RESUMEN
Foliar development involves successive phases of cell proliferation and expansion that determine the final leaf size, and is characterized by an early burst of reactive oxygen species generated in the photosynthetic electron transport chain (PETC). Introduction of the alternative PETC acceptor flavodoxin in tobacco chloroplasts led to a reduction in leaf size associated to lower cell expansion, without affecting cell number per leaf. Proteomic analysis showed that the biogenesis of the PETC proceeded stepwise in wild-type leaves, with accumulation of light-harvesting proteins preceding that of electron transport components, which might explain the increased energy and electron transfer to oxygen and reactive oxygen species build-up at this stage. Flavodoxin expression did not affect biogenesis of the PETC but prevented hydroperoxide formation through its function as electron sink. Mature leaves from flavodoxin-expressing plants were shown to contain higher levels of transcripts encoding components of the proteasome, a key negative modulator of organ size. Proteome profiling revealed that this differential accumulation was initiated during expansion and led to increased proteasomal activity, whereas a proteasome inhibitor reverted the flavodoxin-dependent size phenotype. Cells expressing plastid-targeted flavodoxin displayed lower endoreduplication, also associated to decreased organ size. These results provide novel insights into the regulation of leaf growth by chloroplast-generated redox signals, and highlight the potential of alternative electron shuttles to investigate the link(s) between photosynthesis and plant development.
Asunto(s)
Cloroplastos , Nicotiana , Hojas de la Planta , Complejo de la Endopetidasa Proteasomal , Cloroplastos/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Nicotiana/genética , Nicotiana/metabolismo , Nicotiana/crecimiento & desarrollo , Transporte de Electrón , Fotosíntesis , Flavodoxina/metabolismo , Flavodoxina/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMEN
Leaf area of dried Flue-cured tobacco is a reflection of climate and stage of growth of fresh tobacco in field; it also serves as the foundation for calculating a number of significant physical properties of tobacco. So the purpose of this paper was to establish a model to estimate the leaf area of dried Flue-cured tobacco in China from linear dimensions. Three Hundred eight tobacco leaves from different growing area and stalk position were sampled randomly and separated for model selection among linear, proportional and power model type and external evaluation individually. Results showed that there was a significant and strong correlation between leaf area and length×width , The equation LA = 0.495(L×W), where LA is the leaf area and L×W is the product of leaf length and width, was optimum and adequate for the estimation of leaf area of dried tobacco in China examined by Fisher's test, Akaike delta information criterion (AIC) and Bayesian information criterion (BIC). Growing area and stalk position had minor effect on the parameter before (L×W). The equation can sufficiently predict the area of leaf for external evaluation.
A área foliar do tabaco curado pelo Flue seco é um reflexo do clima e do estágio de crescimento do tabaco fresco no campo; também serve como base para o cálculo de várias propriedades físicas significativas do tabaco. Portanto, o objetivo deste artigo foi estabelecer um modelo para estimar a área foliar do tabaco curado por Flue seco na China a partir de dimensões lineares. Foram amostradas aleatoriamente 308 folhas de tabaco de diferentes áreas de cultivo e posição do colmo e separadas para seleção de modelos entre tipo linear, proporcional e de potência e avaliação externa individualmente. Os resultados mostraram que houve uma correlação significativa e forte entre área foliar e comprimento×largura. A equação LA = 0,495 (L×W), em que LA é a área foliar e L×W é o produto do comprimento e largura da folha, ótima e adequada para a estimativa da área foliar de tabaco seco na China examinada pelo teste de Fisher, critério de informação delta de Akaike (AIC) e critério de informação bayesiana (BIC). A área de cultivo e a posição do caule tiveram efeito menor no parâmetro antes (C×L). A equação pode prever suficientemente a área da folha para avaliação externa.
Asunto(s)
Nicotiana/anatomía & histología , Nicotiana/crecimiento & desarrollo , Modelos Lineales , Desarrollo de la PlantaRESUMEN
Rotavirus is the most common cause of severe diarrhea in infants and children worldwide and is responsible for about 215,000 deaths annually. Over 85% of these deaths originate in low-income/developing countries in Asia and Africa. Therefore, it is necessary to explore the development of vaccines that avoid the use of "living" viruses and furthermore, vaccines that have viral antigens capable of generating powerful heterotypic responses. Our strategy is based on the expression of the fusion of the anti-DEC205 single-chain variable fragment (scFv) coupled by an OLLAS tag to a viral protein (VP6) of Rotavirus in Nicotiana plants. It was possible to express transiently in N. benthamiana and N. sylvestris a recombinant protein consisting of the single chain variable fragment linked by an OLLAS tag to the VP6 protein. The presence of the recombinant protein, which had a molecular weight of approximately 75 kDa, was confirmed by immunodetection, in both plant species and in both cellular compartments (cytoplasm and apoplast) where it was expressed. In addition, the recombinant protein was modeled, and it was observed that some epitopes of interest are exposed on the surface, which could favor their immunogenic response.
