Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
Biochem Biophys Res Commun ; 663: 163-170, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37121126

RESUMO

Plant elicitor peptides (Peps) are recognized by two receptor-like kinases, PEPR1 and PEPR2, and trigger plant immunity responses and root growth inhibition. In this study, we reveal that the Pep-PEPR system triggers root immunity responses in Arabidopsis. Pep1 incubation initiated callose and lignin deposition in roots of wild type but not in that of pepr1 pepr2 mutant seedlings. The plasma membrane-associated kinase BIK1, which serves downstream of the Pep-PEPR signaling pathway, was essential for Pep1-induced root immunity responses. Interestingly, disruption of PEPR1/2-associated coreceptor BAK1 enhanced the deposition of both callose and lignin induced by Pep1 in roots. Ethylene and salicylic acid signaling are involved in Pep1-induced root immunity responses. Furthermore, we showed that the successful phytopathogen, P. syringae (DC3000) could effectively suppress Pep1-trigged root callose and lignin accumulation. These results demonstrated the endogenous Pep-triggered root immunity responses and pathogenic suppression of the Pep-PEPR signaling pathway.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Lignina/metabolismo , Transdução de Sinais/fisiologia , Peptídeos/farmacologia , Peptídeos/metabolismo , Imunidade Vegetal , Regulação da Expressão Gênica de Plantas , Proteínas Serina-Treonina Quinases/metabolismo
2.
Am J Gastroenterol ; 118(10): 1848-1854, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37207320

RESUMO

INTRODUCTION: The role of submucosal injection during cold snare polypectomy (CSP) remains uncertain. In this study, we investigated the impact of submucosal saline injection during CSP for colorectal polyps sized 3-9 mm. METHODS: This was a multicenter randomized controlled trial conducted in 6 Chinese centers between July and September 2020 (ChiCTR2000034423). Patients with nonpedunculated colorectal polyps sized 3-9 mm were randomized in a 1:1 ratio to either CSP with submucosal injection (SI-CSP) or conventional CSP (C-CSP). The primary outcome was the incomplete resection rate (IRR). Secondary outcomes included procedure time, intraprocedural bleeding, delayed bleeding, and perforation. RESULTS: One hundred fifty patients with 234 polyps in the SI-CSP group and 150 patients with 216 polyps in the C-CSP group were included in the analysis. The IRR was not decreased in the SI-CSP group compared with that in the C-CSP group (1.7% vs 1.4%, P = 1.000). The median procedure time in the SI-CSP group was significantly longer than that in the C-CSP group (108 seconds vs 48 seconds, P < 0.001). The incidences of intraprocedural bleeding and delayed bleeding were not significantly different between the 2 groups ( P = 0.531 and P = 0.250, respectively). There was no perforation in either group. DISCUSSION: Submucosal saline injection during CSP for colorectal polyps sized 3-9 mm did not decrease the IRR or reduce adverse events but prolonged the procedure time.


Assuntos
Pólipos do Colo , Neoplasias Colorretais , Humanos , Pólipos do Colo/complicações , Colonoscopia/métodos , Microcirurgia/efeitos adversos , Hemorragia Pós-Operatória/epidemiologia , Hemorragia Pós-Operatória/etiologia , Neoplasias Colorretais/etiologia
3.
Appl Opt ; 62(31): 8211-8218, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38037921

RESUMO

A single-point-probe-based slope profiler is a common measurement scheme for the measurement of freeform optical surfaces, which has been a challenging research direction. Efficiency is a key issue in two-dimensional scanning-based measurement. This study establishes a measurement system simulation model and reveals that the height reconstruction accuracy of different reconstruction algorithms is primarily correlated with the sampling density. The spatial resolution calibrated of the slope measurement device is also identified to be an essential part of the strategy. Based on a kind of slope profiler, this paper applies variable sampling intervals for different spatial frequency characteristics of the surface under test (SUT). The result shows that the reconstruction accuracy can be controlled by selecting sampling parameters and calibrating the slope measurement device. For objects with different spatial characteristics, targeted optimization of the measurement scheme can be achieved. This strategy also has a certain universality for general scanning slope measurement and height reconstruction, providing a reference for device selection and sampling settings for different spatial frequency measurement requirements.

4.
Ecotoxicol Environ Saf ; 239: 113655, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35617901

RESUMO

Farmed animals produce excrement containing excessive amounts of toxic heavy metals as a result of consuming compound feed as well as receiving medical treatments, and the presence of these heavy metals may aggravate the risk of spreading drug-resistance genes through co-selection during manure treatment and application processes. However, research on the association between heavy metals and antimicrobial resistance is still lacking. In this study, metagenomic sequencing was used to explore the effects of the co-selection of environmentally toxic heavy metals on the resistome in manure. A relevance network analysis showed that metal-resistance genes (MRGs), especially for copper (Cu) and zinc (Zn), were positively correlated with multiple types of antibiotic-resistance genes (ARGs) and formed a complex network. Most bacteria that co-occurred with both MRGs and ARGs simultaneously are members of Proteobacteria and accounted for 54.7% of the total microbial species in the relevance network. The remaining bacteria belonged to Firmicutes, Bacteroidetes and Actinobacteria. Among the four phyla, Cu- and Zn-resistance genes had more complex correlations with ARGs than other MRG types, reflecting the occurrence of ARG co-selection under the selective pressure of high Cu and Zn levels. In addition, approximately 64.8%, 59.1% and 68.4% of MRGs that correlated with the presence of plasmids, viruses and prophages, respectively, are Cu- or Zn-resistant, and they co-occurred with various ARGs, indicating that mobile genetic elements participate in mediating ARG co-selection in response to Cu and Zn pressure. The results indicated that the use of heavy-metal additives in feed induces the increases of drug resistance genes in manure through co-selection, aggravating the risk of antimicrobial resistance diffusion from animal farm to manure land applications.


Assuntos
Esterco , Metais Pesados , Animais , Antibacterianos/farmacologia , Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Esterco/microbiologia , Metais Pesados/toxicidade , Zinco
5.
Int J Mol Sci ; 23(14)2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35886990

RESUMO

Pseudomonas syringae pv. actinidiae (Psa), a bacterial pathogen, is a severe threat to kiwifruit production. To elucidate the species-specific interaction between Psa and kiwifruit, transcriptomic-profiles analyses were conducted, under Psa-infected treatment and mock-inoculated control, on shoots of resistant Maohua (MH) and susceptible Hongyang (HY) kiwifruit varieties. The plant hormone-signal transduction and plant-pathogen interaction were significantly enriched in HY compared with MH. However, the starch and sucrose metabolism, antigen processing and presentation, phagosome, and galactose metabolism were significantly enriched in MH compared with HY. Interestingly, the MAP2 in the pathogen/microbe-associated molecular patterns (PAMPs)-triggered immunity (PTI) was significantly up-regulated in MH. The genes RAR1, SUGT1, and HSP90A in the effector-triggered immunity (ETI), and the NPR1 and TGA genes involved in the salicylic acid signaling pathway as regulatory roles of ETI, were significantly up-regulated in HY. Other important genes, such as the CCRs involved in phenylpropanoid biosynthesis, were highly expressed in MH, but some genes in the Ca2+ internal flow or involved in the reactive oxygen metabolism were obviously expressed in HY. These results suggested that the PTI and cell walls involved in defense mechanisms were significant in MH against Psa infection, while the ETI was notable in HY against Psa infection. This study will help to understand kiwifruit bacterial canker disease and provide important theoretical support in kiwifruit breeding.


