Pepper Pathogen Research Articles

Inter-species expression of an EF-HAND CALCIUM BINDING PROTEIN in Xanthomonas perforans leads to reduced virulence and decreased immune evasion in tomato plants.

Many phytopathogenic bacteria require a type three secretion system (TTSS) to activate effector triggered immunity (ETI). We identified a calcium binding protein, EfhXXfa, in the citrus pathogen, X. citri subsp. aurantifolii, that does not require a TTSS to activate reactive oxygen species (ROS) and elicit a hypersensitive reaction (HR) in tomato leaves following infection. Purified, recombinant EfhXXfa was shown to bind two moles of calcium per mole of protein, whereas mutation of the first of two EF-hands did not bind calcium . EfhXXfa expression was determined to be inducible in hrp-inducing medium. Additionally, growth of X. perforans transconjugants with and without the efhXXfa gene in hrp-inducing medium differed in intracellular calcium concentration; the transconjugant without efhXXfa yielded higher cell pellet masses and higher increased intracellular calcium concentrations relative to cells expressing EfhXXfa. An EfhXXfa homolog, EfhXXe, present in the pepper pathogen, X. euvesicatoria, when expressed in the tomato pathogen, X. perforans, triggered ROS production and an HR in tomato leaves and is a host-limiting factor. Interestingly, all tested X. perforans and X. euvesicatoria strains pathogenic on tomato contain a stop codon immediately upstream of the first EF-hand domain in the efhXXe gene, whereas most X. euvesicatoria strains pathogenic on pepper do not.

Defensin-like peptides from Capsicum chinense induce increased ROS, loss of mitochondrial functionality, and reduced growth of the fungus Colletotrichum scovillei.

In the present study, we identified and characterized two defensin-like peptides in an antifungal fraction obtained from Capsicum chinense pepper fruits and inhibited the growth of Colletotrichum scovillei, which causes anthracnose. AMPs were extracted from the pericarp of C. chinense peppers and subjected to ion exchange, molecular exclusion, and reversed-phase in a high-performance liquid chromatography system. We investigated the endogenous increase in reactive oxygen species (ROS), the loss of mitochondrial functioning, and the ultrastructure of hyphae. The peptides obtained from the G3 fraction through molecular exclusion chromatography were subsequently fractionated using reverse-phase chromatography, resulting in the isolation of fractions F1, F2, F3, F4, and F5. The F1-Fraction suppressed C. scovillei growth by 90, 70.4, and 44% at 100, 50, and 25 μg mL-1, respectively. At 24 h, the IC50 and minimum inhibitory concentration were 21.5 μg mL-1 and 200 μg mL-1, respectively. We found an increase in ROS, which may have resulted in an oxidative burst, loss of mitochondrial functioning, and cytoplasm retraction, as well as an increase in autophagic vacuoles. MS/MS analysis of the F1-Fraction indicated the presence of two defensin-like proteins, and we were able to identify the expression of three defensin sequences in our C. chinense fruit extract. The F1-Fraction was also found to inhibit the activity of insect α-amylases. In summary, the F1-Fraction of C. chinense exhibits antifungal activity against a major pepper pathogen that causes anthracnose. These defensin-like compounds are promising prospects for further research into antifungal and insecticide biotechnology applications. © 2024 Society of Chemical Industry.

Fusarium Species Causing Pepper Wilt in Russia: Molecular Identification and Pathogenicity.

Fusarium wilt pathogens represent an ongoing threat to pepper production worldwide. This is the first report providing data on the molecular identification of Fusarium fungi that cause wilt in pepper in the southern regions of Russia. Monitoring of the Fusarium infection on pepper was carried out in 2019-2022 in two economically important regions of this culture production: the Krasnodar Krai and Crimea. Based on a phylogenetic analysis of the translation elongation factor (EF1a) and the internal transcribed spacer (ITS), as well as the macro- and micromorphological characteristics of the fungi, the causative agents of Fusarium wilt have been identified. The causative agents identified as representatives of the Fusarium species composition included: F. clavus, F. solani, F. oxysporum, F. verticillioides, F. commune, F. torulosum, and F. sporotrichioides. Depending on the region, the specifics of biodiversity and the ratio of these species in pathocomplexes were noted. In Crimea, wilting could be attributed to all of the identified species; in the Krasnodar Krai, F. verticillioides and F. clavus were found to contribute to wilting. The pathogenicity test showed that the pathogens of pepper wilting in Russia, in addition to the already known F. oxysporum and F. solani, are the species F. clavus and F. verticillioides. This is the first report on the ability of these species to cause Fusarium wilt in pepper cultures. The obtained data will be of practical value for the development of biological control measures for fungi of the genus Fusarium, which cause pepper wilt in areas of industrial production and seed production. In addition, data on species composition and aggressive isolates will be used in a pepper breeding program for resistance to Fusarium wilt.

