Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
1.
Patient Prefer Adherence ; 18: 1373-1383, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38953017

RESUMO

Aim: The aim of this study is to describe the readiness of hospital discharge of patients with coronary heart disease (CHD) who have undergone coronary stent implantation and explore its influencing factors. Methods: This is a cross sectional single center study. Convenient sampling was used to select patients who underwent coronary stent implantation in the Cardiovascular Department of a tertiary hospital in Chengdu from October 2021 to April 2022 as the research subjects. Data were collected using the General Information Questionnaire, which included domains such as uncertainty in illness, the quality of discharge teaching, perceived social support, and health locus of control. The Readiness for Hospital Discharge Scale (RHDS) was used to assess readiness for hospital discharge. Multiple regression adjusted for relevant confounders was used to determine the associations. Results: A total of 276 questionnaires were distributed, and 263 valid questionnaires were collected. The average item score of RHDS is 7.66 ± 1.13. Multiple regression analysis indicated that the influential factors of RHDS of patients who underwent coronary stent implantation included: deliver skill (ß = 0.43), marital status (ß = 0.12), living alone (ß = -0.14), inconsistency (ß = -0.22) and household income per capita (ß = -0.12) (all P<0.05). The RHDS score of patients with CHD after coronary stent implantation were at a moderate level. Conclusion: Discharge readiness was significantly associated with delivery skill, marital status, living alone, inconsistency of information, and household income per capita. The present study highlights the need for improved educational interventions and tailored discharge planning.

2.
Environ Sci Pollut Res Int ; 31(30): 43351-43368, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38900404

RESUMO

To solve the problem of unclear targeted inhibition of key free radicals by antioxidants, this paper took the hydroxyl radical with the highest oxidation activity of coal as the inhibition target and selected five antioxidants such as ethylene diamine tetraacetic acid, tea polyphenol, citric acid, vitamin C, and proanthocyanidins. Based on the theory of quantum chemistry, the characteristics and oxidation pathway of antioxidants inhibiting coal oxidation of hydroxyl radical were analyzed. Analyze the influence characteristics of antioxidants on the evolution of free radicals in coal through an electron paramagnetic resonance experiment (ESR). The results showed that the electron density of antioxidants was mainly distributed in the functional groups of carboxyl and hydroxyl, which played a key inhibitory role, and the vicinity of carboxyl and hydroxyl and other functional groups was positive potential, which was the active site of inhibiting hydroxyl radical. The order of inhibitory capacity of the five antioxidants was determined as GTP > PC > EDTA > CA > VC. It is concluded that the energy barrier of hydroxyl radical inhibition by citric acid is much lower than that of EDTA. For the hydrogen extraction reaction, VC inhibited the hydroxyl radical pathway with a higher energy barrier than the other three antioxidants. The mechanism of five antioxidants inhibiting •OH reaction was comprehensively analyzed. It was found that tea polyphenols have more active sites that can react with •OH to quench it, so the inhibition of tea polyphenols should be the most significant. When antioxidants inhibit coal spontaneous combustion, the type, complexity, concentration, and linewidth of free radicals in coal molecules are lower than those in raw coal, with GTP antioxidants having the best inhibitory effect. The research results have important theoretical and practical significance for revealing the mechanism of coal spontaneous combustion inhibition and developing directional coal spontaneous combustion inhibition technology.


Assuntos
Antioxidantes , Carvão Mineral , Radical Hidroxila , Oxirredução , Radical Hidroxila/química , Antioxidantes/química , Antioxidantes/farmacologia , Espectroscopia de Ressonância de Spin Eletrônica
5.
J Agric Food Chem ; 72(10): 5185-5196, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38427575

RESUMO

Mitogen-activated protein kinase (MAPK) cascades and raffinose have been observed to increase in plants exposed to cold. However, it remains elusive whether and how MAPK regulates raffinose synthesis under cold stress. Here, overexpression of SlMAPK3 promoted the accumulation of galactinol and raffinose under cold stress, while CRISPR/Cas9-mediated mutants showed the opposite results. Moreover, SlMAPK3 promoted the expression of SlWRKY46 at low temperatures and interacted with SlWRKY46 protein. Overexpression of SlWRKY46 enhanced cold resistance. Furthermore, SlWRKY46 directly bound to the promoter of SlGols1 to enhance its expression and promoted the accumulation of raffinose. Virus-induced gene-silencing (VIGS)-mediated knockdown of SlGols1 remarkably elevated cold sensitivity and reduced raffinose content. Meanwhile, exogenous supplementation of raffinose could improve the cold tolerance of tomato plants. Thus, our data indicates that SlMAPK3 modulates cold resistance by regulating raffinose content and SlWRKY46 expression. SlWRKY46 also promotes the accumulation of raffinose by inducing the expression of SlGols1.


Assuntos
Solanum lycopersicum , Rafinose/metabolismo , Proteínas de Plantas/metabolismo , Temperatura Baixa , Proteínas Quinases Ativadas por Mitógeno/genética , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/metabolismo
6.
J Agric Food Chem ; 72(9): 4552-4563, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38379128

RESUMO

Pathogens influence the growth and development of plants, resulting in detrimental damage to their yields and quality. Ethylene, a gaseous phytohormone, serves a pivotal function in modulating diverse physiological processes in plants, including defense mechanisms against pathogen invasion. Ethylene biosynthesis is involved in both plants and pathogens. Recent empirical research elucidates the intricate interactions and regulatory mechanisms between ethylene and pathogens across various plant species. In this review, we provide a comprehensive overview of the latest findings concerning ethylene's role and its regulatory networks in host-pathogen interactions. Additionally, we explore the crosstalk between ethylene and other phytohormones. Points regarding ethylene emission and its modulation by pathogens are also emphasized. Moreover, we also discuss potential unresolved issues in the field that warrant further investigation.


Assuntos
Etilenos , Reguladores de Crescimento de Plantas , Plantas/genética
7.
Eur J Pharm Sci ; 191: 106598, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37783378

RESUMO

Safe and efficacious antiviral therapeutics are in urgent need for the treatment of coronavirus disease 2019. Simnotrelvir is a selective 3C-like protease inhibitor that can effectively inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated the safety, tolerability, and pharmacokinetics of dose escalations of simnotrelvir alone or with ritonavir (simnotrelvir or simnotrelvir/ritonavir) in healthy subjects, as well as the food effect (ClinicalTrials.gov Identifier: NCT05339646). The overall incidence of adverse events (AEs) was 22.2% (17/72) and 6.3% (1/16) in intervention and placebo groups, respectively. The simnotrelvir apparent clearance was 135-369 L/h with simnotrelvir alone, and decreased significantly to 19.5-29.8 L/h with simnotrelvir/ritonavir. The simnotrelvir exposure increased in an approximately dose-proportional manner between 250 and 750 mg when co-administered with ritonavir. After consecutive twice daily dosing of simnotrelvir/ritonavir, simnotrelvir had a low accumulation index ranging from 1.39 to 1.51. The area under the curve of simnotrelvir increased 44.0 % and 47.3 % respectively, after high fat and normal diet compared with fasted status. In conclusion, simnotrelvir has adequate safety and tolerability. Its pharmacokinetics indicated a trough concentration above the level required for 90 % inhibition of SARS-CoV-2 in vitro at 750 mg/100 mg simnotrelvir/ritonavir twice daily under fasted condition, supporting further development using this dosage as the clinically recommended dose regimen.


Assuntos
COVID-19 , Inibidores de Proteases , Adulto , Humanos , Antivirais/efeitos adversos , Inibidores Enzimáticos , Voluntários Saudáveis , Inibidores de Proteases/efeitos adversos , Ritonavir/uso terapêutico , SARS-CoV-2
8.
Environ Sci Pollut Res Int ; 30(41): 94865-94877, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37542016

RESUMO

The intrinsic reaction of coal with oxygen in the process of low-temperature oxidation is the main reaction path leading to self-heating and spontaneous combustion of coal. Most of the existing studies regard the coal oxidation as an overall reaction, ignoring the multi-path characteristics of coal low-temperature oxidation, and it is difficult to accurately explore the intrinsic reaction characteristics between coal with oxygen. Therefore, the low-temperature oxidation process of coal was studied by using a C80 microcalorimeter and in situ FTIR technology from the macro and micro levels. The "profile subtraction method" was used to study the coal-oxygen intrinsic reaction process, and the reaction heat effect and the change characteristics of key functional groups in the process were analyzed. Furthermore, the gray correlation analysis method was used to study the relevant characteristic parameters in the reaction process and grasp the essential structure-activity relationship. The experimental results show that, compared with the overall reaction process in air atmosphere, the change in the heat release of the coal-oxygen intrinsic reaction path has changed to different degrees, and the change in the slow oxidation stage is the most significant (the heat absorption decreases by 70.1-90.9%). In addition, the characteristic temperature points show different degrees of advance, of which the initial exothermic temperature point is the largest (about 21-46 °C), which directly leads to a significant shortening of the slow oxidation stage (30.1-47.4%). The changes of functional groups in the intrinsic reaction path are more regular. With the increase of temperature, the oxygen-containing functional groups -C=O and the aliphatic hydrocarbon functional groups -CH2- and -CH3 showed a fluctuating trend of increasing and decreasing, respectively. The oxidation heat-contributing functional groups of coal are mainly related to the degree of metamorphism and the functional group reaction characteristics during the reaction. With the deepening of coalification degree, the main heat-contributing functional groups as a whole showed the change rule of oxygen-containing functional groups → aliphatic hydrocarbon functional groups → aromatic hydrocarbon functional groups. In addition, the change of -OH content in the three coal samples has a high correlation with the change of the total heat release of coal.


Assuntos
Carvão Mineral , Temperatura Alta , Carvão Mineral/análise , Oxigênio/análise , Temperatura , Hidrocarbonetos
9.
Foods ; 12(14)2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37509842

RESUMO

Tomato fruit is highly susceptible to infection by Botrytis cinerea (B. cinerea), a dominant pathogen, during storage. Recent studies have shown that autophagy is essential for plant defense against biotic and abiotic stresses. Autophagy-related gene 5 (ATG5) plays a key role in autophagosome completion and maturation, and is rapidly induced by B. cinerea, but the potential mechanisms of ATG5 in Solanum lycopersicum (SlATG5) in postharvest tomato fruit resistance to B. cinerea remain unclear. To elucidate the role of SlATG5 in tomato fruit resistant to B. cinerea, CRISPR/Cas9-mediated knockout of SlATG5 was used in this study. The results showed that slatg5 mutants were more vulnerable to B. cinerea and exhibited more severe disease symptoms and lower activities of disease-resistant enzymes, such as chitinase (CHI), ß-1,3-glucanase (GLU), phenylalanine ammonia-lyase (PAL), and polyphenol oxidase (PPO), than the wild type (WT). Furthermore, the study observed that after inoculation with B. cinerea, the relative expression levels of genes related to salicylic acid (SA) signaling, such as SlPR1, SlEDS1, SlPAD4, and SlNPR1, were higher in slatg5 mutants than in WT. Conversely, the relative expression levels of jasmonic acid (JA) signaling-related genes SlLoxD and SlMYC2 were lower in slatg5 mutants than in WT. These findings suggested that SlATG5 positively regulated the resistance response of tomato fruit to B. cinerea by inhibiting the SA signaling pathway and activating the JA signaling pathway.

10.
Expert Opin Investig Drugs ; 32(5): 441-450, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37183631

RESUMO

BACKGROUND: SIM0295, a novel inhibitor of human uric acid transporter 1 (hURAT1), is used to treat patients with gout and hyperuricemia. This study aimed to develop population pharmacokinetics and pharmacodynamics (popPK/PD) models of SIM0295 and explore potential covariates to inform clinical drug development. RESEARCH DESIGN AND METHODS: Data were obtained from four phase I studies conducted in healthy Korean and Chinese subjects and two phase II studies conducted in Korean patients with gout and hyperuricemia. The popPK/PD model of SIM0295 was developed using nonlinear mixed effects modeling. RESULTS: SIM0295 pharmacokinetics was described using a two-compartment model with the absorption of four transit compartments and first-order elimination. PK parameters were normalized to weight via allometric scaling. Food was identified as a factor significantly affecting the absorption rate, with no clinical relevance. The sigmoid Emax model with a semi-mechanism of inhibition of serum uric acid (sUA) reabsorption was used to describe the exposure-response relationship. Additionally, Monte Carlo simulations demonstrated that approimately 9 mg/day of SIM0295 for 7 days could achieve the maximum decrease in sUA. CONCLUSION: The established popPK/PD model characterized the dose-exposure-response relationship for SIM0295 in healthy subjects and patients with gout and hyperuricemia and could be used to inform the drug development.


Assuntos
Gota , Hiperuricemia , Humanos , Hiperuricemia/tratamento farmacológico , Ácido Úrico , Voluntários Saudáveis , Gota/tratamento farmacológico , Supressores da Gota/farmacologia
11.
J Agric Food Chem ; 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37023258

RESUMO

Mitogen-activated protein kinase (MAPK) cascades and ethylene are crucial for plant growth, development, and stress responses, but their potential mechanisms in cold resistance remain unclear. We revealed that SlMAPK3 transcript levels were dramatically induced by cold treatment in an ethylene-dependent manner. Under cold stress, the proline content of SlMAPK3-overexpression fruit was 96.5 and 115.9% higher than that of wild-type fruit (WT), respectively, while the ion leakage was 37.3 and 32.5% lower than that of WT. RNA sequencing revealed that overexpression of SlMAPK3 caused upregulation of genes that are enriched in the ethylene-activated signaling pathway (GO:0009873), cold signaling pathway (GO:0009409), and heat signaling pathway (GO:0009408). RT-qPCR demonstrated that the expression levels of SlACS2, SlACS4, SlSAHH, SlCBF1, SlDREB, SlGolS1, and SlHSP17.7 in the OE.MAPK3 fruits were consistent with the RNA sequencing results. Meanwhile, the knockout of SlMAPK3 reduced the ethylene content, ACC content, and ACS activity. Moreover, the knockout of SlMAPK3 reduced the positive effect of ethylene in cold stress, while suppressing the expression of SlICE1 and SlCBF1. In conclusion, our study demonstrated a novel mechanism by which SlMAPK3 positively regulates the ethylene production of postharvest tomato fruits and is involved in ethylene-mediated cold tolerance.

12.
Risk Anal ; 43(8): 1539-1556, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36307897

RESUMO

As the decision-making basis for "safety" in risk management and risk assessment activities, acceptable risk has always been an important topic of risk-related research. Based on the records in the Science Citation Index Expanded database and Social Sciences Citation Index database via the Web of Science Core Collection, 1124 articles or reviews related to acceptable risk in engineering and operations research and management science were retrieved. These documents, published between 1961 and 2021, covered 3056 authors, 75 countries/territories, 1296 institutions, and 323 journals. In this study, bibliometric data such as annual growth trends were analyzed by using descriptive statistics. Through the co-occurrence maps created by CiteSpace and Gephi, the most productive and influential countries/territories, institutions, and authors as well as their cooperation networks were identified. Further analysis was conducted to determine the core publications and publication sources in this field through co-citation analysis. Insights into focus areas and research topics over time were obtained through keyword co-occurrence analysis. This study provides a macroscopic overview of acceptable risk research and may help researchers better understand this research field and predict its dynamic directions.

13.
Sci Total Environ ; 843: 157072, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-35780872

RESUMO

To explore the thermal behavior and hazard during the spontaneous combustion fires (SCFs) of coal and coal gangue (CG), the characteristics of heat release and thermal transfer during the SCFs of coal and CG were tested. The results indicate that coal contains more combustibles and aromatic hydrocarbons, while CG possesses higher contents of ash and inorganic silicate. Coal has a stronger heat release capacity, while CG owns a smaller specific heat capacity, a larger thermal diffusivity and a greater thermal conductivity. Thus, CG performs better with respect to heat transfer. The apparent activation energy of coal is larger in the endothermic stage, whereas that of CG is more notable in the exothermic stage. Based on heat release and heat transfer performance, hazardous zones during the SCFs of coal and CG were identified, and the combustion growth index was established to quantify the hazard of SCF disasters. The results show that the hazard is determined by both heat release and thermal transfer capacities. Coal or CG with a combustible component of 31.3 %, which not only releases massive heat but also transfers heat quickly, corresponds to the most considerable hazard of SCF disasters.


Assuntos
Incêndios , Combustão Espontânea , Carvão Mineral
14.
Yi Chuan ; 43(10): 962-971, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34702708

RESUMO

Microhaplotype loci (microhaplotype, MHs), defined by two or more closely linked single nucleotide polymorphisms, are a type of molecular marker within a short segment of DNA. As emerging forensic genetic markers, MHs have no stutter artefacts and higher polymorphism, and permit the design of smaller amplicons. In order to identify the markers from a genome wide perspective and explore their potential application further, we constructed the most comprehensive MH dataset to date, based on the whole genome sequencing data of 105 Han individuals in Southern China from 1000 Genomes Project. The results showed that there were 9,490,075 MH loci in the range of 350 bp in the human genome, and the distribution density of microhaplotypes suggests gene variation. Polymorphism analysis of MHs from various base spans showed that the polymorphism of MHs could reach or exceed common short tandem repeat sites. In addition, based on their flexible assembly, a scheme to build the public database of microhaplotypes was proposed.


Assuntos
Impressões Digitais de DNA , Sequenciamento de Nucleotídeos em Larga Escala , China , Genética Forense , Frequência do Gene , Genética Populacional , Genômica , Haplótipos , Humanos , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único/genética
16.
Plant Physiol Biochem ; 166: 1-9, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34087740

RESUMO

WRKY, as one of the largest families of transcription factors (TFs), binds to cis-acting elements of downstream genes to regulate biotic and abiotic stress. However, the role of SlWRKY46 in fungal disease response induced by Botrytis cinerea (B.cinerea) and potential mechanism remains obscure. To ascertain the role of SlWRKY46 in response to B.cinerea, we constructed SlWRKY46-overexpression plants, which were then inoculated with B.cinerea. SlWRKY46-overexpression plants were more susceptible to B.cinerea and accompanied by the inhibited activities of phenylalanine ammonialyase (PAL), polyphenol oxidase (PPO), chitinase (CHI), and ß-1,3-glucanase (GLU). Additionally, SlWRKY46-overexpression plants showed the decreased activities of ascorbate peroxidase (APX), superoxide dismutase (SOD) and the content of H2O2, and the increased content of O2•-. Moreover, over-expression of SlWRKY46 suppressed the salicylic acid (SA) and jasmonic acid (JA) marker genes, pathogenesis related protein (PR1), and proteinase inhibitors (PI Ⅰ and PI Ⅱ) and consequently aggravated the disease symptoms. Therefore, we speculated that SlWRKY46 played negative regulatory roles in B. cinerea infection probably by inhibiting the activities of antioxidants and disease resistance enzymes, regulating SA and JA signaling pathways and modulating reactive oxygen (ROS) homeostasis.


Assuntos
Botrytis , Solanum lycopersicum , Botrytis/metabolismo , Ciclopentanos , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Homeostase , Peróxido de Hidrogênio , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Oxilipinas , Doenças das Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico
17.
Biomaterials ; 275: 120910, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34144373

RESUMO

Anticancer nanomedicines are designed to improve anticancer efficacy by increasing drug accumulation in tumors through enhanced permeability retention (EPR) effect, and to reduce toxicity by decreasing drug accumulation in normal organs through long systemic circulation. However, the inconsistent efficacy/safety of nanomedicines in cancer patients versus preclinical cancer models have provoked debate for nanomedicine design criteria. In this study, we investigate nanomedicine design criteria in three types of preclinical cancer models using five clinically used nanomedicines, which identifies the factors for better clinical translations of their observed clinical efficacy/safety compared to free drug or clinical micelle formulation. When those nanomedicines were compared with drug solution or clinical micelle formulation in breast tumors, long and short-circulating nanomedicines did not enhance tumor accumulation by EPR effect in transgenic spontaneous breast cancer model regardless of their size or composition, although they improved tumor accumulations in subcutaneous and orthotopic breast cancer models. However, when tumors were compared to normal breast tissue, nanomedicines, drug solution and clinical micelle formulation showed enhanced tumor accumulation regardless of the breast cancer models. In addition, long-circulating nanomedicines did not further increase tumor accumulation in transgenic mouse spontaneous breast cancer nor universally decrease drug accumulations in normal organs; they decreased or increased accumulation in different organs, potentially changing the clinical efficacy/safety. In contrast, short-circulating nanomedicines decreased blood concentration and altered drug distribution in normal organs, which are correlated with their clinical efficacy/safety. A reappraisal of current nanomedicine design criteria is needed to ensure consistent clinical translation for improvement of their clinical efficacy/safety in cancer patients.


Assuntos
Antineoplásicos , Neoplasias da Mama , Nanopartículas , Neoplasias , Animais , Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Camundongos , Micelas , Nanomedicina , Neoplasias/tratamento farmacológico , Permeabilidade
18.
J Ginseng Res ; 45(2): 305-315, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33841011

RESUMO

BACKGROUND: Panax stipuleanatus represents a folk medicine for treatment of inflammation. However, lack of experimental data does not confirm its function. This article aims to investigate the analgesic and anti-inflammatory activities of triterpenoid saponins isolated from P. stipuleanatus. METHODS: The chemical characterization of P. stipuleanatus allowed the identification and quantitation of two major compounds. Analgesic effects of triterpenoid saponins were evaluated in two models of thermal- and chemical-stimulated acute pain. Anti-inflammatory effects of triterpenoid saponins were also evaluated using four models of acetic acid-induced vascular permeability, xylene-induced ear edema, carrageenan-induced paw edema, and cotton pellet-induced granuloma in mice. RESULTS: Two triterpenoid saponins of stipuleanosides R1 (SP-R1) and R2 (SP-R2) were isolated and identified from P. stipuleanatus. The results showed that SP-R1 and SP-R2 significantly increased the latency time to thermal pain in the hot plate test and reduced the writhing response in the acetic acid-induced writhing test. SP-R1 and SP-R2 caused a significant decrease in vascular permeability, ear edema, paw edema, and granuloma formation in inflammatory models. Further studies showed that the levels of inflammatory mediators, nitric oxide, malondialdehyde, tumor necrosis factor-α, and interleukin 6 in paw tissues were downregulated by SP-R1 and SP-R2. In addition, the rational harvest of three- to five-year-old P. stipuleanatus was preferable to obtain a higher level of triterpenoid saponins. SP-R2 showed the highest content in P. stipuleanatus, which had potential as a chemical marker for quality control of P. stipuleanatus. CONCLUSION: This study provides important basic information about utilization of P. stipuleanatus resources for production of active triterpenoid saponins.

19.
Front Plant Sci ; 11: 490, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523587

RESUMO

A "Laiyang" pear is a climacteric fruit with a special taste and nutritional value but is prone to a post-harvest aroma compound loss and a loss in fruit quality. In this study, pears were pretreated with 0.5 µl L-1 1-methylcyclopropene (1-MCP) at 20°C for 12 h and then stored at 0 ± 1°C for 150 days to evaluate the influence of 1-MCP on fruit quality and the changes in components of volatile aromas. In addition, pears were further treated with 2 mmol L-1 ethephon. The effects of ethephon on the recovery of aroma production were investigated during the 150 day storage at 0 ± 1°C and the subsequent 7 day shelf life at 20 ± 1°C. Treatment with 1-MCP inhibited firmness loss, increased electrical conductivity, reduced respiration and ethylene production rates as well as the contents of soluble solids, and maintained the storage quality of the fruits. However, 1-MCP treatment inhibited the emission of volatile aromas in pear fruits by decreasing the activities of various enzymes, such as lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH), pyruvate carboxylase (PDC), and alcohol acetyltransferase (AAT). During the shelf-life, activities of the above mentioned enzymes were significantly enhanced, and a higher content of volatile aromas were found in fruits treated with 1-MCP + ethephon, while other qualities were not compromised. These results showed that 1-MCP treatment could effectively maintain the quality of the "Laiyang" pear during cold storage, and the additional application of ethephon on fruits during shelf-life may be a promising way to restore volatile aromas in pear fruits after long-term storage.

20.
J Agric Food Chem ; 68(20): 5529-5538, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32372640

RESUMO

Methyl jasmonate (MeJA), a natural phytohormone, played a critical role not only in plant growth but also in plant defense response to biotic and abiotic stresses. MYC2, a basic helix-loop-helix transcription factor, is a master regulator in MeJA signaling pathway. In the present work, slmyc2 mutants were generated by the clustered regularly interspaced short palindromic repeats and associated Cas9 protein (CRISPR/Cas9) system to investigate the role of SlMYC2 in tomato plant growth and fruit disease resistance induced by exogenous MeJA. The results showed that slmyc2 mutants possessed a higher number of flowers and a lower fruit setting rate in comparison with wild-type plants. In addition, the fruit shape of slmyc2 mutant was prolate, while the control fruits were oblate. Knockout of SlMYC2 significantly decreased the activities of disease defensive and antioxidant enzymes, as well as the expression levels of pathogen-related (PR) genes (SlPR-1 and SlPR-STH2) and the key genes related to jasmonic acid (JA) biosynthesis and signaling pathway including allene oxide cyclase (SlAOC), lipoxygenase D (SlLOXD), SlMYC2, and coronatine insensitive 1 (SlCOI1), and consequently aggravated the disease symptoms. By contrast, the disease symptoms were largely reduced in MeJA-treated fruit that possessed higher activities of these enzymes and expression levels of genes. However, the induction effects of MeJA on fruit disease resistance and these enzymes' activities and genes' expressions were significantly attenuated by knockout of SlMYC2. Therefore, the results indicated that SlMYC2 played positive regulatory roles not only in the growth of tomato plants but also in MeJA-induced disease resistance and the antioxidant process in tomato fruits.


Assuntos
Acetatos/efeitos adversos , Botrytis/fisiologia , Ciclopentanos/efeitos adversos , Oxilipinas/efeitos adversos , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/imunologia , Solanum lycopersicum/genética , Acetatos/farmacologia , Sistemas CRISPR-Cas , Ciclopentanos/farmacologia , Resistência à Doença , Flores/genética , Flores/crescimento & desenvolvimento , Flores/imunologia , Frutas/efeitos dos fármacos , Frutas/genética , Frutas/imunologia , Frutas/microbiologia , Regulação da Expressão Gênica de Plantas , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/imunologia , Solanum lycopersicum/microbiologia , Mutagênese , Oxilipinas/farmacologia , Doenças das Plantas/imunologia , Proteínas de Plantas/imunologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA