Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31.877
Filtrar
1.
Rev Med Liege ; 76(1): 31-35, 2021 Jan.
Artigo em Francês | MEDLINE | ID: mdl-33443326

RESUMO

The use of cannabis is most often associated with that of tobacco. While the addictive power of cannabis is low, that of tobacco is high. The regular use of both tobacco and cannabis is at the origin of the increase in dependence on each substance, which makes stopping this double consumption often difficult. This combined use can cause somatic and mental complications. Practitioners should identify this dual use, advise stopping and offer their help after a careful evaluation of both consumptions and their causes. The management includes psychotherapeutic support; If the efficacy of medications to aid stopping cannabis has not been proven to aid in stopping cannabis, nicotine replacement therapy can limit withdrawal syndrome, craving and improve patients' adherence to monitoring.The mobilization of practitioners in the management of patients and the development of effective cannabis cessation pharmacotherapies are essential.


Assuntos
Cannabis , Abandono do Hábito de Fumar , Tabagismo , Cannabis/efeitos adversos , Humanos , Tabaco , Dispositivos para o Abandono do Uso de Tabaco
2.
Ecotoxicol Environ Saf ; 208: 111623, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396143

RESUMO

Monitoring the consumption of pharmaceuticals and licit drugs is important for assessing the needs of public health owing to the impact on individuals as well as society. The present work applied wastewater-based epidemiology to profile the spatial patterns of metformin, nicotine, and caffeine use and their correlations. Influent wastewater samples were collected from 27 wastewater treatment plants in 22 typical Chinese cities that covered all geographic regions of the country. The consumption of metformin ranged from 0.02 g/d/1000 inh to 8.92 g/d/1000 inh, whereas caffeine and nicotine consumption ranged from 4.33 g/d/1000 inh to 394 g/d/1000 inh and 0.17 g/d/1000 inh to 1.88 g/d/1000 inh, respectively. There were significant regional differences in the consumption of caffeine, with the highest consumption in East China and the lowest consumption in Northeast China. The consumption and concentration of caffeine were related to the gross domestic product and per capita disposable income of urban residents, respectively. There was a correlation between the concentrations of caffeine and cotinine (a nicotine metabolite), thereby indicating that individuals that use one of these substances are likely to use the other substance. A significant relationship was found between the concentration of metformin and cotinine, thereby implying that the use of tobacco may be correlated with type 2 diabetes. Co-analysis of these substances in wastewater may provide a more accurate picture of substance use situations within different communities and provide more information on human health, human behavior, and the economy. This report describes the newest study related to the consumption of metformin among the general population in China.


Assuntos
Cafeína/análise , Metformina/análise , Nicotina/análise , Uso de Tabaco/epidemiologia , Águas Residuárias/química , Vigilância Epidemiológica Baseada em Águas Residuárias , Cafeína/química , China/epidemiologia , Cidades , Diabetes Mellitus Tipo 2/epidemiologia , Humanos , Nicotina/química , Análise Espacial , Tabaco , Águas Residuárias/análise
3.
Ecotoxicol Environ Saf ; 208: 111412, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33039872

RESUMO

Cadmium (Cd) is a severely toxic and carcinogenic heavy metal. Cigarette smoking is one of the major source of Cd exposure in humans. Nicotiana tabacum is primarily a leaf Cd accumulator, while Nicotiana rustica is a root Cd accumulator among Nicotiana species. However, little is known about the mechanisms of differential Cd translocation and accumulation in Nicotiana. To find the key factors, Cd concentration, Cd chemical forms, and transcriptome analysis were comparatively studied between N. tabacum and N. rustica under control or 10 µM Cd stress. The leaf/root Cd concentration ratio of N. tabacum was 2.26 and that of N. rustica was 0.14. The Cd concentration in xylem sap of N. tabacum was significantly higher than that of N. rustica. The root of N. tabacum had obviously higher proportion of ethanol extractable Cd (40%) and water extractable Cd (16%) than those of N. rustica (16% and 6%). Meanwhile the proportion of sodium chloride extracted Cd in N. rustica (71%) was significantly higher than that in N. tabacum (30%). A total of 30710 genes expressed differentially between the two species at control, while this value was 30,294 under Cd stress, among which 27,018 were collective genes, manifesting the two species existed enormous genetic differences. KEGG pathway analysis showed the phenylpropanoid biosynthesis pathway was overrepresented between the two species under Cd stress. Several genes associated with pectin methylesterase, suberin and lignin synthesis, and heavy metal transport were discovered to be differential expressed genes between two species. The results suggested that the higher accumulation of Cd in the leaf of N. tabacum depends on a comprehensive coordination of Cd transport, including less cell wall binding, weaker impediment by the Casparian strip, and efficient xylem loading.


