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Sugars and organic acids are important factors associated with the postharvest quality of fruits and vegetables, but respiratory metabolism effects the metabolite contents. The objectives of this study were to explore the affects of Fusarium proliferatum infection on the postharvest quality and respiratory metabolism of green asparagus. It was found that F. proliferatum caused the soluble sugar concentration of asparagus to increase over the first 2 d of storage and then decrease again to become significantly lower than the control at 4 d. The titratable acidity (TA) of infected asparagus also increased from day 2 to day 6 and then decreased to become significantly lower than the control. Similarly, the key enzyme activities of the Embden-Meyerhof-Parnas (EMP) pathway, tricarboxylic acid (TCA) cycle, and pentose phosphate pathway (PPP) increased in pathogen-infected asparagus at the beginning of storage and then decreased to become lower than the control at the end. These findings demonstrate that F. proliferatum caused quality deterioration and an impairment of respiratory metabolism in postharvest asparagus. This research helps to clarify the relationships between pathogen infection, physiological metabolism, and asparagus quality and will provide valuable information for the control of postharvest diseases of asparagus. [ABSTRACT FROM AUTHOR]

Fruit‐based diets are recognized for their benefits to human health. The safety of fruit is a global concern for scientists. Fruit microbiome represents the whole microorganisms that are associated with a fruit. These microbes are either found on the surfaces (epiphytes) or in the tissues of the fruit (endophytes). The recent knowledge gained from these microbial communities is considered relevant to the field of biological control in prevention of postharvest fruit pathology. In this study, the importance of the microbiome of certain fruits and how it holds promise for solving the problems inherent in biocontrol and postharvest crop protection are summarized. Research needs on the fruit microbiome are highlighted. Data from DNA sequencing and "meta‐omics" technologies very recently applied to the study of microbial communities of fruits in the postharvest context are also discussed. Various fruit parameters, management practices, and environmental conditions are the main determinants of the microbiome. Microbial communities can be classified according to their structure and function in fruit tissues. A critical mechanism of microbial biological control agents is to reshape and interact with the microbiome of the fruit. The ability to control the microbiome of any fruit is a great potential in postharvest management of fruits. Research on the fruit microbiome offers important opportunities to develop postharvest biocontrol strategies and products, as well as the health profile of the fruit. [ABSTRACT FROM AUTHOR]

Brown rot, aspergillosis and soft rot are the primary diseases of postharvest peach fruit. Our study aimed to investigate the biocontrol effect of Wickerhamomyces anomalus on the primary postharvest diseases of peach fruit and to explore its underlying physiological mechanism. The findings demonstrated that W. anomalus had an obvious inhibitory effect on Monilinia fructicola , Aspergillus niger and Rhizopus stolonifer. At the same time, W. anomalus can grow stably on the wound and surface of peach fruit at 25 °C and 4 °C and can form biofilm. W. anomalus increased the activity of resistance-related enzymes such as PPO, POD, GLU and the content of secondary metabolites such as total phenols, flavonoids and lignin in peach. Furthermore, the application of W. anomalus led to a reduced MDA level in peach fruit and increased activity of the active oxygen-scavenging enzyme system. This increase involved various antioxidant defense enzymes such as SOD and CAT, as well as ascorbic acid-glutathione (AsA-GSH) enzymes, including APX, GPX, GR, DHAR, and MDHAR. Our findings demonstrate that W. anomalus exerts its biocontrol effect by growing rapidly, competing with pathogens for nutrition and space, and enhancing the disease resistance and antioxidative capabilities of the peach fruit. • W. anomalus could control brown rot, aspergillosis and soft rot decay of peach • W. anomalus can stably colonize the surface and wounds of peach • W. anomalus enhanced the defense enzyme (PPO, POD, GLU) activities of peach • W. anomalus increased flavonoids, phenolic and lignin content of peach • W. anomalus increased the antioxidant defense enzymes and AsA-GSH enzymes in peach [ABSTRACT FROM AUTHOR]

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. • Transcription factors of pear against P. expansum infection were screened by ATAC-seq. • MAPK signaling pathway in pear was activated by P. expansum. • SAUR , CYCD3 and TF TGA in plant hormone signal transduction pathway were up-regulated. • NCED and CYP707A in carotenoid biosynthesis pathway were up-regulated. [ABSTRACT FROM AUTHOR]

Grey and blue mould diseases are among the most important diseases of grapes worldwide. They are causing extensive decay in postharvest grapes. Chemical fungicides remain the primary treatment for managing these diseases. However, consumer's interest in organic produce, restrictions on chemical use by some countries, and concerns about human and environmental safety have driven research to identify safe and effective alternatives. Among several alternative approaches, the use of biological control agents (BCAs) is getting more acceptance and has been comprehensively studied. This review summarizes the use of BCAs as a postharvest treatment to control the postharvest grey and blue mould of grapes. The review also emphasizes the economic importance of these two major postharvest diseases of grapes. In addition, other non-chemical postharvest treatments, the advantage of an integrated approach and finally problems, challenges, and future trends of the BCAs are described. Several yeasts that have a promising result to control grey and blue mould disease of grapes are thoroughly reviewed. The current market share of BCAs and their future directions on commercialization are also suggested in this review. Biocontrols can be a potential control method for postharvest diseases of fruits and vegetables in place of chemical fungicides. Antagonistic yeasts have high ability to suppress fungal growth. Integrated approach utilizes a combination approaches, which often results in a synergistic effect to control the diseases. USA and Europe are currently the largest markets for biocontrol products. [ABSTRACT FROM AUTHOR]