Isolation, phenotypic characterization and molecular identification of fungal pathogens of sweet pepper (Capsicum annuum L.) Fruit in Sokoto State Nigeria

Isolation, phenotypic characterization and molecular identification of fungal pathogens of sweet pepper (Capsicum annuum L.) Fruit in Sokoto State Nigeria

Population Genomics Reveals an Emerging Lineage of Xanthomonas perforans on Pepper.

Xanthomonas perforans-the dominant causal agent of bacterial leaf spot of tomato-is an emerging pathogen of pepper, indicative of a potential host expansion across the southeastern United States. However, studies of the genetic diversity and evolution of X. perforans from pepper remain limited. In this study, the whole-genome sequences of 35 X. perforans strains isolated from pepper from four fields and two transplant facilities across southwest Florida between 2019 and 2021 were used to compare genomic divergence, evolution, and variation in type III secreted effectors. Phylogenetic analysis based on core genes revealed that all 35 X. perforans strains formed one genetic cluster with pepper and tomato strains from Alabama and Turkey and were closely related to strains isolated from tomato in Indiana, Mexico, and Louisiana. The in planta population growth of tomato strains isolated from Indiana, Mexico, Louisiana, and Turkey in pepper leaf mesophyll was on par with pepper X. perforans and X. euvesicatoria strains. Molecular clock analysis of the 35 Florida strains dated their emergence to approximately 2017. While strains varied in copper tolerance, all sequenced strains harbored the avrHah1 transcription activation-like effector located on a conjugative plasmid, not previously reported in Florida. Our findings suggest that there is a geographically distributed lineage of X. perforans strains on tomato that has the genetic background to cause disease on pepper. Moreover, this study clarifies potential adaptive variants of X. perforans on pepper that could help forecast the emergence of such strains and enable immediate or preemptive intervention.

Black pepper pathogen suppression: Divergent rhizosphere fungal communities of healthy and diseased plants yield new insights for orchard management in Vietnam

Complex interactions involving soil physicochemical parameters and plant-associated microbial communities determine crop health. In Vietnam, this process is poorly understood in the context of black pepper production. Specifically, there is a dearth of information for improving the suppression of pathogenic fungi. Understanding the environmental dynamics influencing the distribution of these pathogens would facilitate the development and use of biological agents in black pepper pathogen management. Here, the molecular profiles of fungal communities from the rhizosphere of healthy and unhealthy Vietnamese black pepper orchards and their relationships were determined. Additionally, co-occurrence analyses with a previously constructed bacterial dataset identified taxa indicative of soil suppression. Alpha diversity of total fungi was influenced by only environmental factors, while that of arbuscular mycorrhizal fungi was more responsive to orchard health state. Glomus sp., Rhizophagus sp., Purpureocillium sp. and Plectosphaerella sp. were the most responsive genera to orchard health state. Potential fungal pathogens were more prevalent in the unhealthy orchards. Co-occurrence network analyses revealed that unhealthy orchards were less connected, had longer path distance and were missing putative pathogen-to-biocontrol interactions common in the healthy orchards. Soil electrical conductivity and potassium may be key factors in differentiating fungal communities of unhealthy from healthy orchards. This work highlights important microbial species and environmental considerations critical to improved black pepper management strategies.

Plant Extracts from the Yucatan Peninsula in the In Vitro Control of Curvularia lunata and Antifungal Effect of Mosannona depressa and Piper neesianum Extracts on Postharvest Fruits of Habanero Pepper.

Plant extracts are a valuable alternative for the control of phytopathogenic fungi in horticultural crops. In the present work, the in vitro antifungal effect of ethanol and aqueous extracts from different vegetative parts of 40 native plants of the Yucatan Peninsula on Curvularia lunata ITC26, a pathogen of habanero pepper (Capsicum chinense), and effects of the most active extracts on postharvest fruits were investigated. Among these, the ethanol extracts of Mosannona depressa (bark from stems and roots) and Piper neesianum (leaves) inhibited 100% of the mycelial growth of C. lunata. The three extracts were partitioned between acetonitrile and n-hexane. The acetonitrile fraction from M. depressa stem bark showed the lowest mean inhibitory concentration (IC50) of 188 µg/mL against C. lunata. The application of this extract and its active principle α-asarone in the postharvest fruits of C. chinense (500 µg/mL) was shown to inhibit 100% of the severity of the infection caused by C. lunata after 11 days of contact. Both samples caused the distortion and collapse of the conidia of the phytopathogen when observed using electron microscopy at 96 h. The spectrum of M. depressa enriched antifungal action is a potential candidate to be a botanical fungicide in the control of C. lunata in cultivating habanero pepper.

Phytophthora capsici: Recent Progress on Fundamental Biology and Disease Management 100 Years After Its Description.

Phytophthora capsici is a destructive oomycete pathogen of vegetable, ornamental, and tropical crops. First described by L.H. Leonian in 1922 as a pathogen of pepper in New Mexico, USA, P. capsici is now widespread in temperate and tropical countries alike. Phytophthora capsici is notorious for its capability to evade disease management strategies. High genetic diversity allows P. capsici populations to overcome fungicides and host resistance, the formation of oospores results in long-term persistence in soils, zoospore differentiation in the presence of water increases epidemic potential, and a broad host range maximizes economic losses and limits the effectiveness of crop rotation. The severity of disease caused by P. capsici and management challenges have led to numerous research efforts in the past 100 years. Here, we discuss recent findings regarding the biology, genetic diversity, disease management, fungicide resistance, host resistance, genomics, and effector biology of P. capsici.

The Dynamic Transcription Activator-Like Effector Family of Xanthomonas.

Transcription activator-like effectors (TALEs) are bacterial proteins that are injected into the eukaryotic nucleus to act as transcriptional factors and function as key virulence factors of the phytopathogen Xanthomonas. TALEs are translocated into plant host cells via the type III secretion system and induce the expression of host susceptibility (S) genes to facilitate disease. The unique modular DNA binding domains of TALEs comprise an array of nearly identical direct repeats that enable binding to DNA targets based on the recognition of a single nucleotide target per repeat. The very nature of TALE structure and function permits the proliferation of TALE genes and evolutionary adaptations in the host to counter TALE function, making the TALE-host interaction the most dynamic story in effector biology. The TALE genes appear to be a relatively young effector gene family, with a presence in all virulent members of some species and absent in others. Genome sequencing has revealed many TALE genes throughout the xanthomonads, and relatively few have been associated with a cognate S gene. Several species, including Xanthomonas oryzae pv. oryzae and X. citri pv. citri, have near absolute requirement for TALE gene function, while the genes appear to be just now entering the disease interactions with new fitness contributions to the pathogens of tomato and pepper among others. Deciphering the simple and effective DNA binding mechanism also has led to the development of DNA manipulation tools in fields of gene editing and transgenic research. In the three decades since their discovery, TALE research remains at the forefront of the study of bacterial evolution, plant-pathogen interactions, and synthetic biology. We also discuss critical questions that remain to be addressed regarding TALEs.

Pepper mild mottle virus coat protein interacts with pepper chloroplast outer envelope membrane protein OMP24 to inhibit antiviral immunity in plants.

Pepper mild mottle virus (PMMoV) is a devastating viral pathogen of pepper (Capsicum annuum) but it is unclear whether and how peppers protect against PMMoV infection. The expression of the chloroplast outer membrane protein 24 (OMP24) of C. annuum was upregulated under PMMoV infection and it interacted with PMMoV coat protein (CP). Silencing of OMP24 in either C. annuum or Nicotiana benthamiana facilitated PMMoV infection, whereas overexpression of N. benthamiana OMP24 in transgenic plants inhibited PMMoV infection. Both C. annuum OMP24 (CaOMP24) and N. benthamiana OMP24 (NbOMP24) localized to the chloroplast and have a moderately hydrophobic transmembrane domain that is necessary for their localization. Overexpression of CaOMP24 induced stromules, perinuclear chloroplast clustering, and accumulation of reactive oxygen species (ROS), the typical defense responses of chloroplasts transferring the retrograde signaling to the nucleus to regulate resistance genes. The expression of PR1 and PR2 was also upregulated significantly in plants overexpressing OMP24. Self-interaction of OMP24 was demonstrated and was required for OMP24-mediated plant defense. Interaction with PMMoV CP interfered with the self-interaction of OMP24 and impaired OMP24-induced stromules, perinuclear chloroplast clustering and ROS accumulation. The results demonstrate the defense function of OMP24 in pepper during viral infection and suggest a possible mechanism by which PMMoV CP modulates the plant defense to facilitate viral infection.

Black pepper rhizomicrobiome: Spectrum of plant health indicators, critical environmental factors and community compartmentation in Vietnam

The biodiversity of the black pepper rhizosphere is a source of economically relevant microbial biocontrol agents that, if properly understood, can be used to improve black pepper pathogen suppression. However, the characterization of this system is poor in Vietnam, where most black pepper is grown. Here, we evaluated black pepper rhizosphere bacterial communities, from healthy and unhealthy orchards in two Vietnamese provinces for the detection of biomarkers and keystone species indicative of plant health status. Rhizosphere samples were collected for 16S rRNA metabarcoding and physicochemical analyses. Results revealed that unhealthy orchards had significantly higher electrical conductivity (EC), clay and available nitrogen. Richness and alpha diversity indices were significantly higher in unhealthy orchards in both provinces. Health state of orchards was the best individual predictor of alpha diversity compared to geographic and physicochemical variables. The compositional structure of the healthy orchards was also significantly different from the unhealthy orchards, though the interaction between orchard state and physicochemical variables explained a far higher proportion of the bacterial community dissimilarities. Actinobacteriota, Proteobacteria and Chloroflexi were the dominant phyla across orchards. Biomarkers of unhealthy orchards included Gemmatimonas, Conexibacter and Byrobacter, among others; biomarkers of healthy orchards included Solirubrobacter, Altererythrobacter and Crossiella. Bacterial co-occurrence networks were more complex in the healthy than unhealthy orchards, and available nutrients and EC notably influenced the assembly of subcommunities in the unhealthy orchards. Gemmatimonas, a potential plant growth antagonist, was detected as a keystone species in unhealthy orchards of both provinces. Overall, this study presents biomarkers and keystone species that may contribute to black pepper rhizosphere pathogen management and suggests that appropriate control of soil nutrients may mitigate the establishment of pathogenic bacterial communities.

MsmR1, a global transcription factor, regulates polymyxin synthesis and carbohydrate metabolism in Paenibacillus polymyxa SC2.

The multiple-sugar metabolism regulator (MsmR), a transcription factor belonging to the AraC/XylS family, participates in polysaccharide metabolism and virulence. However, the transcriptional regulatory mechanisms of MsmR1 in Paenibacillus polymyxa remain unclear. In this study, knocking out msmR1 was found to reduce polymyxin synthesis by the SC2-M1 strain. Chromatin immunoprecipitation assay with sequencing (ChIP-seq) revealed that most enriched pathway was that of carbohydrate metabolism. Additionally, electromobility shift assays (EMSA) confirmed the direct interaction between MsmR1 and the promoter regions of oppC3, sucA, sdr3, pepF, yycN, PPSC2_23180, pppL, and ydfp. MsmR1 stimulates polymyxin biosynthesis by directly binding to the promoter regions of oppC3 and sdr3, while also directly regulating sucA and influencing the citrate cycle (TCA cycle). In addition, MsmR1 directly activates pepF and was beneficial for spore and biofilm formation. These results indicated that MsmR1 could regulate carbohydrate and amino acid metabolism, and indirectly affect biological processes such as polymyxin synthesis, biofilm formation, and motility. Moreover, MsmR1 could be autoregulated. Hence, this study expand the current knowledge of MsmR1 and will be beneficial for the application of P. polymyxa SC2 in the biological control against the certain pathogens in pepper.

Ethylene emitted by viral pathogen-infected pepper (Capsicum annuum L.) plants is a volatile chemical cue that attracts aphid vectors.

Plant viruses are obligate intracellular pathogens, and most depend on insect vectors for transmission between plants. Viral infection causes various physiological and metabolic changes in host traits, which subsequently influence the behavior and fitness of the insect vectors. Cucumber mosaic virus (CMV), one of the most widespread pathogens in pepper (Capsicum annuum L.), is transmitted by aphid vectors in a non-persistent manner. Here, we examined whether CMV infection in pepper affects the behavior of aphid vectors (Myzus persicae and Aphis glycines) in pepper. Aphid preference test revealed that significantly more aphids were attracted to CMV-infected pepper plants than to healthy plants. Comparative transcriptome analysis revealed a significant activation of the ethylene biosynthesis pathway in CMV-infected pepper plants. Indeed, gas chromatography analysis demonstrated that ethylene emission was significantly increased by CMV infection in pepper plants. Elevated ethylene emission in ethephon-treated healthy pepper increased their attractiveness to aphids. In contrast, aphid preference decreased after chemical inhibition of ethylene biosynthesis in CMV-infected pepper plants. Our results suggest that the ethylene emitted by CMV infection is a volatile cue that regulates the attractiveness of pepper plants to M. persicae and A. glycines.

Characterisation of Trichoderma spp. and Assessment as Biocontrol Using Dual Culture Assay Against Fungi Associated with Black Pepper (Piper nigrum L.) Diseases in Sarawak

Black pepper (Piper nigrum L.) is one of the most widely used spices in food, beverage, cosmetics, and medicine. Black pepper production has suffered from various fungal diseases. Microbial biological control is an essential part of integrated disease management to reduce the heavy reliance on chemical fungicides. Trichoderma fungi comprise a large group of rhizocompetent filamentous fungi widely used in the biocontrol of plant pathogens. Three field surveys conducted on five black pepper farms in Belaga, Sarawak, identified three fungal diseases: yellowing, black berry, and foot rot. Based on the morphological and molecular characterisation, the identified fungal causal agents were Fusarium solani (yellowing disease), Colletotrichum gloeosporioides (black berry disease), and Phytophthora palmivora (foot rot disease). Twenty isolates of Trichoderma spp. were isolated from secondary forest and Biopark in Bintulu, Sarawak. Trichoderma isolates were characterised based on the morphological characteristics and molecular phylogenetic analysis using the rDNA internal transcribed spacer (ITS) region. Trichoderma isolates were separated into five distinct species, namely T. harzianum, T. virens, T. brevicompactum, T. tawa, and telomorphic Hypocrea lixii. Among the Trichoderma fungi, T. harzianum was the most frequently (65%) isolated species. Trichoderma harzianum (Isolates of TJ9, 10, and 16) showed antagonistic and inhibitory effects by 61 to 70% on in vitro mycelial growth against three common fungal pathogens of black pepper, P. palmivora, C. gloeosporioides, and F. solani. This study highlights the potential of using native Trichoderma fungi as biocontrol agents in the black pepper integrated disease management program.

N-Methyltransferase CaASHH3 Acts as a Positive Regulator of Immunity against Bacterial Pathogens in Pepper.

Proteins with conserved SET domain play a critical role in plant immunity. However, the means of organization and functions of these proteins are unclear, particularly in non-model plants such as pepper (Capsicum annum L.). Herein, we functionally characterized CaASHH3, a member of class II (the ASH1 homologs H3K36) proteins in pepper immunity against Ralstonia solanacearum and Pseudomonas syringae pv tomato DC3000 (Pst DC3000). The CaASHH3 was localized in the nucleus, and its transcript levels were significantly enhanced by R. solanacearum inoculation (RSI) and exogenous application of salicylic acid (SA), methyl jasmonate (MeJA), ethephon (ETH), and abscisic acid (ABA). Knockdown of CaASHH3 by virus-induced gene silencing (VIGS) compromised peppers’ resistance to RSI. Furthermore, silencing of CaASHH3 impaired hypersensitive-response (HR)-like cell death response due to RSI and downregulated defense-associated marker genes, including CaPR1, CaNPR1, and CaABR1. The CaASHH3 protein was revealed to affect the promoters of CaNPR1, CaPR1, and CaHSP24. Transiently over-expression of CaASHH3 in pepper leaves elicited HR-like cell death and upregulated immunity-related marker genes. To further study the role of CaASHH3 in plant defense in vivo, CaASHH3 transgenic plants were generated in Arabidopsis. Overexpression of CaASHH3 in transgenic Arabidopsis thaliana enhanced innate immunity against Pst DC3000. Furthermore, CaASHH3 over-expressing transgenic A. thaliana plants exhibited upregulated transcriptional levels of immunity-associated marker genes, such as AtNPR1, AtPR1, and AtPR2. These results collectively confirm the role of CaASHH3 as a positive regulator of plant cell death and pepper immunity against bacterial pathogens, which is regulated by signaling synergistically mediated by SA, JA, ET, and ABA.

Pepper pathogens: XopS pumps the brakes on the pepper immune response.

Pepper pathogens: XopS pumps the brakes on the pepper immune response.

Universal gene co-expression network reveals receptor-like protein genes involved in broad-spectrum resistance in pepper (Capsicum annuum L.).

Receptor-like proteins (RLPs) on plant cells have been implicated in immune responses and developmental processes. Although hundreds of RLP genes have been identified in plants, only a few RLPs have been functionally characterized in a limited number of plant species. Here, we identified RLPs in the pepper (Capsicum annuum) genome and performed comparative transcriptomics coupled with the analysis of conserved gene co-expression networks (GCNs) to reveal the role of core RLP regulators in pepper–pathogen interactions. A total of 102 RNA-seq datasets of pepper plants infected with four pathogens were used to construct CaRLP-targeted GCNs (CaRLP-GCNs). Resistance-responsive CaRLP-GCNs were merged to construct a universal GCN. Fourteen hub CaRLPs, tightly connected with defense-related gene clusters, were identified in eight modules. Based on the CaRLP-GCNs, we evaluated whether hub CaRLPs in the universal GCN are involved in the biotic stress response. Of the nine hub CaRLPs tested by virus-induced gene silencing, three genes (CaRLP264, CaRLP277, and CaRLP351) showed defense suppression with less hypersensitive response-like cell death in race-specific and non-host resistance response to viruses and bacteria, respectively, and consistently enhanced susceptibility to Ralstonia solanacearum and/or Phytophthora capsici. These data suggest that key CaRLPs are involved in the defense response to multiple biotic stresses and can be used to engineer a plant with broad-spectrum resistance. Together, our data show that generating a universal GCN using comprehensive transcriptome datasets can provide important clues to uncover genes involved in various biological processes.

Evaluation of some essential oils and Trichoderma spp as a potential alternative technique for controlling Rhizoctonia solani a bell pepper pathogen

Evaluation of some essential oils and Trichoderma spp as a potential alternative technique for controlling Rhizoctonia solani a bell pepper pathogen

Seed, plant, and soil treatment with selected commercial Bacillus-based and Streptomyces-based biofungicides and chemical fungicides and development of Phytophthora blight on chile pepper

There is a need to identify combination treatments with high efficacy against Phytophthora capsici, a serious pathogen of chile pepper (Capsicum sp.) and other vegetable crops in New Mexico and worldwide. A greenhouse study was conducted to determine the effects of seed, plant, and soil treatment with selected commercial formulations of Bacillus and Streptomyces, and chemical fungicides (mefenoxam) on infection of chile pepper by P. capsici. The area under disease progress curve (AUDPC) was evaluated under seed treatment used in conjunction with soil treatment, and plant treatment used in conjunction with soil treatment. There was no significant interaction (P > 0.05) between seed treatment and soil treatment, and between plant treatment and soil treatment. Soil treatment with mefenoxam reduced AUDPC over 50% compared to control (untreated). Percent plant stand and percent plant survival were greater in soil treated with mefenoxam, Streptomyces lydicus, and S. griseoviridis than in untreated soil.

Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black and red pepper by vacuumed hydrogen peroxide vapour.

In this study, the efficacy of using vacuumed hydrogen peroxide vapour (VHPV) to inactivate foodborne pathogens in whole dried black pepper (Piper nigrum) and powdered dried red pepper (Capsicum annuum) was evaluated. Black and red pepper inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium were subjected to 3.81, 7.93, 12.33, 17.04 and 21.67mgl-1 VHPV for 1min, and the change in pepper colour was evaluated after treatment. Pathogen quantities decreased with increasing hydrogen peroxide concentration. For black pepper, the 21.67mgl-1 VHPV treatment decreased E. coli O157:H7 and S. Typhimurium quantities by >6.12 and 4.52log CFU per gram, respectively, without causing colour change. In addition, the 21.67mgl-1 VHPV treatment caused 4.35 and 2.36log CFU per gram reductions in these two pathogen quantities in red pepper, respectively. During the VHPV treatment, colour values of peppers did not significantly change. VHPV effectively reduced the levels of foodborne pathogens in black and red pepper while inducing minimal colour changes. Hydrogen peroxide vapour (HPV) is typically used as a sterilization method for medical devices, and many studies have confirmed the effectiveness of HPV or the gaseous phase of hydrogen peroxide on the inactivation of micro-organisms. However, using HPV for food pasteurization has rarely been studied. In the present study, we confirmed that VHPV effectively reduced the levels of pathogens in black and red pepper without colour changes.