Assuntos
Cádmio/toxicidade , Tabaco/fisiologia , Transcriptoma , Parede Celular/metabolismo , Perfilação da Expressão Gênica , Humanos , Metais Pesados/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Tabaco/metabolismo , Xilema/metabolismo
4.
Chem Biol Interact ; 333: 109321, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33186600

RESUMO

HPV infections in the oral cavity that progress to cancer are on the increase in the USA. Model systems to study co-factors for progression of these infections are lacking as HPVs are species-restricted and cannot grow in preclinical animal models. We have recently developed a mouse papillomavirus (MmuPV1) oral mucosal infection model that provides opportunities to test, for the first time, the hypothesis that tobacco carcinogens are co-factors that can impact the progression of oral papillomas to squamous cell carcinoma (SCC). Four cohorts of mice per sex were included: (1) infected with MmuPV1 and treated orally with DMSO-saline; (2) infected with MmuPV1 and treated orally with the tobacco carcinogen, dibenzo[def,p]chrysene (DBP); (3) uninfected and treated orally with DMSO-saline, and (4) uninfected and treated orally with DBP. Oral swabs were collected monthly for subsequent assessment of viral load. Oral tissues were collected for in situ viral DNA/RNA detection, viral protein staining, and pathological assessment for hyperplasia, papillomas and SCC at study termination. We observed increased rates of SCC in oral tissue infected with MmuPV1 and treated with DBP when compared to mice treated with DBP or virus individually, each of which showed minimal disease. Virally-infected epithelium showed strong levels of viral DNA/RNA and viral protein E4/L1 staining. In contrast, areas of SCC showed reduced viral DNA staining indicative of lower viral copy per nucleus but strong RNA signals. Several host markers (p120 ctn, p53, S100A9) were also examined in the mouse oral tissues; of particular significance, p120 ctn discriminated normal un-infected epithelium from SCC or papilloma epithelium. In summary, we have confirmed that our infection model is an excellent platform to assess the impact of co-factors including tobacco carcinogens for oral PV cancerous progression. Our findings can assist in the design of novel prevention/treatment strategies for HPV positive vs. HPV negative disease.


Assuntos
Crisenos/toxicidade , Progressão da Doença , Poluentes Ambientais/toxicidade , Neoplasias Bucais/patologia , Papillomaviridae/fisiologia , Fumaça/efeitos adversos , Tabaco/efeitos adversos , Animais , Carcinogênese/efeitos dos fármacos , Feminino , Genoma Viral/genética , Masculino , Camundongos , Neoplasias Bucais/virologia , Papillomaviridae/genética , Caracteres Sexuais , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/virologia
5.
Life Sci ; 265: 118862, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33301812

RESUMO

AIMS: The 18 kDa translocator protein (TSPO) - also known as peripheral benzodiazepine receptor, is found to be expressed in lung epithelium and pneumocytes, which is closely associated with the mitochondrial permeability transition pore (mPTP) and apoptosis. Cigarette smoking, a key risk factor for the development of chronic obstructive pulmonary disease (COPD), is known to induce apoptosis. We aimed to investigate TSPO subcellular localization and to examine whether cigarette smoke medium (CSM) induce apoptosis via TSPO in airway epithelial cells. MAIN METHODS: TSPO subcellular localization and expression were evaluated using immunofluorescent staining and Western blot analysis respectively. TSPO ligands either PK 11195 (a specific antagonist) or AC-5216 (a specific agonist) were pre-incubated in human bronchial epithelial cells before treating with 2% CSM for measurements of apoptotic cells, mitochondrial membrane potential (ΔΨm), cytoplasmic/mitochondrial reactive oxygen species (ROS) and inflammatory marker interleukin (IL)-8 respectively. KEY FINDINGS: TSPO was localized around the nucleus and overlapped with mitochondria in BEAS-2B cells. CSM caused an increase in apoptotic cells along with elevation of TSPO protein expression. Pretreatment of PK 11195 suppressed while AC-5216 potentiated CSM-induced apoptosis, collapse of ΔΨm, elevation of cytoplasmic/mitochondrial ROS levels and IL-8 release. In support, knockdown of TSPO caused a significant suppression of CSM-induced IL-8 release in BEAS-2B cells. SIGNIFICANCE: The findings suggest that TSPO may play a crucial role in the regulation of cigarette smoke-induced mitochondrial dysfunction via mPTP. Therefore, the development of specific TSPO antagonists like PK11195 may be beneficial to combat smoking-related diseases, such as COPD.


Assuntos
Apoptose/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Receptores de GABA/metabolismo , Fumaça/efeitos adversos , Brônquios/citologia , Linhagem Celular , Células Epiteliais/patologia , Humanos , Isoquinolinas/farmacologia , Mitocôndrias/patologia , Purinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Tabaco
6.
Toxicol Lett ; 337: 98-110, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33220401

RESUMO

Exposure to aerosol from electronic vapor (e-vapor) products has been suggested to result in less risk of harm to smokers than cigarette smoke (CS) exposure. Although many studies on e-vapor products have tested the effects of liquid formulations on cell cultures, few have evaluated the effects of aerosolized formulations. We examined the effects of acute exposure to the aerosol of an e-vapor device that uses the MESH® technology (IQOS® MESH, Philip Morris International) and to CS from the 3R4F reference cigarette on human organotypic bronchial epithelial culture and alveolar triculture models. In contrast to 3R4F CS exposure, exposure to the IQOS MESH aerosol (Classic Tobacco flavor) did not cause cytotoxicity in bronchial epithelial cultures or alveolar tricultures despite its greater concentrations of deposited nicotine (3- and 4-fold, respectively). CS exposure caused a marked decrease in the frequency and active area of ciliary beating in bronchial cultures, whereas IQOS MESH aerosol exposure did not. Global mRNA expression and secreted protein profiles revealed a significantly lower impact of IQOS MESH aerosol exposure than 3R4F CS exposure. Overall, our whole aerosol exposure study shows a clearly reduced impact of IQOS MESH aerosol relative to CS in bronchial and alveolar cultures, even at greater nicotine doses.


Assuntos
Brônquios/efeitos dos fármacos , Sistemas Eletrônicos de Liberação de Nicotina , Alvéolos Pulmonares/efeitos dos fármacos , Fumaça/efeitos adversos , Adenilato Quinase/metabolismo , Adulto , Aerossóis , Sobrevivência Celular/efeitos dos fármacos , Cílios/efeitos dos fármacos , Humanos , Masculino , Nicotina/química , Técnicas de Cultura de Órgãos , RNA Mensageiro/biossíntese , Tabaco , Transcrição Genética/efeitos dos fármacos
7.
Int J Phytoremediation ; 23(1): 1-9, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32643388

RESUMO

Plants encounter many environmental factors such as low and high temperatures during phytoremediation processes. In this study, our aim was to produce the transgenic tobacco plants by using a newly characterized bacterial nitroreductase, Ntr, which was active at a broad range temperature in order to detoxify 2,4-dinitrotoluene (2,4-DNT) at lower temperature. The presence of Ntr and its heterologous expression was verified in T1 transgenic plants and their growing ability were determined under toxic amount of 2,4-DNT (35 µM). Fresh weight and dry weight of transgenic plants were significantly higher than wild type (WT) under toxic 2,4-DNT at 22 °C, indicating higher growth capacity of the transgenics. Transgenic plants also showed a higher tolerance than WT when exposed to 2,4-DNT at 15 °C. Moreover, transformation rate of 2,4-DNT was gradually decreased through decreasing temperatures in WT media, however, it was increased through decreasing temperatures in transgenic plant TR3-25 media and it had the highest transformation rate (54%) of 2,4-DNT at 4 °C. Correlatively, 2,4-DNT treatment at 4 °C led to a significant decrease in H2O2 level in transgenic plants. Thus, transgenic plants overexpressing nitroreductase might have an important advantage for phytoremediation of toxic nitroaromatic compounds in field applications at low temperatures.


Assuntos
Peróxido de Hidrogênio , Tabaco , Biodegradação Ambiental , Dinitrobenzenos , Nitrorredutases/genética , Plantas Geneticamente Modificadas/genética , Temperatura
8.
Plant Mol Biol ; 105(1-2): 65-82, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32909182

RESUMO

KEY MESSAGE: NbWRKY22 and NbWRKY25 are required for full activation of bacteria-associated pattern- and effector-triggered immunity as well as for the response to other non-bacterial defense elicitors. Plants defend themselves against pathogens using a two-layered immune system. Pattern-triggered immunity (PTI) can be activated upon recognition of epitopes from flagellin including flg22. Pseudomonas syringae pv. tomato (Pst) delivers effector proteins into the plant cell to promote host susceptibility. However, some plants express resistance (R) proteins that recognize specific effectors leading to the activation of effector-triggered immunity (ETI). Resistant tomato lines such as Rio Grande-PtoR (RG-PtoR) recognize two Pst effectors, AvrPto and AvrPtoB, and activate ETI through the Pto/Prf protein complex. Using RNA-seq, we identified two tomato WRKY transcription factor genes, SlWRKY22 and SlWRKY25, whose expression is increased during Pst-induced ETI. Silencing of the WRKY25/22 orthologous genes in Nicotiana benthamiana led to a delay in programmed cell death normally associated with AvrPto recognition or several non-bacterial effector/R protein pairs. An increase in disease symptoms was observed in silenced plants infiltrated with Pseudomonas syringae pv. tabaci expressing AvrPto or HopQ1-1. Expression of both tomato WRKY genes is also induced upon treatment with flg22 and callose deposition and cell death suppression assays in WRKY25/22-silenced N. benthamiana plants supported their involvement in PTI. Our results reveal an important role for two WRKYs as positive regulators of plant immunity against bacterial and potentially non-bacterial pathogens.


Assuntos
Imunidade Vegetal/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tabaco/genética , Tabaco/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Apoptose , Arabidopsis/genética , Proteínas de Arabidopsis , Morte Celular , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes de Plantas/genética , Lycopersicon esculentum/genética , Filogenia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Proteínas de Plantas/classificação , Pseudomonas syringae/patogenicidade , Fatores de Transcrição/classificação
9.
Plant Mol Biol ; 105(1-2): 115-132, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32926249

RESUMO

KEY MESSAGE: Over-expression of CAX3 encoding a cation/proton exchanger enhances Cd tolerance by decreasing ROS (Reactive Oxygen Species) through activating anti-oxidative enzymes via elevation of Ca level in Arabidopsis CAXs (cation/proton exchangers) are involved in the sequestration of cations such as Mn, Li, and Cd, as well as Ca, from cytosol into the vacuole using proton gradients. In addition, it has been reported that CAX1, 2 and 4 are involved in Cd tolerance. Interestingly, it has been reported that CAX3 expressions were enhanced by Cd in Cd-tolerant transgenic plants expressing Hb1 (hemoglobin 1) or UBC1 (Ub-conjugating enzyme 1). Therefore, to investigate whether CAX3 plays a role in increasing Cd tolerance, CAX3 of Arabidopsis and tobacco were over-expressed in Arabidopsis thaliana. Compared to control plants, both transgenic plants displayed an increase in Cd tolerance, no change in Cd accumulation, and enhanced Ca levels. In support of these, AtCAX3-Arabidopsis showed no change in expressions of Cd transporters, but reduced expressions of Ca exporters and lower rate of Ca efflux. By contrast, atcax3 knockout Arabidopsis exhibited a reduced Cd tolerance, while the Cd level was not altered. The expression of Δ90-AtCAX3 (deletion of autoinhibitory domain) increased Cd and Ca tolerance in yeast, while AtCAX3 expression did not. Interestingly, less accumulation of ROS (H2O2 and O2-) was observed in CAX3-expressing transgenic plants and was accompanied with higher antioxidant enzyme activities (SOD, CAT, GR). Taken together, CAX3 over-expression may enhance Cd tolerance by decreasing Cd-induced ROS production by activating antioxidant enzymes and by intervening the positive feedback circuit between ROS generation and Cd-induced spikes of cytoplasmic Ca.


Assuntos
Antiporters/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cádmio/metabolismo , Cálcio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sequência de Aminoácidos , Antiporters/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Transporte Biológico , Cádmio/toxicidade , Cálcio/toxicidade , Cátions/metabolismo , Tolerância a Medicamentos , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Prótons , Homologia de Sequência de Aminoácidos , Tabaco/genética , Vacúolos/metabolismo
10.
Cancer Causes Control ; 32(1): 67-74, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33108615

RESUMO

PURPOSE: Studies have shown consistent associations between youth e-cigarette use and subsequent smoking uptake. However, it remains unclear why, as limited evidence exists regarding the mechanisms underlying these associations. Our study investigated whether having one or more smoking friends mediated the association between e-cigarette use and cigarette smoking onset among a longitudinal sample of Canadian youth who were never smokers at baseline. METHODS: A longitudinal sample of youth that participated in three waves of the COMPASS study (2015-2016 to 2017-2018) was identified (N = 5,535). The product of coefficients method was used to assess whether having one or more smoking friends mediated the association between: (1) past 30-day e-cigarette use and cigarette smoking onset and (2) past 30-day e-cigarette use and subsequent dual use of e-cigarettes and cigarettes. RESULTS: Having one or more smoking friends did not mediate the association between (1) past 30-day e-cigarette use and cigarette smoking onset (ß = 0.38, 95% CI - 0.12, 0.89) or (2) past 30-day e-cigarette use and subsequent dual use (ß = 0.46, 95% CI - 0.16, 1.07). Post hoc tests indicated that smoking friends significantly predicted past 30-day e-cigarette use and cigarette smoking at wave 3 (aOR 1.68 and 2.29, respectively). CONCLUSION: Having smoking friends did not explain the association between e-cigarette use and smoking uptake despite being a common risk factor for both e-cigarette use and cigarette smoking. Prevention efforts should consider how best to incorporate effective programming to address these social influences.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Adolescente , Comportamento do Adolescente , Canadá , Fumar Cigarros , Feminino , Amigos , Humanos , Estudos Longitudinais , Masculino , Fatores de Risco , Tabaco , Vaping
11.
Environ Pollut ; 268(Pt B): 115863, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33126161

RESUMO

Cigarette smoke (CS) affects immune functions, leading to severe outcomes in smokers. Robust evidence addresses the immunotoxic effects of combustible tobacco products. As heat-not-burn tobacco products (HNBT) vaporize lower levels of combustible products, we here compared the effects of cigarette smoke (CS) and HNBT vapor on Jurkat T cells. Cells were exposed to air, conventional cigarettes or heatsticks of HNBT for 30 min and were stimulated or not with phorbol myristate acetate (PMA). Cell viability, proliferation, reactive oxygen species (ROS) production, 8-OHdG, MAP-kinases and nuclear factor κB (NFκB) activation and metallothionein expression (MTs) were assessed by flow cytometry; nitric oxide (NO) and cytokine levels were measured by Griess reaction and ELISA, respectively. Levels of metals in the exposure chambers were quantified by inductively coupled plasma mass spectrometry. MT expressions were quantified by immunohistochemistry in the lungs and liver of C57Bl/6 mice exposed to CS, HNBT or air (1 h, twice a day for five days: via inhalation). While both CS and HBNT exposures increased cell death, CS led to a higher number of necrotic cells, increased the production of ROS, NO, inflammatory cytokines and MTs when compared to HNBT-exposed cells, and led to a higher expression of MTs in mice. CS released higher amounts of metals. CS and HNBT exposures decreased PMA-induced interleukin-2 (IL-2) secretion and impaired Jurkat proliferation, effects also seen in cells exposed to nicotine. Although HNBT vapor does not activate T cells as CS does, exposure to both HNBT and CS suppressed proliferation and IL-2 release, a pivotal cytokine involved with T cell proliferation and tolerance, and this effect may be related to nicotine content in both products.


Assuntos
Produtos do Tabaco , Tabaco , Animais , Temperatura Alta , Camundongos , Fumaça/efeitos adversos , Fumar
12.
Phytochemistry ; 181: 112582, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33246307

RESUMO

Salinity is a major cause of crop losses worldwide. Acetylcholine (ACh) can ameliorate the adverse effects of abiotic stresses on plant growth, including salinity stress; however, the underlying molecular mechanisms of this process are unclear. Here, seedlings of Nicotiana benthamiana grown under normal conditions or exposed to 150 mmol L-1 NaCl salinity stress were then treated with a root application of 10 µM ACh. Exogenous ACh application resulted in the downregulation of the activity of the antioxidant enzymes, ascorbate peroxidase, and catalase. ACh-treated plants had lower levels of reactive oxygen species, including the superoxide anion radical and hydrogen peroxide. Transcriptome analysis indicated that ACh treatment under salt stress promoted the differential expression of 658 genes in leaves of N. benthamiana (527 were upregulated and 131 were downregulated). Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that exogenous ACh application was associated with a substantial increase in the transcripts of genes related to cell wall peroxidases, xyloglucan endotransglucosylases or hydrolases, and expansins, indicating that ACh activates cell wall biosynthesis in salt-stressed plants. ACh also enhanced the expression of genes associated with the auxin, gibberellin, brassinosteroid, and salicylic acid signalling pathways, indicating that ACh induces the activation of these pathways under salt stress. Collectively, these findings indicate that ACh-induced salt tolerance in N. benthamiana seedlings is mediated by the inhibition of antioxidant enzymes, activation of cell wall biosynthesis, and hormone signalling pathways. Stress-induced genes involved in osmotic regulation and oxidation resistance were induced by ACh under salt stress. The genes whose transcript levels were elevated by ACh treatment in salt-stressed N. benthamiana could be used as molecular markers of the physiological status of plants under salt stress.


Assuntos
Tolerância ao Sal , Tabaco , Acetilcolina , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Salinidade , Tolerância ao Sal/genética , Estresse Fisiológico , Tabaco/genética , Transcriptoma
13.
Pest Manag Sci ; 77(1): 354-364, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32741113

RESUMO

BACKGROUND: Systemic acquired resistance (SAR) induced by elicitors is a highly satisfying form of resistance that protects plants against invading pathogens. Exploration and development of new elicitors is a promising alternative to conventional biocides in resistant pest management. In our previous broad screening, fruit peel extract of Citrus reticulata Blanco exhibited the ability to induce SAR in tobacco. RESULT: A new potent elicitor reticine A was isolated from the fruit peel extract of industrial crop C. reticulate and its structure was well elucidated. In vivo assays showed that reticine A had considerable control efficacies at 100 and 500 µg mL-1 , being superior to commercial elicitor benzothiadiazole (BTH) (100 µg mL-1 ). Reticine A had no significant impact on the virulence of tobacco mosaic virus (TMV) particles under in vitro conditions. Application of reticine A induced a local hypersensitive reaction (HR), systemic accumulation of H2 O2 and salicylic acid (SA), systemic increase in defensive enzyme activities and systemic upregulated expression of pathogenesis-related (PR) proteins, suggesting its induction of SAR in tobacco. The expression of NPR1 and SA biosynthesis genes ICS and PAL were systemically upregulated. CONCLUSION: SAR induced by reticine A against TMV in tobacco was demonstrated and the mechanism might be attributed to activating the expression of several defensive genes mediated by an SA signal. This study highlights the potential of reticine A which is recommended to be applied directly or as an active ingredient in the crude extract formulation ahead of time in the field, as well as being a potential lead compound for further optimization.


Assuntos
Citrus , Micoses , Vírus do Mosaico do Tabaco , Frutas , Humanos , Doenças das Plantas , Proteínas de Plantas , Ácido Salicílico/farmacologia , Tabaco
14.
Pest Manag Sci ; 77(1): 502-509, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32816401

RESUMO

BACKGROUND: (E)-4,8-dimethylnona-1,3,7-triene (DMNT), one of the homoterpenes, is thought to contribute to plant indirect defense against insect herbivores. DMNT-enriched plants have great application potential to regulate insect behavior in the 'push & pull' strategy of pest management. However, de novo biosynthesis of DMNT in plants without a homoterpene metabolic pathway in their wild type is still not achieved, and the role of DMNT played in these plants and their interacted insects remains unclear. RESULTS: Cytochrome P450s and terpene synthases involved in homoterpenes biosynthesis in cotton plants were employed to generate DMNT-releasing tobacco plants. Single GhTPS14 transgenic Nicotiana tabacum only emitted (E)-nerolidol, the precursor of DMNT. Transgenic tobaccos expressing single GhCYP82Ls were unable to produce DMNT or TMTT, while DMNT was detected when exogenous (E)-nerolidol was added. Compared to wild-type plants, only co-expression of GhCYP82Ls and GhTPS14 in transgenic tobaccos triggered the constitutive release of single-component DMNT. Furthermore, DMNT-emitting transgenic tobacco plants, whether infested with Helicoverpa armigera larvae or not, significantly incited orientation behavior of parasitoid wasps Microplitis mediator. CONCLUSION: Wild type N. tabacum plants have no DMNT metabolic pathway. DMNT could be de novo biosynthesized via co-expression of GhCYP82Ls and GhTPS14. What is more, the parasitoid wasp M. mediator could be recruited by DMNT-releasing transgenic tobaccos, especially by H. armigera-infested transgenic tobaccos, suggesting the potential roles of engineered N. tabacum in regulating the behavioral preference of M. mediator.


Assuntos
Vespas , Animais , Herbivoria , Insetos , Plantas Geneticamente Modificadas/genética , Tabaco/genética , Vespas/genética
15.
Food Chem ; 335: 127600, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32736155

RESUMO

Toosendanin (TSN), as an important Chinese traditional insecticide, has been registered and commercialized in China. In this report, the residual analytical methods, residue dynamics and final residues of TSN in tobacco, cabbage and soil under field condition were studied by IC-ELISA and HPLC. The sensitivity, precision and repeatability of IC-ELISA method were more suitable in comparison with HPLC for the demand of TSN residue analysis. Using IC-ELISA, the half-lives (t1/2) of TSN were found to be 1.30 days in cabbage, 1.70 days in tabacco and 0.71 days in soil, respectively. At the recommended dose, the final residues of TSN detection by IC-ELISA was 0.009 mg·kg-1 in cabbage and 0.043 mg·kg-1 in tobacco, as well as was not detected in soil. Therefore, TSN is easily degradable, and IC-ELISA could be a convenient and supplemental analytical tool for monitoring TSN residue in crops and environment.


Assuntos
Brassica/metabolismo , Medicamentos de Ervas Chinesas/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Poluentes do Solo/metabolismo , Solo/química , China , Cromatografia Líquida de Alta Pressão/métodos , Meia-Vida , Cinética , Resíduos de Praguicidas/análise , Tabaco
16.
Ecotoxicol Environ Saf ; 207: 111295, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32949930

RESUMO

Cadmium (Cd) easily accumulates in tobacco, which endangers public health through Cd exposure from smoking. However, its uptake, translocation, and distribution in tobacco plants during plant development or its response to biochar application are poorly understood. A pot experiment was conducted with tobacco (Yunyan 87) grown in soil severely contaminated with Cd (30 mg kg-1) amended with 0, 1, and 2% (w/w) tobacco stem-derived biochar (BC). The absorption and accumulation of Cd in all parts of the tobacco plants were most active from the rosette stage to the fast growing stage, during which approximately 90% of the Cd deposited in the tobacco leaves occurred, especially in the lower leaves. The Cd concentrations in most plant parts without added biochar decreased significantly by 52.61-78.30% due to the rapid increase in biomass (dilution effect), although the Cd concentration in the lower leaves increased by 48.89% (P < 0.05). However, with the slowdown of the growth rate of tobacco at the maturity stage, the proportion of Cd accumulation in roots and stems without biochar addition increased by 29.01%, resulting in an increased Cd concentration in roots and stems by 63.29-86.80% (P < 0.05). In the different growth stages, the application of biochar reduced the contents of DTPA-extractable and exchangeable Cd in the soil by 5.11-35.14% and 9.20-54.05%, respectively, thus reducing the absorption, accumulation and concentration of Cd in all parts of the tobacco plant. In addition, the inhibitive effect of biochar on the Cd concentration in the leaves was weak at the rosette stage (22.17-53.72%) compared with the other stages (46.14-78.88%), and the degree of inhibition of biochar on the Cd concentration in the middle leaves (37.94-59.24%) was lower than that in the upper and lower leaves (49.04-73.54%) at all developmental stages. However, the long-term remediation effect of biochar on soil Cd contamination needs to be further verified, and the combination of biochar and other technologies should receive additional attention.


Assuntos
Bioacumulação , Cádmio/análise , Carvão Vegetal/química , Poluentes do Solo/análise , Tabaco/crescimento & desenvolvimento , Biomassa , Cádmio/metabolismo , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/química , Raízes de Plantas/crescimento & desenvolvimento , Solo/química , Poluentes do Solo/metabolismo , Tabaco/química , Tabaco/metabolismo
17.
Ecotoxicol Environ Saf ; 207: 111297, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32949932

RESUMO

The metal tolerance mechanism of plants is of great importance to explore the plant-based clean-up of environmental substrata contaminated by heavy metals. Indoor experiment of tobacco (Nicotiana tabacum L.) seedlings growing hydroponically in nutrient solution containing 0, 0.1, 0.5, 2.0, and 4.0 mg L-1 V was conducted. The results indicated that plant overall growth performance was significantly affected at ≥ 2.0 mg L-1 V. Oxidative stress degree as indicated by foliar O2-· and H2O2 content intensified markedly at ≥ 0.5 mg L-1 V treatments. In response, the plant activated its enzyme and non-enzyme protecting mechanism to cope with oxidative stress inflicted by vanadium. The activities of antioxidant enzymes, including SOD, POD, CAT, APX, and the concentration of non-enzyme antioxidants, e.g., AsA and GSH were all conspicuously (p < 0.5 or p < 0.1) enhanced at ≥ 0.5 mg L-1 V treatments. Vanadium accumulated in leaves, stems, and roots increased with increasing vanadium level. The majority of the absorbed vanadium retained in plant root, and minor portions were transferred to aerial parts. Vanadium concentration in plant tissues ordered as root ˃ stem ˃ leaf. Translocation factors (TF) in vanadium-treated tobaccos (TF « 1) were significantly lower than that of control (TF ˃ 1). In conclusion, although vanadium at ≥ 2.0 mg L-1 inhibited plant growth, tobacco exhibited a relatively good vanadium tolerance through self-adaptive regulation and has the potential as a phytostabilizer in decontaminating the environment contaminated by vanadium.


Assuntos
Bioacumulação , Poluentes do Solo/metabolismo , Tabaco/crescimento & desenvolvimento , Vanádio/metabolismo , Antioxidantes/metabolismo , Biodegradação Ambiental , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/metabolismo , Poluentes do Solo/toxicidade , Tabaco/efeitos dos fármacos , Tabaco/metabolismo , Vanádio/toxicidade
18.
Chemosphere ; 263: 128349, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297274

RESUMO

Biochars (BCs) are currently widely used, yet their impact on human health is mostly unknown. We generated micro-tobacco stem-pyrolysed BCs (mTBCs) at different pyrolysis temperatures and assessed pulmonary toxicity in normal human lung epithelial BEAS-2B cells. mTBCs generated at 350 °C (mTBC350) and 650 °C (mTBC650) were analysed and compared for physicochemical properties and adverse effects. Pyrolysis temperature had a significant influence on chemical composition, particle size, specific surface area and aromatic carbon structure. mTBC650 displayed a highly ordered aromatic carbon structure with smaller particle size, high surface area (20.09 m2/g) and high polycyclic aromatic hydrocarbon and metal content. This composition could promote reactive oxygen species accumulation accompanied by greater cytotoxicity, genotoxicity and epithelial barrier malfunction in cultured cells. Thus, the risk of pulmonary toxicity owing to micro-BCs (mBCs) is affected by pyrolysis temperature. Long-term exposure to mBCs produced at high temperatures may lead to or exacerbate pulmonary disease.


Assuntos
Pirólise , Tabaco , Carvão Vegetal , Temperatura Alta , Humanos , Temperatura
19.
Artigo em Alemão | MEDLINE | ID: mdl-33284361

RESUMO

BACKGROUND: In the German context, there is hardly any quantitative data about the implementation of school tobacco polices that include the perspective of both teachers and students. The aim of the study is to investigate the associations between implemented school tobacco policies and the perceived prevalence of smoking at the level of school staff and adolescents. METHODS: The repeated cross-sectional study (2013 and 2017) is based on pooled responses of 13- to 17-year-old adolescents (N = 2393) and school staff (N = 85) from 25 schools located in the West German metropolitan region of Hanover. In linear regression models, average marginal effects (AMEs) with 95% confidence intervals (CI95%) and robust standard errors for perceived tobacco prevalence are reported separately for school tobacco policies assessed by teachers and students (scale 0-6). All models were controlled for sociodemographic, school-, and smoking-specific covariates. RESULTS: On average, adolescents perceive a smoking prevalence of 30% ([Formula: see text]; s: 24.0) for their school. A comprehensive school tobacco policy is consistently associated with lower school smoking prevalence both from the point of view of teachers (AME: -3.54 CI95% -6.49 to -0.58) and students (AME: -1.69 CI95% -2.52 to -0.86). The number of smoking friends (e.g., "most of them are smokers" +14%: AME: 14.13 CI95% 10.46 to 17.80) and the type of school are the most relevant determinants of a high school smoking prevalence. School types with a nonacademic track report a 15% (AME: 15.03 CI95% 10.13 to 19.93) higher prevalence compared to grammar schools. DISCUSSION: Progressive school tobacco control policies should focus more on school types with nonacademic tracks, certain groups at risk, and those schools that do not strictly enforce school tobacco policies.


Assuntos
Instituições Acadêmicas , Tabaco , Adolescente , Estudos Transversais , Alemanha/epidemiologia , Humanos , Políticas , Prevalência , Fumar/epidemiologia , Prevenção do Hábito de Fumar
20.
Pestic Biochem Physiol ; 171: 104697, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33357538

RESUMO

Glycoprotein (GP)-1 is a glycoprotein elicitor with antiviral activity found in Streptomyces kanasensis zx01. GP-1 can induce programmed cell death (PCD) in vitro; however, the underlying mechanism is unclear. In the present study, we demonstrated that GP-1 induced PCD in tobacco suspension cells, which was modulated by hydrogen peroxide (H2O2). GP-1 participated in and modulated biologically relevant signaling in plant cells. GP-1 induced tobacco cell death in a dose- and time-dependent manner; affected the expression of BRI1-associated receptor kinase 1 (BAK1) and the accumulation of salicylic acid (SA), which are related to PCD; and enzymatic activities and mitochondrial functions. In conclusion, GP-1-induced PCD in tobacco may be mediated by H2O2 which alters BAK1 and SA levels, as well as mitochondrial and gene function. This cell signal cascade played an important role in the process of GP-1 induced plant disease resistance.


Assuntos
Peróxido de Hidrogênio , Tabaco , Apoptose , Glicoproteínas , Streptomyces
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA