RESUMO
Soybean is a globally important legume crop which is highly sensitive to drought. The identification of genes of particular relevance for drought responses provides an important basis to improve tolerance to environmental stress. Chloroplast Vesiculation (CV) genes have been characterized in Arabidopsis and rice as proteins participating in a specific chloroplast-degradation vesicular pathway (CVV) during natural or stress-induced leaf senescence. Soybean genome contains two paralogous genes encoding highly similar CV proteins, CV1 and CV2. In this study, we found that expression of CV1 was differentially upregulated by drought stress in soybean contrasting genotypes exhibiting slow-wilting (tolerant) or fast-wilting (sensitive) phenotypes. CV1 reached higher induction levels in fast-wilting plants, suggesting a negative correlation between CV1 gene expression and drought tolerance. In contrast, autophagy (ATG8) and ATI-PS (ATI1) genes were induced to higher levels in slow-wilting plants, supporting a pro-survival role for these genes in soybean drought tolerance responses. The biological function of soybean CVs in chloroplast degradation was confirmed by analyzing the effect of conditional overexpression of CV2-FLAG fusions on the accumulation of specific chloroplast proteins. Functional specificity of CV1 and CV2 genes was assessed by analyzing their specific promoter activities in transgenic Arabidopsis expressing GUS reporter gene driven by CV1 or CV2 promoters. CV1 promoter responded primarily to abiotic stimuli (hyperosmolarity, salinity and oxidative stress), while the promoter of CV2 was predominantly active during natural senescence. Both promoters were highly responsive to auxin but only CV1 responded to other stress-related hormones, such as ABA, salicylic acid and methyl jasmonate. Moreover, the dark-induced expression of CV2, but not of CV1, was strongly inhibited by cytokinin, indicating similarities in the regulation of CV2 to the reported expression of Arabidopsis and rice CV genes. Finally, we report the expression of both CV1 and CV2 genes in roots of soybean and transgenic Arabidopsis, suggesting a role for the encoded proteins in root plastids. Together, the results indicate differential roles for CV1 and CV2 in development and in responses to environmental stress, and point to CV1 as a potential target for gene editing to improve crop performance under stress without compromising natural development.
RESUMO
Lychee is a fruit of Asian origin with an exquisite flavor and an attractive reddish color. However, according to recent reports, the consumption of this fruit reduces the levels of blood glucose with adverse effects on human health such as encephalopathy and hypoglycemic. The objective of this work was to determine if the peel, pulp, and seed of "Brewster" lychee fruits harvested at two stages of maturity had antihyperglycemic effect. This effect was determined by an oral glucose tolerance test using Wistar rats. In addition, ultraviolet-visible spectrophotometry and high-resolution liquid chromatography were used to quantify phenolic compounds, flavonoids, organic acids (OAs), sugars, and antioxidant activity. Results indicated that stage I pulp (immature fruits) and stage II peel and seed (export mature fruits) reduced blood glucose levels, and the effects of the former two were synergistic with metformin. The pulp of mature fruits (stage II), however, lacked a hypoglycemic effect. Additionally, the peel and the seeds of these fruits presented a high antioxidant activity (as determined by DPPH [2,2-diphenyl-2-picryl-hydracyl] and ABTS+ [2,2-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid] methods), which correlated well with the total content of phenolic compounds. The highest content of polyphenolics, flavonoids, and OAs was found in the extracts of the peel and seeds of both stages of maturity. It was therefore concluded that "Brewster" mature lychees are safe for human consumption, and both the seed and the peel can be useful sources for obtaining new compounds with antihyperglycemic activity.