Asunto(s)
Antígenos Virales/genética , Proteínas de la Cápside/genética , Nicotiana/crecimiento & desarrollo , Rotavirus/metabolismo , Anticuerpos de Cadena Única/genética , Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/metabolismo , Antígenos Virales/química , Antígenos Virales/metabolismo , Proteínas de la Cápside/química , Proteínas de la Cápside/metabolismo , Citoplasma/genética , Citoplasma/metabolismo , Modelos Moleculares , Peso Molecular , Ingeniería de Proteínas , Estructura Secundaria de Proteína , Proteínas Recombinantes/metabolismo , Rotavirus/genética , Anticuerpos de Cadena Única/química , Anticuerpos de Cadena Única/metabolismo , Nicotiana/genética , Nicotiana/metabolismoRESUMEN
Leaf area is an important growth variable in agricultural crops and the leaf is the main variable of interest in the tobacco industry. So, the aim of this scientific research was to estimate the Burley tobacco leaf area by linear dimensions of the leaves and to determine which mathematical model is more adequate for this purpose. Two experiments were carried out with Burley tobacco, cultivar DBH 2252, in 2016/2017 and 2018/2019 agricultural years, respectively, in the municipalities of Itaqui and Vanini - RS - Brazil. In 600 leaves were measured length (L), width (W), length×width product (LW), length/width ratio (L/W) and determined the real leaf area (LA). Four hundred and fifty leaves were separated to generate models of the leaf area as a function of linear dimension and the other 150 leaves were used for models validation. The power model LA = 0.5037LW1.04435 (R² = 0.9960) is the most adequate for Burley tobacco DBH 2252 leaf area estimation. Alternatively, the models LA=2.0369W1.8619 (R²=0.9796) and LA=0.1222L2.2771 (R²=0.9738) based on width and length, respectively, can be used when only one leaf dimension is measured.(AU)
A área foliar é uma importante variável de crescimento em culturas agrícolas, sendo a folha a principal variável de interesse na indústria do tabaco. Assim, o objetivo deste estudo científico foi determinar a área foliar de tabaco tipo Burley por meio de dimensões lineares da folha e determinar qual modelo matemático é mais adequado para essa finalidade. Dois experimentos foram conduzidos com tabaco tipo Burley, cultivar DBH 2252, nos anos agrícolas de 2016/2017 e 2018/2019, respectivamente, nos municípios de Itaqui e Vanini, RS, Brasil. Em 600 folhas foram medidos o comprimento (L), a largura (W), o produto comprimento×largura (LW), a razão comprimento/largura (L/W) e determinada a área foliar real (LA). Foram separadas 450 folhas para a geração de modelos de estimativa de área foliar em função da dimensão linear e 150 folhas foram utilizadas para a validação dos modelos. O modelo LA = 0,5037LW1,04435 (R² = 0,9960) é adequado para a estimação da área foliar de tabaco Burley cultivar DBH 2252. Alternativamente, os modelos LA=2,0369W1,8619 (R²=0,9796) e LA=0,1222L2,2771 (R²=0,9738) baseados na largura e comprimento, respectivamente, podem ser utilizados quando apenas uma dimensão da folha é medida.(AU)
Asunto(s)
Nicotiana/crecimiento & desarrolloRESUMEN
Tobacco is one of the major industrial crops cultivated worldwide. Chemical control is the main method employed to reduce damage by insect pests. The use of entomopathogenic fungi represents an alternative to replace insecticides. The search for effective strains in the field constitutes a first step when developing a formulation. The objective of this work was to study genetic differences among isolates of entomopathogenic fungi obtained from tobacco grown soils using ISSR markers. The pathogenicity of the strains towards Helicoverpa gelotopoeon and Diabrotica speciosa was also assessed in order to search for a relationship between virulence and genetic diversity. Nineteen isolates were identified according to morphological features and molecular techniques as Beauveria bassiana (11) and Purpureocillium lilacinum (8). The diversity tree generated by ISSR analysis showed a high diversity among the strains. The pathogenicity towards H. gelotopoeon and D. speciosa was assessed and the logistic models generated showed that B. bassiana isolates LPSc1215 and LPSc1364 were the most pathogenic against both insect pests tested. In the diversity tree, these strains were grouped in a same cluster with a similarity level of approximately 85%, indicating a possible relationship between virulence and the band pattern generated.
