Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Mais filtros

Base de dados
Intervalo de ano de publicação
Plant J ; 102(5): 931-947, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31908046


Phytohormone brassinosteroids (BRs) are essential for plant growth and development, but the mechanisms of BR-mediated pollen development remain largely unknown. In this study, we show that pollen viability, pollen germination and seed number decreased in the BR-deficient mutant d^im , which has a lesion in the BR biosynthetic gene DWARF (DWF), and in the bzr1 mutant, which is deficient in BR signaling regulator BRASSINAZOLE RESISTANT 1 (BZR1), compared with those in wild-type plants, whereas plants overexpressing DWF or BZR1 exhibited the opposite effects. Loss or gain of function in the DWF or BZR1 genes altered the timing of reactive oxygen species (ROS) production and programmed cell death (PCD) in tapetal cells, resulting in delayed or premature tapetal degeneration, respectively. Further analysis revealed that BZR1 could directly bind to the promoter of RESPIRATORY BURST OXIDASE HOMOLOG 1 (RBOH1), and that RBOH1-mediated ROS promote pollen and seed development by triggering PCD and tapetal cell degradation. In contrast, the suppression of RBOH1 compromised BR signaling-mediated ROS production and pollen development. These findings provide strong evidence that BZR1-dependent ROS production plays a critical role in the BR-mediated regulation of tapetal cell degeneration and pollen development in Solanum lycopersicum (tomato) plants.

Lycopersicon esculentum/metabolismo , Pólen/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Apoptose/genética , Apoptose/fisiologia , Brassinosteroides/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Lycopersicon esculentum/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pólen/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
J Hazard Mater ; 388: 121727, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-31796366


Bisphenol A (BPA), a widely distributed organic compound, is toxic to animals and plants. Here we show the mechanism of BPA detoxification by melatonin (MEL) in tomato, which is otherwise poorly understood in plants. BPA treatment decreased the quantum yield of photosystem II (Fv/Fm) and increased the membrane lipid peroxidation and reactive oxygen species (ROS) accumulation dose-dependently, whereas exogenous MEL alleviated the BPA effects on Fv/Fm, lipid peroxidation, ROS accumulation and BPA uptake. Furthermore, BPA elevated the glutathione (GSH) content, activities of glutathione S-transferase (GST), and glutathione reductase (GR), and the transcript levels of GSH1, GR1, GST1 and MEL biosynthesis genes (COMT, T5H, and SNAT), whereas BPA + MEL showed even a more profound induction. Silencing GSH1, GR1 and GST1 genes compromised the BPA detoxification potential of tomato plants as revealed by an increased level of ROS, lipid peroxidation and BPA uptake, and a decreased Fv/Fm and GST activity; these changes were alleviated by MEL application. Under in vitro conditions, BPA was glutathionylated by GSH, which was further catalyzed by GST to cysteine and N-acetylcysteine conjugates. These findings suggest a crucial role for MEL in BPA detoxification via GSH and GST, and can be useful to reduce BPA residue for food safety.

Antioxidantes/metabolismo , Compostos Benzidrílicos/metabolismo , Poluentes Ambientais/metabolismo , Lycopersicon esculentum/efeitos dos fármacos , Melatonina/farmacologia , Fenóis/metabolismo , Compostos Benzidrílicos/toxicidade , Poluentes Ambientais/toxicidade , Glutationa/metabolismo , Glutationa Transferase/metabolismo , Inativação Metabólica , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/toxicidade
Cancer Med ; 6(10): 2222-2233, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28940986


Lentinan is a common biological response modifier. This study was sought to evaluate the efficacy of adjuvant lentinan combined with chemotherapy for advanced cancer. A meta-analysis of published prospective controlled trials investigating the effects of lentinan for kinds of advanced cancer was performed. Sensitivity analysis, inverted funnel plots, and trial sequence analysis were conducted to explore the reliability and stability of results. Seventeen clinical studies were identified containing 1423 patients. Twelve trials included gastrointestinal cancer (GIC), three trials included lung cancer (LC), and two trials included the two cancers. There was a increase in survival rate in 1 year (risk ratios [RR], 1.46, P = 0.001) and overall response rate including both complete and partial response (RR, 1.28, P = 0.005). There was also a reduction in progressive disease (RR, 0.57, P = 0.0005), nonsevere adverse events (RR, 0.88, P = 0.004), and severe adverse events (RR, 0.73, P = 0.007). Similar results were shown in the two subgroups of GIC and LC. Limited trials reported the data of median overall survival and time to treatment failure, and the data were insufficient for quantitative analysis, and no significant difference were found in 2-year survival rate. Adjuvant lentinan used with chemotherapy achieved improvements in 1-year survival rate, response rate, and adverse events in advanced cancer. The effect seemed to be similar irrespective of cancer type. However, its sustained efficacy on survival was still unclear.

Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Progressão da Doença , Humanos , Fatores Imunológicos/administração & dosagem , Lentinano/administração & dosagem , Estadiamento de Neoplasias , Neoplasias/mortalidade , Viés de Publicação , Análise de Sobrevida , Falha de Tratamento , Resultado do Tratamento
World J Gastroenterol ; 11(30): 4634-7, 2005 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-16094701


AIM: To characterize the histochemical type and pattern of intestinal metaplasia (IM) adjacent to gastric cardia adenocarcinoma (GCA) and distal gastric cancer (GC) in Linzhou, Henan Province, China. METHODS: Alcian-blue-periodic acid Schiff and high iron diamine-Alcian blue histochemical methods were performed on 142 cases of IM, including 49 cases of GCA and 93 cases of GC. All the patients were from Linzhou, Henan Province, China, the highest incidence area for both GCA and squamous cell carcinoma. Radio- or chemotherapy was not applied to these patients before surgery. RESULTS: The detection rate of IM in tissues adjacent to GCA tissues was 44.9%, which was significantly lower than that in GC tissues (80.64%, P<0.01). The rates of both incomplete small intestinal and colonic IM types identified by histochemistry in GCA tissues (31.82% and 63.64%, respectively) were significantly higher than those in GC (5.33% and 21.33%, respectively, P<0.01). CONCLUSION: IM in GCA and GC should be considered as a separate entity. Further research is needed to evaluate whether neoplastic progression of IM is related to its mucin profile in GCA.

Adenocarcinoma/patologia , Cárdia , Intestinos/patologia , Neoplasias Gástricas/patologia , Adenocarcinoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Histocitoquímica , Humanos , Mucosa Intestinal/metabolismo , Masculino , Metaplasia , Pessoa de Meia-Idade , Neoplasias Gástricas/metabolismo