Assuntos
Litchi , Animais , Antioxidantes/farmacologia , Frutas , Hipoglicemiantes , Extratos Vegetais/farmacologia , Ratos , Ratos WistarRESUMO
Background: Spontaneous coronary dissection is a disruption of the arterial wall, with clinical manifestations ranging from unstable angina to sudden cardiac death. It is presented a case of an obstetric patient who is successfully resuscitated after a spontaneous coronary dissection. Clinical case: 37-year-old female patient with a 33-week pregnancy and a history of preeclampsia in the previous pregnancy. She consulted for a 30-min chest pain. After her admission, the patient presented loss of consciousness and cardiorespiratory arrest. Basic and advanced life supports were given and then she was transferred to the intensive care unit where a dissection of the right coronary artery was diagnosed. After 14 days, the patient was discharged from the hospital without neurological sequelae. Conclusions: Spontaneous coronary dissection in the obstetric patient corresponds to a medical emergency, in which pharmacological and surgical measures must be implemented early in order to promote the fetal maternal well-being.
Introducción: La disección coronaria espontánea consiste en la disrupción de la pared arterial, con manifestaciones clínicas que van desde la angina inestable hasta la muerte súbita cardiaca. Se presenta el caso de una paciente obstétrica resucitada exitosamente tras una disección coronaria espontánea. Caso clínico: Mujer de 37 años con embarazo de 33 semanas y antecedente de preeclampsia en el embarazo anterior, quien consultó por dolor torácico de 30 minutos. Posterior a su ingreso presentó pérdida de la consciencia y paro cardiorrespiratorio. Se realizaron maniobras básicas y avanzadas de resucitación, y se trasladó a la unidad de cuidados intensivos donde se diagnosticó disección de arteria coronaria derecha. A los 14 días se dio alta hospitalaria, sin secuelas neurológicas. Conclusiones: La disección coronaria espontánea en la paciente obstétrica corresponde a una urgencia médica, en la cual deben implementarse medidas farmacológicas y quirúrgicas tempranamente con el fin de promover el bienestar del binomio madre-feto.
Assuntos
Dissecção Aórtica/diagnóstico , Vasos Coronários/patologia , Parada Cardíaca , Adulto , Dor no Peito , Feminino , Parada Cardíaca/diagnóstico , Parada Cardíaca/etiologia , Humanos , Gravidez , RessuscitaçãoRESUMO
COR413 genes belong to a poorly characterized group of plant-specific cold-regulated genes initially identified as part of the transcriptional activation machinery of plants during cold acclimation. They encode multispanning transmembrane proteins predicted to target the plasma membrane or the chloroplast inner membrane. Despite being ubiquitous throughout the plant kingdom, little is known about their biological function. In this study, we used reverse genetics to investigate the relevance of a predicted chloroplast localized COR413 protein (PpCOR413im) from the moss Physcomitrella patens in developmental and abiotic stress responses. Expression of PpCOR413im was strongly induced by abscisic acid (ABA) and by various environmental stimuli, including low temperature, hyperosmosis, salinity and high light. In vivo subcellular localization of PpCOR413im-GFP fusion protein revealed that this protein is localized in chloroplasts, confirming the in silico predictions. Loss-of-function mutants of PpCOR413im exhibited growth and developmental alterations such as growth retardation, reduced caulonema formation and hypersensitivity to ABA. Mutants also displayed altered photochemistry under various abiotic stresses, including dehydration and low temperature, and exhibited a dramatic growth inhibition upon exposure to high light. Disruption of PpCOR413im also caused altered chloroplast ultrastructure, increased ROS accumulation, and enhanced starch and sucrose levels under high light or after ABA treatment. In addition, loss of PpCOR413im affected both nuclear and chloroplast gene expression in response to ABA and high light, suggesting a role for this gene downstream of ABA in the regulation of growth and environmental stress responses. Developmental alterations exhibited by PpCOR413im knockout mutants had remarkable similarities to those exhibited by hxk1, a mutant lacking a major chloroplastic hexokinase, an enzyme involved in energy homeostasis. Based on these findings, we propose that PpCOR413im is involved in coordinating energy metabolism with ABA-mediated growth and developmental responses.
RESUMO
Plants respond to pathogen infection by activating signaling pathways leading to the accumulation of proteins with diverse roles in defense. Here, we addressed the functional role of PpPR-10, a pathogenesis-related (PR)-10 gene, of the moss Physcomitrella patens, in response to biotic stress. PpPR-10 belongs to a multigene family and encodes a protein twice the usual size of PR-10 proteins due to the presence of two Bet v1 domains. Moss PR-10 genes are differentially regulated during development and inoculation with the fungal pathogen Botrytis cinerea. Specifically, PpPR-10 transcript levels increase significantly by treatments with elicitors of Pectobacterium carotovorum subsp. carotovorum, spores of B. cinerea, and the defense hormone salicylic acid. To characterize the role of PpPR-10 in plant defense against pathogens, we conducted overexpression analysis in P. patens and in Arabidopsis thaliana. We demonstrate that constitutive expression of PpPR-10 in moss tissues increased resistance against the oomycete Pythium irregulare. PpPR-10 overexpressing moss plants developed less symptoms and decreased mycelium growth than wild type plants. In addition, PpPR-10 overexpressing plants constitutively produced cell wall depositions in protonemal tissue. Ectopic expression of PpPR-10 in Arabidopsis resulted in increased resistance against P. irregulare as well, evidenced by smaller lesions and less cellular damage compared to wild type plants. These results indicate that PpPR-10 is functionally active in the defense against the pathogen P. irregulare, in both P. patens and Arabidopsis, two evolutionary distant plants. Thus, P. patens can serve as an interesting source of genes to improve resistance against pathogen infection in flowering plants.
RESUMO
The appropriate selection and accurate interpretation of diagnostic imaging is a crucial skill for emergency practitioners. To date, the majority of the published literature and research on competency assessment comes from the subspecialty of point-of-care ultrasound. A group of radiologists, physicists, and emergency physicians convened at the 2015 Academic Emergency Medicine consensus conference to discuss and prioritize a research agenda related to education, assessment, and competency in ordering and interpreting diagnostic imaging. A set of questions for the continued development of an educational curriculum on diagnostic imaging for trainees and competency assessment using specific assessment methods based on current best practices was delineated. The research priorities were developed through an iterative consensus-driven process using a modified nominal group technique that culminated in an in-person breakout session. The four recommendations are: 1) develop a diagnostic imaging curriculum for emergency medicine (EM) residency training; 2) develop, study, and validate tools to assess competency in diagnostic imaging interpretation; 3) evaluate the role of simulation in education, assessment, and competency measures for diagnostic imaging; 4) study is needed regarding the American College of Radiology Appropriateness Criteria, an evidence-based peer-reviewed resource in determining the use of diagnostic imaging, to maximize its value in EM. In this article, the authors review the supporting reliability and validity evidence and make specific recommendations for future research on the education, competency, and assessment of learning diagnostic imaging.
Assuntos
Diagnóstico por Imagem/estatística & dados numéricos , Medicina de Emergência/educação , Serviço Hospitalar de Emergência/organização & administração , Pesquisa sobre Serviços de Saúde/organização & administração , Internato e Residência/organização & administração , Competência Clínica/normas , Conferências de Consenso como Assunto , Currículo , Humanos , Reprodutibilidade dos TestesRESUMO
The moss Physcomitrella patens can withstand extreme environmental conditions including drought and salt stress. Tolerance to dehydration in mosses is thought to rely on efficient limitation of stress-induced cell damage and repair of cell injury upon stress relief. Dehydrin proteins (DHNs) are part of a conserved cell protecting mechanism in plants although their role in stress tolerance is not well understood. Four DHNs and two DHN-like proteins were identified in the predicted proteome of P. patens. Expression of PpDHNA and PpDHNB was induced by salt and osmotic stress and controlled by abscisic acid. Subcellular localization of the encoded proteins suggested that these dehydrins are localized in cytosol and accumulate near membranes during stress. Comparative analysis of dhnA and dhnB targeted knockout mutants of P. patens revealed that both genes play a role in cellular protection during salt and osmotic stress, although PpDHNA has a higher contribution to stress tolerance. Overexpression of PpDHNA and PpDHNB genes in transgenic Arabidopsis improved rosette and root growth in stress conditions, although PpDHNA was more efficient in this role. These results suggest that specific DHNs contribute considerably to the high stress tolerance of mosses and offer novel tools for genetic engineering stress tolerance of higher plants.
Assuntos
Adaptação Fisiológica/genética , Bryopsida/genética , Genes de Plantas/genética , Osmose/fisiologia , Proteínas de Plantas/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico/genética , Adaptação Fisiológica/efeitos dos fármacos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Bryopsida/efeitos dos fármacos , Bryopsida/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Técnicas de Inativação de Genes , Mutação/genética , Osmose/efeitos dos fármacos , Filogenia , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Transporte Proteico/efeitos dos fármacos , Proteínas Recombinantes de Fusão/metabolismo , Reprodutibilidade dos Testes , Estresse Fisiológico/efeitos dos fármacos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismoRESUMO
The moss Physcomitrella patens is an evolutionarily basal model system suitable for the analysis of plant defence responses activated after pathogen assault. Upon infection with the necrotroph Botrytis cinerea, several defence mechanisms are induced in P. patens, including the fortification of the plant cell wall by the incorporation of phenolic compounds and the induced expression of related genes. Botrytis cinerea infection also activates the accumulation of reactive oxygen species and cell death with hallmarks of programmed cell death in moss tissues. Salicylic acid (SA) levels also increase after fungal infection, and treatment with SA enhances transcript accumulation of the defence gene phenylalanine ammonia-lyase (PAL) in P. patens colonies. The expression levels of the genes involved in 12-oxo-phytodienoic acid (OPDA) synthesis, including lipoxygenase (LOX) and allene oxide synthase (AOS), increase in P. patens gametophytes after pathogen assault, together with a rise in free linolenic acid and OPDA concentrations. However, jasmonic acid (JA) could not be detected in healthy or infected tissues of this plant. Our results suggest that, although conserved defence signals, such as SA and OPDA, are synthesized and are probably involved in the defence response of P. patens against B. cinerea infection, JA production appears to be missing. Interestingly, P. patens responds to OPDA and methyl jasmonate by reducing moss colony growth and rhizoid length, suggesting that jasmonate perception is present in mosses. Thus, P. patens can provide clues with regard to the evolution of different defence pathways in plants, including signalling and perception of OPDA and jasmonates in nonflowering and flowering plants.
Assuntos
Apoptose/fisiologia , Evolução Biológica , Botrytis/patogenicidade , Bryopsida/fisiologia , Morte Celular/fisiologia , Parede Celular/fisiologia , Ciclopentanos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Oxilipinas/metabolismo , Ácido Salicílico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de SinaisRESUMO
The moss Physcomitrella patens (P. patens) is a useful model to study abiotic stress responses since it is highly tolerant to drought, salt and osmotic stress. However, very little is known about the defense mechanisms activated in this moss after pathogen assault. In this study, we show that P. patens activated multiple and similar responses against Pythium irregulare and Pythium debaryanum, including the reinforcement of the cell wall, induction of the defense genes CHS, LOX and PAL, and accumulation of the signaling molecules jasmonic acid (JA) and its precursor 12-oxo-phytodienoic acid (OPDA). However, theses responses were not sufficient and infection could not be prevented leading to hyphae colonization of moss tissues and plant decay. Pythium infection induced reactive oxygen species production and caused cell death of moss tissues. Taken together, these data indicate that Pythium infection activates in P. patens common responses to those previously characterized in flowering plants. Microscopic analysis also revealed intracellular relocation of chloroplasts in Pythium-infected tissues toward the infection site. In addition, OPDA, JA and its methyl ester methyl jasmonate induced the expression of PAL. Our results show for the first time JA and OPDA accumulation in a moss and suggest that this defense pathway is functional and has been maintained during the evolution of plants.
Assuntos
Briófitas/fisiologia , Pythium/patogenicidade , Briófitas/microbiologia , DNA de Plantas/genética , Reguladores de Crescimento de Plantas/fisiologiaRESUMO
BACKGROUND: Vascular plants respond to pathogens by activating a diverse array of defense mechanisms. Studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. However, very little is known about the infection and defense responses of the bryophyte, Physcomitrella patens, to well-studied phytopathogens. The purpose of this study was to determine: i) whether two representative broad host range pathogens, Erwinia carotovora ssp. carotovora (E.c. carotovora) and Botrytis cinerea (B. cinerea), could infect Physcomitrella, and ii) whether B. cinerea, elicitors of a harpin (HrpN) producing E.c. carotovora strain (SCC1) or a HrpN-negative strain (SCC3193), could cause disease symptoms and induce defense responses in Physcomitrella. RESULTS: B. cinerea and E.c. carotovora were found to readily infect Physcomitrella gametophytic tissues and cause disease symptoms. Treatments with B. cinerea spores or cell-free culture filtrates from E.c. carotovoraSCC1 (CF(SCC1)), resulted in disease development with severe maceration of Physcomitrella tissues, while CF(SCC3193) produced only mild maceration. Although increased cell death was observed with either the CFs or B. cinerea, the occurrence of cytoplasmic shrinkage was only visible in Evans blue stained protonemal cells treated with CF(SCC1) or inoculated with B. cinerea. Most cells showing cytoplasmic shrinkage accumulated autofluorescent compounds and brown chloroplasts were evident in a high proportion of these cells. CF treatments and B. cinerea inoculation induced the expression of the defense-related genes: PR-1, PAL, CHS and LOX. CONCLUSION: B. cinerea and E.c. carotovora elicitors induce a defense response in Physcomitrella, as evidenced by enhanced expression of conserved plant defense-related genes. Since cytoplasmic shrinkage is the most common morphological change observed in plant PCD, and that harpins and B. cinerea induce this type of cell death in vascular plants, our results suggest that E.c. carotovora CFSCC1 containing HrpN and B. cinerea could also induce this type of cell death in Physcomitrella. Our studies thus establish Physcomitrella as an experimental host for investigation of plant-pathogen interactions and B. cinerea and elicitors of E.c. carotovora as promising tools for understanding the mechanisms involved in defense responses and in pathogen-mediated cell death in this simple land plant.
Assuntos
Botrytis/fisiologia , Bryopsida/imunologia , Bryopsida/microbiologia , Pectobacterium carotovorum/fisiologia , Doenças das Plantas/microbiologia , Bryopsida/citologia , Bryopsida/genética , Morte Celular , Cloroplastos/metabolismo , Citoplasma/microbiologia , Fluorescência , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/imunologia , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
O consumo de alimentos vendidos nas ruas é um hábito cultural muito disseminado. Nos últimos anos, diversos fatores, particularmente sócio-econômicos, impulsionaram a comercializaçäo de alimentos nas vias públicas, em especial nos países em desenvolvimento. Entretanto, na maioria dos países ainda näo existe regulamentaçäo legal desta atividade e säo quase inexistentes os procedimentos de fiscalizaçäo. Analisa alguns dos aspectos sociais, econômicos, legais e higiênico-sanitários relacionados à venda de alimentos na rua, sugerindo estratégias para aprimorar esta atividade do ponto de vista da saúde pública.
Assuntos
Inspeção de Alimentos , Vigilância de Produtos ComercializadosRESUMO
The objective of this study was to standardize a cysticerci evagination test to be used to clarify doubts related to the diagnosis of cattle cysticercosis in the slaughterhouse. According to the technical rules of the Brazilian Regulation on Industrial and Sanitary Inspection of Animal Products (1980 and 1997), cysticercosis is classified as live, calcified, localized or generalized. However, There is no definition for the degenerated cysticerci. In order to prevent risks to the health of consumers, this presentation is classified as live cysticercosis, as visual inspection alone is not able to identify the degeneration process. Eighty live cysticerci with evident viability characteristics were selected as group I (control), divided into eight subgroups, and 30 cysticerci with undefined aspect formed group 2. Group I was submitted to different concentrations of fresh cattle bile. In group I, results showed a 100% efficiency as all cysticerci (10/10) evaginated when immersed in a medium containing 0.9% saline, 10% fresh bile and 2.5% RPMI 1640. Cysticerci of group 2 did not evaginate and mechanical rupture and examination of vesical contents confirmed their degeneration.
O objetivo deste trabalho consistiu na padronização de uma técnica de evaginação de cisticercos para o esclarecimento de dúvidas relativas ao diagnóstico da cisticercose bovina em estabelecimentos frigoríficos. Segundo normas técnicas estabelecidas pelo RIISPOA (Regulamento de Inspeção Industrial e Sanitária de Produtos de Origem Animal- Brasil, 1980 e 1997), a cisticercose classifica-se como viva, calcificada, localizada ou generalizada. Todavia, não há definição para a forma em degeneração do cisticerco, que na inspeção final se classifica como cisticercose viva para evitar riscos à saúde dos consumidores, já que a inspeção visual por si só não é capaz de identificar o processo degenerativo do cisticerco. Oitenta cisticercos vivos, com características evidentes de viabilidade, foram selecionados para compor o grupo I (controle) e 30 cisticercos de aspecto duvidoso constituíram o grupo 2. O grupo I foi dividido em oito subgrupos submetidos a diferentes concentrações de bile bovina fresca. Os resultados revelaram que todos os cisticercos evaginaram quando submergidos em meio composto por solução salina a 0,9%, 10% de bile fresca e 2,5% de RPMI 1640, apresentando 100% de eficiência (10/10). Os cisticercos do grupo 2 não sofreram evaginação e a degeneração confirmou-se através de ruptura mecânica e exame do conteúdo vesicular.
RESUMO
The objective of this study was to standardize a cysticerci evagination test to be used to clarify doubts related to the diagnosis of cattle cysticercosis in the slaughterhouse. According to the technical rules of the Brazilian Regulation on Industrial and Sanitary Inspection of Animal Products (1980 and 1997), cysticercosis is classified as live, calcified, localized or generalized. However, There is no definition for the degenerated cysticerci. In order to prevent risks to the health of consumers, this presentation is classified as live cysticercosis, as visual inspection alone is not able to identify the degeneration process. Eighty live cysticerci with evident viability characteristics were selected as group I (control), divided into eight subgroups, and 30 cysticerci with undefined aspect formed group 2. Group I was submitted to different concentrations of fresh cattle bile. In group I, results showed a 100% efficiency as all cysticerci (10/10) evaginated when immersed in a medium containing 0.9% saline, 10% fresh bile and 2.5% RPMI 1640. Cysticerci of group 2 did not evaginate and mechanical rupture and examination of vesical contents confirmed their degeneration.
O objetivo deste trabalho consistiu na padronização de uma técnica de evaginação de cisticercos para o esclarecimento de dúvidas relativas ao diagnóstico da cisticercose bovina em estabelecimentos frigoríficos. Segundo normas técnicas estabelecidas pelo RIISPOA (Regulamento de Inspeção Industrial e Sanitária de Produtos de Origem Animal- Brasil, 1980 e 1997), a cisticercose classifica-se como viva, calcificada, localizada ou generalizada. Todavia, não há definição para a forma em degeneração do cisticerco, que na inspeção final se classifica como cisticercose viva para evitar riscos à saúde dos consumidores, já que a inspeção visual por si só não é capaz de identificar o processo degenerativo do cisticerco. Oitenta cisticercos vivos, com características evidentes de viabilidade, foram selecionados para compor o grupo I (controle) e 30 cisticercos de aspecto duvidoso constituíram o grupo 2. O grupo I foi dividido em oito subgrupos submetidos a diferentes concentrações de bile bovina fresca. Os resultados revelaram que todos os cisticercos evaginaram quando submergidos em meio composto por solução salina a 0,9%, 10% de bile fresca e 2,5% de RPMI 1640, apresentando 100% de eficiência (10/10). Os cisticercos do grupo 2 não sofreram evaginação e a degeneração confirmou-se através de ruptura mecânica e exame do conteúdo vesicular.