• M. caribbica can reduced the natural decay rate of postharvest kiwifruit. • M. caribbica increased the expression of stress resistance-related genes in kiwifruit. • M. caribibica enhanced the ability of kiwifruit to eliminate ROS and activate immune signals. Meyerozyma caribbica, an antagonistic yeast, effectively controls the postharvest blue mold decay of kiwifruit. Our previous study explored the mechanism of M. caribbica inhibiting the postharvest blue mold in kiwifruit at the physiological level, but its molecular mechanism is still unknown. This study investigated the related molecular mechanisms of disease-resistance in kiwifruits induced by M. caribbica based on transcriptome analysis. In addition, the effects of M. caribbica on the natural decay and storage quality of postharvest kiwifruit were investigated. The research showed that M. caribbica could reduce natural decay during kiwifruit storage without an apparent adverse effect on quality. The transcriptome analysis of postharvest kiwifruit found that there were 2916 DEGs, of which 1986 were up-regulated and 930 were down-regulated. KEGG pathway analysis showed that the plant-pathogen interaction pathway, glycolysis/gluconeogenesis pathway, flavonoid biosynthesis pathway, glutathione metabolism pathway and phenylpropane biosynthesis pathway were associated with the enhancement of kiwifruit resistance. The analysis of related metabolic pathways and functional analysis of related DEGs showed that M. caribbica could improve the expression of genes related to kiwifruit resistance, which are associated with induction of fruit resistance, mediated substance transport, improvement of cell wall strength, enhancement of plant antioxidant capacity, signal transduction and secondary metabolite synthesis, etc. These results provide a reference for future research on the use of antagonistic yeasts to prevent and control postharvest diseases of fruits and vegetables, and provide a theoretical basis for the practical application of antagonistic yeasts. [ABSTRACT FROM AUTHOR]

Microbial antagonists provide a new perspective on biological control by altering microbial diversity to control postharvest diseases of fruit. In this study, the biological control effect of Debaryomyces hansenii on postharvest diseases of strawberry and the influence on strawberry quality were determined. At the same time, the effect of D. hansenii on the composition of surface microbiome of strawberry fruit was analyzed by high-throughput sequencing technology. The results showed that D. hansenii treatment can inhibit the natural decay rate of strawberries, and the treatment group maintained a higher ascorbic acid content than the control group. However, there was no difference between the control and treatment groups in firmness, weight loss rate, soluble solids, titratable acidity, and other quality indicators. On the surface of strawberries treated with D. hansenii , the diversity of fungal community was changed, the composition and structure of the community were also altered (except the abundance of Debaryomyces spp.). Strawberries treated with D. hansenii could alter bacterial and fungal populations, inhibit plant pathogens, and lower the frequency of postharvest diseases in strawberries. This study helps to understand the microbial community structure on the surface of strawberries and guides the synthesis of strawberry postharvest disease complex biocontrol strains to achieve stable and sustainable postharvest disease control strategies of the fruits. • Debaryomyces hansenii reduced the natural decay rate of strawberries. • The surface microbiome of D. hansenii treated-strawberries was investigated. • D. hansenii treatment inhibited Erwinia and Cladosporium at the genus level. • The fungal community diversity of D. hansenii was changed. [ABSTRACT FROM AUTHOR]

• GABA increased the activities of CAT and CHI in S. pararoseus Y16. • GABA decreased the MDA content of S. pararoseus Y16. • GABA increased the expression of stress resistance-related genes in S. pararoseus Y16. • The expression levels of CAT and CHI in S. pararoseus Y16 were increased. Our previous study showed that γ-aminobutyric acid (GABA) can significantly enhance the biological control efficacy of Sporidiobolus pararoseus Y16 on postharvest diseases of grapes. The possible physiological biocontrol mechanisms of the yeast have been reported previously, however, the associated molecular mechanisms were unclear. This study aimed to investigate the possible molecular mechanisms behind the enhanced biological control efficacy of S. pararoseus Y16 cultured with GABA based on transcriptome analysis. In addition, the activities of catalase (CAT) and chitinase (CHI) and the content of malondialdehyde (MDA) in S. pararoseus Y16 were investigated. The results showed that after the addition of 4 mg/mL GABA, the activities of CAT and CHI in S. pararoseus Y16 were significantly increased, and the content of MDA accumulation was decreased. Transcriptome analysis found that GABA-treated S. pararoseus Y16 can improve the ability of yeast ion transport, cell wall remodeling, antioxidants, growth and reproduction, resistance to stress, amino acid synthesis, etc., resulting in increased antagonistic efficacy of S. pararoseus Y16. These results provide a reference for future research on the use of antagonistic yeasts to prevent and control postharvest diseases of fruits and vegetables, and provide a theoretical basis for the practical application of antagonistic yeasts. [ABSTRACT FROM AUTHOR]

• D. hansenii significantly reduced the incidence of postharvest soft rot of strawberry. • D. hansenii can stably colonize the surface and wounds of strawberry. • D. hansenii reduced the spore germination rate and germ tube length of R. stolonifer. • D. hansenii induced the activities of SOD, POD, CAT, APX, PPO and PAL in strawberry. • D. hansenii increased total phenolic, flavonoid and anthocyanin content in strawberry. The postharvest disease of strawberries caused by Rhizopus stolonifer caused enormous financial losses. This study investigates the efficacy of antagonistic yeast Debaryomyce hansenii in the biocontrol of postharvest soft rot of strawberries and the physiological mechanisms involved. The results showed that D. hansenii significantly reduced the incidence of postharvest soft rot of strawberry, reduced the natural decay incidence of postharvest strawberry, and had no adverse effects on quality parameters of strawberries. In vitro experiments showed that D. hansenii reduced the spore germination rate and germ tube length of R. stolonifer. D. hansenii can also stably colonize the surface and wounds of strawberries at either 4 °C or 20 °C. Meanwhile, the activities of antioxidant-related enzymes superoxide dismutase, peroxidase, catalase, ascorbate oxidase and resistance-related enzymes polyphenol oxidase and phenylalanine ammonia-lyase were significantly higher in D. hansenii -treated strawberries than in control. Meanwhile, the contents of resistance-related substances including total phenols, flavonoids and anthocyanins were also increased in D. hansenii -treated strawberries. This study suggested that D. hansenii has the potential to control postharvest soft rot of strawberry by the mechanism involving inhibition of spore germination and germ tube length of R. stolonifer and induction of increased activities of defense-related enzymes and substances in strawberry. [ABSTRACT FROM AUTHOR]

• M. guilliermondii combined with AOS effectively reduced the natural decay of pears. • M. guilliermondii induced genes related to disease resistance in pears. • Genes of the WRKY signaling pathway in pears were induced by M. guilliermondii. • M. guilliermondii combined with AOS could further improve the resistance of pears. It has been reported that the antagonistic efficacy of M. guilliermondii combined with alginate oligosaccharide (AOS) could enhanced in controlling the postharvest diseases of pears. The possible physiological biocontrol mechanisms has been unveiled in our previously research, however, the related molecular mechanisms were unclear. In this study, the possible molecular mechanisms behind the enhanced antagonistic efficacy of M. guilliermondii combined with AOS based on transcriptome technology were investigated. Our results suggested that M. guilliermondii can induce the resistance of pears mainly from promoting signal transduction, inducing up-regulation of several disease-resistance genes and defense genes, improving the ability of antioxidant stress, promoting the synthesis of resistant substances, maintaining the integrity of cell membrane and cell wall strength and increasing the expression levels of genes closely related to resistance. M. guilliermondii combined with AOS can further improve the resistance of pears by promoting the synthesis of resistant substances, inducing the up-regulation of resistance related genes, promoting signal transduction, regulating the expression levels of genes closely related to resistance and maintaining the strength of cell wall. [ABSTRACT FROM AUTHOR]

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. • MeJA improved antioxidant activity and cell wall synthesis of M. guilliermondii. • M. guilliermondii induced by MeJA enhanced disease-resistance pathways of apples. • The expression levels of PPO , EXPA1 , TFT6 , GHR5 , CYP73 in apples were increased. [ABSTRACT FROM AUTHOR]

• Y. lipolytica enhanced β-1,3-glucanase, SOD and APX activities of mandarins. • MDA content of mandarins was decreased induced by Y. lipolytica. • Transcriptome analysis of mandarins induced by Y. lipolytica was investigated. Yarrowia lipolytica can effectively control blue mold and green mold decay of mandarins (Citrus reticulata), and the potential physiological mechanisms underlying this efficacy were examined in our previous research. The molecular mechanisms related to the resistance response, however, were not clearly elucidated. In the present study, the molecular mechanisms associated disease-resistance response induced by Y. lipolytica in mandarins were investigated. Results indicated the activity of disease-resistance related enzymes, including β-1,3-glucanase, superoxide dismutase, and ascorbate peroxidase was enhanced in mandarins when they were treated with Y. lipolytica , while malondialdehyde content decreased. Notably, based on transcriptome analysis, it was found that Y. lipolytica induced the up-regulation of genes related to the synthesis of resistance-related compounds; key genes associated with plant-pathogen interactions; reactive oxygen species scavenging genes; and genes involved in the jasmonic acid, salicylic acid and ethylene signal transduction pathways in mandarins. Y. lipolytica also down-regulated the expression levels of genes encoding cell-wall-degrading enzymes. Elucidating the molecular mechanisms associated with the biocontrol efficacy of Y. lipolytica will contribute to its potential use as an effective biocontrol agent against post-harvest diseases of mandarins. [ABSTRACT FROM AUTHOR]

• The proteomics of grapes induced by Y. lipolytica was analyzed. • The transcriptomics of grapes induced by Y. lipolytica was analyzed. • Y. lipolytica increased the expression of resistance-related proteins in grapes. • Y. lipolytica induced the expression levels of resistance-related genes in grapes. Grape berries are vulnerable to pathogen infections, during the process of harvesting and transporting, which cause tremendous economic losses. It has been reported that Yarrowia lipolytica could effectively control postharvest diseases of grapes, however, there is a very limited amount of studies available to the researchers about molecular mechanism of induced resistance. This study aimed to reveal the molecular regulation of resistance mechanism of grapes induced by Y. lipolytica , using proteomics and transcriptomics approaches. The results of the proteomics analysis of Y. lipolytica triggered grape showed that resistant related proteins involved in the process of response to stress, pathogenesis related allergenic proteins, energy production, signal transduction and oxidoreductase of grapes were all induced by Y. lipolytica and up-regulated. Similarly, transcriptomics analysis also provided the information about the up-regulation of defence related genes in grapes treated with Y. lipolytica. Meanwhile, 9 up-regulated DEGs, identified through transcriptomics analysis were selected to validate the expression levels of the genes by RT-qPCR. The DEGs include pathogenesis related allergenic proteins (PR4 , PR5 and PR10) , hypersensitivity protein, WRKY transcription factor, peroxidase isoenzyme and DEGs related to the synthesis of phytoalexin. The present study evidenced that Y. lipolytica induced and increased the expression of resistance-related proteins in grapes, which were related to response stress, energy production, signal transduction and oxidoreductase, while the expression of resistance-related genes were also up-regulated, so as to enhance the defense response of grapes against various postharvest infections. [ABSTRACT FROM AUTHOR]

• W. anomalus significantly reduced the natural decay of pear fruit. • W. anomalus induced the accumulation of resistance-related proteins in pear fruit. • W. anomalus induced the expression of resistance-related genes in pear fruit. Wickerhamomyces anomalus, a yeast used for the biocontrol of postharvest diseases of fruits, significantly reduces the natural decay of pear fruit without causing any adverse changes in the pear fruit quality. In the present research, the proteome of control pear fruit and pear fruit treated with W. anomalus were analyzed by 2-dimensional electrophoresis (2-DE). Several differentially expressed proteins (DEPs) were identified in pear fruit treated with W. anomalus , among which 13 were up-regulated and 14 were down-regulated. The transcriptome of control and W. anomalus -treated pear fruits was also analyzed. RNA sequencing results revealed 1076 differentially expressed genes (DEGs) in W. anomalus -treated pear fruits, in which 51.67% (556) were up-regulated and 48.33% (520) were down-regulated (at a log 2 Fold Change ≥ 1, FDR < 0.05). Notably, W. anomalus induced several disease resistance-related genes and their corresponding proteins in pear fruit, as well as genes associated with the jasmonic acid signaling pathway, flavonoid biosynthesis, and carbohydrate metabolism. [ABSTRACT FROM AUTHOR]

Our previous study demonstrated that the combined application with oligochitosan (OCH) improved the biocontrol efficacy of Pichia caribbica against postharvest black spot of tomato fruits. The involved mechanisms were elucidated based on the induction of fruit resistance. However, the mechanisms needed to be further explored from the antagonistic yeast perspective. The current study determined the effects of OCH on P. caribbica growth in vitro and the effects of combined application with OCH on the colonization ability, the reactive oxygen species (ROS) accumulation, especially the gene expression levels of P. caribbica in fruit wounds. The findings revealed that OCH increased the viable cell number of P. caribbica in NYDB and in tomato fruit wounds. Additionally, combined application with OCH could alleviate ROS accumulation in P. caribbica inoculated in fruit wounds. Transcriptome analysis revealed that the genes related to MAPK signal transduction, meiosis – yeast, DNA replication, tryptophan metabolism and glutathione metabolism of P. caribbica were induced by the combined application with OCH in fruit wounds, which triggered its MAPK signal transduction, promoted its growth and reproduction, and improved its antioxidant capability. Therefore, the capability of P. caribbica to survive and colonize fruit wounds were raised and its antagonistic efficacy against postharvest black spot pathogen was heightened by combined application with OCH. This study will open up new possibilities for improving the biocontrol efficacy of antagonists against postharvest pathogens of fruits and vegetables. • OCH improved P. caribbica growth and reproduction in NYDB and in tomato wounds. • ROS accumulation in P. caribbica inoculated in fruit wounds was alleviated by OCH. • Genes related to MAPK signaling in P. caribbica were induced by OCH. • OCH up-regulated genes related to P. caribbica growth and reproduction. • The expression of antioxidant response genes in P. caribbica was heightened by OCH. [ABSTRACT FROM AUTHOR]

Soft rot caused by Pectobacterium carotovorum is one of the most serious postharvest bacterial diseases of green peppers. The present research aimed to determine the biocontrol effect of Bacillus subtilis on postharvest soft rot of green peppers and to further delve into biocontrol mechanisms by analyzing the metabolism of reactive oxygen species (ROS) in green peppers. As key results, soft rot occurrence of green peppers was alleviated with the increase of the concentration of B. subtilis , and the disease incidence and index of the fruits treated with 1 × 109 CFU/mL of B. subtilis for 4 d were 28.3% and 12.7%, respectively, which were significantly decreased compared with that of the control. B. subtilis could significantly increase NADPH oxidase (NOX) activity in green peppers to trigger ROS outbreaks, which induced defense response of the fruits. Furthermore, it promoted the enzymatic activities of the ROS scavenging system, including antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), ascorbic acid-glutathione (AsA-GSH) cycle-related enzymes (ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR)), glutathione peroxidase (GPX) cycle-related enzymes (GPX, GR and glutathione- s -transferase (GST)). Besides, B. subtilis increased the non-enzymatic ROS scavenging system contents, including ascorbate (AsA) and glutathione (GSH) in green peppers. Importantly, the levels of O 2 −·, H 2 O 2 and malondialdehyde (MDA) in green peppers were reduced, thereby enhancing green pepper disease resistance. This study offers novel insights to advanced strategies in preventing and controlling postharvest soft rot in green peppers. • B. subtilis effectively reduced postharvest soft rot of green peppers. • B. subtilis alleviated the production of O 2 ‾·, and the contents of H 2 O 2 and MDA. • NOX activity in green peppers was increased by B. subtilis. • Antioxidant enzyme activities in green peppers were stimulated by B. subtilis. • B. subtilis triggered AsA-GSH and GPX cycles, along with GST in green peppers. [ABSTRACT FROM AUTHOR]

Fungal diseases pose significant threats to the production of asparagus, resulting in economic losses and decreased crop quality. The potential of the yeast Yarrowia lipolytica as a biocontrol agent against Fusarium proliferatum , a common pathogen of asparagus, was investigated in this study. The effects of Y. lipolytica treatment on decay incidence, disease index, and activities of major disease defense-related enzymes were investigated. In addition, we examined the levels of antifungal compounds such as total phenols, flavonoids, and lignin in asparagus plants exposed to Y. lipolytica. The results showed that Y. lipolytica treatment significantly reduced decay incidence and disease index caused by F. proliferatum when compared to the control group. Furthermore, Y. lipolytica -treated plants showed increased activity of disease defense-related enzymes, indicating that defense responses were activated. The activities of all evaluated enzymes were significantly higher in Y. lipolytica -treated asparagus, indicating an improved ability to combat fungal pathogens. Furthermore, Y. lipolytica treatment increased the content of antifungal compounds such as total phenols, flavonoids, and lignin, which are known to possess antimicrobial properties. These findings highlight the potential of Y. lipolytica as a biocontrol agent for fungal diseases in asparagus crops. The ability of Y. lipolytica to reduce disease incidence, boost disease defense-related enzymes, and increase antifungal compound content provides valuable insights into its efficacy as a natural and sustainable approach to disease management. However, further investigations are needed to optimize application methods and determine its efficacy under field conditions. [Display omitted] • Y. lipolytica reduced decay incidence and disease index in postharvest asparagus. • Activities of POD, PPO, PAL, CAT, SOD, and GR enzymes of asparagus increased. • Contents of antifungal compounds o increased after treated with Y. lipolytica. • There is correlation between antifungal compounds and disease defense enzymes. [ABSTRACT FROM AUTHOR]

[Display omitted] • P. caribbica combined with OCH improved resistant enzyme activity in tomato fruits. • Combined application upregulated the genes involved in α-linolenic acid metabolism. • The genes in Ca2+, MAPK and plant hormones signaling pathways were induced. • The expression levels of genes participated in ROS metabolism were enhanced. • The genes related to resistant secondary metabolite synthesis were upregulated. Our previous study showed that postharvest treatment of tomato with Pichia caribbica along with oligochitosan (OCH) significantly alleviated postharvest black spot of tomato fruit compared with P. caribbica alone. This study was to explore the effect of combined application of OCH and P. caribbica on disease resistance of tomato fruits through analyzing the activities of disease resistance-related enzymes, as well as transcriptome analysis of the fruit gene expression. Our findings indicated that P. caribbica , together with OCH, improved the activities of key enzymes associated with disease resistance in tomato fruit. Moreover, the combined application further upregulated the expression of genes involved in α-linolenic acid metabolism, the signal transduction pathways such as Ca2+, MAPK and plant hormone signaling pathways, resistant substance synthesis, and ROS metabolism, which improved the fruit disease resistance. Considering the significance of these results, OCH hold great potential for use in microbial biocontrol strategies against postharvest tomato diseases. [ABSTRACT FROM AUTHOR]

This study assessed the biocontrol efficacy of Meyerozyma guilliermondii against blue mold decay caused by Penicillium expansum in pears and the possible mechanisms involved. The results indicated that M. guilliermondii significantly inhibited the blue mold decay caused by P. expansum without affecting the quality of the pears. M. guilliermondii rapidly colonized the wounds and surfaces of the pears at both 4 °C and 20 °C. The rapid growth in the population of M. guilliermondii in the wounds and surface environments of pears indicated that it has the potential to inhibit pathogens in pears. The activities of antioxidant enzymes (peroxidase and catalase) in the pear were improved after the application of the yeast. Phenylalanine ammonialyase (PAL), a key enzyme involved in lignin biosynthesis and defense related activity, was also markedly enhanced. Generally, the application of yeast induced disease resistance in the pear. The results pear proteomics profile after M. guilliermondii treatment showed that 17 proteins were significantly up-regulated and 13 were down-regulated in response to induction with M. guilliermondii . Most of the proteins were involved in defense and stress responses based on biological process. These results provided a new insight into the biocontrol mechanism of the antagonist yeast in the pear fruit. [ABSTRACT FROM AUTHOR]

• P. caribbica combined with OCH could further reduce black spot of tomato fruits. • O 2 –·, H 2 O 2 and MDA production in tomato fruits were decreased. • NOX activity in tomato fruits was increased by P. caribbica combined with OCH. • SOD, POD, and CAT activities in tomato fruits were induced. • AsA-GSH cycle and GPX cycle in tomato fruits were triggered. Black spot caused by Alternaria alternata is one of the main postharvest diseases of tomato fruits. This research aimed to investigate biocontrol efficacy of Pichia caribbica combined with oligochitosan (OCH) against black spot of tomato fruits and explore the mechanisms involved in improved disease resistance of the fruits by yeast combined with OCH based on analysis of reactive oxygen species (ROS) metabolism. The results indicated that in comparison with P. caribbica alone, yeast combined with OCH (2000 μg/mL) could further reduce black spot of tomato fruits. P. caribbica combined with OCH increased NADPH oxidase (NOX) activity in the fruits compared with the control and the group treated with yeast alone. The activities of enzymatic system for ROS scavenging including antioxidant enzymes, enzymes involved in ascorbate–glutathione (AsA-GSH) and GPX (glutathione peroxidase) cycles, and glutathione S-transferase (GST) in the fruits were induced by yeast combined with OCH. Additionally, the contents of ascorbic acid (AsA) and glutathione (GSH) belonging to non-enzymatic system for ROS scavenging were enhanced in the fruits. Collectively, the induction of NOX and the improvement of enzymatic and non-enzymatic systems for ROS scavenging resulted in the decrease in O 2 –·, H 2 O 2 and malondialdehyde (MDA) production in the fruits, thus promoting the disease resistance of tomato fruits. This research will provide new ideas for the control of postharvest diseases of tomato fruits. [ABSTRACT FROM AUTHOR]

• M. guilliermondii decreased natural decay of postharvest broccoli. • Energy production and supply in broccoli were increased by M. guilliermondii. • M. guilliermondii significantly induced the synthesis of secondary metabolites. • Accumulation of sugar alcohols were enhanced by the yeast. • The levels of unsaturated fatty acids and intermediates, GSH were also increased. Postharvest diseases of broccoli resulted in quality deterioration and huge economic loss. This study investigated the biocontrol efficacy of Meyerozyma guilliermondii against natural decay of postharvest broccoli. Meanwhile, the mechanisms involved in the enhanced disease resistance of broccoli by M. guilliermondii were explored based on energy metabolism modulation and metabolomic analysis of broccoli. The results showed that M. guilliermondii could alleviate the disease index of postharvest broccoli. This yeast could potentially increase energy production and supply through inducing the activities of related enzymes and maintaining a higher ATP level. Metabolomic analysis illustrated that the treatment with M. guilliermondii significantly increased secondary metabolites synthesis, sugar alcohols accumulation, the level of unsaturated fatty acids and their metabolic intermediates, and glutathione level. In conclusion, M. guilliermondii improved the disease resistance of postharvest broccoli through enhancing energy production and supply, synthesis of resistant compounds, and thus reducing the natural decay disease index of broccoli. [Display omitted] [ABSTRACT FROM AUTHOR]

• M. guilliermondii alleviated black spot disease index of postharvest broccoli. • M. guilliermondii stimulated AsA-GSH and GPX cycles in broccoli to scavenge ROS. • M. guilliermondii raised antioxidant enzymes activities in broccoli to scavenge ROS. • M. guilliermondii lowed ROS accumulation and membrane lipid peroxidation in broccoli. Black spot caused by Alternaria brassicicola is one of the most common fungal diseases of postharvest broccoli. The present study investigated the biocontrol efficacy of Meyerozyma guilliermondii against black spot of postharvest broccoli and the mechanisms involved in the enhanced disease resistance of broccoli based on its effects on reactive oxygen species (ROS) metabolism. Our investigation proved that M. guilliermondii could decrease the disease index of postharvest broccoli caused by A. brassicicola. This antagonistic yeast could potentially increase peroxidase, catalase and superoxide dismutase activities, and the activities of enzymes involved in ascorbate–glutathione cycle and glutathione peroxidase cycle, such as ascorbate peroxidase, glutathione peroxidase and glutathione reductase. Furthermore, the contents of non-enzymatic antioxidants, including ascorbic acid and glutathione, were enhanced by this yeast. Accordingly, the accumulation of ROS, including hydrogen peroxide (H 2 O 2) and superoxide anion (O 2 –), was reduced by M. guilliermondii , as well as malondialdehyde amount which was one of the membrane lipid peroxides. Our results suggested that M. guilliermondii could improve the activities of ROS scavenging enzymatic system and the levels of antioxidant substances to scavenge excessive ROS, and then protect cells from oxidative damage, which enhanced the disease resistance of broccoli to pathogens. Overall, our study provides a new disease control strategy for postharvest broccoli by improving the ability of ROS scavenging to resist pathogens. [ABSTRACT FROM AUTHOR]

• P. caribbica decreased the occurrence of black spot in postharvest cherry tomatoes. • The production rate of O 2 ¯· and the contents of H 2 O 2 and MDA were reduced. • P. caribbica increased SOD, POD and CAT activities in cherry tomatoes. • P. caribbica stimulated AsA-GSH cycle, GPX cycle and GST activity in cherry tomatoes. Black spot caused by Alternaria alternata is one of major diseases of postharvest cherry tomatoes. This study intends to investigate biocontrol efficacy of Pichia caribbica against black spot and explore the mechanisms involved in improved disease resistance of cherry tomatoes through analyzing reactive oxygen species (ROS) metabolism. The results demonstrated that P. caribbica significantly decreased the occurrence of black spot in cherry tomatoes. P. caribbica improved the activities of enzymatic system for ROS scavenging in cherry tomatoes, including some antioxidant enzymes, the enzymes in ascorbic acid-glutathione (AsA-GSH) and glutathione peroxidase (GPX) cycles, and glutathione S-transferase (GST). Furthermore, P. caribbica maintained the high level of the key antioxidant substances and then decreased the production rate of O 2 ¯·, the contents of H 2 O 2 and malondialdehyde (MDA). These results revealed that P. caribbica induced the enzymatic and non-enzymatic systems to remove ROS, and then improved the disease resistance of cherry tomatoes against pathogen. This study will provide new strategy for controlling postharvest disease of fruits and vegetables by improving the ability of ROS scavenging to defense against pathogens. [ABSTRACT FROM AUTHOR]

Abstract: The control activity of Rhodotorula mucilaginosa, alone or in combination with phytic acid (PA) on gray mold spoilage and natural spoilage of strawberries was investigated. R. mucilaginosa as stand-alone treatment significantly reduced the disease incidence of gray mold spoilage of strawberries at 20 °C, and the combination of R. mucilaginosa and PA at the concentration of 4 mol/ml and 6 mol/ml were more effective than R. mucilaginosa alone treatment. In vitro test showed that PA at the concentration of 4 mol/ml and 6 mol/ml significantly enhanced the inhibition of the growth of Botrytis cinerea on PDA. PA at all the tested concentrations enhanced the growth of R. mucilaginosa in NYDB media. PA at the concentration of 4 mol/ml slightly increased the population growth of R. mucilaginosa in strawberry wounds at the first day at 20 °C, and slightly increased the population growth of R. mucilaginosa in fruit wounds at 4 °C at the whole storage time. The combination of R. mucilaginosa and PA at the concentration of 4 mol/ml was the most effective treatment in controlling the natural spoilage of strawberries following storage at 4 °C for 20 d followed by 20 °C for 5 d. [Copyright &y& Elsevier]

• Pear gene expression response to P. expansum were clustered by STEM analysis. • Functional annotation of DEGs in profiles were done by GO and KEGG enrichment. • Pears can produce a complex defense reactions after P. expansum infection. • P. expansum can increase the activities of resistant enzymes in pears. In pears, blue mold decay caused by Penicillium expansum, is a destructive postharvest disease around the world, which leads to stasis of the pear industry and creates huge economic losses. Our previous research work proved that P. expansum mainly secretes cell wall degrading enzymes (CWDEs) to infect pears. To further understand the molecular basis of P. expansum infection and disease progression, in the present study we have tried to investigate the transcriptome of pears infected with P. expansum. The differentially expressed genes (DEGs) identified from the RNA-seq results were clustered into 2 upward trends and 6 downward trends according to their gene expression patterns. Comparison of Gene ontology (GO) terms in downward and upward trend profiles evidenced that the enriched GO terms (included metabolic processes for l -phenylalanine, aromatic amino acid family and ethylene, etc.), found in upward trend profiles were more relevant to pear defense. Moreover, the Kyoto Encyclopedia of Genes and Genomes (KEGG) results revealed that pears can produce a complex defense response against P. expansum infection. Briefly, P. expansum produced CWDEs to establish infection, which triggers relevant transduction pathways in pear. These pathways led to further activation of the secondary regulatory networks. Finally, some metabolites were synthesised to defense against P. expansum. In general, the information obtained in this study will be supportive to develop new strategies to control fungal diseases. [ABSTRACT FROM AUTHOR]

Our previous study showed that the biocontrol efficacy of Rhodotorula mucilaginosa against postharvest diseases of strawberries can be significantly enhanced by chitosan. Proteome analysis of R. mucilaginosa induced by chitosan has preliminarily explored the molecular mechanisms involved in the enhanced antagonistic efficacy of R. mucilaginosa induced by chitosan. In this study, transcriptome analysis of R. mucilaginosa cultured with and without chitosan was performed, and the activities of CAT, PPO, POD, and SOD were also investigated to further explore the involved mechanisms. The results indicated that the activities of these antioxidant enzymes in R. mucilaginosa were all significantly increased by 0.5 g/100 mL chitosan. Especially, POD activity was about 1.5 - fold higher than the control. Transcriptome and bioinformatic analysis revealed that significant number of genes involved in growth and reproduction, adhesion, energy production, oxidative stress response and other stress response were all induced by chitosan, which resulted in the enhanced antagonistic efficacy of R. mucilaginosa. These results provide a reference for the future study on controlling postharvest disease of fruit and vegetables by antagonist yeast and provide a theoretical basis for the practical application of antagonist yeast. • Chitosan induced certain genes related to growth and reproduction in R. mucilaginosa. • Expression of some genes involved in energy production was enhanced. • Antioxidant enzyme activities and oxidative stress response genes were induced. • Expression of genes correspond to various adversity response was increased. [ABSTRACT FROM AUTHOR]

• JA/ET, ABA, GA signaling pathways and downstream genes and protein were activated. • Some DEGs and DEPs involved in synthesis of resistance substances were induced. • The expression of DEG and DEP involved in ROS regulation were enhanced. • Some DEGs involved in cell wall reinforcement of strawberry were up-regulated. Rhodotorula mucilaginosa cultured in a medium amended with chitosan significantly enhances biological control efficacy against postharvest fungal diseases of strawberries. The molecular mechanisms underlying the enhanced disease resistance of strawberries, however, have not been explored. In this study, a transcriptomic and proteomic approach was used to analyze the induced resistance response in strawberry. Results revealed that several genes involved in JA/ET, ABA and GA signal transduction pathways, as well as downstream genes and protein, were up-regulated by R. mucilaginosa cultured in a medium amended with 0.5% (w/v) chitosan. Several genes and proteins related to the synthesis of resistance-related compounds and processes were also up-regulated, including genes related to ROS regulation, and genes involved in cell wall reinforcement. Collectively, results indicated that disease resistance in strawberry can be induced by R. mucilaginosa cultured with chitosan. A global view of gene expression and protein abundance in hosts treated with an antagonist provides a theoretical reference for understanding the enhancement of disease resistance of fruits by antagonistic yeast incubated with elicitors, information that will also help in obtaining regulatory approval for the commercial use of yeast as biocontrol agents. [ABSTRACT FROM AUTHOR]

• R. mucilaginosa induced by chitosan for 24 h showed the best biocontrol efficacy. • Proteins involved in growth and reproduction, energy metabolism were up-regulated. • Proteins related to stress response were induced by chitosan. • The expression of CTS2 (chitinase) was also increased by chitosan. • The ROS accumulation was decreased in R. mucilaginosa incubated with chitosan. The biocontrol efficacy of the yeast, Rhodotorula mucilaginosa against postharvest diseases of strawberries can be significantly enhanced by culturing the yeast in a medium containing chitosan. The molecular mechanisms involved in the enhanced biocontrol efficacy of R. mucilaginosa , however, have not been comprehensively explored. Results of the present study indicate that the biocontrol efficacy of the yeast against gray mold (Botrytis cinerea) of strawberry was greatest when the yeast was cultured in a medium containing 0.5% (w:v) chitosan for 24 h before use. Proteomic and bioinformatic analyses revealed that proteins involved in growth and reproduction, energy metabolism, antioxidant response, response to abiotic stress, and degradation of pathogen cell walls were all up-regulated by chitosan resulting in the enhanced antagonistic activity of R. mucilaginosa against B. cinerea. The decrease in ROS accumulation in R. mucilaginosa cultured in a medium containing chitosan was in agreement with the increased abundance of proteins related to antioxidant defense. Key differentially expressed proteins (DEPs) were identified and 12 randomly-selected DEPs were validated by parallel reaction monitoring. The present results provide a theoretical reference for further study of the molecular mechanisms involved in the improvement of biocontrol efficacy of antagonistic yeast by elicitor molecules and also provide a novel approach for improving biological control of postharvest diseases. [ABSTRACT FROM AUTHOR]