Asunto(s)
Hongos/genética , Nicotiana/crecimiento & desarrollo , Control Biológico de Vectores , Microbiología del Suelo , Animales , Beauveria/genética , Beauveria/patogenicidad , Hongos/crecimiento & desarrollo , Hongos/patogenicidad , Variación Genética/genética , Hypocreales/genética , Hypocreales/patogenicidad , Insectos/microbiología , Insectos/parasitología , Mariposas Nocturnas/microbiología , Mariposas Nocturnas/parasitología , Filogenia , Nicotiana/microbiologíaRESUMEN
During the harvest period, tobacco workers are exposed to nicotine and it is known that absorption of the alkaloid via the leaves causes green tobacco sickness (GST). We investigated if GST and its symptoms are associated with DNA damage and alterations of the redox status. DNA damage was measured in lymphocytes of tobacco workers and controls (n = 40/group) in single cell gel electrophoresis assays. Exposure to nicotine was determined by plasma cotinine measurements, alterations of the redox status by quantification of the total antioxidant capacity (TEAC) and of thiobarbituric acid reactive substances (TBARS). The symptoms of GTS included nausea, abdominal cramps, headache, vomiting and dizziness, and 50% of the workers had more than one symptom. Cotinine levels were enhanced in the workers (111 ng/mL); furthermore, the extent of DNA damage was ca. 3-fold higher than in the controls. This effect was more pronounced in participants with GST compared to healthy nicotine exposed workers and increased in individuals with specific symptoms (range 22-36%). TBARS levels did not differ between workers and unexposed controls, while TEAC values were even increased (by 14.3%). Contact with nicotine present in tobacco leaves causes GTS and leads to damage of the DNA; this effect is more pronounced in workers with GTS symptoms and is associated with alterations of the redox status. Damage of the genetic material which was found in the workers may lead to adverse long-term effects that are caused by genomic instability such as cancer and accelerated ageing.
Asunto(s)
Enfermedades de los Trabajadores Agrícolas/inducido químicamente , Daño del ADN , Agricultores , Nicotiana/crecimiento & desarrollo , Nicotina/toxicidad , Exposición Profesional/efectos adversos , Estrés Oxidativo/efectos de los fármacos , Adulto , Enfermedades de los Trabajadores Agrícolas/genética , Enfermedades de los Trabajadores Agrícolas/metabolismo , Brasil , Estudios de Casos y Controles , Cotinina/sangre , Femenino , Inestabilidad Genómica/efectos de los fármacos , Humanos , Masculino , Nicotina/metabolismo , Exposición Profesional/análisis , Oxidación-Reducción , Estrés Oxidativo/genética , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Nicotiana/metabolismo , Adulto JovenRESUMEN
The initial stimulation of photosynthesis under elevated CO2 concentrations (eCO2) is often followed by a decline in photosynthesis, known as CO2 acclimation. Changes in N levels under eCO2 can have different effects in plants fertilized with nitrate (NO3-) or ammonium (NH4+) as the N source. NO3- assimilation consumes approximately 25% of the energy produced by an expanded leaf, whereas NH4+ requires less energy to be incorporated into organic compounds. Although plant-N interactions are important for the productivity and nutritional value of food crops worldwide, most studies have not compared the performance of plants supplied with different forms of N. Therefore, this study aims to go beyond treating N as the total N in the soil or the plant because the specific N compounds formed from the available N forms become highly engaged in all aspects of plant metabolism. To this end, plant N metabolism was analyzed through an experiment with eCO2 and fertigation with NO3- and/or NH4+ as N sources for tobacco (Nicotiana tabacum) plants. The results showed that the plants that received only NO3- as a source of N grew more slowly when exposed to a CO2 concentration of 760 µmol mol-1 than when they were exposed to ambient CO2 conditions. On the other hand, in plants fertigated with only NH4+, eCO2 enhanced photosynthesis. This was essential for the maintenance of the metabolic pathways responsible for N assimilation and distribution in growing tissues. These data show that the physiological performance of tobacco plants exposed to eCO2 depends on the form of inorganic N that is absorbed and assimilated.
Asunto(s)
Dióxido de Carbono/metabolismo , Nicotiana/fisiología , Nitrógeno/metabolismo , Fotosíntesis , Compuestos de Amonio/metabolismo , Nitratos/metabolismo , Suelo/química , Nicotiana/crecimiento & desarrolloRESUMEN
Chloroplast transformation has many potential advantages for the production of recombinant proteins in plants. However, it has been reported that chloroplast expression of many proteins, such as human epidermal growth factor (hEGF), results hindered by post-transcriptional mechanisms. hEGF degradation has been related to the redox potential of the stroma and protein misfolding. To solve this problem, we proposed the redirection of hEGF into the thylakoid lumen where the environment could improve disulfide bonds formation stabilizing the functional conformation of the protein. We generated transplastomic tobacco plants targeting hEGF protein to the thylakoid lumen by adding a transit peptide (Str). Following this approach, we could detect thylakoid lumen-targeted hEGF by western blotting while stromal accumulation of hEGF remained undetectable. Southern blot analysis confirmed the integration of the transgene through homologous recombination into the plastome. Northern blot analysis showed similar levels of egf transcripts in the EGF and StrEGF lines. These results suggest that higher stability of the hEGF peptide in the thylakoid lumen is the primary cause of the increased accumulation of the recombinant protein observed in StrEGF lines. They also highlight the necessity of exploring different sub-organellar destinations to improve the accumulation levels of a specific recombinant protein in plastids.
Asunto(s)
Cloroplastos/metabolismo , Factor de Crecimiento Epidérmico/metabolismo , Nicotiana/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Tilacoides/metabolismo , Transgenes , Cloroplastos/genética , Factor de Crecimiento Epidérmico/genética , Humanos , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Plastidios/genética , Plastidios/metabolismo , Proteínas Recombinantes de Fusión/genética , Tilacoides/genética , Nicotiana/genética , Nicotiana/crecimiento & desarrolloRESUMEN
The expression of recombinant proteins in plants is a valuable alternative to bioreactors using mammalian cell systems. Ease of scaling, and their inability to host human pathogens, enhance the use of plants to generate complex therapeutic products such as monoclonal antibodies. However, stably transformed plants expressing antibodies normally have a poor accumulation of these proteins that probably arise from the negative positional effects of their flanking chromatin. The induction of boundaries between the transgenes and the surrounding DNA using matrix attachment regions (MAR) and insulator elements may minimize these effects. With the PHB-01 antibody as a model, we demonstrated that the insertion of DNA elements, the TM2 (MAR) and M4 insulator, flanking the transcriptional cassettes that encode the light and heavy chains of the PHB-01 antibody, increased the protein accumulation that remained stable in the first plant progeny. The M4 insulator had a stronger effect than the TM2, with over a twofold increase compared to the standard construction. This effect was probably associated with an enhancer-promoter interference. Moreover, transgenic plants harboring two transcriptional units encoding for the PHB-01 heavy chain combined with both TM2 and M4 elements enhanced the accumulation of the antibody. In summary, the M4 combined with a double transcriptional unit of the heavy chain may be a suitable strategy for potentiating PHB-01 production in tobacco plants.
Asunto(s)
Anticuerpos/metabolismo , Cadenas Pesadas de Inmunoglobulina/metabolismo , Elementos Aisladores , Regiones de Fijación a la Matriz/genética , Nicotiana/genética , Proteínas Recombinantes/metabolismo , Transgenes/genética , Anticuerpos/genética , Regulación de la Expresión Génica de las Plantas , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Prohibitinas , Regiones Promotoras Genéticas , Proteínas Recombinantes/genética , Nicotiana/crecimiento & desarrolloRESUMEN
BACKGROUND: Glycogen storage disease type III (GSDIII, Cori/Forbes disease) is a metabolic disorder due to the deficiency of the Glycogen Debranching Enzyme (GDE), a large monomeric protein (about 176 kDa) with two distinct enzymatic activities: 4-α-glucantransferase and amylo-α-1,6-glucosidase. Several mutations along the amylo-alpha-1,6-glucosidase,4-alphaglucanotransferase (Agl) gene are associated with loss of enzymatic activity. The unique treatment for GSDIII, at the moment, is based on diet. The potential of plants to manufacture exogenous engineered compounds for pharmaceutical purposes, from small to complex protein molecules such as vaccines, antibodies and other therapeutic/prophylactic entities, was shown by modern biotechnology through "Plant Molecular Farming". OBJECTIVE AND METHODS: In an attempt to develop novel protein-based therapeutics for GSDIII, the Agl gene, encoding for the human GDE (hGDE) was engineered for expression as a histidinetagged GDE protein both in Nicotiana benthamiana plants by a transient expression approach, and in axenic hairy root in vitro cultures (HR) from Lycopersicum esculentum and Beta vulgaris. RESULTS: In both plant-based expression formats, the hGDE protein accumulated in the soluble fraction of extracts. The plant-derived protein was purified by affinity chromatography in native conditions showing glycogen debranching activity. CONCLUSION: These investigations will be useful for the design of a new generation of biopharmaceuticals based on recombinant GDE protein that might represent, in the future, a possible therapeutic option for GSDIII.
Asunto(s)
Sistema de la Enzima Desramificadora del Glucógeno/genética , Nicotiana/crecimiento & desarrollo , Raíces de Plantas/citología , Beta vulgaris/citología , Beta vulgaris/genética , Beta vulgaris/metabolismo , Técnicas de Cultivo de Célula , Cromatografía de Afinidad , Regulación de la Expresión Génica de las Plantas , Sistema de la Enzima Desramificadora del Glucógeno/aislamiento & purificación , Sistema de la Enzima Desramificadora del Glucógeno/metabolismo , Humanos , Solanum lycopersicum/citología , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Ingeniería de Proteínas , Proteínas Recombinantes/aislamiento & purificación , Nicotiana/genética , Nicotiana/metabolismoRESUMEN
The article presents a review of Brazilian tobacco control policies from 1986 to 2016, based on contributions from political economics and analyses of public policies. The institutionalization of tobacco control in the country was marked by more general changes in health policies and by specific events related to the theme. Brazil's international leadership role, a robust National Tobacco Control Policy, the role of civil society and the media all contributed to the success of tobacco control in this country. However, challenges remain regarding crop diversification in tobacco farms, illegal trade in cigarettes, pressure from the tobacco industry and the sustainability of the Policy. This study reinforces the importance of bearing in mind the relationship between the domestic and international context, and the articulation between different governmental and non-governmental sectors and players when analyzing complex health policies. Continuity and consolidation of the tobacco control policies depend on the persistence of a broad institutional framework to guide the State's actions in social protection, in accordance with Unified Healthcare System guidelines.
O artigo apresenta um balanço da política brasileira de controle do tabaco de 1986 a 2016, baseando-se em contribuições dos referenciais da economia política e da análise de políticas públicas. A institucionalização do controle do tabaco no país foi marcada por mudanças mais gerais da política de saúde e por eventos específicos relacionados ao tema. A liderança brasileira no cenário internacional, a sólida estruturação da Política Nacional de Controle do Tabaco e o papel da sociedade civil e dos meios de comunicação contribuíram para o sucesso do controle do tabaco no Brasil. No entanto, persistem desafios relacionados à diversificação de produção em áreas plantadas de fumo, ao comércio ilícito, à interferência da indústria do fumo e à sustentabilidade da Política. O estudo reforça a relevância de serem consideradas, na análise de políticas de saúde complexas, as relações entre contexto internacional e nacional e a articulação entre diferentes setores e atores governamentais e não governamentais. A continuidade e a consolidação da política de controle do tabaco dependem da persistência de um marco institucional amplo que norteie a atuação do Estado na proteção social, consoante com as diretrizes do Sistema Único de Saúde.
Asunto(s)
Programas Nacionales de Salud/organización & administración , Política Pública , Prevención del Hábito de Fumar/legislación & jurisprudencia , Industria del Tabaco/legislación & jurisprudencia , Brasil , Guías como Asunto , Política de Salud , Humanos , Fumar/legislación & jurisprudencia , Nicotiana/crecimiento & desarrollo , Productos de Tabaco/legislación & jurisprudenciaRESUMEN
Resumo O artigo apresenta um balanço da política brasileira de controle do tabaco de 1986 a 2016, baseando-se em contribuições dos referenciais da economia política e da análise de políticas públicas. A institucionalização do controle do tabaco no país foi marcada por mudanças mais gerais da política de saúde e por eventos específicos relacionados ao tema. A liderança brasileira no cenário internacional, a sólida estruturação da Política Nacional de Controle do Tabaco e o papel da sociedade civil e dos meios de comunicação contribuíram para o sucesso do controle do tabaco no Brasil. No entanto, persistem desafios relacionados à diversificação de produção em áreas plantadas de fumo, ao comércio ilícito, à interferência da indústria do fumo e à sustentabilidade da Política. O estudo reforça a relevância de serem consideradas, na análise de políticas de saúde complexas, as relações entre contexto internacional e nacional e a articulação entre diferentes setores e atores governamentais e não governamentais. A continuidade e a consolidação da política de controle do tabaco dependem da persistência de um marco institucional amplo que norteie a atuação do Estado na proteção social, consoante com as diretrizes do Sistema Único de Saúde.
Abstract The article presents a review of Brazilian tobacco control policies from 1986 to 2016, based on contributions from political economics and analyses of public policies. The institutionalization of tobacco control in the country was marked by more general changes in health policies and by specific events related to the theme. Brazil's international leadership role, a robust National Tobacco Control Policy, the role of civil society and the media all contributed to the success of tobacco control in this country. However, challenges remain regarding crop diversification in tobacco farms, illegal trade in cigarettes, pressure from the tobacco industry and the sustainability of the Policy. This study reinforces the importance of bearing in mind the relationship between the domestic and international context, and the articulation between different governmental and non-governmental sectors and players when analyzing complex health policies. Continuity and consolidation of the tobacco control policies depend on the persistence of a broad institutional framework to guide the State's actions in social protection, in accordance with Unified Healthcare System guidelines.
Asunto(s)
Humanos , Política Pública , Industria del Tabaco/legislación & jurisprudencia , Prevención del Hábito de Fumar/legislación & jurisprudencia , Programas Nacionales de Salud/organización & administración , Nicotiana/crecimiento & desarrollo , Brasil , Fumar/legislación & jurisprudencia , Guías como Asunto , Productos de Tabaco/legislación & jurisprudencia , Política de SaludAsunto(s)
Humanos , Masculino , Femenino , Nicotiana/crecimiento & desarrollo , Industria del Tabaco , Geografía MédicaRESUMEN
The study aimed to explore the knowledge, attitudes, and practices of women farmers working in tobacco production concerning the social, environmental, and health impacts of this economic activity. Focus groups were used in this qualitative study, and themes were explored until reaching saturation. The study was conducted in a municipality (county) in southern Brazil in 2013 and included 64 women farmers. The discussions revealed participants' familiarity with health problems associated with workloads in tobacco production: green tobacco sickness, pesticide poisoning, musculoskeletal disorders, and others. The discussions also revealed a concern with the negative impacts of tobacco agriculture on the environment. They also revealed apprehension concerning decisions on switching to alternatives for sustainable agricultural production, emphasizing that on-going and systematic government support would be necessary for such a transition. Women farmers identified various factors that contribute to the persistence of tobacco farming: small holdings for cultivation, lack of guarantees for marketing crops, and indebtedness to tobacco companies. The study showed that an integrated approach is needed to deal with tobacco farmers' problems, considering a balance between farmers' beliefs and government decisions. This approach, in keeping with the recommendations of the WHO Framework Convention on Tobacco Control, may help strengthen policies and measures to promote health and sustainable local development.
Asunto(s)
Enfermedades de los Trabajadores Agrícolas/etiología , Agricultores , Conocimientos, Actitudes y Práctica en Salud , Nicotiana/crecimiento & desarrollo , Exposición Profesional/efectos adversos , Adulto , Anciano , Agricultura , Brasil , Femenino , Grupos Focales , Humanos , Persona de Mediana Edad , Factores de Riesgo , Salud Rural , Población Rural , Factores Socioeconómicos , Encuestas y Cuestionarios , Lugar de Trabajo , Adulto JovenRESUMEN
MAIN CONCLUSION: Overexpression of the citrus CsTIP2;1 improves plant growth and tolerance to salt and drought stresses by enhancing cell expansion, H 2 O 2 detoxification and stomatal conductance. Tonoplast intrinsic proteins (TIPs) are a subfamily of aquaporins, belonging to the major intrinsic protein family. In a previous study, we have shown that a citrus TIP isoform, CsTIP2;1, is highly expressed in leaves and also transcriptionally regulated in leaves and roots by salt and drought stresses and infection by 'Candidatus Liberibacter asiaticus', the causal agent of the Huanglongbing disease, suggesting its involvement in the regulation of the flow of water and nutrients required during both normal growth and stress conditions. Here, we show that the overexpression of CsTIP2;1 in transgenic tobacco increases plant growth under optimal and water- and salt-stress conditions and also significantly improves the leaf water and oxidative status, photosynthetic capacity, transpiration rate and water use efficiency of plants subjected to a progressive soil drying. These results correlated with the enhanced mesophyll cell expansion, midrib aquiferous parenchyma abundance, H2O2 detoxification and stomatal conductance observed in the transgenic plants. Taken together, our results indicate that CsTIP2;1 plays an active role in regulating the water and oxidative status required for plant growth and adaptation to stressful environmental conditions and may be potentially useful for engineering stress tolerance in citrus and other crop plants.
Asunto(s)
Adaptación Fisiológica , Antioxidantes/metabolismo , Acuaporinas/metabolismo , Citrus/genética , Proteínas de la Membrana/metabolismo , Proteínas de Plantas/metabolismo , Acuaporinas/genética , Citrus/citología , Citrus/crecimiento & desarrollo , Citrus/fisiología , Sequías , Expresión Génica , Peróxido de Hidrógeno/metabolismo , Proteínas de la Membrana/genética , Fotosíntesis , Hojas de la Planta/citología , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/fisiología , Proteínas de Plantas/genética , Raíces de Plantas/citología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/fisiología , Estomas de Plantas/citología , Estomas de Plantas/genética , Estomas de Plantas/crecimiento & desarrollo , Estomas de Plantas/fisiología , Transpiración de Plantas , Isoformas de Proteínas , Cloruro de Sodio/metabolismo , Estrés Fisiológico , Nicotiana/citología , Nicotiana/genética , Nicotiana/crecimiento & desarrollo , Nicotiana/fisiología , Agua/fisiologíaRESUMEN
OBJECTIVE: To investigate the effects of exposure to pesticides on the central auditory functions (CAF) of Brazilian tobacco growers. DESIGN: This was a cross-sectional study carried out between 2010 and 2012. Participants were evaluated with two behavioural procedures to investigate CAF, the random gap detection test (RGDT) and the dichotic digit test in Portuguese (DDT). STUDY SAMPLE: A total of 22 growers exposed to pesticides (study group) and 21 subjects who were not exposed to pesticides (control group) were selected. RESULTS: No significant differences between groups were observed for pure-tone thresholds. A significant association between pesticide exposure and the results for RGDT and DDT was found. Significant differences between pesticide-exposed and nonexposed subjects were found for RGDT frequency average and DDT binaural average, when including age and hearing level as covariates. Age was significantly associated with RGDT frequency average, DDT left ear score, DDT binaural average and DDT right ear advantage. Hearing levels were not significantly associated with any of the test scores. The relative risk of failing the DDT and RGDT for the study group was 1.88 (95% CI: 1.10-3.20) and 1.74 (95% CI: 1.06-2.86), respectively, as compared with the control group. CONCLUSIONS: The results showed that tobacco growers exposed to pesticides exhibited signs of central auditory dysfunction characterised by decrements in temporal processing and binaural integration processes/abilities.
Asunto(s)
Enfermedades de los Trabajadores Agrícolas/inducido químicamente , Enfermedades Auditivas Centrales/inducido químicamente , Percepción Auditiva/efectos de los fármacos , Agricultores , Audición/efectos de los fármacos , Nicotiana/crecimiento & desarrollo , Exposición Profesional/efectos adversos , Salud Laboral , Plaguicidas/efectos adversos , Adulto , Factores de Edad , Enfermedades de los Trabajadores Agrícolas/diagnóstico , Enfermedades de los Trabajadores Agrícolas/fisiopatología , Enfermedades de los Trabajadores Agrícolas/psicología , Audiometría de Tonos Puros , Enfermedades Auditivas Centrales/diagnóstico , Enfermedades Auditivas Centrales/fisiopatología , Enfermedades Auditivas Centrales/psicología , Vías Auditivas/efectos de los fármacos , Vías Auditivas/fisiopatología , Estudios de Casos y Controles , Pruebas de Audición Dicótica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Factores de Tiempo , Adulto JovenRESUMEN
Resumo: O estudo objetivou compreender os conhecimentos, atitudes e práticas de agricultoras que trabalham no processo de produção do tabaco sobre os impactos sociais, ambientais e à saúde, decorrentes desta atividade econômica. Nesta pesquisa qualitativa, a técnica de grupos focais foi empregada e os temas foram explorados até a saturação. O estudo foi realizado em um município da Região Sul do Brasil, em 2013, e contou com 64 agricultoras. As discussões mostraram que as participantes conhecem os agravos à saúde associados às cargas de trabalho presentes no processo de produção do fumo, como: doença da folha verde do tabaco, intoxicação por agrotóxicos, distúrbios osteoarticulares, entre outros. Igualmente, evidenciou a preocupação com os impactos negativos da fumicultura sobre o ambiente. Contudo, demonstraram apreensão frente à tomada de decisões a favor da mudança para outra alternativa de produção sustentável, enfatizando que sem apoio continuado e sistemático do poder público não há garantias para o enfrentamento da situação. Sob esse aspecto, elencaram um conjunto de fatores que contribuem para a permanência na fumicultura, como: pequenas áreas para cultivo, falta de garantia de mercado para o escoamento de produção, endividamento com as indústrias fumageiras. A pesquisa mostrou que uma abordagem integradora é necessária para enfrentar os problemas dos produtores de tabaco, considerando-se um equilíbrio entre as crenças dos agricultores e decisões políticas. Essa abordagem, em consonância com as recomendações da Convenção-Quadro para o Controle do Tabaco da OMS , pode resultar no fortalecimento de políticas e ações para promover a saúde e o desenvolvimento sustentável local.
Resumen: El objetivo del estudio fue comprender los conocimientos, actitudes y prácticas de agricultoras, que trabajan en el proceso de producción del tabaco, así como sus impactos sociales, ambientales y a la salud, derivados de esta actividad económica. En esta investigación cualitativa, se empleó la técnica de grupos focales y los temas se exploraron a fondo. El estudio se realizó en un municipio de la región sur de Brasil, en 2013, y contó con 64 agricultoras. Las discusiones mostraron que las participantes conocen los problemas de salud asociados a las cargas de trabajo presentes en el proceso de producción del tabaco, como: la enfermedad del tabaco verde, la intoxicación por pesticidas, enfermedades osteoarticulares, entre otras. Igualmente, se evidenció la preocupación por los impactos negativos del cultivo del tabaco sobre el medioambiente. No obstante, demostraron aprehensión frente a la toma de decisiones a favor del cambio hacia otra alternativa de producción sostenible, enfatizando que sin el apoyo continuado y sistemático del poder público no existen garantías para hacer frente a esta situación. Desde esta perspectiva, expresaron un conjunto de factores que contribuyen a su continuidad en el cultivo del tabaco, como: pequeñas áreas para el cultivo, falta de garantía del mercado para la salida de la producción, endeudamiento con las industrias del tabaco. La investigación mostró que es necesario un enfoque integrador para enfrentar los problemas de los productores del tabaco, considerándose un equilibrio entre las creencias de los agricultores y las decisiones políticas. Este enfoque, en consonancia con las recomendaciones del Convenio Marco para el Control del Tabaco de la OMS , puede resultar en el fortalecimiento de políticas y acciones para promover la salud y el desarrollo sostenible local.
Abstract: The study aimed to explore the knowledge, attitudes, and practices of women farmers working in tobacco production concerning the social, environmental, and health impacts of this economic activity. Focus groups were used in this qualitative study, and themes were explored until reaching saturation. The study was conducted in a municipality (county) in southern Brazil in 2013 and included 64 women farmers. The discussions revealed participants' familiarity with health problems associated with workloads in tobacco production: green tobacco sickness, pesticide poisoning, musculoskeletal disorders, and others. The discussions also revealed a concern with the negative impacts of tobacco agriculture on the environment. They also revealed apprehension concerning decisions on switching to alternatives for sustainable agricultural production, emphasizing that on-going and systematic government support would be necessary for such a transition. Women farmers identified various factors that contribute to the persistence of tobacco farming: small holdings for cultivation, lack of guarantees for marketing crops, and indebtedness to tobacco companies. The study showed that an integrated approach is needed to deal with tobacco farmers' problems, considering a balance between farmers' beliefs and government decisions. This approach, in keeping with the recommendations of the WHO Framework Convention on Tobacco Control, may help strengthen policies and measures to promote health and sustainable local development.
Asunto(s)
Humanos , Femenino , Adulto , Anciano , Adulto Joven , Nicotiana/crecimiento & desarrollo , Conocimientos, Actitudes y Práctica en Salud , Exposición Profesional/efectos adversos , Enfermedades de los Trabajadores Agrícolas/etiología , Agricultores , Población Rural , Factores Socioeconómicos , Brasil , Salud Rural , Encuestas y Cuestionarios , Factores de Riesgo , Lugar de Trabajo , Grupos Focales , Agricultura , Persona de Mediana EdadRESUMEN
Cinnamyl alcohol dehydrogenase (CAD) catalyzes the final step in lignin biosynthesis. The genus Eucalyptus belongs to the family Myrtaceae, which is the main cultivated species in China. Eucalyptus urophylla GLU4 (GLU4) is widely grown in Guangxi. It is preferred for pulping because of its excellent cellulose content and fiber length. Based on GLU4 and CAD gene expression, a Eucalyptus variety low in lignin content should be obtained using transgenic technology, which could reduce the cost of pulp and improve the pulping rate, and have favorable prospects for application. However, the role and function of CAD in GLU4 is still unclear. In the present study, EuCAD was cloned from GLU4 and identified using bioinformatic tools. Subsequently, in order to evaluate its impact on lignin synthesis, a full-length EuCAD RNAi vector was constructed, and transgenic tobacco was obtained via Agrobacterium-mediated transformation. A significant decrease in CAD expression and lignin content in transgenic tobacco demonstrated a key role for EuCAD in lignin biosynthesis and established a regulatory role for RNAi. In our study, the direct molecular basis of EuCAD expression was determined, and the potential regulatory effects of this RNAi vector on lignin biosynthesis in E. urophylla GLU4 were demonstrated. Our results provide a theoretical basis for the study of lignin biosynthesis in Eucalyptus.
Asunto(s)
Oxidorreductasas de Alcohol/genética , Clonación Molecular/métodos , Eucalyptus/enzimología , Nicotiana/genética , Oxidorreductasas de Alcohol/metabolismo , China , Eucalyptus/genética , Regulación de la Expresión Génica de las Plantas , Lignina/biosíntesis , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Nicotiana/crecimiento & desarrolloRESUMEN
This study aimed to analyze the tobacco farming and marketing process in an integrated system and tobacco farmers' living and working conditions in Southern Brazil. A qualitative study was conducted from December 2010 to August 2011, with 31 semi-structured interviews with tobacco farmers and key informants, besides participant observation. The principal analytical reference was the ergological perspective. The integrated system allows the tobacco industry to control the amounts paid and the tobacco's quality. Tobacco growing features high cost of inputs, farmers' indebtedness, insufficient crop insurance, and intensive use of family labor. Accident and disease risks were associated with work in tobacco farming. According to the dynamic three-pole model proposed by ergology, dealing with these problems requires confronting the workers' knowledge with technical and scientific knowledge, linked with ethical and social responsibility.