Phenotypic, genotypic and proteomic variations between poor and robust colonizing Campylobacter jejuni strains.

Campylobacter jejuni is one of the major causes of bacterial gastrointestinal disease in humans worldwide. This foodborne pathogen colonizes the intestinal tracts of chickens, and consumption of chicken and poultry products is identified as a common route of transmission. We analyzed two C. jejuni strains after oral challenge with 105 CFU/ml of C. jejuni per chick; one strain was a robust colonizer (A74/C) and the other a poor colonizer (A74/O). We also found extensive phenotypic differences in growth rate, biofilm production, and in vitro adherence, invasion, intracellular survival, and transcytosis. Strains A74/C and A74/O were genotypically similar with respect to their whole genome alignment, core genome, and ribosomal MLST, MLST, flaA, porA, and PFGE typing. The global proteomes of the two congenic strains were quantitatively analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and 618 and 453 proteins were identified from A74/C and A74/O isolates, respectively. Cluster of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that carbon metabolism and motility proteins were distinctively overexpressed in strain A74/C. The robust colonizer also exhibited a unique proteome profile characterized by significantly increased expression of proteins linked to adhesion, invasion, chemotaxis, energy, protein synthesis, heat shock proteins, iron regulation, two-component regulatory systems, and multidrug efflux pump. Our study underlines phenotypic, genotypic, and proteomic variations of the poor and robust colonizing C. jejuni strains, suggesting that several factors may contribute to mediating the different colonization potentials of the isogenic isolates.

Preharvest spraying of phenylalanine activates the sucrose and respiratory metabolism in muskmelon wounds during healing.

Phenylalanine (Phe) accelerates fruit wound healing by activating phenylpropanoid metabolism. However, whether Phe affects sucrose and respiratory metabolism in fruit during wound healing remains unknown. In this research, we found that preharvest Phe spray promoted sucrose degradation and increased glucose and fructose levels by activating acid invertase (AI), neutral invertase (NI), sucrose synthase (SS) and sucrose phosphate synthase (SPS) on harvested muskmelons. The spray also activated hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), malate dehydrogenase (MDH), succinate dehydrogenase (SDH) and glucose-6-phosphate dehydrogenase (G6PDH). In addition, the spray improved energy and reducing power levels in the fruit. Taken together, preharvest Phe spray can provide carbon skeleton, energy and reducing power for wound healing by activating the sucrose metabolism, Embden-Meyerhof-Parnas (EMP) pathway, tricarboxylic acid (TCA) cycle and pentose phosphate (PPP) pathway in muskmelon wounds during healing, which is expected to be developed as a new strategy to accelerate fruit wound healing.

Trends in the prevalence of cognitive impairment at old age in China, 2002-2018.

INTRODUCTION: China has the world's largest number of older adults with cognitive impairment (CI). We aimed to examine secular trends in the prevalence of CI in China from 2002 to 2018. METHODS: Generalized estimating equations (GEE) was used to assess changes in CI trend in 44,154 individuals (72,027 observations) aged 65 to 105 years old. RESULTS: The prevalence of CI increased from 2002 to 2008 and then decreased until 2018. The age-standardized prevalence increased from 25.7% in 2002, 26.1% in 2005, to 28.2% in 2008, then decreased to 26.0% in 2011, 25.3% in 2014, and 24.9% in 2018. Females and those ≥ 80 years old had greater CI prevalence. DISCUSSION: The prevalence of CI showed an inverted U shape from early 2000s to late 2010s with a peak in 2008. Follow-up studies are needed to confirm the decreasing trend after 2008 and examine the contributing factors and underlying mechanisms of this trend. HIGHLIGHTS: Generalized estimating equations (GEE) were used to assess trends of changes in cognitive impairment (CI). CI prevalence in China increased from 2002 to 2008 and then decreased until 2018. Females and those ≥ 80 years old had greater CI prevalence. Stroke, diabetes, and cigarette smoking were risk factors for CI.

COL1A1 regulates the apoptosis of embryonic stem cells by mediating the PITX1/TBX4 signaling.