Assuntos
Actinidia , Pseudomonas syringae , Actinidia/metabolismo , Genótipo , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Pseudomonas syringae/fisiologia
6.
Int J Mol Sci ; 23(20)2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36292977

RESUMO

The kiwifruit (Actinidia arguta var. purpurea) produces oval shaped fruits containing a slightly green or mauve outer exocarp and a purple-flesh endocarp with rows of tiny black seeds. The flesh color of the fruit results from a range of anthocyanin compounds, and is an important trait for kiwifruit consumers. To elucidate the molecular mechanisms involved in anthocyanin biosynthesis of the sarcocarp during A. arguta fruit development, de novo assembly and transcriptomic profile analyses were performed. Based on significant Gene Ontology (GO) biological terms, differentially expressed genes were identified in flavonoid biosynthetic and metabolic processes, pigment biosynthesis, carbohydrate metabolic processes, and amino acid metabolic processes. The genes closely related to anthocyanin biosynthesis, such as phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), and anthocyanidin synthase (ANS), displayed significant up-regulation during fruit development according to the transcriptomic data, which was further confirmed by qRT-PCR. Meanwhile, a series of transcription factor genes were identified among the DEGs. Through a correlation analysis. AaMYB1 was found to be significantly correlated with key genes of anthocyanin biosynthesis, especially with CHS. Through a transient expression assay, AaMYB1 induced anthocyanin accumulation in tobacco leaves. These data provide an important basis for exploring the related mechanisms of sarcocarp anthocyanin biosynthesis in A. arguta. This study will provide a strong foundation for functional studies on A. arguta and will facilitate improved breeding of A. arguta fruit.


Assuntos
Actinidia , Actinidia/genética , Actinidia/metabolismo , Antocianinas/metabolismo , Transcriptoma , Regulação da Expressão Gênica de Plantas , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Melhoramento Vegetal , Frutas/genética , Frutas/metabolismo , Flavonoides/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Aminoácidos/metabolismo
7.
Ecotoxicol Environ Saf ; 208: 111464, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33075589

RESUMO

Ambient fine particulate matter (PM2.5) exposure correlates with adverse cardiometabolic effects. The underlying mechanisms have not yet been fully understood. Hypothalamic-pituitary-adrenal (HPA) axis, as the central stress response system, regulates cardiometabolic homeostasis and is implicated in the progression of various adverse health effects caused by inhalational airborne pollutant exposure. In this study, we investigated whether ambient PM2.5 exposure activates HPA axis and its effect mediating PM2.5-induced pulmonary inflammation. C57Bl/6 J mice were intratracheally instilled with different concentrations of diesel exhaust PM2.5 (DEP), and plasma was harvested at different times. Assessments of plasma stress hormones revealed that DEP instillation dose- and time-dependently increased mouse circulating corticosterone and adrenocorticotropic hormone (ACTH) levels, strongly supporting that DEP instillation activates HPA axis. To determine which components of DEP activate HPA axis, C57Bl/6J mice were intratracheally instilled with water-soluble and -insoluble fractions of DEP. Plasma analyses showed that water-insoluble but not -soluble fraction of DEP increased circulating corticosterone and ACTH levels. Consistently, concentrated ambient PM2.5 (CAP) exposure significantly increased mouse urine and hair corticosterone levels, corroborating the activation of HPA axis by ambient PM2.5. Furthermore, deletion of stress hormones by total bilateral adrenalectomy alleviated PM2.5-induced pulmonary inflammation, providing insights into the contribution of central neurohormonal mechanisms in modulating adverse health effects caused by exposure to PM2.5.


