of P. expansum infestation in apples. The identified genes can serve as potential candidates for further investigation. The present study provides new ideas for further research on the function of C2H2-ZFPs genes and the innovation of disease resistance technology in apples.

Proteomic Analysis of Apple Response to Penicillium expansum Infection Based on Label-Free and Parallel Reaction Monitoring Techniques

Blue mold, caused by Penicillium expansum, is the most destructive fungal disease of apples and causes great losses during the post-harvest storage of the fruit. Although some apple cultivars are resistant to P. expansum, there has been little information on the molecular mechanism of resistance. In this study, differential proteomic analysis was performed on apple samples infected and uninfected with P. expansum. Parallel reaction monitoring (PRM) technology was used to target and verify the expression of candidate proteins. The label-free technique identified 343 differentially expressed proteins, which were mainly associated with defense responses, metal ion binding, stress responses, and oxidative phosphorylation. The differential expression of enzymes related to reactive oxygen species (ROS) synthesis and scavenging, the activation of defense-related metabolic pathways, and the further production of pathogenesis-related proteins (PR proteins) during P. expansum infection in apples, and direct resistance to pathogen invasion were determined. This study reveals the mechanisms of apple response at the proteomic level with 9 h of P. expansum infection.

Screening and Regulation Mechanism of Key Transcription Factors of Penicillium expansum Infecting Postharvest Pears by ATAC-Seq Analysis

Transcription factors play a key role in Penicillium expansum infection process. Although the crucial characteristics of some transcription factors of pathogenic fungi have been found, many transcription factors involved in P. expansum infections have not been explored and studied. This study aimed to screen the transcription factors of P. expansum involved in postharvest pear infections by ATAC-seq analysis and to analyze the differentially expressed peak-related genes by GO enrichment and KEGG pathway analysis. Our results found the up-regulation of differentially expressed peak-related genes involved in the MAPK signaling pathway, pentose phosphate pathway, starch and sucrose metabolism, and pentose and glucuronate interconversions. Our study especially confirmed the differential regulation of transcription factors MCM1, Ste12 and gene WSC in the MAPK signaling pathway and PG1, RPE1 in the pentose and glucuronate interconversions pathway. These transcription factors and related genes might play an essential role in pear fruit infection by P. expansum. RT-qPCR validation of twelve expressed peak-related genes in P. expansum showed that the expression levels of these twelve genes were compatible with the ATAC-Seq. Our findings might shed some light on the regulatory molecular networks consisting of transcription factors that engaged in P. expansum invasion and infection of pear fruits.

Comparative proteome and transcriptome analyses of the response of postharvest pears to Penicillium expansum infection

Penicillium expansum causes blue mold disease in pears during storage and transportation, causing huge economic losses. However, researches on the defense mechanisms of pears against P. expansum are still in the early stages. Therefore, many unknown disease-resistant factors have yet to be excavated, severely limiting the breakthrough progress of pear blue mold control strategies. The current study used transcriptome and proteome approaches to evaluate pear defense mechanisms following infection with P. expansum. 96% of pear proteins were associated with the transcriptome data. Gene Ontology (GO) enrichment analysis determined that the remaining associated genes/proteins were significantly enriched in 80 GO terms. The significantly enriched GO terms included oxyacid metabolism, aldehyde-lyase activity, transition metal ion binding, terpenoid metabolic process, response to stimulus, etc. An enrichment analysis conducted by the Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that 122 metabolic pathways were enriched, of which 11 were closely related to other metabolic pathways. In these 11 metabolic pathways, the genes/proteins (such as peroxidase, histidinol-phosphate aminotransferase (hisC), prephenate dehydratase (ADT), etc.) related to the biosynthesis of plant secondary metabolites, and the genes/proteins (such as ethylene-responsive transcription factor 1 (ERF), BR-signaling kinase (BSK), brassinosteroid insensitive 1-associated receptor kinase 1 (BAK1), etc.) related to plant hormones were significantly enriched. Overall, this study provides a deep understanding of pear’s defense response, which could be used in future research to develop strategies to control fungal diseases.

(E)-2-Hexenal-based coating induced acquired resistance in apple and its antifungal effects against Penicillium expansum

(E)-2-Hexenal is one of the most prevalent and abundant volatile substances in fruits. Many researchers have attempted fumigation with (E)-2-hexenal to control fungal diseases with poor or no results; the key is the inability to maintain an effective concentration for a long time. Therefore, a new starch-based antifungal coating with (E)-2-hexenal microcapsules was prepared. The obtained results showed that the microcapsule embedding rate reached 78.95% by orthogonal optimization experiments and that the (E)-2-hexenal-based coating was effective at reducing the lesion diameter of apple fruit during storage at 25 °C after Penicillium expansum infection, and in other fruits; it also achieved a good antifungal effect. Moreover, the activities of the main defense-related enzymes and the expression of key genes involved in the salicylic acid (SA) signaling pathway, such as CHI, GLU, PAL, NPR1, and PR1, were enhanced by (E)-2-hexenal-based coating treatment. These findings suggest that the (E)-2-hexenal-based coating has the dual effect of direct antifungal and induction of apple system resistance. E2H-based coating is a promising approach to control postharvest Penicillium expansum in fruit.

Transcriptomic analysis of the mechanisms involved in enhanced antagonistic efficacy of Meyerozyma guilliermondii by methyl jasmonate and disease resistance of postharvest apples

The biological control ability of the yeast, Meyerozyma guilliermondii, in restaining Penicillium expansum infection in apples, has been reported to be enhanced by methy jasmonate (MeJA). Our previous research unveiled the possible physiological biocontrol mechanisms of the yeast; however, the related molecular mechanisms were unclear. This study aimed to investigate the possible molecular mechanisms behind the enhanced biological control efficacy of M. guilliermondii cultured with MeJA through transcriptomic approaches. The transcriptome analysis of MeJA cultured M. guilliermondii indicated that MeJA induced changes in oxidative stress response, energy metabolism, cell wall synthesis and stability and cell growth. Meanwhile, transcriptomic analysis of apples treated with M. guilliermondii and MeJA cultured M. guilliermondii was also investigated. Our results witnessed that MeJA cultured M. guilliermondii enhanced the cell wall synthesis, antioxidant activity, plant disease resistance, increased peroxisome proliferation, energy metabolism, phenylpropane metabolism and other pathways of apples. Expression levels of PPO, EXPA1, TFT6, GHR5, CYP73 and other genes were increased, which enhanced the apple's stability, antioxidant, stress resistance and energy metabolism. This study will provide a theoretical basis for improving the biocontrol efficacy of antagonistic yeast cultured with MeJA.

Metabolite changes of apple Penicillium expansum infection based on a UPLC-Q-TOF metabonomics approach

The Penicillium expansum (P. expansum) infection causes apple postharvest deterioration and declines the quality of apple derived products. Investigation into the metabolic process of apple P. expansum infection will help to illustrate the mechanism of pathology and discover the biomarkers for quality control. Here, the changes of metabolite during the apple P. expansum infection were explored by ultra performance liquid chromatography and the quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) based metabonomics. Between four group of 32 samples, average 1720 positive and 1761 negative peaks were obtained, which aligned into comparable peaks of 5048 and 4945. Significantly metabonomic differences were observed between the control and P. expansum infected samples. A total of 485 differential metabolites were screened. In these different metabolites, the majority of sugars were decreased during P. expansum infection, whereas the majority of organic acids, amino acids and peptides were increased. Changes in the profile of phenolics and fatty acids were diverse, and major of them were increased for disease resistance. Disturbed metabolic pathways in early infection were mainly secondary metabolite biosynthesis, ATP-binding cassette transporters, amino acid and carbon metabolism. The intergroup comparison obtained 140 differential metabolites to represent the core metabolic changes during infection. And 27 metabolites were strongly increased along with the disease process, which could aid the biomarker discovery. This study highlights the differential metabolites during the apple P. expansum infection, and provide a basis for further investigation.

Effects of Penicillium expansum infection on the quality and flavor of yellow flesh kiwifruit during cold storage.

This study aimed to assess the effects of Penicillium expansum (P. expansum) infection on the quality and flavor of Jinmi (JM) and Jinyan (JY) kiwifruit. Kiwifruit were inoculated with P. expansum and stored at 0±1°C, and the changes in quality indicators and volatile substances (VCs) at different stages of disease were determined. Results showed that in wound-inoculated kiwifruit, the soluble solid content (SSC) increased. Conversely, their titratable acidity and vitamin C (VC) content, firmness, lightness, and saturation decreased. The taste-related parameters and nutritional value of kiwifruit declined after infection. VCs such as ethanol, 3-methyl-1-butanol, and 2-methylisoborneol were detected only in the diseased fruit and gradually increased as the disease aggravated, suggesting that they may be the main sources of odor during P. expansum infection. Therefore, VCs detection can be used to determine possible P. expansum infection, as well as the degree of infection in kiwifruit. PRACTICAL APPLICATIONS: In practical application, we can use the results of this study to determine possible Penicillium expansum infection, as well as the degree of infection in kiwifruit according to the indicators such as volatile substances. Kiwifruit enterprises can use the nondestructive detection model established in this study to screen out the kiwifruit infected with P. expansum more efficiently, quickly, and accurately, in order to prevent harm to the health of consumers.

Genome-wide investigation and analysis of U-box Ubiquitin–Protein ligase gene family in apple: Expression profiles during Penicillium expansum infection process

U-box is the protein domain, which was presented in proteins of yeasts to higher organisms. The U-box domain-contains proteins encoded by the U-box gene family, which is a huge gene family in plants. However, information about all U-box genes in apple, one of the most popular fruits all around the world is not clear and organized. In the present study, identification of the apple U-box genes was performed based on its whole-genome sequence. From the analysis, 69 U-box genes were found in apple according to the U-box domain. The U-box genes of apple distributed across all the 17 chromosomes at different densities. Phylogenetic analysis of U-box genes between apple and Arabidopsis thaliana suggested that the genes can be clustered into seven subgroups (I–VII) on the basis of their structural and phylogenetic features. Sixty-nine U-box genes and the structure of the encoded proteins were identified in apple. The RNA-seq results showed that 23 (56.1% of the detectable genes) U-box genes were found up-regulated and 18 (43.9% of the detectable genes) U-box genes were found down-regulated under P. expansum infection stress. RT-qPCR results showed the same trend with the transcriptome. The RT-qPCR validation showed that the results obtained in the transcriptomic analysis were accurate. The U-box genes of apple were strongly expressed during P. expansum infection. These results suggested that the U-box gene family of apple may play important role in the resistance mechanism of apple against P. expansum infection. This systematic research provided a foundation for further functional investigation of U-box genes with the aim of improving apple production.

Ultrastructure observation and transcriptome analysis of Penicillium expansum invasion in postharvest pears

Abstract Pears are one of the most essential fruit worldwide, they are susceptible to Penicillium expansum infection during postharvest storage, which results in high economic losses. Due to the dearth of information involving the mechanisms of infection of P. expansum in pear fruit it is very important to clarify its pathogenicity. In this study, the fungus strain was isolated from rotten pears and identified as P. expansum, which has strong pathogenicity. The results from SEM revealed that P. expansum relies on the growth of spores or the secretion of filamentous materials to degrade the cell wall of infected pear tissues. In addition, it was found that tissues were completely damaged after 24 h of infection. The RNA-seq results of P. expansum in infected pear tissue suggested that total differentially expressed genes (DEGs) were grouped into 4 profiles due to an upward trend in their gene expression patterns using the STEM software. The DEGs of the 4 profiles were involved in extracellular enzyme activity, cellular response to reactive oxygen, glutathione metabolic species, and polysaccharide metabolic process particularly the plant cell wall degrading enzyme (CWDEs) synthesis pathway. In summary, this research provides a piece of new information with regards to the infection mechanisms of P. expansum on pears, which could be useful in understanding the phenomenon of pathogen -host -fruit interaction and the development of new measures for the control of fungal diseases.

Induced resistance in peach fruit as treated by Pichia guilliermondii and their possible mechanism

ABSTRACT This research aims to assess the effect of Pichia guilliermondii treatment on the improved disease resistance of the peach fruit and to explore the biocontrol mechanisms. Infection rate and lesion diameter of the yeast-treated fruit were substantially inhibited after Rhizopus stolonifer and Penicillium expansum infection, respectively. A significant increase in endogenous salicylic acid (SA) content was stimulated in peach fruit treated with P. guilliermondii. The activities of defense-related enzymes and the SA synthase in peaches were also improved after P. guilliermondii treatment, and the expression of pathogenesis-related genes was activated. Thus, P. guilliermondii may be a biological elicitor-activated systemic acquired resistance by the SA signaling pathway. The new understanding regarding the mechanism of antagonist yeast could could be conducive for controlling fruit postharvest diseases in the future.

Investigating the effect of methyl jasmonate on the biocontrol activity of Meyerozyma guilliermondii against blue mold decay of apples and the possible mechanisms involved

Apple is one of the largely grown fruits in China, and it suffers great economic losses caused by Penicillium expansum infection every year. In the present study, we ascertained the efficacy of Meyerozyma guilliermondii enhanced by 200 μmol/L methyl jasmonate (MeJA) in controlling the postharvest blue mold decay of apples and the possible mechanisms involved. The results demonstrated that the biological control ability of M. guilliermondii induced by MeJA in restraining P. expansum infection in apples. The efficacy of M. guilliermondii induced by MeJA significantly decreased the decay incidence and lesion diameter of apples. When treated with M. guilliermondii induced by MeJA, the decay incidence of apples was only 21.6%, while apples treated with M. guilliermondii was 42.4%. M. guilliermondii induced by MeJA also reduced the germ tube length, spore germination rate of P. expansum in PDB and colony diameter of P. expansum in PDA. The results also showed that antagonistic yeast induced by MeJA proliferated better in apple wounds and surface at 4 °C or 20 °C. Meanwhile, the activities of resistance-related peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), Catalase (CAT), and the antibacterial substances of flavonoid contents, total phenolic content were all increased. The results manifested that M. guilliermondii induced by MeJA increased the expression levels of defense-related enzymes in apples.

Effects of the combination of Baobab (Adansonia digitata L.) and Sporidiobolus pararoseus Y16 on blue mold of apples caused by Penicillium expansum

The utilization of natural compounds to preserve fruit quality and extend the shelf life has gained great interest worldwide. African Baobab (AB) fruit (Adansonia digitata L.) produces some of these natural compounds, which contain several bioactive antioxidants with ascorbic acid being the major component. Sporidiobolus pararoseus Y16 combined with African Baobab extract (100 mg/ml) significantly inhibited the growth of Penicillium expansum infection than either yeast or African Baobab alone during storage at either 4 °C for 30 days followed by 20 °C for 15 days or 20 °C for 30 days. Furthermore, the apple treated with Sporidiobolus pararoseus Y16 and African Baobab significantly (P < 0.05) reduced the decay incidence and lesion diameter (in vivo), and colony diameter (in vitro) compared to the control. Moreover, fruits preserved with either Sporidiobolus pararoseus Y16 or African Baobab alone or their combination indicated no significant influence on the quality parameters of apple. The results of this study demonstrated a promising approach to enhancing the biocontrol performance of antagonistic yeast by employing African Baobab, and it has potential to help commercial producers and retailers in prolonging the shelf life of agricultural produce over a wider range in the future.

Chlorogenic acid induces resistance against Penicillium expansum in peach fruit by activating the salicylic acid signaling pathway

The objective of this study was to investigate the effect of chlorogenic acid (CGA) treatment on induction of resistance against pathogens in peach fruit. Treatment with CGA at 25–150 mg L−1 was effective at reducing lesion diameter and decay index of peach fruit during storage at 25 °C after Penicillium expansum infection. CGA treatment had also significant beneficial effects on fruit quality parameters including firmness, soluble solids contents, pH value, and titratable acidity. Activities of main defense-related enzymes and expression of key genes involved in the salicylic acid (SA) signaling pathway, such as PAL, ICS, WRKY, NPR1, PR1, CHI, GLU, PR5, and POD, were enhanced by CGA treatment. These findings suggest that CGA treatment is a promising approach to controlling postharvest blue mold rot in peach fruit, and activation of the SA signaling pathway may play a potential role in mechanisms involving CGA-induced plant disease resistance.

Effects of quercetin on postharvest blue mold control in kiwifruit

Abstract The effects of quercetin on inhibiting Penicillium expansum infections of ‘Qinmei’ kiwifruit during postharvest storage were evaluated. Severe damage to P. expansum’s mycelial structure was observed by transmission electron microscope at a quercetin concentration of 0.25 mg/mL. With the quercetin treatment, kiwifruit infected with P. expansum had higher chitinase, β-1,3-glucanase, phenylalanine ammonialyase, polyphenol oxidase and peroxidase activities, as well as nonexpressor of pathogenesis-related gene 1, pathogenesis-related gene 1, chitinase and β-1,3-glucanase expression levels, compared with those of kiwifruit only treated with quercetin or inoculated with P. expansum. Thus, the inhibitory effects of quercetin on the P. expansum blue mold may be associated with its toxic properties against fungal pathogens and inhibition of defense responses.

Unravelling the contribution of the Penicillium expansum PeSte12 transcription factor to virulence during apple fruit infection

Blue mould disease caused by Penicillium expansum infection is one of the most important diseases of pome fruit accounting for important economic losses. In the present study, the PeSte12 transcription factor gene was identified, and deletant mutants were produced by gene replacement. Knockout mutants showed a significant decrease of virulence during apple fruit infection. Virulence was affected by the maturity stage of the fruit (immature, mature and over-mature), and disease severity was notably reduced when the apples were stored at 0 °C. The ΔPeSte12 mutants resulted defective in asexual reproduction, producing less conidia, but this characteristic did not correlate with differences in microscopic morphology. In addition, the ΔPeSte12 mutants produced higher quantity of hydrogen peroxide than the wild type strain.Gene expression analysis revealed that PeSte12 was induced over time during apple infection compared to axenic growth, particularly from 2 dpi, reinforcing its role in virulence. Analysis of transcriptional abundance of several genes in ΔPeSte12 mutants showed that in most of the evaluated genes, PeSte12 seemed to act as a negative regulator during axenic growth, as most of them exhibited an increasing expression pattern along the time period evaluated. The highest expression values corresponded to detoxification, ATPase activity, protein folding and basic metabolism. Gene expression analysis during apple infection showed that 3 out of 9 analysed genes were up regulated; thus, PeSte12 seemed to exert a positive control to particular type of aldolase. These results demonstrate the PeSte12 transcription factor could play an important role in P. expansum's virulence and asexual reproduction.

Combined effect of antagonistic yeast and modified atmosphere to control Penicillium expansum infection in sweet cherries cv. Ambrunés

Fruit decay caused by pathogenic moulds is a major concern in the postharvest quality and shelf life of fruit. Blue mould decay is caused by Penicillium expansum (P. expansum) and is one of the most important postharvest diseases in cherries (Prunus avium L.). Synthetic fungicides are the main medium used to control pathogenic moulds. However, alternative approaches are available for developing safer technologies to control postharvest disease. An integrated approach that combines biological control, using antagonistic yeasts and modified atmosphere packaging (MAP) with cold storage is a promising alternative to synthetic fungicide treatment. In this work, two microperforated films (M10 and M50) and two antagonistic yeast strains (Hanseniaspora opuntiae L479 and Metschnikowia pulcherrima L672) were evaluated for their effectiveness to control the development of P. expansum in wounded cherries stored at 1°C. Results showed that the microperforated films had fungistatic effects, particularly M50, due to the level of CO2 achieved (mean CO2 of 11.2kPa at 35days), and the decrease in disease severity. Antagonistic yeasts, particularly Metschnikowia pulcherrima L672, delayed the development of P. expansum and decreased disease incidence and severity. The combination of MAP and antagonistic yeasts was the most effective approach to control P. expansum, during cold storage.