PURPOSE: The purpose of this study is to explore the regulatory function of COL1A1 against the apoptosis of embryonic stem cells (ESCs) and the potential function in congenital talipes equinovarus (CTEV). METHODS: Muscle tissues were collected from 20 children with CTEV and 20 children without CTEV, followed by detecting the expression of COL1A1 using the RT-PCR method. COL1A1 was knocked down in H1 and H9 human ESCs using the RNA interference technology, followed by determining the level of COL1A1, PITX1, TBX4, HOXD10, Fas, FasL, and Bax using the Western blotting assay. RESULTS: COL1A1 was found markedly upregulated in muscle tissues of CTEV children. In H1 and H9 human ESCs, compared to the empty vector, COL1A1, PITX1, TBX4, HOXD10, Fas, FasL, and Bax were found notably downregulated after transfected with the siRNA targeting COL1A1. CONCLUSION: COL1A1 induced the apoptosis of ESCs by mediating the PITX1/TBX4 signaling and might be a potential target for treating CTEV.

Current Practices in LC-MS Untargeted Metabolomics: A Scoping Review on the Use of Pooled Quality Control Samples.

Untargeted metabolomics is an analytical approach with numerous applications serving as an effective metabolic phenotyping platform to characterize small molecules within a biological system. Data quality can be challenging to evaluate and demonstrate in metabolomics experiments. This has driven the use of pooled quality control (QC) samples for monitoring and, if necessary, correcting for analytical variance introduced during sample preparation and data acquisition stages. Described herein is a scoping literature review detailing the use of pooled QC samples in published untargeted liquid chromatography-mass spectrometry (LC-MS) based metabolomics studies. A literature query was performed, the list of papers was filtered, and suitable articles were randomly sampled. In total, 109 papers were each reviewed by at least five reviewers, answering predefined questions surrounding the use of pooled quality control samples. The results of the review indicate that use of pooled QC samples has been relatively widely adopted by the metabolomics community and that it is used at a similar frequency across biological taxa and sample types in both small- and large-scale studies. However, while many studies generated and analyzed pooled QC samples, relatively few reported the use of pooled QC samples to improve data quality. This demonstrates a clear opportunity for the field to more frequently utilize pooled QC samples for quality reporting, feature filtering, analytical drift correction, and metabolite annotation. Additionally, our survey approach enabled us to assess the ambiguity in the reporting of the methods used to describe the generation and use of pooled QC samples. This analysis indicates that many details of the QC framework are missing or unclear, limiting the reader's ability to determine which QC steps have been taken. Collectively, these results capture the current state of pooled QC sample usage and highlight existing strengths and deficiencies as they are applied in untargeted LC-MS metabolomics.

Noonan syndrome: rhGH treatment and PTPN11 mutation.

OBJECTIVE: To analyze the clinical data and genetic characteristics of Noonan syndrome, both the effect and side effects of recombinant human growth hormone (rhGH) treatment. METHODS: We collected clinical data from 8 children with Noonan syndrome diagnosed from November 2017 to June 2021. The diagnosis was clarified by exome second-generation sequencing and parental PCR-NGS validation and interpretation of the preceding evidence, and growth hormone therapy was administered. Of the cases, four males and four females were seen for slow height growth and the median age at diagnosis was 8 years 7 months (1 year 7 months to 12 years 6 months). RESULTS: Here, 7 children were treated with rhGH. Compared to the pre-treatment period, the growth rate increased after rhGH treatment [3.7 ± 0.5 cm/year before treatment and 8.0 ± 1.0 cm/year after treatment, p < 0.01], with the maximum growth rate between 3 and 6 months of treatment and decreasing with the duration of treatment thereafter. The growth hormone treatment was discontinued and the orthopedic consultation was ordered with regular follow-up, which was considered to be related to the PTPN11 mutation. CONCLUSION: Noonan syndrome is characterized by slow growth, short stature, mental retardation, peculiar facial features, structural heart abnormalities and abnormal bone metabolism. and osteochondroma was found after case 2 rhGH treatment. Genetic examination is mostly caused by PTPN11 mutation. It is recommended to pay attention to bone metabolism abnormalities before growth hormone treatment, especially in children with PTPN11 mutations.

The role of lifestyle factors in cognitive health and dementia in oldest-old: A systematic review.

Oldest-old is the fastest growing segment of society. A substantial number of these individuals are cognitively impaired or demented. Given the lack of a cure, attention is directed to lifestyle interventions that could help alleviate the stress in patients, their families, and society. The aim of this review was to identify lifestyle factors with important roles in dementia prevention in oldest-old. Searches were conducted in PubMed, EMBASE, Scopus and Web of Science. We identified 27 observational cohort studies that met the inclusion criteria. Results showed that eating a healthy diet with plenty of fruits and vegetables, and participation in leisure and physical activities may protect against cognitive decline and cognitive impairment among oldest-old regardless of the APOE genotype. Combined lifestyles may generate multiplicative effects than individual factors. This is the first review known to systematically examine the association between lifestyle and cognitive health in oldest-old. Lifestyle interventions for diet, leisure, or a combination of lifestyles could be beneficial for cognitive function in oldest-old. Interventional studies are warranted to strengthen the evidence.

Chitosan and chitooligosaccharide regulated reactive oxygen species homeostasis at wounds of pear fruit during healing.

Both chitosan (CTS) and chitooligosaccharide (COS) can promote fruit healing. However, whether the two chemicals regulate reactive oxygen species (ROS) homeostasis during wound healing of pear fruit remains unknown. In this study, the wounded pear fruit (Pyrus bretschneideri cv. Dongguo) was treated with a 1 g L-1 CTS and COS. We found CTS and COS treatments increased NADPH oxidase and superoxide dismutase activities, and promoted O2.- and H2O2 production at wounds. CTS and COS also enhanced the activities of catalase, peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase, and elevated the levels of ascorbic acid and glutathione. In addition, the two chemicals improved antioxidant capacity in vitro and maintained cell membrane integrity at fruit wounds during healing. Taken together, CTS and COS can regulate ROS homeostasis at wounds of pear fruit during healing by scavenging excessive H2O2 and improving antioxidant capacity. Overall, the COS demonstrated superior performance over the CTS.

Prevalence, Virulence, and Antibiotics Gene Profiles in Lactococcus garvieae Isolated from Cows with Clinical Mastitis in China.

Lactococcus garvieae (L. garvieae) is a pathogenic gram-positive, catalase-negative (GPCN) bacterium that causes bovine mastitis. A total of 49 L. garvieae isolates were identified from 1441 clinical mastitis (CM) samples. The pathogenic effects of L. garvieae were studied with two infection models: bovine mammary epithelial cells cultured in vitro and murine mammary infections in vivo. The overall farm prevalence was 15.5% (13/84 farms in 9/19 provinces) and sample prevalence was 3.40% (49/1441). Post-treatment somatic cell count (SCC) post L. garvieae infection was significantly higher than the other GPCN pathogens isolated, and the bacteriological cure fraction was 41.94% (13/31) after intramammary antibiotic treatment. All L. garvieae isolates were resistant to rifaximin, 12.24% of isolates were resistant to cephalexin, and 10.20% (5/49) were multidrug-resistant (MDR). The most prevalent virulence genes were Hemolysin 1 (hly1)(100%), Hemolysin 2 (hly2) (97.96%), NADH oxidase (NADHO) (100%), Superoxide dismutase (SOD) (100%), Adhesin Pav (Pav) (100%), Adhesin PsaA (PsaA) (100%), Enolase (eno) (100%), Adhesin cluster 1(AC1) (100%), Adhesin cluster 2 (AC2) (100%), and several exopolysaccharides. L. garvieae rapidly adhered to bovine mammary epithelial cells, resulting in an elevated lactate dehydrogenase release. Edema and congestion were observed in challenged murine mammary glands and bacteria were consistently isolated at 12, 24, 48, 72, and 120 h after infection. We concluded that L. garvieae had good adaptive ability in the bovine and murine mammary cells and tissue. Given the resistance profile, penicillin and ampicillin are potential treatments for CM cases caused by L. garvieae.

Modeling Clinical Phenotype Variability: Consideration of Genomic Variations, Computational Methods, and Quantitative Proteomics.

Advances in biomedical and computer technologies have presented the modeling community the opportunity for mechanistically modeling and simulating the variability in a disease phenotype or in a drug response. The capability to quantify response variability can inform a drug development program. Quantitative systems pharmacology scientists have published various computational approaches for creating virtual patient populations (VPops) to model and simulate drug response variability. Genomic variations can impact disease characteristics and drug exposure and response. Quantitative proteomics technologies are increasingly used to facilitate drug discovery and development and inform patient care. Incorporating variations in genomics and quantitative proteomics may potentially inform creation of VPops to model and simulate virtual patient trials, and may help account for, in a predictive manner, phenotypic variations observed clinically.

Comprehensive physical and psychological training of modern pentathlon athletes / Treinamento físico e psicológico abrangente de atletas modernos do pentatlo / Entrenamiento físico y psicológico integral de los atletas del pentatlón moderno

ABSTRACT Introduction: The modern pentathlon requires athletes to participate in 5 individual sports (fencing, swimming, equestrian, running, and shooting combined) in one day. All of these belong to different categories, resulting in high demand for physical and mental control by the athlete. The importance of psychological factors in everyday physical activity has increased attention. Objective: This paper explores the role of comprehensive psychological training in modern pentathlon. Methods: Forty-seven modern pentathletes were selected by random sampling method. A questionnaire survey method was used to analyze the volunteers. Interviews on the psychological status of the athletes before the competition were also conducted. Finally, a statistical method was used to determine the participants' interview and questionnaire results. Results: The athletes in all five sports experienced high stress before the competitions. The second highest stress was during preparation, before the games. The incidence of anxiety, indifference, and disproportionate confidence before the competition was lower. Conclusion: The psychological state of modern pentathletes before competition is directly related to their competitive state and level. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: O pentatlo moderno exige que os atletas participem de 5 esportes individuais (esgrima, natação, hipismo, corrida e tiro combinados) em um dia. Todos esses itens são pertencentes a diferentes categorias, resultando numa alta demanda de controle físico e mental pelo atleta. A importância dos fatores psicológicos na atividade física cotidiana tem aumentado a atenção. Objetivo: Este artigo explora o papel da formação psicológica abrangente no pentatlo moderno. Métodos: Foram selecionados 47 pentatletas modernos por método de amostragem aleatória. Utilizou-se um método de pesquisa de questionário para analisar os voluntários. Também foram realizadas entrevistas sobre o estado psicológico dos atletas antes da competição. Por fim, utilizou-se o método estatístico para trabalhar os resultados das entrevistas e questionários sobre os participantes. Resultados: Os atletas dos cinco esportes experimentaram um estresse elevado antes das competições. O segundo maior momento de tensão foi durante a preparação, antes dos jogos. A incidência de ansiedade, indiferença e confiança desproporcional antes da competição é menor. Conclusão: O estado psicológico dos pentatletas modernos antes da competição está diretamente relacionado ao estado competitivo e nível desses atletas. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El pentatlón moderno requiere que los atletas participen en 5 deportes individuales (esgrima, natación, hípica, carrera y tiro combinados) en un día. Todos estos elementos pertenecen a diferentes categorías, lo que supone una gran exigencia de control físico y mental por parte del atleta. La importancia de los factores psicológicos en la actividad física diaria ha aumentado la atención. Objetivo: Este trabajo explora el papel del entrenamiento psicológico integral en el pentatlón moderno. Métodos: Se seleccionaron 47 pentatletas modernos por el método de muestreo aleatorio. Para analizar a los voluntarios se utilizó un método de encuesta por cuestionario. También se realizaron entrevistas sobre el estado psicológico de los atletas antes de la competición. Por último, se utilizó el método estadístico para elaborar los resultados de las entrevistas y los cuestionarios sobre los participantes. Resultados: Los atletas de los cinco deportes experimentaron un gran estrés antes de las competiciones. El segundo momento de mayor estrés fue durante la preparación, antes de los partidos. La incidencia de la ansiedad, la indiferencia y la confianza desproporcionada antes de la competición es menor. Conclusión: El estado psicológico de los pentatletas modernos antes de la competición está directamente relacionado con el estado y el nivel competitivo de estos atletas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Watermelon responds to organic fertilizer by enhancing root-associated acid phosphatase activity to improve organic phosphorus utilization.

Organic fertilizer is commonly used to increase crop yields and improve soil quality. However, it is unclear whether crops adapt to organic fertilizer by regulating metabolic pathways that are involved in nutrient utilization. In this study, we focused on the organic phosphorus (Po) in organic fertilizer and, using watermelon, investigated changes in gene expression and metabolic pathways in response to organic fertilizer and the combination of chemical fertilizer and organic fertilizer (chemical fertilizer 70% and organic fertilizer 30%, based on phosphorus supply). Purple acid phosphatase (PAP) gene expression was upregulated in leaves and roots of watermelon grown in organic fertilizer alone and in the combination of chemical/organic fertilizer, resulting in enhanced phosphatase activity in roots. When the ratio of chemical to organic fertilizer was 85/15, root-associated acid phosphatase (APase) activity increased over chemical fertilizer alone. This formulation also resulted in increased inorganic phosphate (Pi) concentration in roots and leaves, and the upregulation of the secretory APase genes ClaPAP10/12/15/26, and ClaPAP18 in roots. In conclusion, watermelon responds to organic fertilizer by upregulating expression of secretory ClaPAP genes, subsequently enhancing root-associated APase activity further improving the hydrolysis of phosphomonoesters, and ultimately facilitating Po utilization by roots. The mechanisms of P utilization by roots comprise the enhancement of APase and phytase activity, absorption of small Po molecules, uptake of Pi, and the increase of lateral root number when organic fertilizer is applied to the plants. These findings help to establish the mechanisms by which plants respond to organic fertilizer by regulating metabolic pathways at the transcriptional level.

Chitooligosaccharide Maintained Cell Membrane Integrity by Regulating Reactive Oxygen Species Homeostasis at Wounds of Potato Tubers during Healing.

Chitooligosaccharide (COS) is a degradation product of chitosan. Although COS increased fruit resistance by regulating the metabolism of reactive oxygen species (ROS), few reports are available on whether COS regulates ROS homeostasis at wounds of potato tubers during healing. In this study, COS increased gene expression and activities of NADPH oxidase and superoxide dismutase, and promoted the generation of O2●- and H2O2. Moreover, COS increased gene expression and activities of catalase, peroxidase, and AsA-GSH cycle-related enzymes, as well as the levels of ascorbic acid and glutathione levels. In addition, COS elevated the scavenging ability of DPPH, ABTS+, and FRAP, and reduced cell membrane permeability and malondialdehyde content. Taken together, COS could maintain cell membrane integrity by eliminating excessive H2O2 and improving the antioxidant capacity in vitro, which contributes to the maintainance of cell membrane integrity at wounds of potato tubers during healing.

Quality assurance and quality control reporting in untargeted metabolic phenotyping: mQACC recommendations for analytical quality management.

BACKGROUND: Demonstrating that the data produced in metabolic phenotyping investigations (metabolomics/metabonomics) is of good quality is increasingly seen as a key factor in gaining acceptance for the results of such studies. The use of established quality control (QC) protocols, including appropriate QC samples, is an important and evolving aspect of this process. However, inadequate or incorrect reporting of the QA/QC procedures followed in the study may lead to misinterpretation or overemphasis of the findings and prevent future metanalysis of the body of work. OBJECTIVE: The aim of this guidance is to provide researchers with a framework that encourages them to describe quality assessment and quality control procedures and outcomes in mass spectrometry and nuclear magnetic resonance spectroscopy-based methods in untargeted metabolomics, with a focus on reporting on QC samples in sufficient detail for them to be understood, trusted and replicated. There is no intent to be proscriptive with regard to analytical best practices; rather, guidance for reporting QA/QC procedures is suggested. A template that can be completed as studies progress to ensure that relevant data is collected, and further documents, are provided as on-line resources. KEY REPORTING PRACTICES: Multiple topics should be considered when reporting QA/QC protocols and outcomes for metabolic phenotyping data. Coverage should include the role(s), sources, types, preparation and uses of the QC materials and samples generally employed in the generation of metabolomic data. Details such as sample matrices and sample preparation, the use of test mixtures and system suitability tests, blanks and technique-specific factors are considered and methods for reporting are discussed, including the importance of reporting the acceptance criteria for the QCs. To this end, the reporting of the QC samples and results are considered at two levels of detail: "minimal" and "best reporting practice" levels.

Microcalorimetric Investigations of Reversible Staphylococcal Enterotoxin Unfolding.

Staphylococcal food poisoning (SFP) is a common food-borne illness often associated with contamination during food handling. The genes for Staphylococcal enterotoxin (SE) isoforms SEA and SEB are frequently detected in human nasal Staphylococcus aureus isolates and these toxins are commonly associated with SFP. Past studies described the resistance of preformed SE proteins to heat inactivation and their reactivation upon cooling in foods. Full thermodynamic analyses for these processes have not been reported, however. The thermal stabilities of SEA, SEB, and SEH and reversibility of unfolding in simple buffers were investigated at pH 4.5 and pH 6.8 using differential scanning calorimetry (DSC). SEA and SEB unfolding was irreversible at pH 6.8 and at least partially reversible at pH 4.5 while SEH unfolding was irreversible at pH 4.5 and reversible at pH 6.8. Additional studies showed maximum refolding for SEB at pH 3.5-4.0 and diminished refolding at pH 4.5 with increasing ionic strength. SE-stimulated secretion of interferon-gamma by human peripheral blood mononuclear cells was used to assess residual SE biological activity following heat treatments using conditions matching those used for DSC studies. The biological activities of SEB and SEH exhibited greater resistance to heat inactivation than that of SEA. The residual activities of heat-treated SEB and SEH were measurable but diminished further in the presence of reconstituted nonfat dry milk adjusted to pH 4.5 or pH 6.8. To different extents, the pH and ionic strengths typical for foods influenced the thermal stabilities of SEA, SEB, and SEH and their potentials to renature spontaneously after heat treatments.

Ultrasonography-Guided Combination with Elbow Arthrography-Assisted Minimally Invasive Treatment of Radial Neck Fractures in Young Children.

Background: A radius neck fracture in children is a common fracture that not only affects the growth and development of children but also has a certain impact on the function of children's elbow joints. Objective: To probe into the application value of ultrasonography- (US-) guided combination with elbow arthrography in the minimally invasive treatment of radial neck fractures in young children, summarize its clinical effect and provide a minimally invasive, safe, effective, and reliable method for treating radial neck fractures in young children. Methods: Seventy-three patients with type III or IV radial neck fractures were treated from June 2013 to December 2020 and were divided into the Métaizeau group (n = 31, treatment group) and Kirschner wire (k-wire) k-wire group (n = 42, control group). The Métaizeau group was given US-guided combination with elbow arthrography-assisted modified Métaizeau technique, the k-wire group received open reduction and internal fixation with k-wire and compared the surgical effect of the two groups. Results: In comparison with the k-wire group, time of operation, intraoperative bleeding volume, and hospital stay were signally junior to those in the Métaizeau group (P < 0.05). After surgery, in comparison with the k-wire group, the number of degrees to contralateral flexion or forearm rotation was visually lower in the Métaizeau group (P < 0.05), and postoperative complication incidence in the Métaizeau group was visually lower than that in k-wire group (P < 0.05). Conclusion: In the minimally invasive treatment of radial neck fractures, US-guided combination with elbow arthrography in young children has better efficacy and high safety. It can be widely promoted and applied clinically.

Mass Spectrometry-Based Proteomics for Biomarker Discovery.

Proteomics plays a pivotal role in systems medicine, in which pharmacoproteomics and toxicoproteomics have been developed to address questions related to efficacy and toxicity of drugs. Mass spectrometry is the core technology for quantitative proteomics, providing the capabilities of identification and quantitation of thousands of proteins. The technology has been applied to biomarker discovery and understanding the mechanisms of drug action. Both stable isotope labeling of proteins or peptides and label-free approaches have been incorporated with multidimensional LC separation and tandem mass spectrometry (LC-MS/MS) to increase the coverage and depth of proteome analysis. A protocol of such an approach exemplified by dimethyl labeling in combination with 2D-LC-MS/MS is described. With further development of novel proteomic tools and increase in sample throughput, the full spectrum of mass spectrometry-based proteomic research will greatly advance systems medicine.

Both chitosan and chitooligosaccharide treatments accelerate wound healing of pear fruit by activating phenylpropanoid metabolism.

This study aimed to compare the effects of chitosan (CTS) and chitooligosaccharide (COS) treatments on wound healing of pear fruits and to investigate the related mechanisms during postharvest storage under ambient conditions. The results revealed that CTS and COS treatments reduced the weight loss and disease index of the wounded pears (Pyrus bretschneideri cv. Dongguo), and accelerated suberin polyphenolic and lignin deposition at wounds during 7 d of investigation. Furthermore, CTS and COS elevated the level of the genes expression and activities of key enzymes and increased product contents of phenylpropanoid metabolism. Collectively, these treatments at a concentration of 1 g/L could promote wound healing in pears by activating phenylpropanoid metabolism. Comparatively, COS treatment presented better effects to CTS and could be useful as a preservative method to enhance storability of fresh produce.