Assuntos
Poluentes Atmosféricos/toxicidade , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Material Particulado/toxicidade , Pneumonia/induzido quimicamente , Animais , Corticosterona/sangue , Exposição por Inalação/análise , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Emissões de Veículos/análise
8.
Plant Cell Physiol ; 60(10): 2231-2242, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31198959

RESUMO

Vegetable oils are mainly stored in the form of triacylglycerol (TAG) in oilseeds. Fatty acids (FAs), one of the building blocks for TAG assembly, are synthesized in plastids and then exported to the endoplasmic reticulum for storage oil synthesis. A recent study demonstrated that the export of FAs from plastids was mediated by a FAX (FA export) family protein. However, the significance of FAs export from plastid during seed oil accumulation has not been investigated. In this study, we found that FAX2 was highly expressed in developing Arabidopsis seeds and the expression level was consistent with FAs synthesis activity. FAX2 mutant seeds showed an approximately 18% reduction of lipid levels compared with wild-type seeds. By contrast, overexpression of FAX2 enhanced seed lipid accumulation by up to 30%. The FAs export activity of FAX2 was confirmed by yeast mutant cell complementation analysis. Our results showed that FAX2 could interact with other proteins to facilitate FAs transport. Taken together, these results indicate that FAX2-mediated FA export from plastids is important for seed oil accumulation, and that FAX2 can be used as a target gene for increasing lipid production in oilseeds.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos , Proteínas de Membrana/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Transporte Biológico , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana/genética , Óleos de Plantas/metabolismo , Plantas Geneticamente Modificadas , Plastídeos/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Triglicerídeos/metabolismo
9.
Glob Chang Biol ; 25(2): 686-698, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30449058

RESUMO

Rice is a staple food for nearly half of the world's population, but rice paddies constitute a major source of anthropogenic CH4 emissions. Root exudates from growing rice plants are an important substrate for methane-producing microorganisms. Therefore, breeding efforts optimizing rice plant photosynthate allocation to grains, i.e., increasing harvest index (HI), are widely expected to reduce CH4 emissions with higher yield. Here we show, by combining a series of experiments, meta-analyses and an expert survey, that the potential of CH4 mitigation from rice paddies through HI improvement is in fact small. Whereas HI improvement reduced CH4 emissions under continuously flooded (CF) irrigation, it did not affect CH4 emissions in systems with intermittent irrigation (II). We estimate that future plant breeding efforts aimed at HI improvement to the theoretical maximum value will reduce CH4 emissions in CF systems by 4.4%. However, CF systems currently make up only a small fraction of the total rice growing area (i.e., 27% of the Chinese rice paddy area). Thus, to achieve substantial CH4 mitigation from rice agriculture, alternative plant breeding strategies may be needed, along with alternative management.


Assuntos
Poluentes Atmosféricos/análise , Produção Agrícola/métodos , Recuperação e Remediação Ambiental/métodos , Gases de Efeito Estufa/análise , Metano/análise , Poluição do Ar/prevenção & controle , Oryza/crescimento & desenvolvimento
10.
Environ Sci Technol ; 53(18): 10781-10791, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31438664

RESUMO

Assessment of indirect emission factors (EF5r) of nitrous oxide (N2O) from agricultural river networks remains challenging, and results are uncertain due to limited data availability. This study compared two methods of assessing EF5r using data from long-term observations at high temporal resolution in a typical agricultural catchment in subtropical central China. The concentration method (method 1) and the Intergovernmental Panel on Climate Change (IPCC) 2006 method (method 2) were employed to evaluate the emission factor. EF5r estimated using method 1 (i.e., EF5r1) was 0.00077 ± 0.00025 (0.00038-0.00097). EF5r calculated using method 2 (i.e., EF5r2) was lower than EF5r1, with a mean value of 0.00004 (0.000015-0.00012). Both EF5r1 and EF5r2 were significantly lower than the IPCC 2006 default value of 0.0025, suggesting that N2O emissions from China and world river networks may be grossly overestimated. A complex N2O production pathway and diffusion mechanism were responsible for the transfer of N2O from the sediment to river water and then to the atmosphere. These findings provide essential data for refining national greenhouse gas inventories and contribute evidence for downward revision of indirect emission factors adopted by the IPCC.


Assuntos
Monitoramento Ambiental , Rios , Agricultura , China , Óxido Nitroso
11.
Am J Physiol Endocrinol Metab ; 315(1): E72-E80, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29351483

RESUMO

Environmental stressors that encounter in early-life and cause abnormal fetal and/or neonatal development may increase susceptibility to non-communicable diseases such as diabetes. Maternal exposure to ambient fine particulate matter (PM2.5) is associated with various fetal abnormalities, suggesting that it may program offspring's susceptibility to diabetes. In the present study, we therefore examined whether maternal exposure to diesel exhaust PM2.5 (DEP), one of the major sources of ambient PM2.5 in urban areas, programs adult offspring's glucose metabolism. Female C57Bl/6J mice were intratracheally instilled with DEP or vehicle throughout a 7-wk preconceptional period, gestation, and lactation, and the glucose homeostasis of their adult male offspring was assessed. Intraperitoneal glucose tolerance test (IPGTT) revealed that the maternal exposure to DEP significantly impaired adult male offspring's glucose tolerance. Unexpectedly, it did not influence their insulin sensitivity, whereas it significantly decreased their glucose-induced insulin secretion (GIIS). This deficit in insulin secretion was corroborated by their significant decrease in arginine-induced insulin secretion. Histological analysis demonstrated that the deficit in insulin secretion was accompanied by the decrease in pancreatic islet and ß cell sizes. To differentiate the effects of maternal exposure to DEP before birth and during lactation, some offspring were cross-fostered once born. We did not observe any significant effect of cross-fostering on the glucose homeostasis of adult male offspring and the function and morphology of their ß cells. Prenatal exposure to DEP programs the morphology and function of ß cells and thus homeostatic regulation of glucose metabolism in adult male offspring.


Assuntos
Poluentes Atmosféricos/toxicidade , Células Secretoras de Insulina/efeitos dos fármacos , Material Particulado/toxicidade , Emissões de Veículos/toxicidade , Animais , Tamanho Celular/efeitos dos fármacos , Feminino , Glucose/metabolismo , Teste de Tolerância a Glucose , Resistência à Insulina , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Masculino , Exposição Materna , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo
13.
Part Fibre Toxicol ; 14(1): 20, 2017 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-28645299

RESUMO

BACKGROUND: Many diseases including obesity may originate through alterations in the early-life environment that interrupts fetal development. Increasing evidence has shown that exposure to ambient fine particles (PM2.5) is associated with abnormal fetal development. However, its long-term metabolic effects on offspring have not been systematically investigated. RESULTS: To determine if maternal exposure to PM2.5 programs offspring obesity, female C57Bl/6j mice were exposed to filtered air (FA) or concentrated ambient PM2.5 (CAP) during pre-conception, pregnancy, and lactation, and the developmental and metabolic responses of offspring were assessed. The growth trajectory of offspring revealed that maternal exposure to CAP significantly decreased offspring birth weight but increased body weight of adult male but not female offspring, and the latter was expressed as increased adiposity. These adult male offspring had increased food intake, but were sensitive to exogenous leptin. Their hypothalamic expression of Socs3 and Pomc, two target genes of leptin, was not changed, and the hypothalamic expression of NPY, an orexigenic peptide that is inhibited by leptin, was significantly increased. These decreases in central anorexigenic signaling were accompanied by reduced plasma leptin and its expression in adipose tissues, the primary source of circulating leptin. In contrast, maternal exposure did not significantly change any of these indexes in adult female offspring. Pyrosequencing demonstrated that the leptin promoter methylation of adipocytes was significantly increased in CAP-exposed male but not female offspring. CONCLUSIONS: Our data indicate that maternal exposure to ambient PM2.5 programs obesity in male offspring probably through alterations in the methylation of the promoter region of the leptin gene.


Assuntos
Exposição Materna , Obesidade/induzido quimicamente , Material Particulado/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Adipócitos/metabolismo , Adiposidade , Fatores Etários , Animais , Peso ao Nascer , Metilação de DNA , Ingestão de Alimentos , Comportamento Alimentar , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Hipotálamo/metabolismo , Hipotálamo/fisiopatologia , Lactação , Leptina/sangue , Leptina/genética , Masculino , Camundongos Endogâmicos C57BL , Neuropeptídeo Y/metabolismo , Obesidade/genética , Obesidade/metabolismo , Obesidade/fisiopatologia , Material Particulado/administração & dosagem , Gravidez , Pró-Opiomelanocortina/metabolismo , Regiões Promotoras Genéticas , Medição de Risco , Fatores Sexuais , Transdução de Sinais , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Aumento de Peso
14.
Part Fibre Toxicol ; 14(1): 3, 2017 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-28100227

RESUMO

BACKGROUND: Obesity is one of the leading threats to global public health. It is consequent to abnormal energy metabolism. Currently, it has been well established that maternal exposure to environmental stressors that cause inappropriate fetal development may have long-term adverse effects on offspring energy metabolism in an exposure timing-dependent manner, known as developmental programming of health and diseases paradigm. Rapidly increasing evidence has indicated that maternal exposure to ambient fine particles (PM2.5) correlates to abnormal fetal development. In the present study, we therefore assessed whether maternal exposure to diesel exhaust PM2.5 (DEP), the major component of ambient PM2.5 in urban areas, programs offspring energy metabolism, and further examined how the timing of exposure impacts this programming. RESULTS: The growth trajectory of offspring shows that although prenatal maternal exposure to DEP did not impact the birth weight of offspring, it significantly decreased offspring body weight from postnatal week 2 until the end of observation. This weight loss effect of prenatal maternal exposure to DEP coincided with decreased food intake but not alteration in brown adipose tissue (BAT) morphology. The hypophagic effect of prenatal maternal exposure to DEP was in concord with decreased hypothalamic expression of an orexigenic peptide NPY, suggesting that the prenatal maternal exposure to DEP impacts offspring energy balance primarily through programming of food intake. Paradoxically, the reduced body weight resulted from prenatal maternal exposure to DEP was accompanied by increased mass of epididymal adipose tissue, which was due to hyperplasia as morphological analysis did not observe any hypertrophy. In direct contrast, the postnatal mothering by DEP-exposed dams increased offspring body weight during lactation and adulthood, paralleled by markedly increased fat accumulation and decreased UCP1 expression in BAT but not alteration in food intake. The weight gain induced by postnatal mothering by DEP-exposed dams was also expressed as an increased adiposity. But it concurred with a marked hypertrophy of adipocytes. CONCLUSION: Prenatal and postnatal mothering by DEP-exposed dams differentially program offspring energy metabolism, underscoring consideration of the exposure timing when examining the adverse effects of maternal exposure to ambient PM2.5.


Assuntos
Comportamento Animal , Metabolismo Energético/efeitos dos fármacos , Exposição Materna , Material Particulado/toxicidade , Emissões de Veículos/toxicidade , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Efeitos Tardios da Exposição Pré-Natal
15.
Mol Biol Rep ; 42(5): 937-45, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25433432

RESUMO

High chilling-susceptibility is becoming the bottleneck for cultivation and commercialization of Jatropha curcas L. For insights to chilling resistance ability of this plant species, a cold response transcription factor, JcCBF2, was cloned and studied. It codes a 26 kDa protein, which contains all conserved motifs unique to the C-repeat binding factor (CBF) family and has high similarity to CBFs of Ricinus communis and Populus. Its transcripts express specifically in leaves of Jatropha at cold temperature. After transmitting the report vector, 35S::JcCBF2-GFP, into Arabidopsis thaliana, JcCBF2 protein is main detected in cell nucleus, being consistent to the nuclear orientation signal in its N-terminal. Compared to the control Arabidopsis, the frozen leaves of JcCBF2-overexpressed seedlings grow stronger with less malondialdehyde, smaller leaf conductivity and activer superoxide dismutase, showing their higher freezing tolerance. RT-PCR tests revealed that JcCBF2 functioned mainly at the early stage (0-6 h) of resistance events in Arabidopsis, and its transcripts reduced after 6 h. In addition, JcCBF2 could quickly regulate transcripts of some cold-responsive (COR) genes such as RD29A, COR105A and COR6.6, also during the early stage of frozen treatment. This study not only proves the chilling resistance roles of JcCBF2, but also presents a candidate gene engineering for improvement of chilling tolerance in J. curcas.


Assuntos
Aclimatação/genética , Arabidopsis/genética , Resposta ao Choque Frio/genética , Congelamento , Jatropha/genética , Proteínas de Plantas/genética , Transativadores/genética , Sequência de Aminoácidos , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Dados de Sequência Molecular , Filogenia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Plantas Geneticamente Modificadas/fisiologia , Plântula/genética , Plântula/fisiologia , Transgenes
17.
Planta ; 239(2): 511-20, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24240518

RESUMO

Jatropha curcas, a biodiesel plant with a short life cycle, has great potentials to be a new model woody plant. In this study, we found a plant-specific transcription factor JcNAC1, an intriguing regulator modulating plant responses to abiotic stresses and pathogen infection. Expression of JcNAC1 was strongly increased when plants were treated with abscisic acid, salt and polyethylene glycol, and was decreased with salicylic acid, ethylene, and pathogens. Overexpressing JcNAC1 plants showed enhanced tolerance to drought and increased susceptibility to pathogens. Furthermore, over-expression of JcNAC1 in plants also resulted in the expression changes of some stress-related maker genes including curcin-L, which is a special stress-inducible ribosome-inactivating protein gene in J. curcas. These results indicate that JcNAC1 is responsible for stress responses in J. curcas.


Assuntos
Regulação da Expressão Gênica de Plantas , Jatropha/genética , Estresse Fisiológico , Fatores de Transcrição/genética , Arabidopsis/genética , Arabidopsis/microbiologia , Arabidopsis/fisiologia , Botrytis/crescimento & desenvolvimento , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Secas , Expressão Gênica , Genes Reporter , Jatropha/microbiologia , Jatropha/fisiologia , Doenças das Plantas/microbiologia , Epiderme Vegetal/genética , Epiderme Vegetal/microbiologia , Epiderme Vegetal/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Caules de Planta/genética , Caules de Planta/microbiologia , Caules de Planta/fisiologia , Plantas Geneticamente Modificadas , Pseudomonas syringae/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes de Fusão , Plântula/genética , Plântula/microbiologia , Plântula/fisiologia , Cloreto de Sódio/farmacologia , Fatores de Transcrição/metabolismo , Ativação Transcricional
19.
Lancet Gastroenterol Hepatol ; 9(1): 34-44, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37952555

RESUMO

BACKGROUND: Despite the usefulness of white light endoscopy (WLE) and non-magnified narrow-band imaging (NBI) for screening for superficial oesophageal squamous cell carcinoma and precancerous lesions, these lesions might be missed due to their subtle features and interpretation variations among endoscopists. Our team has developed an artificial intelligence (AI) system to detect superficial oesophageal squamous cell carcinoma and precancerous lesions using WLE and non-magnified NBI. We aimed to evaluate the auxiliary diagnostic performance of the AI system in a real clinical setting. METHODS: We did a multicentre, tandem, double-blind, randomised controlled trial at 12 hospitals in China. Eligible patients were aged 18 years or older and underwent sedated upper gastrointestinal endoscopy for screening, investigation of gastrointestinal symptoms, or surveillance. Patients were randomly assigned (1:1) to either the AI-first group or the routine-first group using a computerised random number generator. Patients, pathologists, and statistical analysts were masked to group assignment, whereas endoscopists and research assistants were not. The same endoscopist at each centre did tandem upper gastrointestinal endoscopy for each eligible patient on the same day. In the AI-first group, the endoscopist did the first examination with the assistance of the AI system and the second examination without it. In the routine-first group, the order of examinations was reversed. The primary outcome was the miss rate of superficial oesophageal squamous cell carcinoma and precancerous lesions, calculated on a per-lesion and per-patient basis. All analyses were done on a per-protocol basis. This trial is registered with the Chinese Clinical Trial Registry (ChiCTR2100052116) and is completed. FINDINGS: Between Oct 19, 2021, and June 8, 2022, 5934 patients were randomly assigned to the AI-first group and 5912 to the routine-first group, of whom 5865 and 5850 were eligible for analysis. Per-lesion miss rates were 1·7% (2/118; 95% CI 0·0-4·0) in the AI-first group versus 6·7% (6/90; 1·5-11·8) in the routine-first group (risk ratio 0·25, 95% CI 0·06-1·08; p=0·079). Per-patient miss rates were 1·9% (2/106; 0·0-4·5) in AI-first group versus 5·1% (4/79; 0·2-9·9) in the routine-first group (0·37, 0·08-1·71; p=0·40). Bleeding after biopsy of oesophageal lesions was observed in 13 (0·2%) patients in the AI-first group and 11 (0·2%) patients in the routine-first group. No serious adverse events were reported by patients in either group. INTERPRETATION: The observed effect of AI-assisted endoscopy on the per-lesion and per-patient miss rates of superficial oesophageal squamous cell carcinoma and precancerous lesions under WLE and non-magnified NBI was consistent with substantial benefit through to a neutral or small negative effect. The effectiveness and cost-benefit of this AI system in real-world clinical settings remain to be further assessed. FUNDING: National Natural Science Foundation of China, 1·3·5 project for disciplines of excellence, West China Hospital, Sichuan University, and Chengdu Science and Technology Project. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Lesões Pré-Cancerosas , Humanos , Inteligência Artificial , Endoscopia/métodos , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/diagnóstico por imagem , Lesões Pré-Cancerosas/diagnóstico por imagem , Adolescente , Adulto
20.
Front Plant Sci ; 14: 1108701, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36844093

RESUMO

Magnolia hypoleuca Sieb. & Zucc, a member of the Magnoliaceae of magnoliids, is one of the most economically valuable, phylogenetic and ornamental tree species in Eastern China. Here, the 1.64 Gb chromosome-level assembly covers 96.64% of the genome which is anchored to 19 chromosomes, with a contig N50 value of 1.71 Mb and 33,873 protein-coding genes was predicted. Phylogenetic analyses between M. hypoleuca and other 10 representative angiosperms suggested that magnoliids were placed as a sister group to the eudicots, rather than sister to monocots or both monocots and eudicots. In addition, the relative timing of the whole-genome duplication (WGD) events about 115.32 Mya for magnoliid plants. M. hypoleuca was found to have a common ancestor with M. officinalis approximately 23.4 MYA, and the climate change of OMT (Oligocene-Miocene transition) is the main reason for the divergence of M. hypoleuca and M. officinalis, which was along with the division of Japanese islands. Moreover, the TPS gene expansion observed in M. hypoleuca might contribute to the enhancement of flower fragrance. Tandem and proximal duplicates of younger age that have been preserved have experienced more rapid sequence divergence and a more clustered distribution on chromosomes contributing to fragrance accumulation, especially phenylpropanoid, monoterpenes and sesquiterpenes and cold tolerance. The stronger selective pressure drived the evolution of tandem and proximal duplicates toward plant self-defense and adaptation. The reference M. hypoleuca genome will provide insights into the evolutionary process of M. hypoleuca and the relationships between the magnoliids with monocots and eudicots, and enable us to delve into the fragrance and cold tolerance produced by M. hypoleuca and provide more robust and deep insight of how the Magnoliales evolved and diversified.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA